[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (9,353)

Search Parameters:
Keywords = flowers

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
12 pages, 4261 KiB  
Article
Functional Verification of the Soybean Pseudo-Response Factor GmPRR7b and Regulation of Its Rhythmic Expression
by Ziye Song, Jia Liu, Xueyan Qian, Zhengjun Xia, Bo Wang, Nianxi Liu, Zhigang Yi, Zhi Li, Zhimin Dong, Chunbao Zhang, Bo Zhang, Million Tadege, Yingshan Dong and Yuqiu Li
Int. J. Mol. Sci. 2025, 26(6), 2446; https://doi.org/10.3390/ijms26062446 (registering DOI) - 9 Mar 2025
Abstract
The pseudo response regulator (PRR) gene is an important component of the core oscillator involved in plant circadian rhythms and plays an important role in regulating plant growth and development and stress responses. In this study, we investigated the function of [...] Read more.
The pseudo response regulator (PRR) gene is an important component of the core oscillator involved in plant circadian rhythms and plays an important role in regulating plant growth and development and stress responses. In this study, we investigated the function of GmPRR7b by overexpression and gene editing approaches. It was found that GmPRR7b plays a role in delaying flowering. While GmPRR7b overexpressing plants showed significantly delayed flowering compared to untransformed WT, GmPRR7b edited plants flowered earlier than the control WT. On the basis of previous research results and bioinformatics analysis, we re-identified 14 soybean PRR genes and analysed their rhythmic expression. Based on the rhythmic expression pattern, we found that GmPRR5/9a and GmPRR5/9b interacted with GmPRR7b by yeast two-hybrid and bimolecular fluorescence complementation (BiFC) experiments. Combined with the expression regulatory networks of the GmPRR7b, we inferred a possible regulatory mechanism by which GmPRR7b affects flowering through quit rhythm expression. These research elements provide valuable references for understanding growth, development, and circadian regulation in soybean. Full article
(This article belongs to the Special Issue Molecular Biology of Soybean)
Show Figures

Figure 1

Figure 1
<p>Mutant, over-expression, and control plants and flowering time. (<b>a</b>), Mutant, overexpression, and control plants; (<b>b</b>) flowering time. * Statistical significance at 0.05 level; ** Statistical significance at 0.01 level.</p>
Full article ">Figure 2
<p>Rhythmic expression of gene family members.</p>
Full article ">Figure 3
<p>Subcellular localization. Transient expression of <span class="html-italic">pEarleygate104-GmPRR7b</span>, <span class="html-italic">pEarleygate104-GmPRR5/9a</span>, <span class="html-italic">pEarleygate104-GmPRR5/9b</span>, and <span class="html-italic">PC1302-RFP-PIP2</span> fusion proteins in tobacco; green indicates the fluorescent colour of YFP, red indicates the fluorescent colour of RFP, and yellow indicates the fluorescent colour of YFP and RFP complexed out (bar = 20 μm).</p>
Full article ">Figure 4
<p>Interaction protein screening of GmPRR7b.</p>
Full article ">Figure 5
<p>BIFC for GmPRR7b.</p>
Full article ">Figure 6
<p>qRT-PCR validation of gene regulatory networks.</p>
Full article ">
14 pages, 3844 KiB  
Article
Cultivated St. John’s Wort Flower Heads Accumulate Tocotrienols over Tocopherols, Regardless of the Year of the Plant
by Ieva Miķelsone, Elise Sipeniece, Inga Mišina, Elvita Bondarenko and Paweł Górnaś
Plants 2025, 14(6), 852; https://doi.org/10.3390/plants14060852 (registering DOI) - 9 Mar 2025
Viewed by 43
Abstract
St. John’s wort (Hypericum perforatum L.) has been extensively utilized across various traditional medicinal systems, including ancient Greek medicine, traditional Chinese medicine, and Islamic medicine. H. perforatum is a well-known medicinal plant due to the presence of hypericin and hyperforin, which are [...] Read more.
St. John’s wort (Hypericum perforatum L.) has been extensively utilized across various traditional medicinal systems, including ancient Greek medicine, traditional Chinese medicine, and Islamic medicine. H. perforatum is a well-known medicinal plant due to the presence of hypericin and hyperforin, which are natural antidepressants. Recent studies indicate that the inflorescences of wild H. perforatum are a source of rare tocotrienols, primarily δ-T3. Similar studies are lacking for cultivated species. H. perforatum was grown for three years. At full bloom each year, the plant was cut and separated into its parts: stems, leaves, flower buds, and flowers. Tocotrienols (T3s) were present in each part of the H. perforatum. The lowest concentration of tocotrienols was recorded in stems and the highest in flower buds (1.7–4.2 and 88.2–104.7 mg/100 g dry weight, respectively). Flower buds and flowers were the main source of α-T3 and δ-T3 tocotrienols. The plant part has a significant impact on the tocochromanol profile and concentration, while the year of harvest/plant aging does not. The present study demonstrates that cultivated H. perforatum flower heads are the first known flowers with relatively high concentrations of tocotrienols. St. John’s wort flower buds accumulate tocotrienols over tocopherols, regardless of the year of the plant. Full article
Show Figures

Figure 1

Figure 1
<p>Chemical structures of four tocopherol (T) and four tocotrienol (T3) homologues.</p>
Full article ">Figure 2
<p>The average proportion (%) of individual tocotrienol (T3) and tocopherol (T) homologues (α, β, γ, and δ) in stems, leaves, flower buds, and flowers of cultivated <span class="html-italic">H. perforatum</span> harvested during 2022–2024.</p>
Full article ">Figure 3
<p>The boxplots illustrate the distribution of four dependent variables (α-T, β-T, γ-T, and δ-T) in cultivated <span class="html-italic">H. perforatum</span> across groups defined by the ‘year’ and ‘plant part’ factors. Different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.005. T, tocopherol; dw, dry weight.</p>
Full article ">Figure 4
<p>The boxplots illustrate the distribution of four dependent variables (α-T3, β-3T, γ-T3, and δ-T3) in cultivated <span class="html-italic">H. perforatum</span> across groups defined by the ‘year’ and ‘plant part’ factors. Different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.005. T3, tocotrienol; dw, dry weight.</p>
Full article ">
16 pages, 2365 KiB  
Article
Ecological Interactions Between Camellia oleifera and Insect Pollinators Across Heterogeneous Habitats
by Linqing Cao, Qiuping Zhong, Chao Yan, Xiaoning Ge, Feng Tian, Yaqi Yuan, Jinfeng Wang, Jia Wang, Shengtian Chen and Hong Yang
Insects 2025, 16(3), 282; https://doi.org/10.3390/insects16030282 (registering DOI) - 8 Mar 2025
Viewed by 45
Abstract
Camellia oleifera is an important woody oil plant in southern China, and developing its industry can enhance forest resource uses and increase edible oil supply. This study investigated the floral characteristics of different C. oleifera varieties, analysed the species and diversity of flower-visiting [...] Read more.
Camellia oleifera is an important woody oil plant in southern China, and developing its industry can enhance forest resource uses and increase edible oil supply. This study investigated the floral characteristics of different C. oleifera varieties, analysed the species and diversity of flower-visiting insects in different habitats, identified the main pollinators and their flower-visiting behaviours, and explored the relationship between pollinating insects and their floral characteristics. The floral lifespan of individual C. oleifera flowers was 5–8 d across cultivars, which is essentially the same. However, floral traits and nectar sugar composition exhibited distinct differences. There were 22 species of insect pollinators from 14 genera and 8 families, including Hymenoptera and Diptera, in 3 habitats. High-potential pollinators varied by habitat, with Apis cerana and Phytomia zonata being the most frequent. A comparison showed that A. cerana was the best pollinator, whereas P. zonata had a larger population, was not affected by oil tea nectar poisoning, and could still pollinate. Therefore, the contribution of P. zonata cannot be overlooked. Redundancy analysis revealed the response relationship between the floral traits of C. oleifera and three insect population characteristics. Stamen length was the main floral trait affecting insect populations. Full article
(This article belongs to the Section Insect Ecology, Diversity and Conservation)
Show Figures

Figure 1

Figure 1
<p>Investigation of pollinating insects in <span class="html-italic">C. oleifera</span> plots (trap device method). (<b>A</b>) Trapping devices; (<b>B</b>) Yellow-trapping plate.</p>
Full article ">Figure 2
<p>Pollen viability of different <span class="html-italic">C. oleifera</span> varieties.</p>
Full article ">Figure 3
<p>Images of floral morphology from different <span class="html-italic">C. oleifera</span> varieties. (<b>A</b>) Changlin 3; (<b>B</b>) Changlin 4; (<b>C</b>) Changlin 40; (<b>D</b>) Changlin 53; (<b>E</b>) Changlin C31; (<b>F</b>) Changlin C43.</p>
Full article ">Figure 4
<p>Floral trait characteristics of different <span class="html-italic">C. oleifera</span> varieties. (<b>A</b>) Corolla diameter; (<b>B</b>) Androecium diameter; (<b>C</b>) Stamen length; (<b>D</b>) Pistil length; (<b>E</b>) Style length. Different letters indicate significant differences at <span class="html-italic">p</span> &lt; 0.05.</p>
Full article ">Figure 5
<p>Sugar composition content in nectar of different <span class="html-italic">C. oleifera</span> varieties. (<b>A</b>) Composition of saccharides in nectar of different <span class="html-italic">C. oleifera</span> varieties; (<b>B</b>) Total sugar and oligosaccharides in nectar of different <span class="html-italic">C. oleifera</span> varieties. Different letters indicate significant differences at <span class="html-italic">p</span> &lt; 0.05.</p>
Full article ">Figure 6
<p>Insect flower visitors for <span class="html-italic">C. oleifera</span>. (<b>A</b>) <span class="html-italic">Apis cerana</span>; (<b>B</b>) <span class="html-italic">Vespa bicolor</span>; (<b>C</b>) <span class="html-italic">Vespa affinis</span>; (<b>D</b>) <span class="html-italic">Apis mellifera ligustica</span>; (<b>E</b>) <span class="html-italic">Polistes gigas</span>; (<b>F</b>) <span class="html-italic">Phytomia zonata</span>; (<b>G</b>) <span class="html-italic">Eristalis arvorum</span>; (<b>H</b>) <span class="html-italic">Lathyrophthalmus arvorum</span>; (<b>I</b>) <span class="html-italic">Helicophagella melanura</span>.</p>
Full article ">Figure 7
<p>RDA biplot of <span class="html-italic">C. oleifera</span> floral traits and insect abundance. Stam: Stamen length; Sty: Style length; Fru: Fructose; Gal: Galactose; Suc: Sucrose; Man: Manninotriose; Sta: Stachyose; DN: number of Diptera insects; HN: number of hymenopteran insects; IPN: number of insect population.</p>
Full article ">
13 pages, 1710 KiB  
Article
A Comparison of Pollination Efficiency Between Wild Bumble Bees and Introduced Honey Bees on Polygonatum cyrtonema
by Ju Tang, Xiang-Xiang Ge, Yu-Jie Xu, Yu Zhang, Jian-Wen Shao and Xiao-Hong Li
Biology 2025, 14(3), 276; https://doi.org/10.3390/biology14030276 - 7 Mar 2025
Viewed by 201
Abstract
To clarify the pollination contributions of introduced honey bees and native wild bees, we compared their pollination efficiency on a perennial herb, Polygonatum cyrtonema Hua. The flower’s traits and bees’ body traits were measured to quantify the mechanical fit between the bee species [...] Read more.
To clarify the pollination contributions of introduced honey bees and native wild bees, we compared their pollination efficiency on a perennial herb, Polygonatum cyrtonema Hua. The flower’s traits and bees’ body traits were measured to quantify the mechanical fit between the bee species and flower. Pollen removal and deposition per visit, visit frequency, and visit duration per flower were investigated. The results show that both native bumble bees (worker bees of Bombus trifasciatus Smith) and introduced honey bees (Apis mellifera L.) are effective pollinators, but bumble bees play a more important role in pollination, due to their higher visit frequency and slightly higher pollen transfer efficiency. The bumble bees removed and deposited significantly more pollen grains per visit than the honey bees (both p < 0.001). The faster visiting speed and shorter visit duration of the bumble bees, combined with their larger body size and longer proboscises, may have contributed to their higher pollen transfer efficiency. The pollination success of P. cyrtonema depends on its pollinators. This study is the first to report on the pollination efficiency of floral visitors on P. cyrtonema. Our findings highlight the importance of conserving native bumble bee populations to ensure the reproductive success of P. cyrtonema. Future studies should focus on their management to minimize potential disruptions to native pollination contribution. Full article
(This article belongs to the Section Conservation Biology and Biodiversity)
25 pages, 2281 KiB  
Article
Phenological Shifts Since 1830 in 29 Native Plant Species of California and Their Responses to Historical Climate Change
by Andros Solakis-Tena, Noelia Hidalgo-Triana, Ryan Boynton and James H. Thorne
Plants 2025, 14(6), 843; https://doi.org/10.3390/plants14060843 - 7 Mar 2025
Viewed by 151
Abstract
Climate change is affecting Mediterranean climate regions, such as California. Retrospective phenological studies are a useful tool to track biological response to these impacts through the use of herbarium-preserved specimens. We used data from more than 12,000 herbarium specimens of 29 dominant native [...] Read more.
Climate change is affecting Mediterranean climate regions, such as California. Retrospective phenological studies are a useful tool to track biological response to these impacts through the use of herbarium-preserved specimens. We used data from more than 12,000 herbarium specimens of 29 dominant native plant species that are characteristic of 12 broadly distributed vegetation types to investigate phenological patterns in response to climate change. We analyzed the trends of four phenophases: preflowering (FBF), flowering (F), fruiting (FS) and growth (DVG), over time (from 1830 to 2023) and through changes in climate variables (from 1896 to 2023). We also examined these trends within California’s 10 ecoregions. Among the four phenophases, the strongest response was found in the timing of flowering, which showed an advance in 28 species. Furthermore, 21 species showed sequencing in the advance of two or more phenophases. We highlight the advances found over temperature variables: 10 in FBF, 28 in F, 17 in FS and 18 in DVG. Diverse and less-consistent results were found for water-related variables with 15 species advancing and 11 delaying various phenophases in response to decreasing precipitation and increasing evapotranspiration. Jepson ecoregions displayed a more pronounced advance in F related to time and mean annual temperature in the three of the southern regions compared to the northern ones. This study underscores the role of temperature in driving phenological change, demonstrating how rising temperatures have predominantly advanced phenophase timing. These findings highlight potential threats, including risks of climatic, ecological, and biological imbalances. Full article
(This article belongs to the Section Plant Response to Abiotic Stress and Climate Change)
14 pages, 3683 KiB  
Article
Monodisperse Hierarchical N-Doped Carbon Microspheres with Uniform Pores as a Cathode Host for Advanced K–Se Batteries
by Hyun-Jin Kim, Jeong-Ho Na and Seung-Keun Park
Batteries 2025, 11(3), 101; https://doi.org/10.3390/batteries11030101 - 7 Mar 2025
Viewed by 251
Abstract
K–Se batteries offer high energy density and cost-effectiveness, making them promising candidates for energy storage systems. However, their practical applications are hindered by Se aggregation, sluggish ion diffusion, and significant volumetric expansion. To address these challenges, monodisperse hierarchical N-doped carbon microspheres (NCHS) with [...] Read more.
K–Se batteries offer high energy density and cost-effectiveness, making them promising candidates for energy storage systems. However, their practical applications are hindered by Se aggregation, sluggish ion diffusion, and significant volumetric expansion. To address these challenges, monodisperse hierarchical N-doped carbon microspheres (NCHS) with uniformly sized pores were synthesized as cathode hosts. The flower-like microstructure, formed by the assembly of two-dimensional building blocks, mitigated Se aggregation and facilitated uniform distribution within the pores, enhancing Se utilization. Nitrogen doping, introduced during synthesis, strengthened chemical bonding between selenium and the carbon host, suppressed side reactions, and accelerated reaction kinetics. These synergistic effects enabled efficient ion transport, improved electrolyte accessibility, and enhanced redox reactions. Additionally, the uniform particle and pore sizes of NCHS effectively mitigated volumetric expansion and surface accumulation, ensuring long-term cycling stability and superior electrochemical performance. Se-loaded NCHS (Se@NCHS) exhibited a high discharge capacity of 199.4 mA h g−1 at 0.5 C after 500 cycles with 70.4% capacity retention and achieved 188 mA h g−1 at 3.0 C, outperforming conventional carbon hosts such as Super P. This study highlights the significance of structural and chemical modifications in optimizing cathode materials and offers valuable insights for developing high-performance energy storage systems. Full article
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Schematic of Se@NCHS synthesis process.</p>
Full article ">Figure 2
<p>Morphology and structure characterizations of NCHS: (<b>a</b>,<b>b</b>) SEM images; (<b>c</b>,<b>d</b>) TEM images; (<b>e</b>–<b>g</b>) HR-TEM image and inlet SAED pattern, and (<b>h</b>) EDX mapping image.</p>
Full article ">Figure 3
<p>Morphology and structure characterizations of Se@NCHS: (<b>a</b>,<b>b</b>) SEM images; (<b>c</b>,<b>d</b>) TEM images; (<b>e</b>) HR-TEM image and inlet SAED pattern, and (<b>f</b>) EDX mapping image.</p>
Full article ">Figure 4
<p>(<b>a</b>) N<sub>2</sub> adsorption-desorption isotherm curve, (<b>b</b>) HK method differential pore volume plot, (<b>c</b>) BJH pore-size distribution graph of NCHS and Super P, (<b>d</b>) N<sub>2</sub> adsorption-desorption isotherm curve, (<b>e</b>) TGA profiles of Se@NCHS and Se@Super P and (<b>f</b>) the Raman spectra of NCHS, Super P, Se@NCHS and Se@Super P.</p>
Full article ">Figure 5
<p>Charge–discharge mechanism of Se@NCHS electrodes; (<b>a</b>) CV curve, (<b>b</b>) charge-discharge 1st profiles at 0.1 C and (<b>c</b>) 1st discharge profile at 0.1 C.</p>
Full article ">Figure 6
<p>Electrochemical properties of Se@NCHS and Se@Super P electrodes; (<b>a</b>) Long-term cycle stability and efficiency of charge transfer at 0.5 C current rate and (<b>b</b>) Rate-dependent performance evaluated at varying current densities.</p>
Full article ">Figure 7
<p>EIS Nyquist plots of Se@NCHS and Se@Super P electrodes; (<b>a</b>) at fresh cells, (<b>b</b>) after the first cycle, (<b>c</b>) after 100 cycles and (<b>d</b>) Z<sub>re</sub>–w<sup>−1/2</sup> relationship after the 100 cycles.</p>
Full article ">Figure 8
<p>GITT analysis of Se@NCHS and Se@Super P electrodes: (<b>a</b>) GITT profiles, the calculated ion diffusion coefficient values (<b>b</b>) during discharging process and (<b>c</b>) during charging process.</p>
Full article ">
16 pages, 5369 KiB  
Article
Genome-Wide Identification and Expression Analysis of Phytosulfokine Peptide Hormone Genes in Camellia sinensis
by Fengshui Yang, Lan Zhang, Qiuying Lu, Qianying Wang, Yanjun Zhou, Qiuhong Wang, Liping Zhang, Kai Shi, Shibei Ge and Xin Li
Int. J. Mol. Sci. 2025, 26(6), 2418; https://doi.org/10.3390/ijms26062418 - 7 Mar 2025
Viewed by 111
Abstract
Phytosulfokine (PSK) is a tyrosine-sulfated pentapeptide found throughout the plant kingdom, playing key roles in plant growth, development, and responses to biotic and abiotic stresses. However, there is still a lack of a comprehensive analysis of the CsPSK gene family in Camellia sinensis [...] Read more.
Phytosulfokine (PSK) is a tyrosine-sulfated pentapeptide found throughout the plant kingdom, playing key roles in plant growth, development, and responses to biotic and abiotic stresses. However, there is still a lack of a comprehensive analysis of the CsPSK gene family in Camellia sinensis. In this study, we conducted a genome-wide identification and characterized 14 CsPSK genes in tea plants, which are unevenly distributed across seven chromosomes. CsPSK genes encode proteins ranging from 75 to 124 amino acids in length, all belonging to the PSK-α type and containing conserved PSK domains. A synteny analysis revealed that the expansion of the CsPSK gene family is primarily attributed to whole-genome duplication, with homology to Arabidopsis thaliana PSK genes. A promoter region analysis identified cis-regulatory elements related to hormone and stress responses. An expression profile analysis showed that CsPSK genes are highly expressed in roots, stems, flowers, and leaves, and are induced by both biotic and abiotic stresses. Furthermore, an RT-qPCR assay demonstrated that the expression levels of CsPSK8, CsPSK9, and CsPSK10 are significantly upregulated following Discula theae-sinensis infection. These findings establish a basis for further research into the role of the CsPSK gene family in tea plant disease resistance and underlying molecular mechanisms, offering valuable perspectives for developing novel antimicrobial peptides. Full article
(This article belongs to the Special Issue Plants Redox Biology)
Show Figures

Figure 1

Figure 1
<p>Chromosomal localization of the <span class="html-italic">CsPSK</span> gene family members in tea plants. Chromosome numbers are labeled on the left in organe font color (abbreviated as Chr), while gene positions are indicated on the right in red font color.</p>
Full article ">Figure 2
<p>Phylogenetic relationships of the <span class="html-italic">CsPSK</span> gene family in <span class="html-italic">C. sinensis</span> and other plant species. The sequences of PSKs used in this analysis are provided in <a href="#app1-ijms-26-02418" class="html-app">Table S1</a>. Red pentagrams indicate CsPSK proteins. Different clades are highlighted in distinct colors.</p>
Full article ">Figure 3
<p>Synteny analysis of <span class="html-italic">CsPSK</span> genes in <span class="html-italic">C. sinensis</span>. Red lines represent duplicated gene pairs, while gray lines indicate syntenic gene pairs in the whole genome.</p>
Full article ">Figure 4
<p>Synteny analysis of <span class="html-italic">PSK</span> genes among <span class="html-italic">C. sinensis</span>, <span class="html-italic">A. thaliana, S. lycopersicum</span>. Cs represents the tea plant genome (sky blue), At represents the Arabidopsis genome (soft amber), and Sl represents the tomato genome (deep blue). Gray lines represent syntenic relationships among different genomes and red lines indicate syntenic relationships among the <span class="html-italic">PSK</span> genes.</p>
Full article ">Figure 5
<p>The phylogenetic tree, conserved motif, domain and gene structure of the CsPSK proteins. Different motif patterns are indicated by different colored numbered boxes. The blue squares represent the PSK superfamily in the domain pattern. The distribution of untranslated regions (UTRs) and coding sequences (CDSs) of the <span class="html-italic">CsPSK</span> gene family members. The soft green gradient represents UTRs and gradual orange represents CDSs.</p>
Full article ">Figure 6
<p>The multiple sequence alignment of the <span class="html-italic">CsPSK</span> gene family. Conserved pentapeptides are indicated by black triangles.</p>
Full article ">Figure 7
<p>Analysis of cis-acting elements in the promoter regions of <span class="html-italic">CsPSK</span> genes. The numbers in the grid represent the quantity of cis-acting elements, while the color intensity indicates the abundance of these elements. The right side displays the statistics of cis-acting elements for each gene under four types, including light-responsive elements, hormone-responsive elements, stress-responsive elements, and development-related elements.</p>
Full article ">Figure 8
<p>Expression patterns of <span class="html-italic">CsPSK</span> genes under different tissues and stress conditions. (<b>A</b>) Expression patterns of <span class="html-italic">CsPSK</span> genes in eight different tissues of tea plants. Expression responses of tea plants under (<b>B</b>) drought stress, (<b>C</b>) salt stress, (<b>D</b>) leafhopper infestation, and (<b>E</b>) gray blight infection. The size and color of the circles represent high and low expression levels, with red indicating high expression and dark blue indicating low expression.</p>
Full article ">Figure 9
<p>The relative expression patterns of <span class="html-italic">CsPSK</span> genes under <span class="html-italic">Discula theae-sinensis</span> infection within 12 h after inoculation. The error bars indicate the standard deviation (SD) based on three biological replicates. Asterisks (*) denote the level of statistical significance, where * indicates <span class="html-italic">p</span> &lt; 0.05, ** indicates <span class="html-italic">p</span> &lt; 0.01), and ns indicates non-significant. Dts, <span class="html-italic">D. theae-sinensis</span>.</p>
Full article ">
21 pages, 1112 KiB  
Article
Investigating the Mechanisms of Adventitious Root Formation in Semi-Tender Cuttings of Prunus mume: Phenotypic, Phytohormone, and Transcriptomic Insights
by Xiujun Wang, Yue Li, Zihang Li, Xiaowen Gu, Zixu Wang, Xiaotian Qin and Qingwei Li
Int. J. Mol. Sci. 2025, 26(6), 2416; https://doi.org/10.3390/ijms26062416 - 7 Mar 2025
Viewed by 91
Abstract
Mei (Prunus mume Sieb. et Zucc.) is a rare woody species that flowers in winter, yet its large-scale propagation is limited by the variable ability of cuttings to form adventitious roots (ARs). In this study, two cultivars were compared: P. mume [...] Read more.
Mei (Prunus mume Sieb. et Zucc.) is a rare woody species that flowers in winter, yet its large-scale propagation is limited by the variable ability of cuttings to form adventitious roots (ARs). In this study, two cultivars were compared: P. mume ‘Xiangxue Gongfen’ (GF), which roots readily, and P. mume ‘Zhusha Wanzhaoshui (ZS), which is more recalcitrant. Detailed anatomical observations revealed that following cutting, the basal region expanded within 7 days, callus tissues had appeared by 14 days, and AR primordia emerged between 28 and 35 days. Notably, compared to the recalcitrant cultivar ZS, the experimental cultivar GF exhibited significantly enhanced callus tissue formation and AR primordia differentiation. Physiological analyses showed that the initial IAA concentration was highest at day 0, whereas cytokinin (tZR) and gibberellin (GA1) levels peaked at 14 days, with ABA gradually decreasing over time, resulting in increased IAA/tZR and IAA/GA1 ratios during the rooting process. Transcriptomic profiling across these time points identified significant upregulation of key genes (e.g., PmPIN3, PmLOG2, PmCKX5, PmIAA13, PmLAX2, and PmGA2OX1) and transcription factors (PmWOX4, PmSHR, and PmNAC071) in GF compared to ZS. Moreover, correlation analyses revealed that PmSHR expression is closely associated with IAA and tZR levels. Overexpression of PmSHR in tobacco further validated its role in enhancing lateral root formation. Together, these findings provide comprehensive insights into the temporal, hormonal, and genetic regulation of AR formation in P. mume, offering valuable strategies for improving its propagation. Full article
(This article belongs to the Section Molecular Plant Sciences)
17 pages, 4332 KiB  
Article
Impacts of Leaf Damage Intensity on Ant–Plant Protection Mutualism and Plant Fitness
by Isabela Cristina de Oliveira Pimenta, Eduardo Soares Calixto and Kleber Del-Claro
Plants 2025, 14(6), 837; https://doi.org/10.3390/plants14060837 - 7 Mar 2025
Viewed by 70
Abstract
Herbivores can negatively impact plant reproduction by altering floral traits, pollination, and fruit production. To counteract this, plants developed defense mechanisms, such as the biotic defense resulting from associations with ants. The aim of this study was to investigate whether leaf herbivory at [...] Read more.
Herbivores can negatively impact plant reproduction by altering floral traits, pollination, and fruit production. To counteract this, plants developed defense mechanisms, such as the biotic defense resulting from associations with ants. The aim of this study was to investigate whether leaf herbivory at different intensities influences reproductive success and extrafloral nectar secretion patterns in a savanna plant, Banisteriopsis malifolia (Malpighiaceae). Plants were subjected to simulated leaf herbivory and divided into three groups: Control (damage < 5%), T15 (15% leaf area removed), and T50 (50% leaf area removed). Assessments continued until fruiting. The findings indicate an increase in extrafloral nectar sugar concentration after simulated herbivory. Increasing foliar damage significantly delayed the time to bloom, decreased the number of inflorescences per plant, and reduced the size of buds and flowers. Foliar damage significantly decreased fruit size. Furthermore, ant foraging was influenced by herbivory, with a predominance of aggressive ants on plants with high levels of damage. Our study shows that varying levels of leaf damage affect extrafloral nectar secretion, ant foraging behavior, and plant reproductive structures. These findings highlight how insect herbivores and the level of damage they cause influence plant fitness and consequently community structure. Full article
(This article belongs to the Special Issue Plant Behavioral Ecology)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Variation in the sugar concentration of the extrafloral nectar produced by the extrafloral nectaries in <span class="html-italic">Banisteriopsis malifolia</span> (Malpighiaceae) plants under two conditions: without simulated herbivory (Control) and with simulated herbivory (T15, T50). T15—plants with 15% simulated herbivory; T50—plants with 50% simulated herbivory. Different letters represent statistical difference by the estimated marginal mean. The figures display boxplots with raw data represented as colored points and the mean indicated by a black point.</p>
Full article ">Figure 2
<p>Interaction between treatments and sugar concentration of extrafloral nectar produced by extrafloral nectaries on ant abundance in <span class="html-italic">Banisteriopsis malifolia</span> (Malpighiaceae) plants without (Control) and with simulated herbivory (T15, T50). The data points represent raw data.</p>
Full article ">Figure 3
<p>Interaction between treatments and (<b>a</b>) abundance and (<b>b</b>) ant richness in relation to the total number of samaras produced, in <span class="html-italic">Banisteriopsis malifolia</span> (Malpighiaceae) plants, under control conditions (no simulated herbivory) and with simulated herbivory (T15, T50). Data points represent raw values.</p>
Full article ">Figure 4
<p>Variation in the (<b>a</b>) difference (in days) between simulated herbivory and the appearance of the first inflorescence, (<b>b</b>) difference (in days) between simulated herbivory and the blooming of the first flower, and (<b>c</b>) total number of inflorescences per plant in <span class="html-italic">Banisteriopsis malifolia</span> (Malpighiaceae) plants under two conditions: without simulated herbivory (Control) and with simulated herbivory treatments (T15 and T50), with 25 replicates per treatment. Different letters in (<b>a</b>–<b>c</b>) represent statistical difference by the estimated marginal mean. The figures display boxplots with raw data represented as colored points and the mean indicated by a black point.</p>
Full article ">Figure 5
<p>Variation in (<b>a</b>) bud height, (<b>b</b>) bud diameter, (<b>c</b>) flower width, and (<b>d</b>) flower length (in millimeters) in <span class="html-italic">Banisteriopsis malifolia</span> (Malpighiaceae) plants under two conditions: without simulated herbivory (Control) and with simulated herbivory treatments (T15 and T50), with 25 replicates per treatment. Different letters in (<b>a</b>–<b>c</b>) represent statistical difference by the estimated marginal mean. The figures display boxplots with raw data represented as colored points and the mean indicated by a black point.</p>
Full article ">Figure 6
<p>Variation in (<b>a</b>) inflorescence size (in centimeters), (<b>b</b>) log of the number of flowers per inflorescence, and (<b>c</b>) flowers produced as a function of inflorescence size in <span class="html-italic">Banisteriopsis malifolia</span> (Malpighiaceae) plants under two conditions: without simulated herbivory (Control) and with simulated herbivory treatments (T15 and T50), with 25 replicates per treatment. Different letters in (<b>a</b>–<b>c</b>) represent statistical difference by the estimated marginal mean. The figures display boxplots with raw data represented as colored points and the mean indicated by a black point.</p>
Full article ">Figure 7
<p>Variation in (<b>a</b>) the area of samarids collected (measured in centimeters) and (<b>b</b>) the number of samaras produced per flower in <span class="html-italic">Banisteriopsis malifolia</span> (Malpighiaceae) plants under two conditions: without simulated herbivory (Control) and with simulated herbivory treatments (T15 and T50), with 25 replicates per treatment. Different letters represent statistical difference by the estimated marginal mean. The figures display boxplots with raw data represented as colored points and the mean indicated by a black point.</p>
Full article ">Figure 8
<p>Treatments with simulated leaf herbivory in <span class="html-italic">Banisteriopsis malifolia</span>. (<b>A</b>) Control Group—leaves without any experimental manipulation, leaf damage less than 5%. (<b>B</b>) Group T15—leaves with 15% damage. (<b>C</b>) Group T50—leaves with 50% damage. Photos by the author.</p>
Full article ">Figure 9
<p>(<b>A</b>) Bud in pre-anthesis, the arrows indicate the directions that the height (blue arrow) and diameter (pink arrow) of the buds were measured. (<b>B</b>) Open flower, the arrows indicate how the width (red arrow) and length (black arrow) of the flowers were measured after anthesis. (<b>C</b>) Fruit (samaras). Photos by the author.</p>
Full article ">
14 pages, 6393 KiB  
Article
Solenopsis gutermannii (Campanulaceae), a New Species from Kefalonia (Ionian Islands, Greece)
by Salvatore Brullo, Christian Gilli, Andreas Berger, Salvatore Cambria, Emanuele Costanzo, Giuseppe Siracusa and Gianpietro Giusso del Galdo
Taxonomy 2025, 5(1), 13; https://doi.org/10.3390/taxonomy5010013 - 7 Mar 2025
Viewed by 76
Abstract
A new species of Solenopsis (Campanulaceae), S. gutermannii is described and illustrated. It is endemic to Kefalonia island, Greece, where it is very rare and localized in flat clay surfaces that are periodically submerged. This species is a very small annual hygrophyte, characterized [...] Read more.
A new species of Solenopsis (Campanulaceae), S. gutermannii is described and illustrated. It is endemic to Kefalonia island, Greece, where it is very rare and localized in flat clay surfaces that are periodically submerged. This species is a very small annual hygrophyte, characterized by rosulate leaves or with slightly caulescent stems, long-pedunculated flowers, bilabiate corolla, and papillate near the throat. It exhibits close affinities primarily with S. minuta, with which it was previously identified, and additionally with S. antiphonitis, due to similarities in habit and certain flower traits. Nevertheless, several relevant morphological features serve to distinguish it from these species. Its morphology, seed coat and pollen SEM micro-sculpturing, ecology, phenology, distribution, conservation status, and taxonomic relationships are also examined. Full article
Show Figures

Figure 1

Figure 1
<p><span class="html-italic">Solenopsis gutermannii</span> from type locality. (<b>A</b>) Habit; (<b>B</b>) Habit magnification (×2); (<b>C</b>) Leaves; (<b>D</b>) Bracteoles; (<b>E</b>) Flower (frontal view); (<b>F</b>) Flower (lateral view); (<b>G</b>) Open corolla; (<b>H</b>) Open calyx; (<b>I</b>) Calyx with capsule; (<b>J</b>) Anthers (frontal view); (<b>K</b>) Anthers (lateral view); (<b>L</b>) Style and stigma; (<b>M</b>) Corolla papillae; (<b>N</b>) Seeds. Drawing: S. Brullo.</p>
Full article ">Figure 2
<p>Habit of living plants of <span class="html-italic">Solenopsis gutermannii</span> from Kefalonia. (<b>A</b>) Stemless individual. (<b>B</b>) Caulescent individual.</p>
Full article ">Figure 3
<p>Distribution map of <span class="html-italic">Solenopsis gutermannii</span> from Kefalonia (<b>A</b>) and <span class="html-italic">S. minuta</span> from Crete (<b>B</b>) based on herbarium material (red dots).</p>
Full article ">Figure 4
<p>Phenological features of <span class="html-italic">Solenopsis gutermannii.</span> (<b>A</b>) Natural habitat (Kefalonia). (<b>B</b>) Habit. (<b>C</b>) Flower (frontal view). (<b>D</b>) Flower (lateral view). Photos by S. Cambria.</p>
Full article ">Figure 5
<p><span class="html-italic">Solenopsis minuta</span> from living plant sourced from Preveli Beach (Crete) collected by S. Cambria. (<b>A</b>) Habit; (<b>B</b>) Habit magnification (×2); (<b>C</b>) Leaves; (<b>D</b>) Bracteoles; (<b>E</b>) Flower (lateral view); (<b>F</b>) Flower (frontal view); (<b>G</b>) Open corolla; (<b>H</b>) Corolla papillae; (<b>I</b>) Calyx; (<b>J</b>) Open calyx; (<b>K</b>) Anthers (ventral view); (<b>L</b>) Anthers (lateral view); (<b>M</b>) Calyx with capsule; (<b>N</b>) Style and stigma; (<b>O</b>) Seeds. Drawing: S. Brullo.</p>
Full article ">Figure 6
<p>SEM micrographs of seed coat (<b>A</b>,<b>B</b>) and pollen grain (<b>C</b>) of <span class="html-italic">Solenopsis gutermannii</span> and seed coat (<b>D</b>,<b>E</b>) and pollen grain (<b>F</b>) of <span class="html-italic">S. minuta</span>. (<b>A</b>,<b>D</b>) Seed shape (×250). (<b>B</b>,<b>E</b>) Detailed seed testa (×1000). (<b>C</b>,<b>F</b>). Pollen grain equatorial view (×2800).</p>
Full article ">Figure 7
<p>Comparative phenological features of <span class="html-italic">Solenopsis gutermannii</span> (<b>A</b>), <span class="html-italic">S. minuta</span> (<b>B</b>), and <span class="html-italic">S. antiphonitis</span> (<b>C</b>). <b>1.</b> Flower. <b>2.</b> Habit. (Photos by S. Cambria).</p>
Full article ">
20 pages, 6065 KiB  
Article
Major Bioactive Compounds, Volatile and Sensory Profiles of Coffea canephora Flowers and Infusions for Waste Management in Coffee Production
by Juliana DePaula, Sara C. Cunha, Fábio Luiz Partelli, José O. Fernandes and Adriana Farah
Foods 2025, 14(6), 911; https://doi.org/10.3390/foods14060911 - 7 Mar 2025
Viewed by 131
Abstract
This study aimed to investigate the content of major bioactive compounds and characterize the volatile and sensory profiles of Coffea canephora flowers and their infusions. Dried flowers from six selected genotypes of C. canephora trees and their infusions were analyzed for bioactive compounds [...] Read more.
This study aimed to investigate the content of major bioactive compounds and characterize the volatile and sensory profiles of Coffea canephora flowers and their infusions. Dried flowers from six selected genotypes of C. canephora trees and their infusions were analyzed for bioactive compounds using HPLC–DAD, while volatile organic compounds (VOC) were analyzed using GC–MS. Eight chlorogenic acids (CGA), seven phenolic acids, and the alkaloids caffeine and trigonelline were quantified in all methanolic flower extracts. Total CGA, phenolic acids, caffeine, and trigonelline contents in the methanolic extracts ranged between 342.8 and 1079.4 mg/100 g, 27.1 and 41.0 mg/100 g, 515.6 and 745.9 mg/100 g, and 453.8 and 645.2 mg/100 g, respectively. CGA, caffeine, and trigonelline were well extracted (84%, 91%, and 74%, respectively) when the flowers were infused in hot water. No free phenolic acids were identified in the infusions. Eighty-five VOC were identified in the flowers. Aldehydes, monoterpenes, esters, alcohols, monoterpene alcohols, acids, and ketones prevailed in order of the number of compounds. In the infusions, 38 VOC were accurately identified. Monoterpenes and monoterpene alcohols prevailed. In general, floral, jasmine and orange blossom, herbal, green coffee, woody, and sweet were the most cited sensory attributes for fragrance, aroma, and flavor. Considering the typically weak aroma of C. canephora seeds, the aroma and flavor of the flower’s infusions were surprisingly strong and pleasant, showing great marketing potential. Full article
Show Figures

Figure 1

Figure 1
<p>(<b>A</b>) Pollination of <span class="html-italic">Coffea canephora</span> flowers. (<b>B</b>) Flowers ready for harvest.</p>
Full article ">Figure 2
<p>(<b>A</b>) Drying of <span class="html-italic">Coffea canephora</span> flowers. (<b>B</b>) Dried flowers.</p>
Full article ">
25 pages, 3990 KiB  
Article
The Relationship Between Phenological Characteristics and Life Forms Within Temperate Semi-Natural Grassland Ecosystems in the Central Himalaya Region of India
by Archana Fartyal, Ravi Kant Chaturvedi, Surendra Singh Bargali and Kiran Bargali
Plants 2025, 14(6), 835; https://doi.org/10.3390/plants14060835 - 7 Mar 2025
Viewed by 163
Abstract
The seasonal phenological segregation observed among various species within a plant community can be interpreted as a form of niche differentiation that facilitates the coexistence of these species. In the present study, life forms and phenological attributes of dominant plant species in temperate [...] Read more.
The seasonal phenological segregation observed among various species within a plant community can be interpreted as a form of niche differentiation that facilitates the coexistence of these species. In the present study, life forms and phenological attributes of dominant plant species in temperate semi-natural grasslands of Central Himalaya, India, were assessed between January 2022 and December 2022. This study was carried out in three sites in different forest zones, viz. oak, cypress and pine. In each site, plots measuring 0.5 hectares were established and phenological assessments were conducted within each of these plots. A total of 50, 36, and 49 herbaceous species were identified in the grasslands of oak, cypress and pine zones, respectively, with these species categorized into five distinct life form classes. In the grasslands of both oak and pine zones, hemicryptophytes emerged as the predominant life form, whereas in the cypress zone grasslands, it was found that chamaephytes take precedence. The differences observed in the classifications of life forms can be ascribed to the geographical distribution and the biotic interactions present in these sites. The three grasslands exhibit comparable climatic conditions and day lengths, resulting in no significant variations in soil temperature, light intensity or overall climatic factors. The majority of species commenced their flowering phase during the monsoon season, attributed to the favorable conditions characterized by warm, humid weather and adequate soil moisture. Various phenological events, including germination, growth, and senescence, are significantly affected by weather and climate, and their timing subsequently influences ecosystem processes in a reciprocal manner. This study provides valuable foundational data for ecological and environmental research, aiding in the comparison and distinction of plant compositions across the Himalayas and its ecosystems. Full article
(This article belongs to the Section Plant Ecology)
Show Figures

Figure 1

Figure 1
<p>Monthly variation in climatic conditions (<b>a</b>), light intensity (<b>b</b>) and soil temperature (<b>c</b>) during the study period.</p>
Full article ">Figure 2
<p>Proportional distributions of species in different categories of life form and growth form.</p>
Full article ">Figure 3
<p>Percentage of the species under different phenophases in different months—(<b>a</b>) oak zone grassland, (<b>b</b>) cypress zone grassland and (<b>c</b>) pine zone grassland.</p>
Full article ">Figure 3 Cont.
<p>Percentage of the species under different phenophases in different months—(<b>a</b>) oak zone grassland, (<b>b</b>) cypress zone grassland and (<b>c</b>) pine zone grassland.</p>
Full article ">Figure 4
<p>Phenophases for dominant plant species representing (<b>a</b>) vegetative, (<b>b</b>) reproductive and (<b>c</b>) senescence phases of dominant species in oak zone grassland.</p>
Full article ">Figure 4 Cont.
<p>Phenophases for dominant plant species representing (<b>a</b>) vegetative, (<b>b</b>) reproductive and (<b>c</b>) senescence phases of dominant species in oak zone grassland.</p>
Full article ">Figure 5
<p>Phenophases for dominant plant species representing (<b>a</b>) vegetative, (<b>b</b>) reproductive and (<b>c</b>) senescence phases of dominant species in cypress zone grassland.</p>
Full article ">Figure 6
<p>Phenophases for dominant plant species representing (<b>a</b>) vegetative, (<b>b</b>) reproductive and (<b>c</b>) senescence phases of dominant species in pine zone grassland.</p>
Full article ">Figure 6 Cont.
<p>Phenophases for dominant plant species representing (<b>a</b>) vegetative, (<b>b</b>) reproductive and (<b>c</b>) senescence phases of dominant species in pine zone grassland.</p>
Full article ">Figure 7
<p>Correlation matrix among climatic parameters and phenophases (where LI = light intensity; ST = soil temperature; AT = average temperature; PPT = precipitation; RH = relative humidity; GR = germination; VG = vegetative; FI = flowering induction; FL = flowering; FR = fruiting and maturation; S = senescence).</p>
Full article ">Figure 8
<p>Principal component analysis (PCA) correlation plot of climatic parameters and phenophases of species in different months (January = blue; February= violet; March = brown; April = aqua; May = crimson; June = darkcyan; July = golden; August = green; September = pink; October = olive; November = orange; December = Yellow; LI = light intensity; ST= soil temperature; AT = average temperature; RH = relative humidity; GR = germination; VG = vegetative; FI = flowering induction; FL = flowering; FR = fruiting and maturation; S = senescence.</p>
Full article ">Figure 9
<p>Map of the study area.</p>
Full article ">
16 pages, 9628 KiB  
Article
Genome-Wide Identification of the NAC Gene Family in Brassica rapa (L.) and Expression Pattern Analysis of BrNAC2s
by Weiqiang Li, Fan Ping, Huixuan Jiang, Shuqing Zhang, Tong Zhao, Kaiwen Liu, Hongrui Yu, Iqbal Hussian, Xiliang Ren and Xiaolin Yu
Plants 2025, 14(6), 834; https://doi.org/10.3390/plants14060834 - 7 Mar 2025
Viewed by 168
Abstract
Flowers are one of the most important organs in plants. Their development serves as a key indicator of the transition from vegetative to reproductive growth and is regulated by various internal signals and environmental factors. NAC (NAM, ATAF, CUC) transcription factors (TFs) play [...] Read more.
Flowers are one of the most important organs in plants. Their development serves as a key indicator of the transition from vegetative to reproductive growth and is regulated by various internal signals and environmental factors. NAC (NAM, ATAF, CUC) transcription factors (TFs) play a crucial regulatory role in floral organ development; however, research on the analysis and identification of the NAC TF family in Chinese cabbage (Brassica rapa L.) remains limited. In this study, we performed a comprehensive genome-wide analysis of NACs in B. rapa and identified 279 members of the BrNAC gene family. Their physicochemical properties, domain structure, collinearity relation, and cis-regulatory elements were evaluated. Phylogenetic analysis indicates that NAC proteins from Arabidopsis, B. rapa, B. oleracea, and B. nigra can be classified into seven distinct clades. BrNACs exhibit a tissue-specific expression, and nine BrNACs being specifically expressed in the inflorescence. Furthermore, nine flower-related BrNACs were selected for RT-qPCR analysis to validate their expression profiles. BrNAC2s has been cloned to investigate their subcellular localization, and examine the expression patterns of their promoters in Arabidopsis inflorescences. BrNAC2a and BrNAC2c are highly expressed in stamens while BrNAC2b exhibits elevated expression in pistils and pedicel. Collectively, our findings enhance the understanding of the BrNAC family and provide a foundation for future studies on the molecular mechanisms of BrNACs in floral development. Full article
(This article belongs to the Section Plant Genetics, Genomics and Biotechnology)
Show Figures

Figure 1

Figure 1
<p>Chromosome distribution of <span class="html-italic">BrNAC</span> genes. The distribution of 279 <span class="html-italic">BrNAC</span> genes on ten <span class="html-italic">B. rapa</span> chromosomes.</p>
Full article ">Figure 2
<p>Phylogenetic analysis of NAC proteins in <span class="html-italic">B. rapa</span>. Phylogenetic analyses were conducted on NAC proteins from <span class="html-italic">B. rapa</span>, <span class="html-italic">A. thaliana</span>, <span class="html-italic">B. oleracea</span>, and <span class="html-italic">B. nigra</span>. MUSCLE was used for multiple sequence alignment. Phylogenetic trees were constructed using the Maximum Likelihood (ML) method with 1000 bootstrap repeats. The resulting phylogenetic tree was visualized with the online tool iTOL 6.9.1 (<a href="https://itol.embl.de/" target="_blank">https://itol.embl.de/</a>, accessed on 20 September 2024). Different colors indicate different NAC subgroups.</p>
Full article ">Figure 3
<p>Collinear gene pair analysis of <span class="html-italic">BrNACs</span> between <span class="html-italic">A. thaliana</span>, <span class="html-italic">B. oleracea</span> and <span class="html-italic">B. nigra</span>. The red line represents collinear gene pairs. The orange color represents the <span class="html-italic">A. thaliana</span> chromosome, the green color represents the <span class="html-italic">B. rapa</span> chromosome, and the pink color represents the <span class="html-italic">B. oleracea</span> chromosome, the blue color represents the <span class="html-italic">B. nigra</span> chromosome.</p>
Full article ">Figure 4
<p>Cis-elements in the 2 kb promoter sequences of <span class="html-italic">BrNAC</span> genes. Different colored rectangles represent various cis-elements, with their positions indicated according to their locations within the promoters.</p>
Full article ">Figure 5
<p>The tissue expression pattern of <span class="html-italic">BrNAC</span> genes in different tissues including root, stem, leaf and inflorescence. Red indicates high expression levels, and blue indicates low expression levels.</p>
Full article ">Figure 6
<p>Expression profiles of <span class="html-italic">BrNAC2</span> genes in different tissues and organs. (<b>A</b>) Expression levels of <span class="html-italic">BrNAC2a</span>; (<b>B</b>) Expression levels of <span class="html-italic">BrNAC2b</span>; (<b>C</b>) Expression levels of <span class="html-italic">BrNAC2c.</span> Different letters represent significant difference (<span class="html-italic">p</span> &lt; 0.05).</p>
Full article ">Figure 7
<p>Subcellular localization of the BrNAC2s-eGFP in <span class="html-italic">Nicotiana benthamiana</span> leaves. pFGC5941-35S-eGFP and pFGC5941-35S-<span class="html-italic">BrNAC2s</span>-eGFP fusion proteins were transiently expressed in <span class="html-italic">N. tabacum</span> leaves. The fields included green fluorescence filed (488 nm), nucleus autofluorescence field (570 nm), bright field, and merged filed. Empty vector control showing the expression of 35S-eGFP in epidermal cells of <span class="html-italic">N. tabacum</span>, and co-localization of 35S-eGFP with BrNAC2 proteins observed by nucleus autofluorescence. Bars = 30 µm.</p>
Full article ">Figure 8
<p>Pro<span class="html-italic">BrNAC2s</span>–GUS expression in transgenic <span class="html-italic">A. thaliana</span>. (<b>A</b>) Expression activity of <span class="html-italic">BrNAC2a</span> promoter in inflorescence. (<b>B</b>) Expression activity of <span class="html-italic">BrNAC2b</span> promoter in inflorescence. (<b>C</b>) Expression activity of <span class="html-italic">BrNAC2c</span> promoter in inflorescence. Scale bars = 1 mm.</p>
Full article ">
49 pages, 14633 KiB  
Article
Transmission, Spread, Longevity and Management of Hop Latent Viroid, a Widespread and Destructive Pathogen Affecting Cannabis (Cannabis sativa L.) Plants in North America
by Zamir K. Punja, Cameron Scott, Heather H. Tso, Jack Munz and Liam Buirs
Plants 2025, 14(5), 830; https://doi.org/10.3390/plants14050830 - 6 Mar 2025
Viewed by 119
Abstract
Hop latent viroid (HLVd), a 256-nucleotide RNA strand with complementary base-pairing and internal stem loop structures, forms circular or rod-shaped molecules within diseased plants. RT-PCR/RT-qPCR was used to assess HLVd transmission, spread and longevity. The viroid was detected in asymptomatic stock plants and [...] Read more.
Hop latent viroid (HLVd), a 256-nucleotide RNA strand with complementary base-pairing and internal stem loop structures, forms circular or rod-shaped molecules within diseased plants. RT-PCR/RT-qPCR was used to assess HLVd transmission, spread and longevity. The viroid was detected in asymptomatic stock plants and in rooted vegetative cuttings, as well as in recirculated nutrient solution sampled from propagation tables and nozzles. Plant-to-plant spread through root infection in hydroponic cultivation was demonstrated. The viroid survived for 7 days and 4 weeks, respectively, in crushed leaf extracts (sap) or dried leaves/roots at room temperature. Following stem inoculation with infectious sap, HLVd was detected in root tissues within 2–3 weeks and in the foliage within 4–6 weeks. Plants grown under a 12:12 h photoperiod to induce inflorescence development showed more rapid spread of HLVd compared to 24 h lighting. The viroid was subsequently detected in inflorescence tissues, in trichome glands, in dried cannabis flowers and in crude resinous oil extracts. Anthers and pollen from infected male plants and seeds from infected female plants contained HLVd, giving rise to up to 100% infected seedlings. Artificially inoculated tomato and tobacco plants supported viroid replication in roots and leaves. Infected cannabis leaf and root tissues treated with UV-C for 3–5 min or temperatures of 70–90 °C for 30 min contained amplifiable HLVd-RNA. Infectious plant extract treated with 5–10% bleach (0.825% NaOCl) or 1000 ppm hypochlorous acid yielded no RT-PCR bands, suggesting the RNA was degraded. Meristem tip culture from HLVd-infected plants yielded a high frequency of pathogen-free plants, depending on the genotype. Full article
(This article belongs to the Special Issue Cannabis sativa: Advances in Biology and Cultivation—2nd Edition)
Show Figures

Figure 1

Figure 1
<p>Sampling of different tissues from cannabis stock and flowering plants for hop latent viroid. (<b>a</b>–<b>c</b>) Stock plants of three genotypes were sampled at positions (labelled 1–4) corresponding to roots and leaves from the bottom, middle and top of the canopy. (<b>d</b>–<b>f</b>) RNA banding patterns following RT-PCR of samples from the plants shown in (<b>a</b>–<b>c</b>). Multiple bands were observed in all samples except for a sample from the lower position of the plant in (<b>b</b>). The band sizes were approx. 256 bp, 512 bp and 768 bp. (<b>g</b>) Symptoms of overall stunted growth and reduced inflorescence development due to HLVd infection on a plant of genotype A5 in a flowering room containing trial plants. (<b>h</b>) A noninfected plant shows larger overall plant size and inflorescence development. (<b>i</b>) Comparison of inflorescence development in a noninfected plant (top) and an HLVd-infected plant (bottom) shows reduced overall size and chlorophyll development due to infection. (<b>j</b>,<b>k</b>) RT-PCR analysis of flowering stem tissues from 20 randomly selected symptomatic plants within a trial greenhouse compartment show that the presence of a 256 bp size fragment characteristic of HLVd in all plants, while 9 plants showed multiple banding patterns similar to those observed in stock plants.</p>
Full article ">Figure 2
<p>(<b>a</b>) RNA extracted from HLVd-infected plant tissues exposed to ribonuclease A (an endonuclease) followed by RT-PCR shows the complete digestion of the RNA in all lanes (marked by arrows). (<b>b</b>) RNA extracted from three infected cannabis genotypes exposed to ribonuclease A and ribonuclease R (an exonuclease) followed by RT-PCR shows complete digestion with ribonuclease A (brown arrows) and digestion of only the 512 bp fragment by ribonuclease R (white arrows). C = control samples without enzymes. (<b>c</b>) RNA extracted from five cannabis genotypes (labelled 1–5) exposed to ribonucleases A and R followed by RT-PCR shows complete digestion with ribonuclease A (brown arrows) and digestion of the 512 bp and 768 bp fragments by ribonuclease R (white arrows) for some genotypes. In genotypes 3 and 5, digested with ribonuclease R, the intensity of the 256 bp band was also reduced. C = control samples without enzymes. In all figures, MW = molecular weight standard, +ve = positive control sample infected with hop latent viroid, −ve = water control, A = ribonuclease A, R = ribonuclease R. (<b>d</b>) Schematic representation of the replication steps of the hop latent viroid RNA that are subjected to enzymatic degradation. Starting with the circular monomeric form (+ve strand, 256 bp) (A), replication using the host DNA-dependent RNA polymerase II creates a linear −ve strand (Lariat intermediate) to subsequently produce the linear antigenomic concatemers shown in (B). These are converted to linear genomic concatemers of varying sizes, which are digested by a (presumed) ribozyme to give rise to linear monomeric genomic (+) strands shown in (C). The results from enzyme digestion shown in (<b>a</b>–<b>c</b>) indicate that the circular monomeric form is not degraded by ribonuclease R while the linear concatemers are degraded by both ribonucleases A and R. In addition, the PCR primers detect the circular monomeric form as well as the linear genomic concatemers of varying sizes, giving rise to the multiple bands shown in <a href="#plants-14-00830-f001" class="html-fig">Figure 1</a> and <a href="#plants-14-00830-f002" class="html-fig">Figure 2</a> (adapted from McKernen and Helbert [<a href="#B36-plants-14-00830" class="html-bibr">36</a>]).</p>
Full article ">Figure 3
<p>Transmission of hop latent viroid through vegetative cuttings originating from infected stock plants of several cannabis genotypes. (<b>a</b>,<b>b</b>) Symptomatic and healthy-appearing plants, respectively, of genotype ‘S3’ were sampled at positions marked by 1–4. Symptoms of stunting and shorter internode length are shown in (<b>a</b>). (<b>c</b>) Banding patterns following RT-PCR of the plants shown in (<b>a</b>,<b>b</b>) confirms the viroid was present in all tissue samples taken from (<b>a</b>) but was absent in all samples taken from (<b>b</b>). (<b>d</b>,<b>e</b>) The extent of root emergence from infected and healthy cuttings in rockwool blocks. On the left side in each photo, cuttings were taken from an infected plant compared to a healthy plant (right). (<b>f</b>) Detection of hop latent viroid in roots of cuttings of three cannabis genotypes (G1, G2, G3) infected with HLVd in which the roots had just emerged from the rockwool blocks (time 0) and at various times subsequently (4, 8, 12 days). In genotype G1, the viroid was only detected at day 12 compared to all sampling times in genotypes 2 and 3, suggesting a slower movement of the viroid into the roots had occurred. (<b>g</b>,<b>h</b>) Root development on cuttings of each of three genotypes shown in (<b>f</b>) at 14 days after emergence from the rockwool blocks compared to cuttings from HLVd-infected stock plants (<b>h</b>). (<b>i</b>) Growth comparison of a cutting from an infected stock plant (left) of genotype ‘G1’ compared to a healthy plant (right) at 3 weeks. (<b>j</b>) Banding patterns following RT-PCR of the cuttings shown in (<b>h</b>) plus genotype G4, at 14 days after first emergence of roots from the rockwool blocks. All cuttings contained the viroid. In all figures, MW = molecular weight standard; +ve = positive control sample infected with hop latent viroid; −ve = water control. (<b>k</b>) Infra-red image analysis conducted on four cannabis cuttings, two rooted and two unrooted (top), shows a higher temperature emittance in the rooted cuttings (24.6 °C) compared to the unrooted cuttings (20.3 °C) (bottom). All four cuttings were positive for HLVd, suggesting the IR image was reflecting greater transpiration from rooted cuttings and not the presence/absence of HLVd.</p>
Full article ">Figure 4
<p>Transmission of hop latent viroid through infected roots of cannabis plants and through recirculated nutrient solution. (<b>a</b>) Placement of a HLVd-infected cutting and a healthy cutting of genotype ‘B2’ in the same Kloner. (<b>b</b>) Root development on both plants at 2 weeks shows a difference between the infected and healthy plant. (<b>c</b>) RT-PCR analysis of plants from the Kloner before and after the start of the experiment. Results are shown for duplicate plants (P1, P2). No bands were observed in the healthy plants before inoculation and bands reflecting positive detection of HLVd were observed in the roots of these plants after 2 weeks. (<b>d</b>) Placement of a HLVd-infected plant of ‘B2’ with healthy plants at the opposite ends of a tray. The trays were flooded twice daily for 2 weeks, after which plants were sampled. (<b>e</b>) Underside of the rockwool block showing development of roots in the infected ‘B2’ plant used in the experiment. (<b>f</b>) RT-PCR results from analysis of healthy and infected plants used in the experiment, water (nutrient) sample, and roots and leaves from the previously healthy plants which now contain the viroid. (<b>g</b>) A sample of nutrient solution from around the root zone shows the presence of small broken roots and sloughed off root cells. (<b>h</b>,<b>i</b>) Detection of HLVd (as denoted by +ve) using RT-qPCR. The viroid was present on the root surface, on the surface of the table immediately below the roots, in the grooves of the table where irrigation water accumulated, in drainage water and in the irrigation nozzles releasing recirculated nutrient solution.</p>
Full article ">Figure 5
<p>Transmission of hop latent viroid through stem inoculations conducted on hydroponically grown plants in Kloners. (<b>a</b>) Individual cuttings are inserted into Styrofoam holders and held in place and allowed to root. (<b>b</b>) After 4 weeks of growth, individuals stems on each plant (shown by arrows) were cut and discarded. (<b>c</b>) The exposed cut stem surface (arrow) with a drop of exudate. (<b>d</b>) Sap extracted from leaves of an HLVd-infected plant was dabbed onto the exposed surface of the cut stem using a Q-tip. (<b>e</b>) Two weeks after inoculation, new shoot growth can be seen on either side of the cut stem (arrow). (<b>f</b>) Results from RT-PCR of stem cuttings used in the experiment, showing the absence of HLVd in all cuttings used. (<b>g</b>) RT-PCR conducted on root (R) and leaf (L) tissues of four genotypes inoculated 4 weeks prior with HLVd shows the presence of the viroid in all root samples (blue arrows) and in three out of seven leaf samples. Multiple bands are indicative of active replication of the viroid. (<b>h</b>) Results from RT-PCR conducted 6 weeks after stem inoculation of four genotypes of cannabis (PK, BC, PWE, Mac) shows the presence of the viroid in all tissue samples (roots and leaves).</p>
Full article ">Figure 6
<p>(<b>a</b>) Inoculation of a 6-week-old plant of genotype ‘S3’ on a cut stem surface (arrow) shows the locations (1–6) where samples were taken prior to inoculation and after 2 weeks. (<b>b</b>) RT-PCR of tissues sampled before inoculation shows the plant was HLVd-negative. (<b>c</b>) RT-PCR of tissues sampled 2 weeks after inoculation shows HLVd is present in the youngest leaves (1) and in the roots (6). (<b>d</b>) The same plant shown in (<b>a</b>) was sampled 5 weeks after inoculation at positions (1–6). (<b>e</b>) RT-PCR analysis shows the viroid was present at various sampling positions in the foliage and in the roots. The multiple bands characteristic of HLVd can be seen. In many samples, petiole tissues showed more intense bands compared to leaf tissues. (<b>f</b>) Schematic representation of the spread of HLVd from stem inoculations to various parts of the plant, with detection in the roots (1) followed by detection in young leaves (2) and then in the middle and lower leaves (3). (<b>g</b>) Symptoms on a plant inoculated on a cut stem surface and grown for 10 weeks (left) compared to an uninoculated control plant (right). The leaves are reduced in size and the overall growth is less vigorous. (<b>h</b>) Physical abrasion of leaves that resulted in tearing at positions marked (1, 2, 3) followed by HLVd sap inoculation was compared to the cutting of leaf edges with scissors shown in (<b>i</b>), and then sap inoculated at positions marked (1*, 2*, 3*). (<b>j</b>) RT-PCR analysis of leaves from inoculated plants wounded as shown in (<b>h</b>) revealed the presence of HLVd in three leaf samples while plants wounded as shown in (<b>i</b>) did not become infected, as shown by the absence of bands corresponding to HLVd.</p>
Full article ">Figure 7
<p>The transfer of one set of 4-week-old HLVd-positive plants of genotype ‘H6’ displaying no symptoms of infection (<b>a</b>) from a 24 h photoperiod to a 12:12 h photoperiod in a growth chamber promoted inflorescence development when compared to plants maintained under constant 24 h light (<b>b</b>). The flowering plants were shorter in stature and more compact than the vegetative plants. When the experiment was repeated using artificially inoculated plants of genotypes ‘K4’, ‘M1’ and ‘S3’, inoculated 24 h prior to the transfer to a 12:12 h photoperiod, a similar transition to flowering was observed. When the roots, lower leaves, mid-leaves and flowers were sampled 21 days later and compared to plants kept under constant 24 h light for HLVd presence, the difference was significant (<b>c</b>). All tissues sampled from the plants grown under a 12:12 h photoperiod showed the characteristic multiple banding pattern for HLVd, while those with 24 h light showed the viroid was present in the roots, while faint bands could be seen in the leaves (<b>c</b>). RT-qPCR data from samples taken at 12 and 21 days following transfer to the different photoperiods for genotypes ‘M1’, ‘K4’ and ‘S3’ are shown in <a href="#plants-14-00830-t002" class="html-table">Table 2</a>. When the inoculation experiment was repeated with an autoflower genotype, in which the plants produce inflorescences at a certain growth stage regardless of photoperiod, the transition from vegetative growth (<b>d</b>) to flowering was observed in both sets of plants—those placed under the 12:12 h photoperiod and constant 24 h light (<b>e</b>). The former plants visually appeared to have a slightly more advanced inflorescence development. The RT-PCR results from tissues taken from these two sets of plants showed similar banding patterns, with a predominant band of 256 bp size observed in all tissues (roots, leaves, flowers) and at both photoperiods (12:12 and 24 h). The root samples had a more intense band overall compared to the rest of the plant (<b>f</b>).</p>
Full article ">Figure 8
<p>Artificial inoculation experiments conducted on tobacco (<span class="html-italic">Nicotiana tabacum</span> ’Samsun’) and tomato (<span class="html-italic">Solanum lycopersicum</span> ‘Celebrity’) plants. (<b>a</b>) Two-month old tobacco plant used for inoculations. (<b>b</b>) Infectious sap containing HLVd was introduced at the wound site where a leaf was removed (arrow). (<b>c</b>) Eleven week-old tobacco plant inoculated with HLVd was sampled at the points marked by arrows. (<b>d</b>) Detection of HLVd in the roots of one tobacco plant 2 weeks after inoculation at a petiole wound site as shown by the presence of a 256 bp band (arrow) that was absent in control plants. (<b>e</b>) Detection of HLVd in the roots of five tobacco plant 11 weeks after inoculation at a petiole wound site as shown by the presence of a 256 bp band. (<b>f</b>) Detection of HLVd in the lower leaves of four tobacco plants 8 weeks after inoculation at a petiole wound site as shown by the presence of a 256 bp band that was absent in control plants. (<b>g</b>) Detection of HLVd in the lower and upper leaves of three tobacco plants 11 weeks after inoculation at a petiole wound site as shown by the presence of a 256 bp band. (<b>h</b>) One month-old tomato plant used for inoculations showing the site of inoculation at a cut petiole (arrow). (<b>i</b>) Detection of HLVd in the roots of one out of five tomato plants 2 weeks after inoculation at a petiole wound site as shown by the presence of a 256 bp band that was absent in control plants. (<b>j</b>) Detection of HLVd in the lower and upper leaves of two tomato plants 8 weeks after inoculation at a petiole wound site as shown by the presence of a 256 bp band that was absent in control plants. (<b>k</b>) Detection of HLVd in the roots and lower leaves of four tomato plants 4 weeks after inoculation of the root system as shown by the presence of 256 bp bands.</p>
Full article ">Figure 9
<p>Schematic representation of the spread of hop latent viroid (red arrows reflect the direction of movement from 1 to 2 to 3) following different inoculation methods. (<b>a</b>) Cut-stem inoculation shows a downward movement of the viroid into the roots of inoculated cannabis plants within 2 weeks and subsequent detection in the foliage after 4 weeks. (<b>b</b>) Root inoculation shows detection of the viroid in the roots after 2 weeks and subsequent detection in the foliage after 4 weeks. (<b>c</b>) Seed inoculations shows detection of the viroid in the foliage after 2 weeks and detection in the roots after 3 weeks. (<b>d</b>) Cut-stem inoculation followed by exposure to a 12:12 h photoperiod shows detection in the roots after 12 days and in the foliage after 24 days. (<b>e</b>) Cut-stem inoculation of tomato plants shows detection in the roots after 2 weeks and in the foliage after 8 weeks. (<b>f</b>) Root inoculation of tomato plants shows detection in the roots after 2 weeks and in the foliage after 4 weeks.</p>
Full article ">Figure 10
<p>Impact of hop latent viroid infection on cannabis trichome development and size. (<b>a</b>) A healthy plant of genotype ‘D7’ produces large quantities of yellowish-brown trichomes collected on screen sizes of 150 µm (<b>a</b>) and 75 µm (<b>c</b>). An HLVd-infected plant produces fewer trichomes collected on the 150 µm screen that are yellowish-white in colour (<b>b</b>) and large quantities of smaller, poorly developed trichomes collected on the 75 µm screen (<b>d</b>). These images show a direct negative impact of HLVd infection on trichome development in this cannabis genotype (highly susceptible).</p>
Full article ">Figure 11
<p>Detection of hop latent viroid in inflorescences of cannabis plants. (<b>a</b>) Healthy inflorescence compared to an HLVd-infected one (<b>b</b>) shows yellowing of the bract tissues due to the viroid. (<b>c</b>) Positive detection of HLVd via RT-PCR in the stigmatic tissues, bracts and inflorescence leaves from an infected plant. (<b>d</b>) Samples of dried inflorescences were subjected to RT-PCR, showing that 5 out of 8 were infected by HLVd (<b>e</b>). (<b>f</b>) Total trichome preparations from an infected cannabis inflorescence shows the fraction collected on a 150 µm screen and a 75 µm screen (<b>g</b>) RT-PCR analysis of trichome preparations shows the presence of HLVd in both the 150 um (T1, T2) and 75 µm fractions (T3, T4). (<b>h</b>) Resins extracted from trichomes of cannabis using four different methods. (<b>i</b>) RT-PCR analysis shows the presence of HLVd in three out of four trichome preparations. An extremely faint band can be seen in sample 1 (winterized oil). In all figures, MW = molecular weight standard; +ve = positive control sample infected with hop latent viroid; −ve = water control.</p>
Full article ">Figure 12
<p>Detection of hop latent viroid in hemp seeds, seedlings and pollen grains. (<b>a</b>) The viroid was detected in seeds, cotyledons (C) and leaves (L) of seedlings from natural infection, and in cotyledons and leaves of seedlings following artificial inoculation (+HLVd). (<b>b</b>) Detection of HLVd in true leaves from artificially inoculated and naturally infected seeds. (<b>c</b>) A hemp plant producing male flowers and pollen. (<b>d</b>) Pollen grains from anthers following air-drying. (<b>e</b>) RT-PCR analysis shows the presence of HLVd in pollen and in anthers of hemp.</p>
Full article ">Figure 13
<p>Detection of hop latent viroid in cannabis flowers, pollen, seeds and seedlings (<b>a</b>) Male flowers on a cannabis plant. (<b>b</b>) RT-PCR of whole flowers (FL) and anthers (A) from two cannabis plants showing presence of HLVd. (<b>c</b>) A comparison of seeds from an infected (left) and a healthy cannabis plant (right) showing the impact of HLVd on seed size and development. (<b>d</b>) Detection of HLVd in naturally infected seeds of cannabis showing the presence of a 256 bp band in all 16 seeds. (<b>e</b>) HLVd was detected on the seed coat of cannabis seeds. (<b>f</b>,<b>g</b>) HLVd was not detected in the emerging radicles from infected seeds (arrows). (<b>h</b>) HLVd was detected in the cotyledons (arrow). (<b>i</b>) Summary of seed germination and seedling emergence from infected cannabis seeds. Asterisks (*) denote where HLVd was detected.</p>
Full article ">Figure 14
<p>Survival of hop latent viroid in plant sap, in plant tissues and on the surfaces of utensils. (<b>a</b>) Dried plant sap placed in weighing boats was tested by RT-PCR at varying time periods. (<b>b</b>) The viroid was stable in sap for up to 5 days and displayed the characteristic multiple banding patterns at all time intervals. (<b>c</b>) Dried leaves from infected plants were left under laboratory conditions for periods of up to 4 weeks. (<b>d</b>) RT-PCR showed the viroid was detected in leaves for up to 4 weeks. (<b>e</b>) The viroid was detected in dried roots for up to 4 weeks. (<b>f</b>) Plastic disposable pestles used to grind plant tissues and (<b>g</b>) watering cans used to deliver nutrient solution were tested for the presence of HLVd. (<b>h</b>) RT-PCR analysis revealed the presence of a 256 bp band of HLVd in samples obtained from the surface of pestles (C), from the surface of autoclaved pestles (A), from nutrient solution in storage containers (W1, W2) and from the surface of watering cans (J1, J2). (<b>i</b>) Effect of UV-C irradiation on stability of HLVd in infected leaves and roots. Tissues were either not treated (CON) or exposed for 3 min or 5 min to a UV-C lamp. All samples showed the characteristic banding pattern of control samples. (<b>j</b>) Effect of heat on the stability of HLVd in plant tissues. Infected leaf tissues were exposed to treatments ranging from 30 °C to 90 °C for periods of 15 or 30 min. RT-PCR analysis showed that at temperatures up to 60 °C, multiple banding patterns were observed similar to the untreated control, while at 70 °C and higher, a single band of 256 bp was detected (arrow) and the higher MW bands were diminished in intensity. (<b>k</b>) Root samples from an infected plant grown in hydroponic containers were harvested, cut into small segments as shown in (<b>l</b>) and exposed to heat treatments. (<b>m</b>) RT-PCR analysis showed that at temperatures up to 50 °C, a single 256 bp band was observed similar to the untreated control, while at higher temperatures, the band intensity was diminished. (<b>n</b>) Exposure of intact leaves to four chemical treatments at varying concentrations for 2 min followed by RT-PCR showed that none of the treatments had an effect on the stability of the RNA of HLVd.</p>
Full article ">Figure 15
<p>The effect of various treatments on the stability of HLVd in infected plant sap. (<b>a</b>) The method employed involved saturating filter paper discs with infectious sap and exposing air-dried discs to various chemical and enzymatic treatments for 1 min, following which the discs were transferred to Eppendorf tubes and stored in a −80 °C freezer until RT-PCR analysis could be conducted to determine if HLVd was detectable. (<b>b</b>) Eppendorf tubes containing filter paper discs were subjected to various treatments as indicated. Control discs received water. (<b>c</b>) RT-PCR analysis of RNA extracted from treated discs shows that only bleach at 20% destroyed the RNA to a point where it was not amplified. In the remaining treatments, a 256 bp band and a faint band at 512 bp could be seen similar to the control. (<b>d</b>) Exposure of RNA of <span class="html-italic">C. sativa</span> mitovirus (CasaMV1) to various treatments showed that RNase A (lane R) and bleach (lane B) reduced the intensity of the 980 bp band significantly compared to the other treatments which had no effect. The other treatments were 2% Zerotol (lane Z), 1000 ppm hypochlorous acid (lane H), untreated sap (lane S), exposure to UV-C light for 3 min (lane UV) and 2% Virkon (lane V).</p>
Full article ">Figure 16
<p>The effect of various treatments on the stability of HLVd in infectious plant sap. (<b>a</b>) Eppendorf tubes containing filter paper discs were subjected to various treatments as indicated. Control discs received water. (<b>b</b>) RT-PCR analysis of RNA extracted from treated discs containing sap shows that only bleach destroyed the RNA to where it was not amplified. The effective concentrations were 10% bleach for 2 min (lane 7) or 1 min (lane 8), 20% bleach for 2 min (lane 9) or 1 min (lane 10). In the remaining treatments, a 256 bp band was detected similar to the control. (<b>c</b>) RT-PCR analysis of RNA extracted from treated discs shows that the following treatments destroyed the RNA a point where it was not amplified: 1000 ppm hypochlorous acid (lane H), 10% bleach (lane B), and 20% skim milk powder (lane S). The other treatments in which the bands were still amplified included 2% Virkon (lane V), RNase A (lane R), culture extract from <span class="html-italic">Bacilllus subtilis</span> (lane Bs) and diluted sap (1:10). (<b>d</b>) RT-PCR analysis of RNA extracted from treated discs shows that the following treatments destroyed the RNA where it was not amplified: 10% bleach (lane B) and 1000 ppm hypochlorous acid (lane H). The other treatments where the RNA was not destroyed were 70% ethanol (lane E), 2% Zerotol (lane Z) and water (lane W). (<b>e</b>) RT-PCR analysis of RNA extracted from treated discs containing sap shows that the following treatments destroyed the RNA where it was weakly amplified: exposure to RNase A + 60 °C for 10 or 20 min (R60). The other treatments in which the bands were still amplified included room temperature (rt), exposure to 60 °C for 10 or 20 min (60), exposure to RNase A for 10 or 20 min (R), exposure to RNase A for 10 or 20 min (A) or exposure to RNase A + 60 °C for 10 or 20 min (A60).</p>
Full article ">Figure 17
<p>(<b>a</b>) RT-PCR analysis of RNA extracted from infectious sap shows that the following treatments destroyed the RNA since it was not amplified or was only weakly amplified: 5%, 10% and 20% bleach (8.25% NaOCl) with sap diluted by 1:1, 1:2 and 1:4. (<b>b</b>) The effect of varying concentrations of bleach on the degradation of total RNA extracted from plant tissues that includes 18S/16S RNA. In the left panel, total RNA was undiluted (1:1) or diluted 1:2 and 1:3 and then exposed to 10% or 7.5% bleach. The bleach degraded more RNA at the 1:3 dilution. In the right panel, undiluted total RNA was subjected to bleach concentrations ranging from 1% to 10%. The highest concentration (10%) caused the most degradation. (<b>c</b>) Water containing HLVd added as infectious sap was subjected to a range of treatments, following which RT-PCR was conducted to determine amplification. Treatments that did not produce a band were bleach (B) containing 8.25% NaOCl at 5, 10 and 20%, 2% Virkon in water (V) and 600 ppm hypochlorous acid. Positive controls included infectious sap (+ve) and sap added to water (CO), which showed multiple bands were amplified. In the UV treatments (1, 2 and 5 min), the higher-molecular-weight band (512 bp) representing linear RNA of HLVd was destroyed but the 256 bp band was unaffected.</p>
Full article ">Figure 18
<p>Meristem tip culture for recovery of HLVd-free explants. (<b>a</b>) Cuttings taken from the middle branches of a two-month-old HLVd-infected mother plant. (<b>b</b>) An excised shoot tip (left) and meristem excision of 0.4 mm size (bottom right, arrow) with two or less leaf primordia from the shoot tip. Scale bar = 1 mm. (<b>c</b>) First subculture (three-week growth) of meristematic explants (arrows) on tissue culture medium. (<b>d</b>) Second subculture (six-week growth) of meristem explants (arrows); the first HLVd test was conducted during this subculture. (<b>e</b>) Fourth subculture (12-week growth) of meristem explants. (<b>f</b>) Eighth subculture (24-week growth) of meristem explants. Results from testing for presence/absence of HLVd in these tissue-cultured plants are presented in <a href="#plants-14-00830-t003" class="html-table">Table 3</a>.</p>
Full article ">Figure 19
<p>Summary of the various avenues through which HLVd can be spread in an indoor hydroponic cannabis-growing environment based on the results from this study. Starting from infected stock plants (<b>a</b>), most of which are asymptomatic, cuttings rooted in a propagation room were shown to be infected at a high frequency and mostly remained asymptomatic (<b>b</b>,<b>c</b>). These rooted cuttings gave rise to infected vegetative plants (<b>d</b>), which may show symptoms of stunted growth and reduced root development. Spread of HLVd from exposed roots and through wounds can take place during the vegetative plant stage (<b>e</b>), especially through recirculated nutrient solution. Infected flowering plants originating from infections that occurred at the vegetative or propagative stage can display symptoms of stunting and reduced growth when placed under a 12:12 h photoperiod to induce flowering (<b>f</b>). These plants continue to display symptoms throughout the flowering period, including smaller inflorescences and reduced cannabinoid production (<b>g</b>). Plants grown for seed that are infected can produce infected pollen and seed at a high frequency, resulting in further spread of the viroid (<b>h</b>).</p>
Full article ">
16 pages, 3432 KiB  
Article
Characterization of Pollinators Associated with Cocoa Cultivation and Their Relationship with Natural Effective Pollination
by Diana Katherinne Ríos-Moyano, Fredy Alexander Rodríguez-Cruz, Paola Andrea Hormaza-Martínez and Augusto Ramírez-Godoy
Diversity 2025, 17(3), 189; https://doi.org/10.3390/d17030189 - 6 Mar 2025
Viewed by 173
Abstract
Cocoa (Theobroma cacao L.) relies on insect pollination for fruit production, making it essential to understand the pollinators involved. This study aimed to identify the insects associated with cocoa pollination and their relationship with effective natural pollination in a cocoa agroforestry system [...] Read more.
Cocoa (Theobroma cacao L.) relies on insect pollination for fruit production, making it essential to understand the pollinators involved. This study aimed to identify the insects associated with cocoa pollination and their relationship with effective natural pollination in a cocoa agroforestry system in Yopal, Colombia. Indirect (wood traps) and direct (manual aspiration in flowers) methods were used to capture pollinators. The number of captured insects was correlated with the percentage of pollinated, fertilized, aborted, and transitioning flowers using Pearson’s correlation coefficient. Additionally, the natural transfer of pollen was assessed by evaluating the coverage of near-opening flowers and staining pollen grains on the stigma under natural conditions. This study identified Diptera from the Ceratopogonidae family, specifically the genera Forcipomyia and Dasyhelea, as key pollinators. The findings highlight the presence of these pollinators in the Yopal cocoa agroforestry system and suggest the need for further pollinator capture and identification efforts on local farms. A positive correlation was found between the number of pollinating insects and the percentage of fertilized flowers, emphasizing the crucial role of these insects in cocoa pollination and the importance of promoting their presence to optimize fruit production. Full article
(This article belongs to the Special Issue Ecology and Diversity of Diptera in the Tropics)
Show Figures

Figure 1

Figure 1
<p>Map of plot locations in the study area (Yopal, Colombia. October 2021).</p>
Full article ">Figure 2
<p>Establishment of the wooden pyramid trap in the AFS (Yopal, Colombia. October 2021).</p>
Full article ">Figure 3
<p>Capture of floral visitors: (<b>a</b>) structure of the container; (<b>b</b>) implementation of the suction tube (Yopal, Colombia. October 2021).</p>
Full article ">Figure 4
<p>Cocoa flower bud (Yopal, Colombia. September 2021).</p>
Full article ">Figure 5
<p>Flower buds enclosed in the cage to prevent the entry of insects (Yopal, Colombia. September 2021).</p>
Full article ">Figure 6
<p>Summary of the study methodology.</p>
Full article ">Figure 7
<p>Box plot for the number of individuals of the genera of Ceratopogonidae collected in cocoa AFS in two sampling periods, Yopal, Colombia 2021.</p>
Full article ">Figure 8
<p>Images of verification of pollen transfer to flower stigmas, cocoa pollen grains. (<b>a</b>) 10× magnification, (<b>b</b>) 40× magnification, and (<b>c</b>) 100× magnification (Yopal, November 2021).</p>
Full article ">
Back to TopTop