[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
Next Article in Journal
Genome-Wide Identification of the ALMT Gene Family in Nine Rosaceae Species and Functional Analysis Associated with Organic Acid Accumulation in Prunus mume
Previous Article in Journal
A Metabolomic Analysis of Tomato Fruits in Response to Salt Stress
You seem to have javascript disabled. Please note that many of the page functionalities won't work as expected without javascript enabled.
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Horticulturae
Volume 10
Issue 12
10.3390/horticulturae10121304
horticulturae-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Evaluation of Sodium Chloride Concentrations on Growth and Phytochemical Production of Mesembryanthemum crystallinum L. in a Hydroponic System

by
Giju Eoh
1,
Chulhyun Kim
2,
Jiwon Bae
1 and
Jongseok Park
1,*
1
Department of Bio-AI Convergence, Chungnam National University, Daejeon 34134, Republic of Korea
2
GCL Farm Co., Ltd., Research Center, Hwaseong-si 18517, Republic of Korea
*
Author to whom correspondence should be addressed.
Horticulturae 2024, 10(12), 1304; https://doi.org/10.3390/horticulturae10121304
Submission received: 5 November 2024 / Revised: 28 November 2024 / Accepted: 5 December 2024 / Published: 6 December 2024
(This article belongs to the Section Plant Nutrition)
Browse Figures
Figure 1
<p>Shoot fresh weight (<b>A</b>), shoot dry weight (<b>B</b>), root fresh weight (<b>C</b>), and root dry weight (<b>D</b>) of <span class="html-italic">Mesembryanthemum crystallinum</span> L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM) at 5 weeks after transplanting. Data are represented as mean values ± standard error of three replicates (<span class="html-italic">n</span> = 10). Different letters above the bars indicate significant differences between treatments via Tukey’s HSD test at <span class="html-italic">p</span> &lt; 0.05.</p> "> Figure 2
<p>Morphology of <span class="html-italic">M. crystallinum</span>. NaCl was stressed at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM) after 4 weeks of treatment.</p> "> Figure 3
<p>Ratio of shoot/root FW (<b>A</b>), ratio of shoot/root DW (<b>B</b>), leaf water content (<b>C</b>) of <span class="html-italic">Mesembryanthemum crystallinum</span> L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Data are represented as mean values ± standard error of three replicates (<span class="html-italic">n</span> = 10). Different letters above the bars indicate significant differences between treatments via Tukey’s HSD test at <span class="html-italic">p</span> &lt; 0.05.</p> "> Figure 4
<p>Total chlorophyll (<b>A</b>), total carotenoids (<b>B</b>) in <span class="html-italic">Mesembryanthemum crystallinum</span> L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (<span class="html-italic">n</span> = 10). Different letters indicate significant differences (<span class="html-italic">p</span> &lt; 0.05).</p> "> Figure 5
<p>Total flavonoids (<b>A</b>), total phenolic contents (<b>B</b>), and D-pinitol concentration (<b>C</b>) in <span class="html-italic">Mesembryanthemum crystallinum</span> L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (<span class="html-italic">n</span> = 10 for (<b>A</b>,<b>B</b>), <span class="html-italic">n</span> = 3 for (<b>C</b>)). Different letters indicate significant differences (<span class="html-italic">p</span> &lt; 0.05).</p> "> Figure 6
<p>DPPH radical scavenging activity in <span class="html-italic">Mesembryanthemum crystallinum</span> L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (<span class="html-italic">n</span> = 3). Different letters indicate significant differences (<span class="html-italic">p</span> &lt; 0.05).</p> ">
Versions Notes

Abstract

:
Mesembryanthemum crystallinum L., commonly known as the ice plant, is a halophyte recognized for its exceptional salinity tolerance. This study aimed to determine the optimal NaCl concentration for promoting plant growth, D-pinitol, and other phytochemicals in M. crystallinum cultivated in a hydroponics system. Seedlings of M. crystallinum were transplanted into a hydroponic system and subjected to different NaCl concentrations (0, 100, 200, 300, 400, and 500 mM) in the nutrient solution. To evaluate the plant’s response to salinity stress, measurements were conducted on growth parameters, chlorophyll and carotenoid levels, total flavonoid and polyphenol contents, and DPPH scavenging activity. The optimal NaCl concentration for growth was found to be 200 mM, at which the shoot fresh and dry weights were highest. Additionally, total chlorophyll and carotenoid contents were maximized at 200 mM NaCl, with a subsequent decrease at higher concentrations. The highest DPPH scavenging activity was observed in the 200 mM NaCl treatment, which correlated with increased levels of total flavonoids and polyphenols. These results indicated that optimizing NaCl concentration can enhance the antioxidant activity of Mesembryanthemum crystallinum L. The D-pinitol content also peaked at 200 mM NaCl treatment, further supporting its role osmotic adjustment under salinity stress. M. crystallinum exhibited enhanced antioxidant production and cellular protective functions at 200 mM NaCl, which optimized its biochemical defense mechanisms and helped maintain physiological functions under salinity stress. These findings provide valuable insights for agricultural and biological applications, particularly in cultivating M. crystallinum for its bioactive compounds.

1. Introduction

Mesembryanthemum crystallinum L., commonly known as the ice plant, belongs to the Aizoaceae family within the order Caryophyllales. This succulent annual herb is notable for its exceptional salt tolerance, serving as a prime example of a halophyte [1,2]. M. crystallinum L. is covered with large glistening bladder cells. These bladder cells are modified unicellular trichomes with diameters ranging from 1 to 3 mm [3]. They contain a water-based solution and function as peripheral reservoirs, protecting the plant from short-term high salinity or water deficit stress [4]. Since M. crystallinum L. has strong salt tolerance, it is often used as an important plant material to study the physiological and metabolic mechanisms underlying plant responses to salt stress [5,6,7]. To respond to salt stress, halophytes typically absorb and transport Na+, Cl−, and K+ to maintain cellular osmotic pressure stability [8,9]. Meanwhile, they also synthesize and accumulate compatible solutes such as glycerol, betaine, proline, D-inositol, and D-galactose to improve their salt tolerance [9,10,11]. Salt stress is often accompanied by the accumulation of reactive oxygen species (ROS). In response to this oxidative stress, halophytes protect themselves from oxidative damage by not only enhancing the activity of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), but also increasing the synthesis of secondary metabolites [12,13,14,15].
When M. crystallinum L. is exposed to salt stress, it accumulates several secondary metabolites, such as polyphenols, flavonoids, and D-pinitol (3-O-methyl-D-chiro-inositol) [6,16,17,18]. These compounds contribute not only to the plant’s enhanced tolerance to oxidative stress but also possess significant pharmacological properties. For example, polyphenols and flavonoids are known for their antioxidant, anti-inflammatory, and anticancer activities [19,20,21,22], while D-pinitol has been reported to have potential benefits in regulating hyperglycemia and diabetes [23]. In particular, D-pinitol, a naturally occurring compound in M. crystallinum, is a key bioactive metabolite that has garnered attention for its potential benefits in treating Type 2 diabetes (T2D). D-pinitol, which is metabolized into a cyclic polyol, influences glucose metabolism by enhancing insulin sensitivity and promoting insulin secretion. Recent studies have shown that D-pinitol improves insulin resistance in T2D patients, largely due to its action on glucose metabolism pathways [23,24,25].
Some studies have shown that M. crystallinum L. achieves optimal growth under suitable salt stress conditions [26,27]. However, research on its optimal salt concentration remains inconsistent. Flowers et al. [26] defined halophytes as plants capable of completing their life cycle at salt concentrations of at least 200 mM NaCl, similar to conditions found in natural saline-alkali soils. Therefore, regarding salt stress treatments on M. crystallinum, NaCl concentrations are typically controlled within the range of 0–500 mM. Some studies have shown that in hydroponic systems, optimal growth is observed at NaCl concentrations of 50 mM and 100 mM [6,7]. On the other hand, Hong’s study indicated that although ice plants can grow normally during the vegetative stage under 400 mM NaCl treatment, its flowering time was shortened [28]. However, these studies did not assess the changes in secondary metabolites in ice plants under salt stress conditions, particularly the content of D-pinitol.
As a plant with both nutritional value and medicinal potential, M. crystallinum L. exhibits secondary metabolite accumulation that is significantly influenced by environmental conditions [29,30]. The advanced environmental regulation in enclosed vertical farms makes them an ideal platform to study the impact of salt stress on the growth and metabolism of M. crystallinum L. Based on the above research background, this study cultivated M. crystallinum L. in a closed vertical farm and applied varying concentrations of salt stress to investigate its growth performance and metabolic responses, with a particular focus on optimizing the accumulation of secondary metabolites such as D-pinitol. The objective is to identify the optimal salt concentration that balances plant growth and medicinal value, thereby maximizing the production potential of ice plants in a hydroponic system.

2. Materials and Methods

2.1. Plant Materials and Environmental Conditions of the Seedlings

Seeds (Asia Seed Co., Ltd., Seoul, Republic of Korea) of Mesembryanthemum crystallinum L. were sown in a 324-cell tray filled with rock wool medium. The seeds were cultivated at a temperature of 22 ± 1 °C in a controlled vertical farming system. Subsequently, they were grown for four weeks under the following growth conditions: 335 ± 15 µmol m−2 s−1 light intensity with a 14/10 h (light/dark) photoperiod and a relative humidity of 75 ± 5%. Once 2–3 true leaves appeared, the plants were irrigated every other day with modified YARA nutrient solution. A modified YARA nutrient solution, optimized for leafy vegetables, was prepared with the following composition: NH4-N (2.10 mg·L−1), K (239 mg·L−1), Ca (152.82 mg·L−1), Mg (90.90 mg·L−1), Na (8.90 mg·L−1), NO3-N (107.89 mg·L−1), P (52.76 mg·L−1), S (105.79 mg·L−1), Cl (15.33 mg·L−1), B (1.36 mg·L−1), Zn (0.86 mg·L−1), Cu (0.17 mg·L−1), Mn (0.65 mg·L−1), Fe (2.74 mg·L−1), and Mo (0.19 mg·L−1). The solution was adjusted to a pH of 6.0 ± 0.5 and an EC (electric conductivity) of 1.8 ± 0.2 dS·m−1.

2.2. Environmental Conditions and Stress Treatments After Transplantation

Four weeks post-sowing, ten uniform seedlings were chosen and transplanted into a semi-nutrient film technique hydroponic system within a controlled vertical farming system for each NaCl concentration treatment. The plants were cultivated for five weeks under the following environmental conditions: 335 ± 15 µmol m−2 s−1 light intensity with a 14/10 h (light/dark) photoperiod, relative humidity of 75 ± 5%, a temperature of 22 ± 1 °C, CO2 of 1000 ppm. The YARA nutrient solution with an EC of 1.8 ± 0.2 dS·m−1 and a pH of 6.0 ± 0.5 was mixed with NaCl at concentrations of 100, 200, 300, 400, and 500 mM for the respective plants throughout the cultivation period. The YARA nutrient solution and NaCl were replaced weekly to maintain consistent nutrient levels.

2.3. Measurement of Plant Growth Parameters

M. crystallinum was harvested from ten plants per treatment, and measurements were conducted to analyze the fresh and dry weight of leaf water content, shoots, and roots. The fresh and dry weights of the shoots and roots were measured using an electronic balance (FD8508, Ilshin Biobase Co., Ltd., Dongducheon-si, Republic of Korea). The samples were freeze-dried at −80 °C for 72 h in a freeze-dryer (FD8508, Ilshin Biobase Co., Ltd., Dongducheon-si, Republic of Korea). After drying, the dry weight of the shoots was measured using an electronic balance. According to [31], leaf water content (LWC) was determined as follows:
LWC (%) = (Lfw − Ldw)/Lfw × 100
  • Lfw: fresh weight (g);
  • Ldw: dry weight (g).

2.4. Chlorophyll Pigments

Chlorophyll a and chlorophyll b contents were measured by the modified Kozukue N and Friedman M method [32]. Prepared samples (10 g) from 10 plants were extracted with 80% acetone at a 1:1 ratio (sample: acetone) followed by centrifugation. The extract was obtained through suction filtration (Whatman grade 2 filter paper, Cytiva Co., Ltd., Amersham, UK). Optical Density (OD) absorbance of the extract was measured at 645 nm and 663 nm using a UV-VIS spectrophotometer (Shimadzu UV mini 1240, Shimadzu Co., Kyoto, Japan). The chlorophyll concentration was calculated using the absorbance values according to the following formulas:
Chlorophyll a: 12.72 OD (663) − 2.58 OD (645)
Chlorophyll b: 22.88 OD (645) − 5.50 OD (663)
Total Chlorophyll: 7.22 OD (663) + 20.3 OD (645)

2.5. Carotenoids

Carotenoid analysis was conducted using a specific HPLC method. Initially, 100 mg of dried powder sample was placed in a 5.0 mL Falcon tube, to which 5 mL of ethanol was added. The mixture was shaken in a constant temperature bath at 75 °C for 5 min, followed by adding 1.5 mL of 80% KOH and further agitation for 10 min. The reaction was then quenched in ice for 5 min. Subsequently, 2.5 mL of ultra-pure water and 2.5 mL of hexane were added, and the tube was vortexed. After centrifugation at 3000 rpm for 3 min, the supernatant (hexane layer) was collected in an evaporating flask. This extraction process was repeated three times, and the supernatants were combined in the flask. The collected supernatant was then concentrated under reduced pressure at 40 °C. To the concentrated extract, 1.0 mL of dichloromethane–methanol [50:50 (v/v)] was added and then fully dissolved via sonication. The dissolved solution was filtered through a 0.45 µm hydrophilic PTFE syringe filter (diameter 13 mm) before being analyzed by an HPLC system (HPLC 1260 Infinity II LC system, Agilent Technologies, Santa Clara, CA, USA) equipped with a YMC Carotenoid C30 column (250 × 4.6 mm ID, particle size 3.0 µm). The analysis was performed with a column temperature of 40 °C, a detection wavelength of 454 nm, a flow rate of 1.0 mL/min, and an injection volume of 20.0 µL.
As mobile phase solvents, A [water–methanol = 25:75 (v/v)] and B [ethyl acetate] were used. The gradient started at 60% B, increasing to 70% at 4 min, 75% at 9 min, and held at this percentage for 20 min. At 23 min, the rate was increased to 100% and held for 5 min. It was then rapidly decreased to 60% at 28.1 min, followed by column washing for 10 min until reaching 38 min. Each component of carotenoids was quantified by comparing the area of each component with the HPLC peak area of the corresponding external standard.

2.6. Total Flavonoids

Total flavonoid contents were measured by Epoch microplate (Epoch Microplate Spectrophotometer, Biotek Instruments Inc., Winooski, VT, USA) using a modified method of Nieva Moreno [33]. First, 0.1 mL of the extract was dissolved in 0.9 mL of 80% ethanol. To this solution, 0.5 mL was added to a mixture of 0.1 mL of 10% aluminum nitrate and 4.3 mL of 80% ethanol in 1 M potassium acetate. The resulting mixture was incubated at room temperature for 40 min, and its absorbance was measured at 415 nm. Total flavonoid content was calculated using a quercetin standard curve. To prepare this curve, 0.1% (w/v) quercetin was dissolved in distilled water to create final concentrations of 0, 50, 100, 150, and 200 µg/mL. The absorbance of these solutions was then measured as described above.

2.7. Total Phenolic Contents

Total phenolic content was measured by the modified AOAC method [34], which quantifies phenolic compounds reactive with the Folin–Ciocalteu reagent, including polyphenols, phenolic acids, and phenolic alcohols. The prepared sample (0.1 g) was extracted with 10 mL of 80% methanol through sonication at 30 °C for 20 min. After centrifugation at 3000 rpm for 10 min, the supernatant was filtered using a 0.45 µm syringe filter. To 60 µL of the diluted extract solution, 60 µL of Folin reagent (diluted 2 times) was added, and the mixture was incubated at room temperature for 3 min. Subsequently, 60 µL of 10% Na2CO3 solution was added to the mixture to react. The absorbance of the resulting reaction solution was measured at 700 nm using a spectrophotometer (Epoch Microplate Reader Spectrophotometer, Vermont Inc., South Burlington, VT, USA).

2.8. DPPH (1-1-Diphenyl-2-Picrylhydrazyl Free Radical Activity)

The antioxidant activity was determined by DPPH radical scavenging activity using the DPPH method [35]. After adding 160 µL of the sample and 40 µL of an ethanol DPPH solution, the mixture was left at room temperature in the dark for 30 min. The absorbance was measured at 517 nm using an Epoch microplate (Epoch Microplate Spectrophotometer, Biotek instruments Inc., Winooski, VT, USA). Trolox was used as a control for comparing relative activity. The scavenging activity of DPPH was calculated using the following equation:
DPPH   radical   scavenging   activity   ( % ) = ( 1 − a b s o r b a n c e   o f   s a m p l e   a t   517   n m a b s o r b a n c e   o f   c o n t r o l   a t   517   n m )   ×   100

2.9. Determination of D-Pinitol

D-Pinitol analysis was conducted using a modified method of HPLC [36]. The samples were mixed with ten times their volume of 80% ethanol and extracted for 4 h at room temperature. After drying the extracts at 50 °C, they were filtered through a 0.45 µm syringe filter. The filtrate was then analyzed using an HPLC (1260 Infinity II LC system, Agilent Technologies Inc., Santa Clara, CA, USA) equipped with column (RSpak DC-613, Shodex Inc., Tokyo, Japan) and a Reflective Index Detector (K-2301, Knauer lnc., Berlin, Germany). The columns were maintained at 70 °C, and the mobile phase flowed at a rate of 0.9 mL/min. D-pinitol and inositol were quantified from the HPLC profile.

2.10. Statistical Analysis

For each treatment, growth parameters and chlorophyll pigments, carotenoids, total flavonoids, and total polyphenols were collected from ten plants (n = 10), and DPPH and D-pinitol were determined from three plants (n = 3). Data were statistically analyzed using a randomized block design with three replications, employing the SPSS program (SPSS 26, SPSS Inc., Chicago, IL, USA) for analysis of variance (ANOVA) with Tukey’s honestly significant difference (HSD) test to assess significance at p ≤ 0.05. Graphs to represent data were produced using Sigmaplot (15.0, Systat Software, Inc., San Jose, CA, USA).

3. Results and Discussion

3.1. Plant Growth Parameters

The shoot fresh weight (FW) and dry weight (DW), and root fresh and dry weights were measured to analyze their growth at different NaCl concentrations. The shoot FW was 78.54 and 4.93 g/plant when grown at 200 and 500 mM NaCl (Figure 1A). Shoot DW was 4.02 and 0.24 g/plant at 200 and 500 mM NaCl (Figure 1B). These results are consistent with the trends reported by Agarie [4], who indicated that the DW of the ice plant was significantly higher at NaCl concentrations between 100 mM and 200 mM than at 400 mM and 800 mM. This observation suggests that M. crystallinum has an optimal salinity range for biomass production, with excessive salinity leading to a significant reduction in growth parameters, potentially due to osmotic stress and ion toxicity [37]. Both shoot FW and DW exhibited a decreasing trend as NaCl concentrations increased from 200 mM to 500 mM. This decline suggests a threshold beyond which the plant’s ability to tolerate salinity diminishes, resulting in impaired growth. Such a response is typical of halophytes, where moderate salt concentrations promote growth but higher levels become detrimental [38]. Concurrently, the root fresh weight was highest at 16.40 g/plant in the control (0 mM) and significantly decreased to the lowest value of 0.52 g/plant at 500 mM NaCl (Figure 1C). Similarly, the root dry weight at 100 mM NaCl was 0.66 g/plant, which was not significantly different from the control, indicating that 100 mM NaCl does not affect root growth (Figure 1D). The reduction in root biomass under high salinity could be due to energy being diverted from growth to maintaining osmotic balance and supporting detoxification mechanisms [37]. Furthermore, these contrasting trend between shoot and root weights highlights the plant’s adaptive mechanisms, where energy is redirected from root growth to support above-ground biomass, likely to maintain osmotic balance and enhance survival under moderate salinity stress [39].
The morphology of M. crystallinum under 200 mM NaCl treatment showed better development compared to the 100 and 300 mM NaCl treatments (Figure 2). Other studies on various plants, such as corn, suggest that roots are more sensitive to salinity than shoots [40]. Consistent with these findings, our study shows that in M. crystallinum, the roots are more responsive to salinity than the shoots. Specifically, the root dry weight was highest at 100 mM NaCl, while the shoot dry weight peaked at 200 mM NaCl, indicating that the roots expend energy to counteract salinity stress even at lower concentrations. This suggests that roots are more responsive to early salinity stress, while shoots begin to be affected at higher concentrations.
Many plants adjust their shoot/root ratio based on available nutrients. This study found that the shoot and root fresh weight ratio of M. crystallinum L. was highest at 200 mM NaCl and then notably decreased at 400 mM NaCl (Figure 3A). The shoot and root dry weight ratio was significantly higher at 200 mM and 500 mM NaCl compared to at 100, 300, and 400 mM NaCl (Figure 3B). These findings align with previous studies suggesting that optimal salinity levels can promote balanced growth, whereas extreme salinity disrupts nutrient uptake and allocation, leading to a disproportionate reduction in root biomass [37]. The leaf water content was lowest at 500 mM NaCl, as shown in (Figure 3C), and increased with salinity up to 200 mM NaCl, suggesting salt tolerance in M. crystallinum, which may act as an osmotic adjustment to lower the external water potential induced by salinity [8]. Furthermore, Herppich et al. reported that 150 mM NaCl did not negatively affect the growth and development of M. crystallinum [41]. The decrease in leaf water content at high salinity is likely a result of increased osmotic pressure, which reduces the plant’s ability to retain water, a common response in halophytes [38].

3.2. Total Chlorophyll and Secondary Metabolite Contents and Antioxidant Activity

This study observed an initial increase in total chlorophyll concentrations from the control to 200 mM NaCl compared to control, followed by a decrease as NaCl concentrations exceeded 200 mM (Figure 4A). However, the reduction in chlorophyll content in all NaCl treatments was not statistically significant compared to the control, suggesting that salt stress did not disrupt chlorophyll content in Mesembryanthemum crystallinum L. The observed trend of increased total chlorophyll concentrations in 200 mM NaCl could suggest a stress acclimation phase where the plant optimizes its photosynthetic apparatus to cope with the oxidative stress [42,43].
Carotenoids are necessary for biological activities such as photoprotection, photosynthesis, and cell signaling in abiotic and biotic stress environments [44]. Carotenoid content increased from the control, peaking at 193.32 mg/100 g at 200 mM NaCl, and was lowest at 116 mg/100 g at 500 mM NaCl (Figure 4B). The peak at 200 mM NaCl indicates a protective response, as carotenoids play a crucial role in quenching ROS and protecting chlorophyll from oxidative damage under stress conditions [45,46]. However, the decline at higher salinity levels suggests that the protective mechanisms are overwhelmed, leading to cellular damage and reducing pigment synthesis [47].
Flavonoids are bioactive compounds in plants that protect plants from biotic and abiotic stresses through their antioxidant activity [48]. These compounds are critical in mitigating ROS (reactive oxygen species)-induced damage by enhancing the plant’s antioxidative capacity, especially under moderate salinity, which aligns with the observed peak flavonoid content at 200 mM and 300 mM NaCl [49,50]. Flavonoids, synthesized by processes such as methylation, facilitate their entry into cells and inhibit degradation [51]. The decline in flavonoid content at 500 mM NaCl suggests that extreme salinity impairs the plant’s ability to produce these protective compounds, leading to heightened oxidative stress [49,52]. Flavonoids in plants have free radical scavenging capacity and antioxidative activity, which can involve mechanisms such as (a) restraining the occurrence of ROS by prohibiting or chelating trace elements in free radical generation, (b) scavenging ROS, and (c) upregulating antioxidant defense [53,54,55]. M. crystallinum under salinity stress brings changes to the cell metabolism and defense mechanisms, which leads to the accumulation of ROS-induced oxidative stress [56]. Total flavonoid content at 200 mM and 300 mM NaCl was higher, with values of 241 mg/100 g and 221 mg/100 g, respectively. Total flavonoid content at 500 mM NaCl was lower than that of control (Figure 5A).
Total phenolic contents are the largest group of plant metabolites that respond to stress conditions and play an important bioactivity in the interaction between plants and the environment [57]. It should be noted that the Folin–Ciocalteu method measures total phenolic contents based on reactivity, which includes phenolic acids and phenolic alcohols as well as other related compounds. Therefore, the measured values may represent an overestimation of phenolics alone. This broader scope should be considered when interpreting the data. Total phenolic contents contribute to the scavenging of ROS and provide structural protection against cellular damage under stress conditions [51,57]. The total phenolic contents were the highest at 200 mM NaCl treatment. This shift towards flavonoid dominance may indicate an adaptive response aimed at maximizing antioxidative activity under optimal salinity stress conditions [57,58,59].
DPPH scavenging activity was highest at 200 mM NaCl (Figure 6), which coincides with a total polyphenol concentration of 415.21 mg/100 g (Figure 5B) and indicates a significant correlation between total polyphenol concentration and DPPH activity (Figure 5B). This strong correlation highlights the central role of polyphenols in M. crystallinum’s antioxidative defense under salinity stress, suggesting that its antioxidant system is most effective at moderate salinity levels where the balance between ROS production and scavenging is optimal [60].
In this study, D-pinitol concentrations increased from the control level, reaching the highest value recorded at 4.71 mg/100 g DW at 200 mM NaCl (Figure 5C). Kim et al. [61] reported a similar level of 5.4 mg/100 g DW of D-pinitol. After peaking at 200 mM, the concentrations began to decline, showing lower levels at 300 mM and 400 mM, and further decreased to the lowest level at 500 mM NaCl. In M. crystallinum, myo-inositol O-methyltransferase (IMEx1) and ononitol epimerase (OEP1) lead to the accumulation of methylated products such as inositols, D-ononitol, and D-pinitol under salinity stress [62,63,64]. These compounds function as osmoprotectants, aiding in the plant’s adaptation to high salinity [65,66,67]. Salinity stress also increased the activity of Myo-inositol 1-phosphate synthase (INPS), which catalyzes the first step in D-pinitol synthesis by converting glucose-6-phosphate to myo-inositol-1-phosphate, indicating a shift in carbon allocation to sugar alcohol production [68,69,70]. This metabolic shift underscores the plant’s adaptive strategy to cope with osmotic stress by accumulating compatible solutes [66,67,71]. These findings confirm that D-pinitol plays a critical role in stabilizing cellular osmotic pressure and supporting the plant’s salinity tolerance at moderate NaCl concentrations [65,66]. The content of D-pinitol per 100 g is not significantly different between 200 mM and 300 mM concentrations. However, there was a significant difference in the fresh weight and dry weight of the plant, total flavonoid content, and total phenol content, which were the highest at the 200 mM concentration. Therefore, it was determined that the overall D-pinitol content of the plant was the highest at the 200 mM concentration when considering the total biomass of the plant. At higher salinity levels, the decline in D-pinitol content suggests that the plant’s protective mechanisms, while effective at moderate salinity, become insufficient to mitigate stress-induced damage under extreme conditions [71].

4. Conclusions

This study focused on the antioxidant response and secondary metabolite biosynthesis of M. crystallinum under salt stress. The results demonstrated that 200 mM NaCl significantly enhanced plant growth and the accumulation of antioxidants, flavonoids, polyphenols, and D-pinitol, thereby improving cellular protection against salt stress. These findings indicated that cultivating M. crystallinum under 200 mM NaCl optimizes its biochemical defense mechanisms and sustains physiological functions, providing ideal conditions and a scientific basis for high-quality production of ice plants in hydroponic systems.

Author Contributions

Experimental design, manuscript writing, data analysis, and protocol development by G.E. and C.K.; experimental setup preparation by J.B.; project management, supervision, and manuscript review by J.P. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by the Ministry of Agriculture, Food and Rural Affairs (MAFRA) of the Republic of Korea [322077-3], Development of water supply technology and foundation for universal use of paddy fields according to changes in agricultural environment, and by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) and Korea Smart Farm R&D Foundation (KosFarm) through the Smart Farm Innovation Technology Development Program, funded by the Ministry of Agriculture, Food and Rural Affairs (MAFRA), Ministry of Science and ICT (MSIT), and Rural Development Administration (RDA) [421034-04].

Data Availability Statement

Data is contained within the article.

Conflicts of Interest

Author Chulhyun Kim was employed by the company GCL Farm Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

  1. Adams, P.; Nelson, D.E.; Yamada, S.; Chmara, W.; Jensen, R.G.; Bohnert, H.J.; Griffiths, H. Growth and development of Mesembryanthemum crystallinum (Aizoaceae). New Phytol. 1998, 138, 171–190. [Google Scholar] [CrossRef] [PubMed]
  2. Atzori, G.; de Vos, A.C.; van Rijsselberghe, M.; Vignolini, P.; Rozema, J.; Mancuso, S.; van Bodegom, P.M. Effects of increased seawater salinity irrigation on growth and quality of the edible halophyte Mesembryanthemum crystallinum L. under field conditions. Agric. Water Manag. 2017, 187, 37–46. [Google Scholar] [CrossRef]
  3. Vivrette, N.J.; Muller, C.H. Mechanism of invasion and dominance of coastal grassland by Mesembryanthemum crystallinum. Ecol. Monogr. 1977, 47, 301–318. [Google Scholar] [CrossRef]
  4. Agarie, S.; Shimoda, T.; Shimizu, Y.; Baumann, K.; Sunagawa, H.; Kondo, A.; Ueno, O.; Nakahara, T.; Nose, A.; Cushman, J.C. Salt tolerance, salt accumulation, and ionic homeostasis in an epidermal bladder-cell-less mutant of the common ice plant Mesembryanthemum crystallinum. J. Exp. Bot. 2007, 58, 1957–1967. [Google Scholar] [CrossRef] [PubMed]
  5. Jēkabsone, A.; Karlsons, A.; Osvalde, A.; Ievinsh, G. Effect of Na, K and Ca salts on growth, physiological performance, ion accumulation and mineral nutrition of Mesembryanthemum crystallinum. Plants 2024, 13, 190. [Google Scholar] [CrossRef]
  6. Liu, Y.; Liu, Q.; Liu, X.; Zhao, Y.; Liu, Y.; Wang, B.; Chen, M. NaCl improves the vegetable quality of Mesembryanthemum crystallinum Linn. by increasing betacyanin and nutrient contents. Plant Soil 2024, 503, 611–628. [Google Scholar] [CrossRef]
  7. Xia, J.; Mattson, N. Response of common ice plant (Mesembryanthemum crystallinum L.) to sodium chloride concentration in hydroponic nutrient solution. HortScience 2022, 57, 750–756. [Google Scholar] [CrossRef]
  8. Flowers, T.J.; Colmer, T.D. Salinity tolerance in halophytes. New Phytol. 2008, 179, 945–963. [Google Scholar] [CrossRef]
  9. Munns, R.; Passioura, J.B.; Colmer, T.D.; Byrt, C.S. Osmotic adjustment and energy limitations to plant growth in saline soil. New Phytol. 2020, 225, 1091–1096. [Google Scholar] [CrossRef]
  10. Munns, R.; Tester, M. Mechanisms of salinity tolerance. Annu. Rev. Plant Biol. 2008, 59, 651–681. [Google Scholar] [CrossRef]
  11. Bueno, M.; Cordovilla, M.P. Ecophysiology and uses of halophytes in diverse habitats. In Handbook of Halophytes: From Molecules to Ecosystems Towards Biosaline Agriculture; Springer: Berlin, Germany, 2020; pp. 1–25. [Google Scholar]
  12. Rahman, M.M.; Mostofa, M.G.; Keya, S.S.; Siddiqui, M.N.; Ansary, M.M.U.; Das, A.K.; Rahman, M.A.; Tran, L.S.-P. Adaptive mechanisms of halophytes and their potential in improving salinity tolerance in plants. Int. J. Mol. Sci. 2021, 22, 10733. [Google Scholar] [CrossRef]
  13. Kumar, A.; Mann, A.; Kumar, A.; Kumar, N.; Meena, B.L. Physiological response of diverse halophytes to high salinity through ionic accumulation and ROS scavenging. Int. J. Phytoremediat. 2021, 23, 1041–1051. [Google Scholar] [CrossRef] [PubMed]
  14. Pirasteh-Anosheh, H.; Samadi, M.; Kazemeini, S.A.; Ozturk, M.; Ludwiczak, A.; Piernik, A. ROS homeostasis and antioxidants in the halophytic plants and seeds. Plants 2023, 12, 3023. [Google Scholar] [CrossRef] [PubMed]
  15. Ishtiyaq, S.; Kumar, H.; Varun, M.; Ogunkunle, C.O.; Paul, M.S. Role of secondary metabolites in salt and heavy metal stress mitigation by halophytic plants: An overview. In Handbook of Bioremediation; Academic Press: Cambridge, MA, USA, 2021; pp. 307–327. [Google Scholar] [CrossRef]
  16. Zhang, X.; Tan, B.; Cheng, Z.; Zhu, D.; Jiang, T.; Chen, S. Overexpression of McHB7 transcription factor from Mesembryanthemum crystallinum improves plant salt tolerance. Int. J. Mol. Sci. 2022, 23, 7879. [Google Scholar] [CrossRef] [PubMed]
  17. Yapias, R.; Soto, J.; Victorio, J.; Huamaní, R.; Astete, J.; Areche, F.; Araujo, V.; Calderón, G.; Tornero, S. Phytoremediation and Nutritional Potential of the Ice Plants (Mesembryanthemum crystallinum L.). SABRAO J. Breed. Genet. 2024, 56, 1621–1631. [Google Scholar] [CrossRef]
  18. Nam, S.; Kang, S.; Kim, S.; Ko, K. Effect of fermented ice plant (Mesembryanthemum crystallinum L.) extracts against antioxidant, antidiabetic and liver protection. J. Life Sci. 2017, 27, 909–918. [Google Scholar]
  19. Calvo, M.M.; Martín-Diana, A.B.; Rico, D.; López-Caballero, M.E.; Martínez-Álvarez, O. Antioxidant, antihypertensive, hypoglycaemic and nootropic activity of a polyphenolic extract from the halophyte Ice Plant (Mesembryanthemum crystallinum). Foods 2022, 11, 1581. [Google Scholar] [CrossRef]
  20. Shen, N.; Wang, T.; Gan, Q.; Liu, S.; Wang, L.; Jin, B. Plant flavonoids: Classification, distribution, biosynthesis, and antioxidant activity. Food Chem. 2022, 383, 132531. [Google Scholar] [CrossRef]
  21. Lee, S.Y.; Choi, H.D.; Yu, S.N.; Kim, S.H.; Park, S.K.; Ahn, S.C. Biological activities of Mesembryanthemum crystallinum (ice plant) extract. J. Life Sci. 2015, 25, 638–645. [Google Scholar] [CrossRef]
  22. Ibtissem, B.; Abdelly, C.; Sfar, S. Antioxidant and antibacterial properties of Mesembryanthemum crystallinum and Carpobrotus edulis extracts. Adv. Chem. Eng. Sci. 2012, 2, 359–365. [Google Scholar] [CrossRef]
  23. Choi, J.H.; Park, S.E.; Kim, S. Effect of Mesembryanthemum crystallinum and its derived D-pinitol on HMG-CoA reductase and tyloxapol-induced hyperlipedemia. eFood 2024, 5, e70020. [Google Scholar] [CrossRef]
  24. Silva, J.A., Jr.; Silva, A.C.D.; Figueiredo, L.S.; Araujo, T.R.; Freitas, I.N.; Carneiro, E.M.; Ribeiro, E.S.; Ribeiro, R.A. d-Pinitol increases insulin secretion and regulates hepatic lipid metabolism in Msg-obese mice. An. Acad. Bras. Ciênc. 2020, 92, e20201382. [Google Scholar] [CrossRef]
  25. Zhang, C.; Wu, W.; Xin, X.; Li, X.; Liu, D. Extract of ice plant (Mesembryanthemum crystallinum) ameliorates hyperglycemia and modulates the gut microbiota composition in type 2 diabetic Goto-Kakizaki rats. Food Funct. 2019, 10, 3252–3261. [Google Scholar] [CrossRef] [PubMed]
  26. Flowers, T.; Hajibagheri, M.; Clipson, N. Halophytes. Q. Rev. Biol. 1986, 61, 313–337. [Google Scholar] [CrossRef]
  27. He, J.; Ng, O.W.J.; Qin, L. Salinity and Salt-Priming Impact on Growth, Photosynthetic Performance, and Nutritional Quality of Edible Mesembryanthemum crystallinum L. Plants 2022, 11, 332. [Google Scholar] [CrossRef]
  28. Hong, H.T.K.; Trang, P.T.H.; Ho, T.-T.; Dang, J.; Sato, R.; Yoshida, K.; Silaguntsuti, P.; Agarie, S. Reproductive growth characteristics of Mesembryanthemum crystallinum L. in High-Salinity stress conditions. Sci. Hortic. 2024, 331, 113172. [Google Scholar] [CrossRef]
  29. Nguyen, D.T.; Lu, N.; Kagawa, N.; Takagaki, M. Optimization of photosynthetic photon flux density and root-zone temperature for enhancing secondary metabolite accumulation and production of coriander in plant factory. Agronomy 2019, 9, 224. [Google Scholar] [CrossRef]
  30. Yang, L.; Wen, K.-S.; Ruan, X.; Zhao, Y.-X.; Wei, F.; Wang, Q. Response of plant secondary metabolites to environmental factors. Molecules 2018, 23, 762. [Google Scholar] [CrossRef]
  31. Garnier, E.; Shipley, B.; Roumet, C.; Laurent, G. A standardized protocol for the determination of specific leaf area and leaf dry matter content. Funct. Ecol. 2001, 15, 688–695. [Google Scholar] [CrossRef]
  32. Kozukue, N.; Friedman, M. Tomatine, chlorophyll, β-carotene and lycopene content in tomatoes during growth and maturation. J. Sci. Food Agric. 2003, 83, 195–200. [Google Scholar] [CrossRef]
  33. Moreno, M.a.I.N.; Isla, M.a.I.; Sampietro, A.R.; Vattuone, M.A. Comparison of the free radical-scavenging activity of propolis from several regions of Argentina. J. Ethnopharmacol. 2000, 71, 109–114. [Google Scholar] [CrossRef] [PubMed]
  34. Kupina, S.; Fields, C.; Roman, M.C.; Brunelle, S.L. Determination of total phenolic content using the Folin-C assay: Single-laboratory validation, first action 2017.13. J. AOAC Int. 2018, 101, 1466–1472. [Google Scholar] [CrossRef] [PubMed]
  35. Kedare, S.B.; Singh, R. Genesis and development of DPPH method of antioxidant assay. J. Food Sci. Technol. 2011, 48, 412–422. [Google Scholar] [CrossRef]
  36. Agarie, S.; Kawaguchi, A.; Kodera, A.; Sunagawa, H.; Kojima, H.; Nose, A.; Nakahara, T. Potential of the common ice plant, Mesembryanthemum crystallinum as a new high-functional food as evaluated by polyol accumulation. Plant Prod. Sci. 2009, 12, 37–46. [Google Scholar] [CrossRef]
  37. Lindberg, S.; Premkumar, A. Ion changes and signaling under salt stress in wheat and other important crops. Plants 2023, 13, 46. [Google Scholar] [CrossRef] [PubMed]
  38. Ludwiczak, A.; Osiak, M.; Cárdenas-Pérez, S.; Lubińska-Mielińska, S.; Piernik, A. Osmotic stress or ionic composition: Which affects the early growth of crop species more? Agronomy 2021, 11, 435. [Google Scholar] [CrossRef]
  39. Zhang, D.; Zhang, Z.; Wang, Y. Effects of Salt Stress on Salt-Repellent and Salt-Secreting Characteristics of Two Apple Rootstocks. Plants 2024, 13, 1046. [Google Scholar] [CrossRef]
  40. Hajlaoui, H.; Denden, M.; Ayeb, N.E. Changes in fatty acids composition, hydrogen peroxide generation and lipid peroxidation of salt-stressed corn (Zea mays L.) roots. Acta Physiol. Plant. 2009, 31, 787–796. [Google Scholar] [CrossRef]
  41. Herppich, W.B.; Huyskens-Keil, S.; Schreiner, M. Effects of saline irrigation on growth, physiology and quality of Mesembryanthemum crystallinum L., a rare vegetable crop. J. Appl. Bot. Food Qual. 2012, 82, 47–54. [Google Scholar]
  42. He, J.; Qin, L. Impacts of reduced nitrate supply on nitrogen metabolism, photosynthetic light-use efficiency, and nutritional values of edible Mesembryanthemum crystallinum. Front. Plant Sci. 2021, 12, 686910. [Google Scholar] [CrossRef]
  43. Chaki, M.; Begara-Morales, J.C.; Barroso, J.B. Oxidative stress in plants. Antioxidants 2020, 9, 481. [Google Scholar] [CrossRef] [PubMed]
  44. Dewanjee, S.; Bhattacharjee, N.; Chakraborty, P.; Bhattacharjee, S. Carotenoids as antioxidants. In Carotenoids: Structure and Function in the Human Body; Springer: Berlin, Germany, 2021; pp. 447–473. [Google Scholar]
  45. Triantaphylides, C.; Krischke, M.; Hoeberichts, F.A.; Ksas, B.; Gresser, G.; Havaux, M.; Van Breusegem, F.; Mueller, M.J. Singlet oxygen is the major reactive oxygen species involved in photooxidative damage to plants. Plant Physiol. 2008, 148, 960–968. [Google Scholar] [CrossRef] [PubMed]
  46. Vellosillo, T.; Vicente, J.; Kulasekaran, S.; Hamberg, M.; Castresana, C. Emerging complexity in reactive oxygen species production and signaling during the response of plants to pathogens. Plant Physiol. 2010, 154, 444–448. [Google Scholar] [CrossRef]
  47. Blokhina, O.; Fagerstedt, K. Oxidative stress and antioxidant defenses in plants. In Oxidative Stress, Disease and Cancer; Imperial College Press: London, UK, 2006; pp. 151–199. [Google Scholar]
  48. Wen, L.; Jiang, Y.; Yang, J.; Zhao, Y.; Tian, M.; Yang, B. Structure, bioactivity, and synthesis of methylated flavonoids. Ann. N. Y. Acad. Sci. 2017, 1398, 120–129. [Google Scholar] [CrossRef]
  49. Winkel-Shirley, B. Biosynthesis of flavonoids and effects of stress. Curr. Opin. Plant Biol. 2002, 5, 218–223. [Google Scholar] [CrossRef]
  50. Agati, G.; Azzarello, E.; Pollastri, S.; Tattini, M. Flavonoids as antioxidants in plants: Location and functional significance. Plant Sci. 2012, 196, 67–76. [Google Scholar] [CrossRef] [PubMed]
  51. Šamec, D.; Karalija, E.; Šola, I.; Vujčić Bok, V.; Salopek-Sondi, B. The role of polyphenols in abiotic stress response: The influence of molecular structure. Plants 2021, 10, 118. [Google Scholar] [CrossRef]
  52. Fini, A.; Guidi, L.; Ferrini, F.; Brunetti, C.; Di Ferdinando, M.; Biricolti, S.; Pollastri, S.; Calamai, L.; Tattini, M. Drought stress has contrasting effects on antioxidant enzymes activity and phenylpropanoid biosynthesis in Fraxinus ornus leaves: An excess light stress affair? J. Plant Physiol. 2012, 169, 929–939. [Google Scholar] [CrossRef]
  53. Halliwell, B.; Gutteridge, J.M. Free Radicals in Biology and Medicine; Oxford University Press: New York, NY, USA, 2015. [Google Scholar]
  54. Mishra, A.; Kumar, S.; Pandey, A.K. Scientific validation of the medicinal efficacy of Tinospora cordifolia. Sci. World J. 2013, 2013, 292934. [Google Scholar] [CrossRef]
  55. Kumar, S.; Pandey, A.K. Chemistry and biological activities of flavonoids: An overview. Sci. World J. 2013, 2013, 162750. [Google Scholar] [CrossRef]
  56. Mohamed, E.; Ansari, N.; Yadav, D.S.; Agrawal, M.; Agrawal, S.B. Salinity alleviates the toxicity level of ozone in a halophyte Mesembryanthemum crystallinum L. Ecotoxicology 2021, 30, 689–704. [Google Scholar] [CrossRef] [PubMed]
  57. Zagoskina, N.V.; Zubova, M.Y.; Nechaeva, T.L.; Kazantseva, V.V.; Goncharuk, E.A.; Katanskaya, V.M.; Baranova, E.N.; Aksenova, M.A. Polyphenols in plants: Structure, biosynthesis, abiotic stress regulation, and practical applications. Int. J. Mol. Sci. 2023, 24, 13874. [Google Scholar] [CrossRef] [PubMed]
  58. Bistgani, Z.E.; Hashemi, M.; DaCosta, M.; Craker, L.; Maggi, F.; Morshedloo, M.R. Effect of salinity stress on the physiological characteristics, phenolic compounds and antioxidant activity of Thymus vulgaris L. and Thymus daenensis Celak. Ind. Crops Prod. 2019, 135, 311–320. [Google Scholar]
  59. Chen, Z.; Ma, Y.; Yang, R.; Gu, Z.; Wang, P. Effects of exogenous Ca2+ on phenolic accumulation and physiological changes in germinated wheat (Triticum aestivum L.) under UV-B radiation. Food Chem. 2019, 288, 368–376. [Google Scholar] [CrossRef]
  60. Singh, A.; Rajput, V.D.; Sharma, R.; Ghazaryan, K.; Minkina, T. Salinity stress and nanoparticles: Insights into antioxidative enzymatic resistance, signaling, and defense mechanisms. Environ. Res. 2023, 235, 116585. [Google Scholar] [CrossRef]
  61. Kim, Y.J.; Kim, H.M.; Kim, H.M.; Lee, H.R.; Jeong, B.R.; Lee, H.-J.; Kim, H.-J.; Hwang, S.J. Growth and phytochemicals of ice plant (Mesembryanthemum crystallinum L.) as affected by various combined ratios of red and blue LEDs in a closed-type plant production system. J. Appl. Res. Med. Aromat. Plants 2021, 20, 100267. [Google Scholar] [CrossRef]
  62. Stefańska, E.; Wendołowicz, A.; Cwalina, U.; Kowzan, U.; Konarzewska, B.; Szulc, A.; Ostrowska, L. Why is it important to monitor the diet of overweight patients with depressive disorders? Arch. Psychiatry Psychother. 2014, 16, 47. [Google Scholar] [CrossRef]
  63. Sánchez-Hidalgo, M.; León-González, A.J.; Gálvez-Peralta, M.; González-Mauraza, N.H.; Martin-Cordero, C. D-Pinitol: A cyclitol with versatile biological and pharmacological activities. Phytochem. Rev. 2021, 20, 211–224. [Google Scholar] [CrossRef]
  64. Loewus, F.A.; Murthy, P.P. myo-Inositol metabolism in plants. Plant Sci. 2000, 150, 1–19. [Google Scholar] [CrossRef]
  65. Morgan, J.M. Osmoregulation and water stress in higher plants. Annu. Rev. Plant Physiol. 1984, 35, 299–319. [Google Scholar] [CrossRef]
  66. Yancey, P.H. Water stress, osmolytes and proteins. Am. Zool. 2001, 41, 699–709. [Google Scholar] [CrossRef]
  67. Rontein, D.; Basset, G.; Hanson, A.D. Metabolic engineering of osmoprotectant accumulation in plants. Metab. Eng. 2002, 4, 49–56. [Google Scholar] [CrossRef]
  68. Ishitani, M.; Majumder, A.L.; Bornhouser, A.; Michalowski, C.B.; Jensen, R.G.; Bohnert, H.J. Coordinate transcriptional induction of myo-inositol metabolism during environmental stress. Plant J. 1996, 9, 537–548. [Google Scholar] [CrossRef] [PubMed]
  69. Streeter, J.; Lohnes, D.; Fioritto, R. Patterns of pinitol accumulation in soybean plants and relationships to drought tolerance. Plant Cell Environ. 2001, 24, 429–438. [Google Scholar] [CrossRef]
  70. Paul, M.; Cockburn, W. Pinitol, a compatible solute in Mesembryanthemum crystallinum L.? J. Exp. Bot. 1989, 40, 1093–1098. [Google Scholar] [CrossRef]
  71. Ahn, C.-H.; Hossain, M.A.; Lee, E.; Kanth, B.K.; Park, P.B. Increased salt and drought tolerance by D-pinitol production in transgenic Arabidopsis thaliana. Biochem. Biophys. Res. Commun. 2018, 504, 315–320. [Google Scholar] [CrossRef]
Horticulturae 10 01304 g001
Figure 1. Shoot fresh weight (A), shoot dry weight (B), root fresh weight (C), and root dry weight (D) of Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM) at 5 weeks after transplanting. Data are represented as mean values ± standard error of three replicates (n = 10). Different letters above the bars indicate significant differences between treatments via Tukey’s HSD test at p < 0.05.
Figure 1. Shoot fresh weight (A), shoot dry weight (B), root fresh weight (C), and root dry weight (D) of Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM) at 5 weeks after transplanting. Data are represented as mean values ± standard error of three replicates (n = 10). Different letters above the bars indicate significant differences between treatments via Tukey’s HSD test at p < 0.05.
Horticulturae 10 01304 g001
Horticulturae 10 01304 g002
Figure 2. Morphology of M. crystallinum. NaCl was stressed at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM) after 4 weeks of treatment.
Figure 2. Morphology of M. crystallinum. NaCl was stressed at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM) after 4 weeks of treatment.
Horticulturae 10 01304 g002
Horticulturae 10 01304 g003
Figure 3. Ratio of shoot/root FW (A), ratio of shoot/root DW (B), leaf water content (C) of Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Data are represented as mean values ± standard error of three replicates (n = 10). Different letters above the bars indicate significant differences between treatments via Tukey’s HSD test at p < 0.05.
Figure 3. Ratio of shoot/root FW (A), ratio of shoot/root DW (B), leaf water content (C) of Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Data are represented as mean values ± standard error of three replicates (n = 10). Different letters above the bars indicate significant differences between treatments via Tukey’s HSD test at p < 0.05.
Horticulturae 10 01304 g003
Horticulturae 10 01304 g004
Figure 4. Total chlorophyll (A), total carotenoids (B) in Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (n = 10). Different letters indicate significant differences (p < 0.05).
Figure 4. Total chlorophyll (A), total carotenoids (B) in Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (n = 10). Different letters indicate significant differences (p < 0.05).
Horticulturae 10 01304 g004
Horticulturae 10 01304 g005
Figure 5. Total flavonoids (A), total phenolic contents (B), and D-pinitol concentration (C) in Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (n = 10 for (A,B), n = 3 for (C)). Different letters indicate significant differences (p < 0.05).
Figure 5. Total flavonoids (A), total phenolic contents (B), and D-pinitol concentration (C) in Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (n = 10 for (A,B), n = 3 for (C)). Different letters indicate significant differences (p < 0.05).
Horticulturae 10 01304 g005
Horticulturae 10 01304 g006
Figure 6. DPPH radical scavenging activity in Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (n = 3). Different letters indicate significant differences (p < 0.05).
Figure 6. DPPH radical scavenging activity in Mesembryanthemum crystallinum L. grown at different NaCl concentrations (0, 100, 200, 300, 400, 500 mM). Values are calculated as means ± standard error of three replicates (n = 3). Different letters indicate significant differences (p < 0.05).
Horticulturae 10 01304 g006
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Eoh, G.; Kim, C.; Bae, J.; Park, J. Evaluation of Sodium Chloride Concentrations on Growth and Phytochemical Production of Mesembryanthemum crystallinum L. in a Hydroponic System. Horticulturae 2024, 10, 1304. https://doi.org/10.3390/horticulturae10121304

AMA Style

Eoh G, Kim C, Bae J, Park J. Evaluation of Sodium Chloride Concentrations on Growth and Phytochemical Production of Mesembryanthemum crystallinum L. in a Hydroponic System. Horticulturae. 2024; 10(12):1304. https://doi.org/10.3390/horticulturae10121304

Chicago/Turabian Style

Eoh, Giju, Chulhyun Kim, Jiwon Bae, and Jongseok Park. 2024. "Evaluation of Sodium Chloride Concentrations on Growth and Phytochemical Production of Mesembryanthemum crystallinum L. in a Hydroponic System" Horticulturae 10, no. 12: 1304. https://doi.org/10.3390/horticulturae10121304

APA Style

Eoh, G., Kim, C., Bae, J., & Park, J. (2024). Evaluation of Sodium Chloride Concentrations on Growth and Phytochemical Production of Mesembryanthemum crystallinum L. in a Hydroponic System. Horticulturae, 10(12), 1304. https://doi.org/10.3390/horticulturae10121304

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop