[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
Next Article in Journal
Gene Effect of Morphophysiological Traits in Popcorn (Zea mays L. var. everta) Grown Under Contrasting Water Regimes
Previous Article in Journal
Does Agricultural Science and Technological Innovation Always Boost Farmers’ Income? Evidence from China
Previous Article in Special Issue
Enhancing Nutritional Value of Rhubarb (Rheum rhaponticum L.) Products: The Role of Fruit and Vegetable Pomace
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
Agriculture
Volume 14
Issue 12
10.3390/agriculture14122156
agriculture-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

Proteomic Analysis Unveils the Protective Mechanism of Active Modified Atmosphere Packaging Against Senescence Decay and Respiration in Postharvest Loose-Leaf Lettuce

by
Lili Weng
1,
Jiyuan Han
1,
Runyan Wu
1,
Wei Liu
1,
Jing Zhou
2,
Xiangning Chen
1,* and
Huijuan Zhang
1,*
1
Key Laboratory of Agricultural Product Processing and Quality Control (Co-Construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Food Science and Engineering College, Beijing University of Agriculture, Beijing 102206, China
2
Beijing Yunong High Quality Agricultural Products Planting Co., Ltd., Beijing 101400, China
*
Authors to whom correspondence should be addressed.
Agriculture 2024, 14(12), 2156; https://doi.org/10.3390/agriculture14122156
Submission received: 18 October 2024 / Revised: 24 November 2024 / Accepted: 25 November 2024 / Published: 27 November 2024
(This article belongs to the Special Issue Nutritional Quality and Health of Vegetables)
Browse Figures
Figure 1
<p>Effects of MAP on the sensory state (<b>A</b>), overall visual quality score (<b>B</b>), and chlorophyll content (<b>C</b>) in postharvest loose-leaf lettuce stored at 4 °C for 6 d. The asterisk (*) denotes a significant difference between MAP treatment and the control (<span class="html-italic">p</span> &lt; 0.05), the asterisk (***) denotes a significant difference between MAP treatment and the control (<span class="html-italic">p</span> &lt; 0.001).</p> "> Figure 2
<p>Effect of MAP on weight loss (<b>A</b>) and gas percentage (<b>B</b>) in postharvest lettuces during storage at 4 °C. The asterisk (***) denotes a significant difference between MAP treatment and the control (<span class="html-italic">p</span> &lt; 0.001).</p> "> Figure 3
<p>Effect of MAP on electrolyte leakage (<b>A</b>), hydroxyl radical superoxide radical (<b>B</b>), and superoxide radical (<b>C</b>) contents in postharvest lettuces during storage at 4 °C. The asterisk (***) denotes a significant difference between MAP treatment and the control (<span class="html-italic">p</span> &lt; 0.001).</p> "> Figure 4
<p>Differentially expressed genes of loose-leaf lettuce at the end of the storage period (control vs. MAP-treated). Enrichment of differentially expressed proteins for cellular components (<b>A</b>), molecular function (<b>B</b>), and biological processes (<b>C</b>).</p> ">
Review Reports Versions Notes

Abstract

:
In this study, physicochemical and proteomic analyses were performed to investigate the effect of modified atmosphere packaging (MAP) on the quality of postharvest loose-leaf lettuce. The results showed that MAP enhanced the sensory characteristics of loose-leaf lettuce and delayed the incidence of postharvest deterioration by suppressing weight loss, electrolyte leakage, and reactive oxygen species levels. MAP-inhibited storage-induced programmed cell death may be attributed to a lower expression of protein disulfide isomerase and a higher expression of oligonucleotide/oligosaccharide binding fold nucleic acid binding site protein and reducing glutamine synthase levels. Also, we explore the potential of MAP to protect against oxidative damage in loose-leaf lettuce by potentially modulating the expression levels of NAC family proteins, which may enhance signaling and the expression of cytochrome c oxidase and membrane-bound pyrophosphate in the oxidative phosphorylation pathway. In addition, MAP potentially delayed postharvest senescence and extended the shelf life of lettuce by regulating key protein metabolic pathways that may reduce respiration rates. These include the NAC family of proteins, enzymes in the oxidative phosphorylation pathway, glutamine synthetize, and other crucial metabolic routes. These findings provide a scientific basis for enhancing the postharvest preservation of leafy vegetables, such as loose-leaf lettuce, through MAP technology.

1. Introduction

Lettuce (Lactuca sativa L.) is a major popular vegetable with high demand on the global market. China is the world’s largest producer of lettuce, accounting for 56.4% of the global market share [1]. Loose-leaf lettuce is one of the most popular varieties because of its crisp texture and rich nutrients, including polyphenols, vitamins, and amino acids [2,3]. The high water and fiber content of loose-leaf lettuce helps maintain digestive health, while its low calorie content makes it an excellent choice for weight loss and healthy eating. With increasing awareness of healthy eating, the lettuce industry is becoming more economically viable globally. For example, in Australia, it is worth up to 100 million Australian dollars and exports around 8 million Australian dollars [1]. However, the high leaf-to-stalk ratio and crisp tissue of loose-leaf lettuce make it highly susceptible to mechanical damage during storage and transport. It can directly contribute to the deterioration of the product and trigger a series of chemical reactions. Exposure to oxygen after damage triggers a reaction in which the polyphenolic compounds in the lettuce undergo enzymatic oxidation. This enzymatic browning results in the formation of quinone derivatives, which further polymerize to form brown pigments, exacerbating the deterioration of the visual and nutritional quality of the lettuce [4]. Postharvest losses pose a significant concern for producers, prompting extensive research into various strategies to mitigate the deterioration of lettuce after harvest. These approaches encompass chemical treatments [5], physical preservation methods [6], and synergistic combinations of these treatments [7], as well as innovative biological applications, such as the use of green tea extracts [8] and whey protein [9]. However, some methods are limited by their inefficiency and high cost, affecting the organoleptic properties of the product and even leading to the loss of nutrients [10]. Therefore, preventing oxidative browning and decay in lettuce requires an economical, safe, and environmentally friendly method.
Modified atmosphere packaging (MAP) is an efficient postharvest preservation method for fruits and vegetables. It can optimize the storage environment by adjusting the ratio of oxygen, carbon dioxide, and other gases in the package, thereby slowing down the metabolism of fruit and vegetables and extending their shelf life [11]. Previous studies have confirmed that MAP significantly reduces respiration and inhibits bacterial growth, oxidative stress production [12,13], and reactive oxygen species production [14,15]. This process decelerates nutrient degradation and preserves the original color and texture of lettuce [16]. Thus, MAP is widely used to extend the shelf life of postharvest vegetables and fruits. It is shown that MAP treatment significantly affects the mechanical properties of lettuce leaves, maintains the crispness of lettuce during storage [17], improves the antioxidant capacity of the product, increases the quality of the product, and prolongs the shelf life of the product [18]. The complex physiological changes that occur during postharvest storage are the result of dynamic changes in protein expression and dramatic alterations in many metabolic pathways [19]. However, the mechanisms underlying protein metabolism regulation, including oxidative, wilting, and deterioration processes, during the storage of MAP-treated loose-leaf lettuce remain unclear. This uncertainty limits the broader application of this technology in lettuce storage.
In this study, the proteomic molecular mechanism involved in MAP that prolonged the postharvest shelf life of loose-leaf lettuce was investigated. Firstly, the effect of MAP treatment on the sensory property of loose-leaf lettuce was evaluated. Then, the changes in weight loss, electrolyte leakage, and reactive oxygen species levels were analyzed. Furthermore, isobaric tags for relative and absolute quantitation (iTRAQ) analysis were used to identify the differential expression of proteins related to mitochondrial respiratory metabolism. Finally, the molecular mechanisms underlying quality changes in loose-leaf lettuce during MAP storage were elucidated from a proteomic perspective. This study aims to provide a reference for prolonging the shelf life of loose-leaf lettuce.

2. Materials and Methods

2.1. Sample Collection and Treatment

Loose-leaf lettuce (Lactuca sativa L. Grand Rapid) was harvested from the Yangzhen plantation of Beijing Yunong Quality Agricultural Products Planting Company and transported immediately to the laboratory. After pre-cooling at 4 °C for 2 h, three replicates of approximately 250 ± 30 g of undamaged lettuce were packaged in a high barrier film (length 350 mm; width 290 mm) under an atmosphere of 10% CO2, 3% O2, 87% N2, and immediately placed in cold storage (4 °C; 90–95% RH). The other portion of loose-leaf lettuce served as a control, encapsulated in a high-barrier film. A 0.5 cm diameter needle was used to make 7 holes in each side of the film, totaling 14 holes, which was also stored in a refrigerator at 4 °C. Samples were taken daily for six days.

2.2. Sensory Properties and the Total Chlorophyll Content

The overall visual quality of the lettuce was analyzed using previously reported methods [20] with some modifications. A sensory panel of 10 members with sensory experience evaluated lettuce’s freshness, crispness, degree of browning, and decay. A score of 9 indicated perfect quality, where the lettuce tissue was fresh, crisp, with no signs of browning or decay, and minor drying was permissible. A score of 7 signified good quality, where the lettuce might have had a slightly dull color, but it was free from any browning or decay overall. A score of 5 marked the boundary for commercial viability; the lettuce might have exhibited slight browning visible to the naked eye without decay, and it was still considered edible. A score of 3 denoted poor qualities, with parts of the lettuce showing browning and slight decay, making it unsuitable for consumption. Lastly, a score of 1 represented completely rotted lettuce with severe decay and browning, rendering it inedible. The average score was used as the final sensory score, with 5 being the acceptable threshold. To quantify the total chlorophyll content, 2 g of homogenized fresh tissue was taken and subsequently combined with a 10 mL mixture of acetone (purchased from Beijing Chemical Works, Beijing, China) and ethanol (1:1). Then, leave it in a dark place for 5 h. Following this, the homogenate was filtered, and the absorbance at wavelengths of 645 nm and 663 nm was measured using a UV spectrophotometer (UV-1800, Shimadzu, Kyoto, Japan). Chlorophyll content was calculated using the following Equation (1).
C h l o r o p h y l l   c o n t e n t   ( g / k g ) = 8.05 × O D 663 + 20.29 × O D 645 × v 1000 × m  
where v is the volume of the solution for substance extraction, and m is the mass of the fresh tissue.

2.3. Weight Loss and Gas Composition in Packaging

The weight of individual lettuces was recorded on the day of harvest and each day during storage. Weight loss was calculated using the following Equation (2).
W e i g h t   l o s s   r a t e   ( % ) = W 0   −   W n W 0 × 100 %
where W0 is the fresh weight on the 0th day, and Wn is the fresh weight on storage day n.
The composition of the packaged headspace gas (%, O2 and CO2) was determined using a gas analyzer (PBI Dansensor A/S, DK-4100, Ringsted, Denmark). Changes in gas composition within the package were monitored daily during storage. The gas inside the package is collected by inserting a syringe into the package (which has a seal on its surface to prevent leakage). The syringe is connected to a gas analyzer, which is equipped with an electrochemical sensor for the measuring of gases with an absolute accuracy of ±0.01% for oxygen and ±0.8% for carbon dioxide [21].

2.4. Electrolyte Leakage and Reactive Oxygen Species Contents

The electrolyte leakage was determined with a conductivity meter. On days 0, 1, 2, 3, 4, 5, and 6 of storage, 50 g samples of lettuce were taken randomly from the packages. A 5 mm tissue was drilled with a cork and immersed in a 10 mL aliquot of 0.4 M mannitol for 3 h. The conductivity was then measured with a conductivity meter (model CM35, Crison, Barcelona, Spain). The total amount of electrolyte was subsequently determined following a freezing and thawing process at −20 °C for 24 h. The loss of electrolyte was expressed as a percentage of the total electrolyte content [22].
The content of O2•− was determined according to the method of Jiang et al. [23]. First, 1 g of lettuce sample was cut into slices, then homogenized in 6 mL of 65 mM phosphate buffer (pH 7.8), 2 mL of 10 mM hydroxylammonium chloride, and 2 mL of 0.1 M EDTA (Ameresco, Inc., Framingham, MA, USA). Then, the samples were left at 4 °C for 30 s. Then, each homogenate was centrifuged at 12,000× g for 15 min at 4 °C. The supernatant (2 mL) was mixed with 2 mL of 17 mm 4-amino benzene sulphonic acid and 2 mL of 7 mm alpha-naphthylamine. After incubation at 40 °C for 15 min, 2 mL of ether was added and centrifuged again at 3000× g for 15 min. Finally, the absorbance was read at 530 nm using an ultraviolet spectrophotometer TU-1810 (Purkinje General Instrument Co., LTD., Beijing, China), while a sodium nitrite standard curve was constructed. Distilled water was used as a blank control.
The OH• content was determined using an ultraviolet spectrophotometer [24]. Samples of lettuce (1 g) were cut into slices and homogenized for 30 s at 4 °C in 15 mL of 20 mM phosphate buffer (pH 6.0). Each homogenate was centrifuged at 3000× g for 20 min at 4 °C. Moreover, 1 mL of the supernatant was incubated with 1.5 mL of 20 mM phosphate buffer (pH 6.0) containing 20 mM 2-deoxy-d-ribose at room temperature for 30 min, followed by the addition of 1 mL of 0.5% w/v 2-thiobarbituric acid in 1.4% w/v trichloroacetic acid. The mixture was boiled in water for 10 min and cooled to room temperature, and the fluorescence intensity was measured at an excitation wavelength of 532 nm and an emission wavelength of 553 nm (TU-1810 ultraviolet spectrophotometer, Purkinje General Instrument Co., Ltd., Beijing, China) against a reagent blank. The OH• concentrations were calculated from the molar extinction coefficient.

2.5. Protein Extraction

Lettuce leaves on day 6 of the MAP and control groups were collected separately, ground to a slurry, then mixed with 10 times the volume of pre-cooled acetone (containing 10% (v/v) trichloroacetic acid) at −20 °C, shaken, and precipitated for 2 h. Each mixture was then centrifuged at 20,000× g for 30 min at 4 °C to remove the supernatant. The precipitate was washed three times with cold acetone, stored at −20 °C for 30 min, and centrifuged at 20,000× g for 30 min at 4 °C. The precipitate was dissolved in lysis buffer containing 1 mM polyvinylpolypyrrolidone (Ameresco, Inc., Framingham, MA, USA), 30 mM HEPES, 8 M urea, 2 mM EDTA, and 10 mM dithiothreitol (DTT) and sonicated for 5 min. The extract was centrifuged at 20,000× g for 30 min at 4 °C. The supernatant was collected and reduced with 10 mM DTT at 56 °C for 1 h and then alkylated with 55 mM iodoacetamide (IAM) for 1 h in the dark. The mixture was precipitated with a 5-fold volume of cold acetone at −20 °C for 3 h, followed by centrifugation at 20,000× g for 30 min. The resulting pellet was dissolved in 0.5 M triethylammonium bicarbonate (TEAB) buffer containing 0.1% (w/v) SDS, sonicated for 5 min, and centrifuged at 20,000× g for 30 min. The supernatant was digested, and the protein concentration was determined by the Bradford method.

2.6. Protein Digestion and iTRAQ Labeling

For each protein sample, 3.3 μL trypsin (1 g/L) (Promega, Madison, WI, USA) was added to 100 μg protein in TEAB buffer, and the mixture was incubated at 37 °C for 24 h to achieve complete digestion. Following digestion, the peptides were dried by vacuum centrifugation and labeled using an iTRAQ kit (AB SCIEX, Framingham, MA, USA). Briefly, one unit of iTRAQ reagent was thawed and reconstituted in 70 μL isopropanol. Lettuce samples from the control and MAP groups on day 6 of storage were labeled with iTRAQ reagents 114 and 119, respectively. Three independent experiments were carried out.

2.7. Strong Cation Exchange and LC-MS/MS SCX

A binary solvent gradient was employed, comprising buffer A (10 mM potassium phosphate mono-basic, KH2PO4, in 25% (v/v) acetonitrile) and buffer B (10 mM KH2PO4 and 2 M potassium chloride, KCl, in 25% (v/v) acetonitrile). The pH of buffers A and B was adjusted to 3 using phosphoric acid. The pooled peptides were dissolved in strong cation exchange buffer A and subsequently fractionated using a high-performance liquid chromatography (HPLC) system (Shimadzu, Kyoto, Japan) equipped with a silica-based strong cation exchange column (250 × 4.6 mm, 5 μm, 100 Å; Phenomenex, Torrance, CA, USA). The 76-min gradient consisted of the following steps: buffer B at 0% for 30 min; increased from 0% to 5% over 1 min; increased from 5% to 30% over 20 min; increased from 30% to 50% over five min; held for 5 min; increased from 50% to 100% over 5 min; and held for a further 10 min. The fractions were desalted in accordance with the manufacturer’s instructions and lyophilized using a high-speed centrifugal vacuum concentrator.
The digested peptides were separated on a reverse-phase C18 column (75 μm × 10 cm; 5 μm, 300 Å; Agela Technologies, Wilmington, DE, USA). A binary solvent gradient was employed, comprising solution A (0.1% (v/v) formic acid) and solution B (100% acetonitrile with 0.1% (v/v) formic acid). The 65-min gradient comprised the following steps: solution B at 5% for 10 min; increased from 5 to 30% over 30 min; then, increased to 60% over 5 min; increased from 60 to 80% over 3 min; held for 7 min; decreased from 80 to 5% over 3 min; and withheld for 5 min. The separated peptides were subjected to analysis using a Q-Exactive mass spectrometer (Thermo Fisher Scientific, Waltham, MA, USA), which was coupled to a Dionex Ultimate 3000 Nano LC system source and operated at a flow rate of 6.7 nL/min. The eluates were directly injected into the Q-Exactive MS, which was operating in the positive ion mode in a data-dependent manner. The full MS scan had a range of 350–2000 (m/z), with a full-scan resolution of 70,000 and an MS/MS scan resolution of 17,500. Each MS/MS scan was set to have a minimum signal threshold of 1 × 105 and an isolation width of 2 Da. The acquired MS/MS spectra were then automatically searched against the UniProt protein database.

2.8. Statistical Analysis

All data were presented as mean ± SD. Independent sample t-tests were conducted using SPSS 26.0. Independent sample t-tests were conducted using the SPSS software, version 26.0. The threshold for a statistically significant difference was set at * p ≤ 0.05, ** p ≤ 0.01, and *** p ≤ 0.001. In the analysis of proteins that were differentially expressed in the experimental and control lettuce samples, only those proteins with quantitative data from at least two replicates and significant changes in abundance (more than 1.2-fold) were considered.

3. Results and Discussion

3.1. Sensory Evaluation of Loose-Leaf Lettuce Under MAP

Consumer acceptance of lettuce is largely influenced by its freshness, color, crispness, degree of browning, and decay. The occurrence of sensory degradation, such as browning and wilting, negatively impacts both marketer and consumer acceptance [25,26]. The sensory properties, including color, taste, and firmness of loose-leaf lettuce under MAP and air packing (control), were evaluated (Figure 1). The results showed that the sensory state of the MAP-treated lettuce was higher than that of the control at the final stage of storage (day 6 in Figure 1A). Overall visual quality scores based on sensory evaluation of loose-leaf lettuces decreased with increasing storage time from 0 to 6 days, whereas the MAP-treated lettuce had a significantly higher score than the control on day 3 (p ≤ 0.001, Figure 1B). On day 4 of storage, the leaves of the lettuce in the control developed yellowing. When it came to day 6, the outer leaves of lettuces in the control showed moderate tear of leaf tissue, indicating an increase in mechanical fragility, and severe browning of the midrib bases.
Chlorophyll breakdown is a major cause of leaf yellowing, and MAP can inhibit this process [27]. The chlorophyll content in lettuce samples under two different storage conditions exhibited a continuous decline over time (Figure 1C). However, the rate of chlorophyll degradation under MAP conditions was significantly lower than that in the control (p ≤ 0.05). The chlorophyll content in the control had decreased from 0.38 g/kg (day 0) to 0.12 g/kg on day 6, while the MAP-treated lettuce showed a more gradual downward trend (0.29 g/kg on day 6). This suggests that MAP effectively delays chlorophyll degradation and helps maintain the green coloration of the lettuce. In the low-oxygen environment of the package, oxidation is reduced and browning enzymes are inhibited [28]. Previous studies suggest that initially high concentrations of carbon dioxide are more conducive to inhibiting browning, which may be related to sensory degradation [29]. These results suggest that MAP effectively maintains the visual quality of lettuce by modulating certain physicochemical reactions.

3.2. Weight Loss of Loose-Leaf Lettuce and Changes in Gas Composition in MAP-Treated Packaging

Water evaporation and respiration are the main causes of postharvest fruit and vegetable weight loss [30]. Postharvest water loss can trigger shriveling, which leads to rapid quality deterioration. The weight loss rate of loose-leaf lettuces tended to increase from day 0 to day 6 under both storage conditions. However, the MAP-treated was found to be significantly lower than that in the control in the first three days (p ≤ 0.001, Figure 2A). Day 6 of the storage period, the weight loss of MAP-treated lettuce was only 4.5%, and the samples exhibited better succulent and freshness properties than those of the control samples. Weight loss of leafy vegetables is mainly mediated by respiration and transpiration [31]. We inferred that MAP reduced weight loss by limiting water vapor diffusion, which was low through the plastic film, leading to maintained vapor pressure and high-level relative humidity inside the package.
Even after being harvested, fresh lettuce continues to consume oxygen and produce carbon dioxide as it ages. This process changes the gas composition within the package. Continued respiration and the good barrier properties of the packaging material meant that the carbon dioxide content in the pack continued to rise while the oxygen content gradually decreased. From day 0 to day 6, there was a tendency for the CO2 content in the MAP-treated loose-leaf lettuce to increase during storage (from 10% to 14.6%), while the O2 content decreased (from 3% to 1.5%, Figure 2B). These results are consistent with those reported in previous studies, which conclude that in MAP, oxygen levels are controlled at 1–5% to slow food spoilage. High levels of carbon dioxide (usually not exceeding 20%) inhibit microorganisms and reduce respiration. Nitrogen (N2) serves as an inert gas, preventing oxidation and protecting food from damage [32]. Therefore, it indicates that MAP effectively modulates lettuce respiration. The dynamic stability of the gas within the package during storage is reflected by the decrease in O2 and increase in CO2. Its stability helps to reduce the stress response of the lettuce and avoid damaging changes in the material.

3.3. Electrolyte Leakage Rate and Reactive Oxygen Species Contents of Loose-Leaf Lettuce Under MAP

The decreased cell membrane activity and increased permeability of fruit and vegetables during post-ripening cause electrolytes to leak, thus increasing relative conductivity [33]. Relative conductivity is an important indicator of the degree of damage to plant cells. It increases with the degree of damage. From day 0 to day 6, the electrolyte leakage rate of loose-leaf lettuce under different storage conditions increased with time (Figure 3A). However, the rate of increase in the MAP-treated was consistently lower than that in the control. On the second day, the rate of increase in the MAP-treated was found to be significantly lower than that in the control (p ≤ 0.001). When stored for 6 days, the relative conductivity of the control had risen rapidly to 24.0%, an increase of 296.5%, whereas that of the MAP-treated lettuce was 9.8%, an increase of only 63.3%, indicating that MAP treatment effectively delayed the rise in relative conductivity. A previous study suggests that the increase in electrolyte leakage is associated with a notable intensification in browning, which suggests that membrane status may be a pivotal factor in the postharvest browning process of lettuce [34].
High levels of ROS, particularly O2•− and OH•, initiate lipid peroxidation, damage mitochondrial membranes, and trigger plant degeneration [35]. During the entire storage period, there was a tendency for the reactive oxygen species content in loose-leaf lettuce under different storage conditions to increase with the duration of storage (Figure 3B,C). However, the rate of increase in the MAP-treated was consistently less than that in the control. On the 2nd day, the rate of increase in the MAP-treated was found to be significantly lower than that in the control (p ≤ 0.001). On day 6, the O2•− and OH• contents of the controls were 53.7% and 58.0% higher than that of the MAP-treated samples, respectively, which indicated that the mitochondrial membrane was severely damaged. This is consistent with data from previous studies on melons [36]. The O2•− and OH• levels of MAP-treated lettuce changed only slightly during storage. This suggested that MAP promoted a better balance between ROS generation and scavenging.

3.4. Lettuce Protein Profiling: Identification, Quantification, and GO Enrichment of Differentially Expressed Proteins

Furthermore, an evaluation was conducted to ascertain alterations in protein composition. The findings pertaining to the quality spectrum identification of the two groups of proteins are as follows: A total of 298,152 secondary spectra were identified, with 45,611 matching spectra, 6092 peptides matched, and 1794 proteins identified (Figure S1 and Table S1 in Supplementary Materials). The data were retrieved from the Uni_Asteraceae library with the assistance of Mascot software, version 2.3.01 [37]. With regard to protein abundance levels, a difference level of greater than 1.2-fold at p < 0.05 was selected as the threshold for statistical significance. A total of 374 distinct proteins were identified, of which 185 were found to be up-regulated and 189 down-regulated (Figure S2 in Supplementary Materials).

3.4.1. Cellular Components

The fundamental unit of plant tissue is the cell, which also plays a crucial role in metabolic processes. In terms of the cellular components, the differentially expressed proteins were found to be enriched in seven broad categories: membrane, cell, cell part, membrane part, organelle part, organelle, and macromolecular complex (Figure 4A). The proportion of the cell and cellular activities categories was 22%, while the proportion of the membrane category was 10%. Cell membranes and organelles represent the fundamental constituents of cells. The differentially expressed proteins were enriched in terms of the aforementioned three processes, indicating that damage to cell structure and function was intrinsic to lettuce decay. This also explains why the relative conductivity of control lettuce was higher than that of MAP lettuce.
In addition, aquaporins are intrinsic membrane proteins located in the cell membrane that typically accumulate in fruits and vegetables in response to environmental stresses such as dehydration [38]. Controls were exposed to aerobic conditions where high oxygen levels accelerate the breakdown of cellular structures, leading to the release of aquaporins and, consequently, increased water loss (Table S2 in Supplementary Materials). In contrast, MAP-treated lettuce maintained in a relatively stable gaseous environment showed minimal disruption of cell structure, resulting in minimal water loss. This is consistent with our finding that the expression of this protein is down-regulated in membrane classes. The stable gaseous environment created by MAP treatment likely helps preserve the integrity of cell membranes and organelles, thereby limiting the stress-induced changes that trigger aquaporin release. Furthermore, MAP may regulate the expression of other membrane-associated proteins, such as those involved in membrane stability and vesicle trafficking, thereby mitigating the damage caused by oxidative stress and dehydration. By modulating the expression of these proteins, MAP treatment enhances the resilience of cell membranes and intracellular structures, which plays a critical role in maintaining cellular functions and delaying senescence. This supports the hypothesis that MAP treatment not only reduces oxidative damage but also maintains cellular homeostasis by stabilizing membrane dynamics and protein function under stress conditions.

3.4.2. Molecular Function

In terms of molecular function, the differentially expressed proteins were found to be enriched in the following four major categories: catalytic activity, binding, transporter activity, and structural molecular activity (Figure 4B). Of these, the proportion of proteins with catalytic activity was the largest, reaching 42%, indicating that MAP could regulate the activity of key enzymes and thus control the physiological and biochemical reactions of fruits and vegetables. The proportion of proteins involved in binding reached 39%, which is indicative of the catalytic roles played by key enzymes. The category of structural molecular activity accounted for 12% of the total, which may indicate that altered enzyme activity affected certain normal physiological and biochemical reactions, leading to structural degradation. In the transporter activity category, only 7% of the differentially expressed proteins were enriched. However, key categories such as signal transduction and transport are crucial. The differential proteins within these categories are important factors reflecting the mechanisms of damage, including apoptosis, membrane rupture, and organelle cleavage, in the large, fast-growing lettuce plants of the control [39].
Peroxidase, cytochrome c oxidase, thioredoxin, and glutathione S-transferase are important for scavenging ROS [40], and we found that the expression of all these reductases was up-regulated (Table S2 in Supplementary Materials), suggesting that MAP can eliminate ROS such as hydrogen peroxide and repair oxidized disulfide bonds in lettuce cells by regulating the expression of these enzymes. Malate dehydrogenase is a key enzyme in the TCA cycle, catalyzing the reversible conversion of malate to oxaloacetate, and is also involved in the redox shuttle, which plays an important role in exporting reducing equivalents from the mitochondria and maintaining the dynamic mitochondrial NADH/NAD+ balance [41]. Alkyl peroxiredoxin reductase subunit C is capable of directly converting peroxide substrates to water or the corresponding alcohols, thus acting as a detoxifier [42]. The down-regulation of malate dehydrogenase and alkyl peroxiredoxin reductase subunit C (Table S2 in Supplementary Materials) expression indicated that NADH/NAD+ was in relative equilibrium in MAP-treated lettuce and ROS production was effectively suppressed. In this way, the damage caused by reactive oxygen species to the cell membrane was reduced, and the onset of browning was delayed.
Within the transporter activity category, increased expression of two proteins belonging to the NAC family was observed (Table S2 in Supplementary Materials). The NAC transcription factor is a recently identified plant-specific transcription factor with a wide range of biological functions. NAC plays an important role in a number of key processes in plants, including growth, development, senescence, signal transduction, and defense [43]. Approximately 20% of the NAC proteins in Arabidopsis thaliana are associated with leaf senescence, with some NAC proteins being up-regulated during the development of senescence. Similarly, an increase in the expression of certain NAC proteins is observed during chickpea storage [44]. In this study, the up-regulation of two NAC family proteins suggested that MAP treatment had enhanced the antioxidant capacity of loose-leaf lettuce by modulating NAC transcription factors, which could have increased the activity of antioxidant enzymes, reduced oxidative damage, delayed senescence, and maintained quality. As previously reported, the up-regulation of the NAC transcription factor BrNAC029 in Chinese cabbage strengthens the antioxidant system, stabilizes chlorophyll, delays leaf senescence, and enhances stress tolerance [45].

3.4.3. Biological Processes

With regard to the biological processes involved, the differentially enriched proteins were found to fall into six principal categories, namely single-organism processes, metabolic processes, responses to stimulus, cellular processes, cellular component organization or biogenesis, and localization (Figure 4C). The metabolic processes category constituted the largest proportion (35%), followed by the cellular processes category (31%). During the postharvest storage period, the metabolic processes of lettuce must continue uninterrupted. As it cannot obtain nutrients from the external environment, lettuce can only rely on catabolic processes to obtain the energy and raw materials it needs. The gradual consumption of intrinsic nutrients and energy ultimately results in dehydration and decay. The enriched, differentially expressed proteins predominantly affected this process, indicating that MAP had a significant impact on metabolic and catabolic activities. Proteins in the cellular processes, single-organism processes, and cellular component organization or biogenesis categories were intimately linked with cell generation and division, which were pivotal aspects of metabolism. The differential expression of the relevant proteins suggested that these processes were influenced by MAP.
Moreover, within the context of cell death, the expression of protein disulfide isomerase was reduced, and OB-fold nucleic acid binding site protein expression was enhanced (Table S2 in Supplementary Materials). With regard to the category of wilting and deterioration processes, the expression of glutamine synthetase was observed to be down-regulated (Table S3 in Supplementary Materials). Protein disulfide isomerase is a multifunctional protein responsible for the correct folding of proteins and metabolic regulation. Within the cell, protein disulfide isomerase not only participates in the formation and isomerization of disulfide bonds but also acts as a molecular chaperone, assisting in protein synthesis and assembly [46]. The reduced expression of protein disulfide isomerase suggested that modified atmosphere packaging treatment had reduced the need for protein folding due to environmental stresses (such as oxidative stress) during storage. Since oxidative stress is a key signal for inducing programmed cell death, the down-regulation of protein disulfide isomerase expression may indicate a more balanced redox state within the cell, thereby reducing the activation of apoptosis-related signaling pathways [47]. This is consistent with the dual role of protein disulfide isomerase as a cellular protective factor under stress conditions. Its high expression may indicate greater cellular stress, while its down-regulation may reflect a reduction in environmental stress. OB-fold nucleic acid-binding proteins are up-regulated under environmental stresses like cold shock, playing a key role in stabilizing nucleic acids and enhancing cellular adaptability [48]. In MAP-treated lettuce, the up-regulation of these proteins may inhibit the cell death program by maintaining nucleic acid integrity and preventing the activation of apoptosis signals. By stabilizing nucleic acid structures and interfering with apoptosis pathways triggered by nucleic acid damage, OB-fold proteins help promote cell survival, aligning with previous studies on their critical role in cellular stress resistance and maintaining biomolecule function [49]. Glutamine synthetase is a key enzyme in plant nitrogen metabolism, responsible for catalyzing the reaction of glutamate and ammonia to form glutamine. In MAP-treated lettuce, the down-regulation of glutamine synthetase expression may have delayed the cell death program by slowing the rate of nitrogen metabolism, thereby reducing the cell’s reliance on nitrogen sources and energy and delaying resource depletion [50]. Additionally, the down-regulation of glutamine synthetase may inhibit certain metabolic activities related to leaf senescence, further slowing down aging and deterioration processes [51]. It suggests that the dynamic regulation of glutamine synthetase expression is a crucial mechanism in maintaining metabolic balance during the storage period, helping to reduce metabolic rates and extend shelf life.

3.5. KEGG Enrichment Analysis of Differentially Expressed Proteins

After identifying differentially expressed proteins through mass spectrometry, we mapped the identified proteins to KEGG Orthology (KO) entries to enable functional classification and pathway annotation. These entries provided a foundation for linking the proteins to known biological pathways curated in the KEGG database. To identify pathways significantly impacted by the experimental conditions, we conducted KEGG enrichment analysis by comparing the observed protein set to a background protein set using statistical tests (Fisher’s exact test). The significance of enrichment was assessed using p-values, which were corrected for multiple comparisons with the Benjamini–Hochberg method to control the false discovery rate. Pathways with corrected p-values below 0.05 were considered significantly enriched. A total of 77 pathways were identified, and the top 15 enriched pathways are listed (Table 1). Among these, pathways such as carbon metabolism, oxidative phosphorylation, glycolysis, the tricarboxylic acid (TCA) cycle, pyruvate metabolism, glyoxylic acid, and dicarboxylic acid metabolism were closely related to mitochondrial respiratory metabolism. This suggests that MAP treatment significantly inhibited the rapid increase in mitochondrial respiratory activity, potentially impacting energy production and overall metabolic stability during postharvest storage.

3.5.1. Analysis of Differentially Expressed Proteins in the Glycolysis and TCA Pathway

In the glycolysis pathway, 14 differentially expressed proteins were enriched. Among these, only dihydrolipoamide dehydrogenase, proteins of the histidine phosphatase family, and glyceraldehyde-3-phosphate dehydrogenase were down-regulated; the other differentially expressed proteins were up-regulated (Table S3 in Supplementary Materials). Fructose diphosphate aldolase, pyruvate kinase, and dihydrolipoamide acetyltransferase are associated with energy metabolism. The histidine phosphatase family of proteins is mainly involved in information transfer. Dihydrolipoamide dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase act at an important node in glucose metabolism. On the 6th day of storage, the glycolytic pathway was more active in the MAP-treated lettuce compared to the control and started to prepare raw materials and energy for the next step of the TCA cycle, so we concluded that the respiration process was effectively delayed during the first 6 days of storage. In the TCA pathway, nine proteins were differentially enriched. Of these, only pyruvate dehydrogenase was up-regulated, while the other proteins were down-regulated (Table S3 in Supplementary Materials). The pyruvate dehydrogenase complex, a multi-enzyme complex that catalyzes the decarboxylation of pyruvate, was up-regulated, indicating that the cells were storing essential substances and energy in the TCA cycle [52]. Pyruvate from the glycolysis phase increased continuously over the short term. However, the expression of dihydrolipoamide dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase at the glucose metabolic node was down-regulated, indicating that the TCA cycle was inactive, as confirmed by the down-regulation of the expression of members of the histidine phosphatase family. Therefore, it suggests that the TCA pathway of MAP-treated lettuces is inhibited compared to that in the control.

3.5.2. Analysis of Differentially Expressed Proteins in the Oxidative Phosphorylation Pathway

In the oxidative phosphorylation pathway, 16 proteins were enriched; only cytochrome c oxidase and membrane-bound pyrophosphatase were up-regulated, while the remaining proteins were down-regulated (Table S3 in Supplementary Materials). After 6 days of storage, control lettuces were destroyed by oxidative damage. Quinones reduced by mitochondrial complexes I and II were oxidized by mitochondrial complex III, and the electrons were used to reduce cytochrome c in the mitochondrial membrane space. Thus, increased expression of cytochrome c oxidase may be a mechanism by which cells resist oxidative damage. Pyrophosphatase is a hydrolytic enzyme that acts on pyrophosphoric acid. Most plants contain two different forms of pyrophosphatase: the insoluble membrane-bound pyrophosphatase, which binds to organelle membranes (such as vacuoles and chloroplast membranes) to act as an H+ transporter, and the soluble inorganic pyrophosphatase, which is found in the cytoplasm and organelle matrix [53]. In the present study, MAP-treated lettuce was exposed to a relatively low O2 and high CO2 environment, and the down-regulation of mitochondrial ATP-related synthase expression rendered the energy supply inadequate. Up-regulation of membrane-bound pyrophosphatase expression triggered down-regulation of the pyrophosphate antiproton pump. The oxidative phosphorylation pathway is the carrier of the respiratory electron transport chain. On the 6th day, compared to the control, the overall differential protein expression showed a downward trend, indicating that respiratory electron transport was effectively inhibited, preventing excessive ROS production and reducing oxidative damage to lettuce.

4. Conclusions

In this study, physicochemical and proteomic methods were used to study the quality changes of loose-leaf lettuce in cold storage after MAP treatment. The physicochemical experiments showed that MAP effectively prolonged the storage time of lettuce. Proteomic analysis suggested that MAP inhibited the apoptotic process by decreasing the expression of protein disulfide bond isomerase and increasing the expression of the OB-folding nucleic acid binding site; It slowed down the decay process of lettuce by down-regulating the expression of glutamine syntheses, enhanced the defense against cellular oxidative damage, and maintained the dynamic balance of the electron transport chain by up-regulating the expression of cytochrome c oxidase and the expression of membrane-bound pyrophosphorylase. Also, MAP regulates energy metabolism in the TCA cycle by down-regulating dihydrolipoic acid dehydrogenase and malate dehydrogenase, inhibits ATPase synthesis, and reduces the rate of electron generation and transfer by down-regulating key enzymes in the oxidative phosphorylation pathway. These results provide the theoretical basis for regulating lettuce metabolism and serve as a reference for further quantitative transcriptomic and metabolomics studies.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/agriculture14122156/s1, Figure S1: Schematic diagram of Q-Exactive mass spectrometry; Figure S2: Protein ratio distribution (MAP vs. Control) (With regard to protein abundance levels, a difference level of greater than 1.2-fold at p < 0.05 was selected as the threshold for statistical significance. Red dots represent proteins with an up-regulation, while green dots indicate proteins with a down-regulation); Table S1: Basic information chart of proteome identification; Table S2: Differential proteins; Table S3: Protein identities and their relative changes in MAP-treated lettuce and control group.

Author Contributions

X.C. and H.Z. designed the whole experiment, managed the project, and revised the manuscript. L.W. and J.H. conducted the experiments, analyzed the data, and wrote the manuscript. W.L. and R.W. helped with the data analysis and manuscript revision. J.Z. provided technical assistance. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by the Beijing Innovation Consortium of Agriculture Research System (BAIC01), Beijing University of Agriculture Young Teachers’ Innovation Ability Enhancement Plan Research Fund (Grant No. QJKC-2023024), and Beijing Municipal Urban Agriculture and Forestry Interdisciplinary Platform Construction Project.

Institutional Review Board Statement

This study did not require ethical approval.

Data Availability Statement

The data presented in this study are available upon request from the corresponding author. The data are not publicly available due to privacy.

Acknowledgments

We would like to thank both the editor and the reviewers for their helpful comments to improve the manuscript.

Conflicts of Interest

Author Jing Zhou was employed by the company Beijing Yunong High Quality Agricultural Products Planting 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. Shi, M.; Gu, J.; Wu, H.; Rauf, A.; Emran, T.B.; Khan, Z.; Mitra, S.; Aljohani, A.S.; Alhumaydhi, F.A.; Al-Awthan, Y.S.; et al. Phytochemicals, Nutrition, Metabolism, Bioavailability, and Health Benefits in Lettuce—A Comprehensive Review. Antioxidants 2022, 11, 1158. [Google Scholar] [CrossRef] [PubMed]
  2. Baslam, M.; Morales, F.; Garmendia, I.; Goicoechea, N. Nutritional quality of outer and inner leaves of green and red pigmented lettuces (Lactuca sativa L.) consumed as salads. Sci. Hortic. 2013, 151, 103–111. [Google Scholar] [CrossRef]
  3. Ru, X.; You, W.; Zhang, J.; Xu, F.; Wu, Z.; Jin, P.; Zheng, Y.; Cao, S. γ-Aminobutyric acid treatment inhibits browning and promotes storage quality by regulating reactive oxygen species and membrane lipid metabolism in fresh-cut stem lettuce. Food Chem. 2024, 459, 140420. [Google Scholar] [CrossRef] [PubMed]
  4. Zhan, L.; Li, Y.; Hu, J.; Pang, L.; Fan, H. Browning inhibition and quality preservation of fresh-cut romaine lettuce exposed to high-intensity light. Innov. Food Sci. Emerg. Technol. 2012, 14, 70–76. [Google Scholar] [CrossRef]
  5. Zhang, X.; Liu, Q.; Han, C.; Chen, Q.; Jiao, W.; Fu, M. Combined treatment of ε-polylysine and UV-C inhibited aerobic bacteria growth, and maintained the color, texture, flavor of vacuum-packed fresh-cut lettuce slices. Postharvest Biol. Technol. 2024, 218, 113156. [Google Scholar] [CrossRef]
  6. Shen, W.; Zhang, W.; Li, J.; Huang, Z.; Tao, Y.; Hong, J.; Zhang, L.; Zhou, Y. Pre-harvest short-term continuous LED lighting improves the nutritional quality and flavor of hydroponic purple-leaf lettuce. Sci. Hortic. 2024, 334, 113304. [Google Scholar] [CrossRef]
  7. Liu, Q.; Zhang, X.; Han, C.; Chen, Q.; Sun, F.; Fu, M.; Zhao, H.; Xiao, Z.; Tang, Z. ε-Polylysine treatment maintains sensory quality, texture, flavor, and inhibits aerobic bacteria growth in vacuum-packed fresh-cut lettuce. Postharvest Biol. Technol. 2024, 214, 113011. [Google Scholar] [CrossRef]
  8. Yousuf, B.; Qadri, O.S.; Srivastava, A. Recent developments in shelf-life extension of fresh-cut fruits and vegetables by application of different edible coatings: A review. LWT—Food Sci. Technol. 2018, 8, 198–209. [Google Scholar] [CrossRef]
  9. Altınkaya, A. Effect of whey protein concentrate on phenolic profile and browning of fresh-cut lettuce (Lactuca sativa). Food Chem. 2011, 128, 754–760. [Google Scholar] [CrossRef]
  10. Chen, X.N.; Jin, W.B.; Dong, Y.R.; Meng, L.C.; Wei, Q. Research progress in preservation of post-harvest edible fungi. Adv. Mater. Res. 2012, 476, 614–619. [Google Scholar] [CrossRef]
  11. Sandhya, R. Modified atmosphere packaging of fresh produce: Current status and future needs. LWT—Food Sci. Technol. 2010, 43, 381–392. [Google Scholar] [CrossRef]
  12. Gill, S.S.; Tuteja, N. Reactive oxygen species and antioxidant machinery in abiotic stress tolerance in crop plants. Plant Physiol. Biochem. 2010, 48, 909–930. [Google Scholar] [CrossRef] [PubMed]
  13. Sharma, P.; Jha, A.B.; Dubey, R.S.; Pessarakli, M. Reactive oxygen species, oxidative damage, and antioxidative defense mechanism in plants under stressful conditions. J. Bot. 2012, 2012, 217037. [Google Scholar] [CrossRef]
  14. E Postiglione, A.; Delange, A.M.; Ali, M.F.; Wang, E.Y.; Houben, M.; Hahn, S.L.; Khoury, M.G.; Roark, C.M.; Davis, M.; Reid, R.W.; et al. Flavonols improve tomato pollen thermotolerance during germination and tube elongation by maintaining reactive oxygen species homeostasis. Plant Cell 2024, 36, 4511–4534. [Google Scholar] [CrossRef] [PubMed]
  15. Noctor, G.; De Paepe, R.; Foyer, C.H. Mitochondrial redox biology and homeostasis in plants. Trends Plant Sci. 2007, 12, 125–134. [Google Scholar] [CrossRef]
  16. Rahman, M.M.; Miaruddin, M.; Chowdhury MG, F.; Khan, M.H.H.; Matin, M.A. Effect of different packaging systems and chlorination on the quality and shelf life of green chili. Bangladesh J. Agric. Res. 2013, 37, 729–736. [Google Scholar] [CrossRef]
  17. Firouz, M.S.; Alimardani, R.; Mobli, H.; Mohtasebi, S.S. Effect of modified atmosphere packaging on the mechanical properties of lettuce during shelf life in cold storage. Inf. Process. Agric. 2021, 8, 485–493. [Google Scholar] [CrossRef]
  18. Islam, M.; Lee, Y.; Mele, M.; Choi, I.; Jang, D.; Ko, Y.; Kim, Y.; Kang, H. Effect of modified atmosphere packaging on quality and shelf life of baby leaf lettuce. Qual. Assur. Saf. Crops Foods 2021, 11, 749–756. [Google Scholar] [CrossRef]
  19. Palma, J.M.; Corpas, F.J.; Del Rio, L.A. Proteomics as an approach to the understanding of the molecular physiology of fruit development and ripening. J. Proteom. 2011, 74, 1230–1243. [Google Scholar] [CrossRef]
  20. Jiang, Q.; Zhao, W.; Zhao, S.; Wang, P.; Wang, Y.; Zhao, Y.; Zhao, X.; Wang, D. Comparison between vacuum and modified-atmosphere packaging on dynamic analysis of flavor properties and microbial communities in fresh-cut potatoes (Solanum tuberosum L.). Food Packag. Shelf Life 2023, 39, 101149. [Google Scholar] [CrossRef]
  21. Zulewska, J.; Lobacz, A.; Bialobrzewski, I.; Grochowina, A.; Kaminska, A. Influence of Different Packaging Materials on the Composition of the Headspace of Rennet Cheeses under Different Modified Atmosphere Conditions. Foods 2024, 13, 2500. [Google Scholar] [CrossRef] [PubMed]
  22. Martínez-Sánchez, A.; Tudela, J.A.; Luna, C.; Allende, A.; Gil, M.I. Low oxygen levels and light exposure affect quality of fresh-cut Romaine lettuce. Postharvest Biol. Technol. 2011, 59, 4–12. [Google Scholar] [CrossRef]
  23. Jiang, L.; Hou, T.; Yuan, X.; Jiang, J.; Yu, Z. Effect of storage temperature and packaging method on the decay and physiology of fresh leaves of Gynura bicolor D.C. J. Food Process. Preserv. 2010, 34, 858–871. [Google Scholar] [CrossRef]
  24. Lin, Y.; Lin, H.; Lin, Y.; Zhang, S.; Chen, Y.; Jiang, X. The roles of metabolism of membrane lipids and phenolics in hydrogen peroxide-induced pericarp browning of harvested longan fruit. Postharvest Biol. Technol. 2016, 111, 53–61. [Google Scholar] [CrossRef]
  25. Francisco, L.G.; Peter, R.; Ladie, A.P.; Markus, E.; Frank, D. Effect of new sanitizing formulations on quality of fresh-cut iceberg lettuce. Postharvest Biol. Technol. 2013, 85, 102–108. [Google Scholar]
  26. Ramos, B.; Miller, F.A.; Brandão TR, S.; Teixeira, P.; Silva, C.L.M. Fresh fruits and vegetables—An overview on applied methodologies to improve its quality and safety. Innov. Food Sci. Emerg. Technol. 2013, 20, 1–15. [Google Scholar] [CrossRef]
  27. Torales, A.C.; Gutiérrez, D.R.; Rodríguez, S.D.C. Influence of passive and active modified atmosphere packaging on yellowing and chlorophyll degrading enzymes activity in fresh-cut rocket leaves. Food Packag. Shelf Life 2020, 26, 100569. [Google Scholar] [CrossRef]
  28. Ren, Z.; Liu, Y.; Huang, J.; An, L.; Zhang, Y.; Yang, W.; Lei, T. Low oxygen concentration alleviates banana peel browning by inhibiting membrane lipid oxidation and polyphenol oxidase activity. Int. J. Food Sci. Technol. 2024, 59, 3350–3359. [Google Scholar] [CrossRef]
  29. Haba, F.; N’guettia, R.K.; Koffi, J.K.; Phaceli, D.E.; Tioté, L.; Djalega, A.F.; Dembélé, A. Post-harvest conservation of mangosteen (Garcinia mangostana): Influence of fruit harvest stage and effectiveness of some practical conservation treatments. J. Hortic. Sci. Biotechnol. 2023, 98, 786–798. [Google Scholar] [CrossRef]
  30. Peng, X.L.; Yang, J.P.; Cui, P.L.; Chen, F.; Fu, Y.; Hu, Y.Y.; Zhang, Q.; Xia, X.D. Influence of allicin on quality and volatile compounds of fresh-cut stem lettuce during cold storage. LWT—Food Sci. Technol. 2015, 60, 300–307. [Google Scholar] [CrossRef]
  31. Caleb, O.J.; Mahajan, P.V.; Al-Said, F.A. Modified atmosphere packaging technology of fresh and freshcut produce and the microbial consequences—A review. Food Bioprocess Technol. 2013, 6, 303–329. [Google Scholar] [CrossRef] [PubMed]
  32. Powrie, W.D.; Skura, B.J. Modified Atmosphere Packaging of Fruits and Vegetables. In Modified Atmosphere Packaging of Food; Springer: Boston, MA, USA, 1991; ISBN 978-0-7476-0064-0. [Google Scholar]
  33. Lei, M.; Guo, L.; Zhang, Y.; Yan, X.; Jiang, F.; Sun, B. Effectiveness of anaerobic treatment combined with microperforated film packaging in reducing Agaricus bisporus postharvest browning. Postharvest Biol. Technol. 2011, 211, 112833. [Google Scholar] [CrossRef]
  34. Li, Z.H.; Zhang, Y.X.; Ge, H.B. The membrane may be an important factor in browning of fresh-cut pear. Food Chem. 2017, 230, 265–270. [Google Scholar] [CrossRef] [PubMed]
  35. Bhattacharjee, S. The language of reactive oxygen species signaling in plants. J. Bot. 2012, 2012, 259–272. [Google Scholar] [CrossRef]
  36. Sharma, T.; Ramana Rao, T.V. Xanthan gum based edible coating enriched with cinnamic acid prevents browning and extends the shelf-life of fresh-cut pears. LWT—Food Sci. Technol. 2015, 62, 791–800. [Google Scholar] [CrossRef]
  37. Noor, Z.; Ahn, S.B.; Baker, M.S.; Ranganathan, S.; Mohamedali, A. Mass spectrometry–based protein identification in proteomics—A review. Brief. Bioinform. 2021, 22, 1620–1638. [Google Scholar] [CrossRef]
  38. Yang, X.; Lu, M.; Wang, Y.; Wang, Y.; Liu, Z.; Chen, S. Response Mechanism of Plants to Drought Stress. Horticulturae 2021, 7, 50. [Google Scholar] [CrossRef]
  39. Monterisi, S.; Zhang, L.; Garcia-Perez, P.; Zuluaga, M.Y.A.; Ciriello, M.; El-Nakhel, C.; Buffagni, V.; Cardarelli, M.; Colla, G.; Rouphael, Y.; et al. Integrated multi-omic approach reveals the effect of a Graminaceae-derived biostimulant and its lighter fraction on salt-stressed lettuce plants. Sci. Rep. 2024, 14, 10710. [Google Scholar] [CrossRef]
  40. Hui, K.-M.; Hao, F.-Y.; Li, W.; Zhang, Z.; Zhang, C.-Y.; Wang, W.; Ren, Q. Cloning and identification of four Mu-type glutathione S-transferases from the giant freshwater prawn Macrobrachium rosenbergii. Fish Shellfish. Immunol. 2013, 35, 546–552. [Google Scholar] [CrossRef]
  41. Yoshida, K.; Hisabori, T. Adenine nucleotide-dependent and redoxindependent control of mitochondrial malate dehydrogenase activity in Arabidopsis thaliana. Biochim. Et Biophys. Acta (BBA)—Bioenerg. 2016, 1857, 810–818. [Google Scholar] [CrossRef]
  42. Yu, Q.; Wu, W.; Tian, X.; Jia, F.; Xu, L.; Dai, R.; Li, X. Comparative proteomics to reveal muscle-specific beef color stability of Holstein cattle during post-mortem storage. Food Chem. 2017, 229, 769–778. [Google Scholar] [CrossRef] [PubMed]
  43. Yuan, X.; Wang, H.; Cai, J.; Li, D.; Song, F. NAC transcription factors in plant immunity. Phytopathol. Res. 2019, 1, 3. [Google Scholar] [CrossRef]
  44. Ramaswamy, M. Genome wide analysis of NAC gene family ‘sequences’ in sugarcane and its comparative phylogenetic relationship with rice, sorghum, maize and Arabidopsis for prediction of stress associated NAC genes. Agri Gene 2017, 3, 1–11. [Google Scholar] [CrossRef]
  45. Li, F.; Shan, Y.; Wang, H.; Jiang, G.; Ding, X.; Liang, H.; Wang, C.; Kong, X.; Xie, L.; Jiang, Y. A NAC transcriptional factor BrNAC029 is involved in cytokinin-delayed leaf senescence in postharvest Chinese flowering cabbage. Food Chem. 2023, 404, 134657. [Google Scholar] [CrossRef] [PubMed]
  46. Hanschmann, E.M.; Godoy, J.R.; Berndt, C.; Hudemann, C.; Lillig, C.H. Thioredoxins, Glutaredoxins, and Peroxiredoxins—Molecular Mechanisms and Health Significance: From Cofactors to Antioxidants to Redox Signaling. Antioxid. Redox Signal. 2013, 19, 1539–1605. [Google Scholar] [CrossRef]
  47. Appenzeller-Herzog, C.; Ellgaard, L. The human PDI family: Versatility packed into a single fold. Biochim. Et Biophys. Acta (BBA)—Mol. Cell Res. 2008, 1783, 535–548. [Google Scholar] [CrossRef]
  48. Amir, M.; Kumar, V.; Dohare, R.; Rehman, M.T.; Hussain, A.; Alajmi, M.F.; El-Seedi, H.R.; Hassan HM, A.; Islam, A.; Ahmad, F. Investigating architecture and structure-function relationships in cold shock DNA-binding domain family using structural genomics-based approach. Int. J. Biol. Macromol. 2019, 133, 484–494. [Google Scholar] [CrossRef]
  49. Amir, M.; Haque, M.A.; Dar, M.A.; Islam, A.; Ahmad, F.; Hassan, M.I. Purification and characterization of oligonucleotide binding (OB)-fold protein from medicinal plant Tinospora cordifolia. J. Chromatogr. B 2016, 1008, 38–44. [Google Scholar] [CrossRef]
  50. Hu, T.; Wu, J.; Lin, Z.; Lin, Y.; Lin, L.; Wei, W.; Wei, D. The impact of glutamine synthetase PbgsA on the growth, conidiation and mycophenolic acid production of Penicillium brevicompactum. Fungal Genet. Biol. 2024, 17, 103941. [Google Scholar] [CrossRef]
  51. Zhou, Q.; Gao, J.; Zhang, R.; Zhang, R. Ammonia stress on nitrogen metabolism in tolerant aquatic plant—Myriophyllum aquaticum. Ecotoxicol. Environ. Saf. 2017, 143, 102–110. [Google Scholar] [CrossRef]
  52. Škerlová, J.; Berndtsson, J.; Nolte, H.; Ott, M.; Stenmark, P. Structure of the native pyruvate dehydrogenase complex reveals the mechanism of substrate insertion. Nat. Commun. 2021, 12, 5277. [Google Scholar] [CrossRef]
  53. Zhang, J.; Li, J.; Wang, X.; Chen, J. OVP1, a vacuolar H+-translocating inorganic pyrophosphatase (V-PPase), overexpression improved rice cold tolerance. Plant Physiol. Biochem. 2011, 49, 33–38. [Google Scholar] [CrossRef]
Agriculture 14 02156 g001
Figure 1. Effects of MAP on the sensory state (A), overall visual quality score (B), and chlorophyll content (C) in postharvest loose-leaf lettuce stored at 4 °C for 6 d. The asterisk (*) denotes a significant difference between MAP treatment and the control (p < 0.05), the asterisk (***) denotes a significant difference between MAP treatment and the control (p < 0.001).
Figure 1. Effects of MAP on the sensory state (A), overall visual quality score (B), and chlorophyll content (C) in postharvest loose-leaf lettuce stored at 4 °C for 6 d. The asterisk (*) denotes a significant difference between MAP treatment and the control (p < 0.05), the asterisk (***) denotes a significant difference between MAP treatment and the control (p < 0.001).
Agriculture 14 02156 g001
Agriculture 14 02156 g002
Figure 2. Effect of MAP on weight loss (A) and gas percentage (B) in postharvest lettuces during storage at 4 °C. The asterisk (***) denotes a significant difference between MAP treatment and the control (p < 0.001).
Figure 2. Effect of MAP on weight loss (A) and gas percentage (B) in postharvest lettuces during storage at 4 °C. The asterisk (***) denotes a significant difference between MAP treatment and the control (p < 0.001).
Agriculture 14 02156 g002
Agriculture 14 02156 g003
Figure 3. Effect of MAP on electrolyte leakage (A), hydroxyl radical superoxide radical (B), and superoxide radical (C) contents in postharvest lettuces during storage at 4 °C. The asterisk (***) denotes a significant difference between MAP treatment and the control (p < 0.001).
Figure 3. Effect of MAP on electrolyte leakage (A), hydroxyl radical superoxide radical (B), and superoxide radical (C) contents in postharvest lettuces during storage at 4 °C. The asterisk (***) denotes a significant difference between MAP treatment and the control (p < 0.001).
Agriculture 14 02156 g003
Agriculture 14 02156 g004
Figure 4. Differentially expressed genes of loose-leaf lettuce at the end of the storage period (control vs. MAP-treated). Enrichment of differentially expressed proteins for cellular components (A), molecular function (B), and biological processes (C).
Figure 4. Differentially expressed genes of loose-leaf lettuce at the end of the storage period (control vs. MAP-treated). Enrichment of differentially expressed proteins for cellular components (A), molecular function (B), and biological processes (C).
Agriculture 14 02156 g004
Table 1. KEGG classification pathways analysis of differential proteins.
Table 1. KEGG classification pathways analysis of differential proteins.
Serial NumberPathwayTarget Protein NumberBackground Protein Numberp-Value
1Metabolic pathway1108760.87 × 10−4
2Secondary metabolite biosynthesis494030.18
3Ribosome metabolism381720.44 × 10−4
4Carbon metabolism313130.78
5Photosynthesis22770.62 × 10−4
6Carbon fixation in photosynthetic organic matter192070.89
7Oxidative phosphorylation16950.10
8Amino acid biosynthesis161640.82
9Glycolysis141010.32
10Glyoxylic acid and dicarboxylic acid metabolism141650.93
11TCA cycle9450.90
12Pyruvate metabolism9680.44
13Photosynthetic-sensitive protein metabolism8200.00
14Glycine, serine, and threonine8420.13
15Cysteine and methionine metabolism7420.24
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

Weng, L.; Han, J.; Wu, R.; Liu, W.; Zhou, J.; Chen, X.; Zhang, H. Proteomic Analysis Unveils the Protective Mechanism of Active Modified Atmosphere Packaging Against Senescence Decay and Respiration in Postharvest Loose-Leaf Lettuce. Agriculture 2024, 14, 2156. https://doi.org/10.3390/agriculture14122156

AMA Style

Weng L, Han J, Wu R, Liu W, Zhou J, Chen X, Zhang H. Proteomic Analysis Unveils the Protective Mechanism of Active Modified Atmosphere Packaging Against Senescence Decay and Respiration in Postharvest Loose-Leaf Lettuce. Agriculture. 2024; 14(12):2156. https://doi.org/10.3390/agriculture14122156

Chicago/Turabian Style

Weng, Lili, Jiyuan Han, Runyan Wu, Wei Liu, Jing Zhou, Xiangning Chen, and Huijuan Zhang. 2024. "Proteomic Analysis Unveils the Protective Mechanism of Active Modified Atmosphere Packaging Against Senescence Decay and Respiration in Postharvest Loose-Leaf Lettuce" Agriculture 14, no. 12: 2156. https://doi.org/10.3390/agriculture14122156

APA Style

Weng, L., Han, J., Wu, R., Liu, W., Zhou, J., Chen, X., & Zhang, H. (2024). Proteomic Analysis Unveils the Protective Mechanism of Active Modified Atmosphere Packaging Against Senescence Decay and Respiration in Postharvest Loose-Leaf Lettuce. Agriculture, 14(12), 2156. https://doi.org/10.3390/agriculture14122156

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