Fruit Ripening Research Articles

The β-galactosidase gene AtrBGAL2 regulates Akebia trifoliata fruit cracking

Cracking of Akebia trifoliata fruit at maturity is problematic for the cultivation of the horticultural crop, shortening shelf-life quality and compromising commercial value. However, the molecular mechanisms underlying this feature of A. trifoliata are not known. Genes involved in cell wall metabolism were identified by genome and transcriptome sequencing, which may play important roles in fruit cracking. One of the galactose metabolism related genes, β-galactosidase (AtrBGAL2), was identified in A. trifoliata, and overexpression (OE) of AtrBGAL2 resulted in early fruit cracking, higher water-soluble pectin contents, and lower acid-soluble pectin, cellulose, and hemicellulose content compared to the wild type. Whereas silencing of AtrBGAL2 in trifoliata by virus induced gene silencing showed opposite trends. The levels of AtrBGAL2 transcripts were 24.6 and 66.0-fold higher in OE A. trifoliata and tomato fruits, respectively, and the cell wall-related genes were also gradually greater than in control plants during fruit ripening. Whereas the expression levels of AtrBGAL2 was significantly down-regulated by 54.1 % and 73.7 % in gene silenced A. trifoliata and CRISPR/Cas9 tomato mutant plants, respectively, and cell wall-related genes were also significantly reduced. These results demonstrate that AtrBGAL2 plays important roles in regulating fruit cracking during fruit ripening.

How the application of supporting substances affects the formation of fertile embryos of crossbred cherries and its germination

The seeds of early ripening cherry cultivars are generally of poor quality, thereby adversely affect the success of the entire breeding process. The current study aimed to examine the application of supporting substances, such as brown algae extract (ALGA), humic and fulvic acids + IAA (LEXIN), and gibberellic acid (GA3), in the blooming and ripening of fruits. Successively, the same substances were applied to seeds within laboratory conditions, to enhance the quality of cherry embryos and promote their germination. For comparison, two cultivars, an early one ‘Burlat’ and late ‘HL 13577’ were used in a multi-year trial. The application of GA3 at the time of blooming in the ‘Burlat’ cultivar had a positive effect on increasing the share of harvested fruits (31.6%), reduction of the share of bad seeds (17.7%) and improving seed germination (21.9%), compared to the untreated control. Cultivar ‘HL 13577’ had 16.6% of developed fruits, 15.0% share of bad seeds and seed germination 9.8%. No remarkable increase in germination was observed in any tested variants after the secondary application of preparations in the laboratory. The impact of the year was most explicit in the proportionality of developed fruits, while its effect on seed germination post-treatment remained uncertain. On the contrary, the treatment exhibited a greater effect on germination testing. Based on these findings, we conclude that direct application of GA3 to the trees (from blooming to fruit harvesting) in the orchard was beneficial. However, the other substances tested did not produce positive effects on the parameters.

O armário: Fruiting phenology data for 4,462 plant taxa in Portugal (1926–2013)

Species phenology - the timing of key life events - is being altered by ongoing climate changes with yet underappreciated consequences for ecosystem stability. While flowering is generally occurring earlier, we know much less about other key processes such as the time of fruit ripening, largely due to the lack of comprehensive long-term datasets. Here we provide information on the exact date and site where seeds of 4,462 taxa were collected for the Index Seminum (seed exchange catalogue) of the Botanic Garden of the University of Coimbra, between 1926 and 2013. Seeds were collected from spontaneous and cultivated individuals across Portugal, including both native and introduced taxa. The database consists of 127,747 curated records with information on the species, or infraspecific taxa (including authority), and the day and site where seeds were collected. All records are georeferenced and provided with a confidence interval for the collection site. Taxonomy was first curated manually by in-house botanists and then harmonized according to the GBIF backbone taxonomy.

Effects of Foliar Ca and Mg Nutrients on the Respiration of ‘Feizixiao’ Litchi Pulp and Identification of Differential Expression Genes Associated with Respiration

The ‘Feizixiao’ litchi cultivar, predominantly grown in Hainan Province, faces the issue of “sugar receding” during fruit ripening. The application of mixed foliar nutrients containing calcium and magnesium (Ca+Mg) during the fruit pericarp’s full coloring stage was investigated to overcome this issue. Experimental trials unveiled significant alterations in litchi pulp physiochemical properties, including the main nutrient and flavor quality, the total respiration rates of the main respiratory pathways, and the activities of some important enzymes associated with Embden–Meyerhof–Parnas (EMP), the tricarboxylic acid cycle (TCA) and the pentose phosphate pathway (PPP). The Ca+Mg treatment showed higher sugar levels than the control (CK) during ripening. Notably, the application of Ca+Mg in litchi pulp inhibited respiration rates through the EMP, TCA, and PPP pathways, resulting in a strong effect. RNA sequencing analysis revealed the impact of Ca+Mg treatment on respiratory pathways, revealing differentially expressed genes (DEGs) such as pyruvate PK1, PK2 (pyruvate kinase), and PDC (pyruvate dehydrogenase complex), validated through qRT-PCR with a significant correlation to RNA-seq results. In general, Ca+Mg treatment during litchi fruit ripening overcame “sugar receding” by inhibiting the expression of respiration key metabolic pathway genes. These findings provide insights for enhancing cultivation management strategies.

The ethylene-responsive transcription factor ERF024 is a novel regulator of climacteric fruit ripening in melon.

Fruit ripening is an essential developmental stage in Angiosperms triggered by hormonal signals such as ethylene, a major player in climacteric ripening. Melon is a unique crop showing both climacteric and non-climacteric cultivars, offering an ideal model for dissecting the genetic mechanisms underpinning this process. The major quantitative trait locus ETHQV8.1 was previously identified as a key regulator of melon fruit ripening. Here, we narrowed down ETHQV8.1 to a precise genomic region containing a single gene, the transcription factor CmERF024. Functional validation using CRISPR/Cas9 knock-out plants unequivocally identified CmERF024 as the causal gene governing ETHQV8.1. The erf024 mutants exhibited suppression of ethylene production, leading to a significant delay and attenuation of fruit ripening. Integrative multi-omic analyses encompassing RNA-seq, DAP-seq, and DNase-seq revealed the association of CmERF024 with chromatin accessibility and gene expression dynamics throughout fruit ripening. Our data suggest CmERF024 as a novel regulator of climacteric fruit ripening in melon.

Sub-acute pathological effects of calcium carbide as an artificial fruit ripening agent on various organs of albino mice

Introduction. Calcium carbide is the most commercially used artificial fruit ripener because it is inexpensive to produce though, involving the use of hazardous elements and can easily be purchased in local markets. This study aimed at investigating the architectural changes of organs extracted from albino mice fed with fruits that were ripened with calcium carbide. Material and methods. About 40 mice of both males and females, weighing between 18g-25g were randomly used for this study. They were divided into five (5) groups, made up of six mice namely Groups 1, 2, 3, 4 & 5 respectively. A set of unripe mature pawpaw and banana were ripened with calcium carbide (CCRP & CCRB) and were fed orally to groups 3 and 5 respectively for four weeks with water. Another set of the unripe mature pawpaw and banana were ripened naturally (NRP & NRB) without subjecting them to any artificial ripening processes and were fed orally to groups 2 and 4 mice respectively for four weeks with water. Rat feed and water were also given to the control group 1. Results. Increased body weights were observed in the calcium carbide ripened banana (CCRB) treated group when compared to the other groups (control and calcium carbide ripened pawpaw). Histological sections revealed increased numbers of inflammatory cells, presence of collapsed epithelial layer, ruptured muscle, disorganized clara cells, aggregation of fibroblasts in the lungs; mild interstitial edema in the brain between the cardiocytes: mononuclear cell infiltration with cloudy swelling of the renal epithelium; dendritic cells in the brain. Discussion and conclusions. According to this study, eating fruits that are ripened with calcium carbide has adverse related health effects thus negatively altering the histological architecture of the organs such as the lungs, liver, kidney, heart as well as the brain. Fruit vendors must therefore use caution when applying calcium carbide and adhere to international regulations that strictly limit its use.

Movement of ACC oxidase 3 mRNA from seeds to flesh promotes fruit ripening in apple

Xenia, the phenomenon in which the pollen genotype directly affects the phenotypic characteristics of maternal tissues (i.e., fruit ripening), has applications in crop production and breeding. However, the underlying molecular mechanism has yet to be elucidated. Here, we investigated whether mobile mRNAs from the pollen affect the ripening and quality-related characteristics of the fruit using cross-pollination between distinct Malus domestica (apple) cultivars. We demonstrated that hundreds of mobile mRNAs originating from the seeds are delivered to the fruit. We found that the movement of one of these mRNAs, ACC oxidase 3 (MdACO3), is coordinated with fruit ripening. Salicylic acid treatment, which can cause plasmodesmal closure, blocks MdACO3 movement, indicating that MdACO3 transcripts may move through the plasmodesmata. To assess the role of mobile MdACO3 transcripts in apple fruit, we created MdACO3-GFP-expressing apple seeds using MdACO3-GFP-overexpressing pollen for pollination and showed that MdACO3 transcripts in the transgenic seeds move to the flesh, where they promote fruit ripening. Furthermore, we demonstrated that MdACO3 can be transported from the seeds to fruit in the fleshy-fruited species tomato and strawberry. These results underscore the potential of mobile mRNAs from seeds to influence fruit characteristics, providing an explanation for the xenia phenomenon. Notably, our findings highlight the feasibility of leveraging diverse pollen genomic resources, without resorting to genome editing, to improve fruit quality.

DNA methylation controlling abscisic acid catabolism responds to light to mediate strawberry fruit ripening.

Phytohormones, epigenetic regulation and environmental factors regulate fruit ripening but their interplay during strawberry fruit ripening remains to be determined. In this study, bagged strawberry fruit exhibited delayed ripening compared with fruit grown in normal light, correlating with reduced abscisic acid (ABA) accumulation. Transcription of the key ABA catabolism gene, ABA 8'-hydroxylase FaCYP707A4, was induced in bagged fruit. With light exclusion whole genome DNA methylation levels were up-regulated, corresponding to a delayed ripening process, while DNA methylation levels in the promoter of FaCYP707A4 were suppressed, correlating with increases in transcript and decreased ABA content. Experiments indicated FaCRY1, a blue light receptor repressed in bagged fruit and FaAGO4, a key protein involved in RNA-directed DNA methylation, could bind to the promoter of FaCYP707A4. The interaction between FaCRY1 and FaAGO4, and an increased enrichment of FaAGO4 directed to the FaCYP707A4 promoter in fruit grown under light suggests FaCRY1 may influence FaAGO4 to modulate the DNA methylation status of the FaCYP707A4 promoter. Furthermore, transient overexpression of FaCRY1, or an increase in FaCRY1 transcription by blue light treatment, increases the methylation level of the FaCYP707A4 promoter, while transient RNA interference of FaCRY1 displayed opposite phenotypes. These findings reveal a mechanism by which DNA methylation influences ABA catabolism, and participates in light-mediated strawberry ripening.

Abscisic Acid Induces DNA Methylation Alteration in Genes Related to Berry Ripening and Stress Response in Grape (Vitis vinifera L).

Abscisic acid (ABA) is a major regulator of nonclimacteric fruit ripening, with its processes involving epigenetic mechanisms. It remains unclear whether DNA methylation is associated with ABA-regulated ripening. In this study, we investigated the patterns of DNA methylation and gene expression following ABA treatment in grape berries by using whole-genome bisulfite sequencing and RNA-sequencing. ABA application changed global DNA methylation in grapes. The hyper-/hypo-differently methylated regions were enriched in defense-related metabolism, degreening processes, or ripening-related metabolic pathways. Many differentially expressed genes showed an alteration in DNA methylation after ABA treatment. Specifically, ten downregulated genes with hypermethylation in promoters were involved in the ripening process, ABA homeostasis/signaling, and stress response. Nine upregulated genes exhibiting hypo-methylation in promoters were related to the ripening process and stress response. These findings demonstrated ABA-induced DNA alteration of ripening related and stress-responsive genes during grape ripening, which provides new insights of the epigenetic regulation of ABA on fruit ripening.

Managing Esca in Susceptible ‘Sauvignon Blanc’ Wine Grapes Through Trunk Renewal

Trunk renewal was evaluated as a treatment for highly susceptible ‘Sauvignon blanc’ wine grapes with moderate leaf and wood symptoms of the trunk disease Esca in a 17-year-old vineyard 7 years after symptoms first appeared. The trunk was cut above the graft union, removing all woody parts of the vine above it, including infected wood. A new trunk was retrained from a shoot off presumably healthy wood at the base of the trunk. Prior to trunk renewal, we detected Esca pathogens from 26% of 97 symptomatic vines. Five years after trunk renewal, 72 retrained vines were still asymptomatic, 24 were replanted (i.e., did not produce a shoot after trunk renewal), and one had leaf and fruit symptoms. Chemical composition of asymptomatic fruit from asymptomatic-retrained vines (RV-AF) was compared to that of vines that were not retrained, the latter of which included asymptomatic fruit from asymptomatic vines (AV-AF) and both asymptomatic fruit (SV-AF) and symptomatic fruit (SV-SF) from the same symptomatic vines. Given the high proportion of asymptomatic retrained vines after five growing seasons, trunk renewal was an effective cultural practice. Although there were no differences in chemistry parameters used to make harvest decisions (total soluble solids, pH, and titratable acidity), SV-SF was unique in having the highest concentrations of the flavonoids catechin and epicatechin and the lowest concentrations of the volatile-aroma compounds hexanal and 2-hexanal. These findings in all three blocks among fruit with visible spots may reflect a host-defense response and/or the effect of Esca on fruit ripening.

Influence of plant growth regulators on fruit set, yield and quality of mango varieties under HDP

Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. Phytohormones determine the formation of flowers, fruit set, stems, leaves, shedding of leaves, and development and ripening of fruits. They shape the plant, affecting seed growth, time of flowering, sex of flowers, senescence of leaves and fruits. Hormones are vital for plant growth and lacking them, plants would be mostly a mass of undifferentiated cells. Plant growth regulators include salicylic acid, CPPU, tricontanol and brassinosteroid. The production of poor quality fruits is a matter of common experience. It would be therefore worth while to improve the yield and quality of fruit crops by foliar application of plant growth regulators. The use of growth regulators has become an important component of agro-technical procedures for most of the cultivated plants and especially for fruit plants. In this review, we focus on the role of plant growth regulators on fruit production.

Genome-wide analysis of AP2/ERF transcription factors that regulate fruit development of Chinese prickly ash

BackgroundAP2/ERF is a large family of plant transcription factor proteins that play essential roles in signal transduction, plant growth and development, and responses to various stresses. The AP2/ERF family has been identified and verified by functional analysis in various plants, but so far there has been no comprehensive study of these factors in Chinese prickly ash. Phylogenetic, motif, and functional analyses combined with transcriptome analysis of Chinese prickly ash fruits at different developmental stages (30, 60, and 90 days after anthesis) were conducted in this study.ResultsThe analysis identified 146 ZbAP2/ERF genes that could be classified into 15 subgroups. The motif analysis revealed the presence of different motifs or elements in each group that may explain the functional differences between the groups. ZbERF13.2, ZbRAP2-12, and ZbERF2.1 showed high levels of expression in the early stages of fruit development. ZbRAP2-4, and ZbERF3.1 were significantly expressed at the fruit coloring stage (R2 and G2). ZbERF16 were significantly expressed at fruit ripening and expression level increased as the fruit continued to develop. Relative gene expression levels of 6 representative ZbAP2/ERFs assessed by RT-qPCR agreed with transcriptome analysis results.ConclusionsThese genes identified by screening can be used as candidate genes that affect fruit development. The results of the analysis can help guide future genetic improvement of Chinese prickly ash and enrich our understanding of AP2/ERF transcription factors and their regulatory functions in plants.

Involvement of the GH38 Family Exoglycosidase α-Mannosidase in Strawberry Fruit Ripening

Exoglycosidase enzymes hydrolyze the N-glycosylations of cell wall enzymes, releasing N-glycans that act as signal molecules and promote fruit ripening. Vesicular exoglycosidase α-mannosidase enzymes of the GH38 family (EC 3.2.1.24; α-man) hydrolyze N-glycans in non-reduced termini. Strawberry fruit (Fragaria × ananassa) is characterized by rapid softening as a result of cell wall modifications during the fruit ripening process. Enzymes acting on cell wall polysaccharides explain the changes in fruit firmness, but α-man has not yet been described in F. × ananassa, meaning that the indirect effects of N-glycan removal on its fruit ripening process are unknown. The present study identified 10 GH38 α-man sequences in the F. × ananassa genome with characteristic conserved domains and key residues. A phylogenetic tree built with the neighbor-joining method and three groups of α-man established, of which group I was classified into three subgroups and group III contained only Poaceae spp. sequences. The real-time qPCR results demonstrated that FaMAN genes decreased during fruit ripening, a trend mirrored by the total enzyme activity from the white to ripe stages. The analysis of the promoter regions of these FaMAN genes was enriched with ripening and phytohormone response elements, and contained cis-regulatory elements related to stress responses to low temperature, drought, defense, and salt stress. This study discusses the relevance of α-man in fruit ripening and how it can be a useful target to prolong fruit shelf life.

Integrative Analysis of Metabolome and Transcriptome of Carotenoid Biosynthesis Reveals the Mechanism of Fruit Color Change in Tomato (Solanum lycopersicum).

Tomato fruit ripening is accompanied by carotenoid accumulation and color changes. To elucidate the regulatory mechanisms underlying carotenoid synthesis during fruit ripening, a combined transcriptomic and metabolomic analysis was conducted on red-fruited tomato (WP190) and orange-fruited tomato (ZH108). A total of twenty-nine (29) different carotenoid compounds were identified in tomato fruits at six different stages. The abundance of the majority of the carotenoids was enhanced significantly with fruit ripening, with higher levels of lycopene; (E/Z)-lycopene; and α-, β- and γ-carotenoids detected in the fruits of WP190 at 50 and 60 days post anthesis (DPA). Transcriptome analysis revealed that the fruits of two varieties exhibited the highest number of differentially expressed genes (DEGs) at 50 DPA, and a module of co-expressed genes related to the fruit carotenoid content was established by WGCNA. qRT-PCR analysis validated the transcriptome result with a significantly elevated transcript level of lycopene biosynthesis genes (including SlPSY2, SlZCIS, SlPDS, SlZDS and SlCRTSO2) observed in WP190 at 50 DPA in comparison to ZH108. In addition, during the ripening process, the expression of ethylene biosynthesis (SlACSs and SlACOs) and signaling (SlEIN3 and SlERF1) genes was also increased, and these mechanisms may regulate carotenoid accumulation and fruit ripening in tomato. Differential expression of several key genes in the fruit of two tomato varieties at different stages regulates the accumulation of carotenoids and leads to differences in color between the two varieties of tomato. The results of this study provide a comprehensive understanding of carotenoid accumulation and ethylene biosynthesis and signal transduction pathway regulatory mechanisms during tomato fruit development.

Uses of Gibberellic Acid for Increasing Grape Production

Grapes are one of the most delicious fruit and have been farmed from thousands of years, growing from wild vine. Plant hormone is used for increase size and yield. This study goes into the significance influence of Gibberalic Acid (GA3) on grape farming, showing the ways in which this plant hormone has transformed the agricultural industry. Gibberellic acid is a hormone that is found naturally in plants and is essential for controlling several physiological functions. Many studies have been conducted on its use in grape cultivation. The main factor is growth and development of grape is vine. In grapes GA3 affects everything from flowering to fruit ripening. Enhancing yield is one of the main ways that GA3 helps with grapes production. GA3 encourage the growth of cluster by inducing cell elongation and division, which leads to increasing yield. In addition to satisfying consumers demand, the rise in grape yield helps for grape grower’s bottom line. Roles of application of GA3 on grape vine are different depends on their stages of flowering and fruit setting. It is also gave positive effect on rachis elongation which helps to get Healthy and export quality production. Overall, this review concluded that the Gibberellic Acid (GA3) is an important component linked with improving quality, size of berry, higher production.

Comparative Cell Wall Polysaccharide Analyses and Transcriptome Profiling during Fruit Ripening Reveal the Molecular Basis of Mealiness in Peach

Mealy peaches are dry and flavorless, which reduces their consumer acceptance. A deeper understanding of the mechanism underlying mealiness is crucial to enhancing peach fruit quality. In this study, comparative profiling was conducted on CP13, CP14, CM, and RM peaches. Sensory evaluation indicated that CP13 and CM are non-mealy clingstone and freestone peaches, respectively, and CP14 and RM are mealy freestone peaches. Both CP13 and CP14, identified as stony hard (SH) peaches, exhibited minimal ethylene release, whereas CM and RM, identified as melting flesh (MF) peaches, released high amounts of ethylene during the ripening process. Scanning electron microscopy (SEM) microstructure observation indicated that cells in the flesh tissue of mealy peaches, CP14 (SH) and RM (MF), were intact and separated, with large intercellular spaces and irregular arrangements. The main factor that promotes mealiness is differences in pectin metabolism, which impact cell wall composition. The fluctuations in polygalacturonase (PG) and pectin methylesterase (PME) activity between mealy and non-mealy peaches were the main factor contributing to mealiness. However, the changes in cell wall metabolism that caused these fluctuations did not have a clear direction. Using transcriptome analysis and weighted gene co-expression network analysis (WGCNA), we were able to identify forty differentially expressed genes (DEGs) that are associated with mealy patterns. Among these DEGs, genes encoding PG were significantly upregulated in mealy peaches (CP14 and RM) compared to non-mealy peaches (CP13 and CM). PpPG1 was the main effector gene for mealiness, while PpPG2, PpEGase2, PpEXP1, PpEXP3, PpAGP2, PpIAA4, and PpABA2 were identified as candidate genes regulating peach mealiness. These findings provide a solid experimental basis for understanding the textual distinctions between mealy and non-mealy peaches.

Characterisation of Position‐Dependant Ripening Dynamics of Nectarines Using Near‐Infrared Spectroscopy and ASCA

ABSTRACTNectarines, a popular pit fruit closely related to peaches, are renowned for their nutritional value and associated health benefits. However, challenges arise in maintaining optimal organoleptic properties during harvest and handling, eventually leading to production waste and heterogeneous quality in the fruit that arrives to the consumer. This study investigates the impact of nectarine position on trees during the whole ripening process using non‐destructive near‐infrared (NIR) spectroscopy. Nectarines exposed to more sunlight mature faster and this influences sugar content and acidity, emphasising the significance of considering height, prominence and orientation in ripening dynamics of the fruit. Different data unfolding strategies were compared, using ANOVA‐Simultaneous Component Analysis (ASCA) to reveal the significance of in‐tree position factors at different ripening stages, and observing high significance at harvest. This underscores the necessity for growers and handlers to consider these factors for reducing waste. NIR spectroscopy, with adequate data analysis, is a valuable tool for the holistic analysis of fruit ripening, providing crucial insights for maintaining optimal fruit organoleptic properties from harvest to consumer.

Dynamic histone modification signatures coordinate developmental programs in strawberry fruit ripening.

Chromatin structure plays a critical role in the regulation of dynamic gene expression in response to different developmental and environmental cues, but as yet their involvement in fruit ripening is not well understood. Here, we profile seven histone modifications in the woodland strawberry (Fragaria vesca) genome and analyze the histone modification signatures during ripening. Collectively, segments painted by the seven marks cover ~85% of the woodland strawberry genome. We report an eight-state chromatin structure model of the woodland strawberry based on the above histone marks, which reveals a diverse chromatin environment closely associated with transcriptional apparatus. Upon this model we build a chromatin-centric annotation to the strawberry genome. Expression of many genes essential for fruit ripening, such as abscisic acid catabolism, anthocyanin accumulation and fruit softening, are associated with shifts of active genic states and polycomb-associated chromatin states. Particularly, the expression levels of ripening-related genes are well correlated with histone acetylation, indicating a regulatory role of histone acetylation in strawberry ripening. Our identification of the chromatin states underpinning genome expression during fruit ripening not only elucidates the coordination of different pathways of morphological and metabolic development but also provides a framework to understand the signals that regulate fruit ripening.

Rapid in situ formation of κ-carrageenan-carboxymethyl chitosan-kaolin clay hydrogel films enriched with arbutin for enhanced preservation of cherry tomatoes

Food waste resulting from perishable fruits and vegetables, coupled with the utilization of non-renewable petroleum-based packaging materials, presents pressing challenges demanding resolution. This study addresses these critical issues through the innovative development of a biodegradable functional plastic wrap. Specifically, the proposed solution involves the creation of a κ-carrageenan/carboxymethyl chitosan/arbutin/kaolin clay composite film. This film, capable of rapid in-situ formation on the surfaces of perishable fruits, adeptly conforms to their distinct shapes. The incorporation of kaolin clay in the composite film plays a pivotal role in mitigating water vapor and oxygen permeability, concurrently bolstering water resistance. Accordingly, tensile strength of the composite film experiences a remarkable enhancement, escalating from 20.60 MPa to 34.71 MPa with the incorporation of kaolin clay. The composite film proves its efficacy by preserving cherry tomatoes for an extended period of 9 days at 28 °C through the deliberate delay of fruit ripening, respiration, dehydration and microbial invasion. Crucially, the economic viability of the raw materials utilized in the film, coupled with the expeditious and straightforward preparation method, underscores the practicality of this innovative approach. This study thus introduces an easy and sustainable method for preserving perishable fruits, offering a cost-effective and efficient alternative to petroleum-based packaging materials.

Dynamic changes of endogenous H2S generation during responding to developmental and environmental signals in Solanum lycopersicum L.

Increasing studies have confirmed the functions of hydrogen sulfide (H2S) as a gas signal molecule (gasotransmitter) in a variety of physiological activities in plants. However, the dynamic changes of endogenous H2S generation, especially the response speed and degree of H2S-generation-associated members, to both developmental and environmental cues in Solanum lycopersicum L. are still poorly understood. Here, we identified and charactered the H2S-generation-associated enzymes in tomato, including O-acetylserine (mercaptan) lyases (OAS-TL), L/D-Cysteine desulfhydrases (L/D-CDes) and nitrogen fixation S (NIFS)-like enzymes, possessing LCD-like activity. Analysis of cis-regulatory elements (CREs) showed that the promoter regions of these H2S-generation-associated genes contained lots of light-, hormone- and stresses-responsive CREs, and transcriptional factors (TFs) binding sites, suggesting that the regulatory mechanism of endogenous H2S generation might involve TFs mediated transcriptional regulation or/and interacting with phytohormones signals. Levels of endogenous H2S exhibited diversity in different organs and developmental stages in tomato, and the top and second highest level of H2S in flowers and ripened fruits hinted the significance of H2S signal in tomato reproduction and fruit development. Furthermore, the expression of SlOAS4, SlLCD, SlDCD2, SlNFS1, and SlNFS2 enhanced continuously during fruit ripening, and the SlOAS4 expression exhibited the most significant up-regulation. The SlDCD enzymatic activity responded more quickly to fruit development cues, while the SlLCD remained at a higher level almost throughout the whole fruit ripening. During environmental stimulus, it was found that the transcriptions of SlDCD2 and SlOAS2 responded faster and stronger to heat stress, while SlOAS4 and SlLCD were activated more quickly and significantly by drought stress. Both SlLCD and SlDCD enzymatic activities could be enhanced by drought and heat stress to varying degrees, and it seemed that the SlLCD was activated to a greater extent and remained at the higher activity for a longer period. With the extension of exogenous phytohormones (ABA, SA, GA, JA, ACC, NAA) treatment, the SlLCD activity and the endogenous H2S content increased in a specific time-dependent manner, and ABA, SA and NAA had more rapid effects on SlLCD activity. By widely explored the dynamic responses of endogenous H2S generation, our study would provide some references for understanding the regulatory mechanism upstream of H2S signaling in tomato growth developments and environmental adaptations.