Search Results (348)

The efficient utilization of light energy is a powerful guarantee to improve the production efficiency of agricultural and forestry facilities. This study investigated the effects of early-morning supplemental lighting on the yield and fruit quality of greenhouse-grown blueberry and examined the physiological and transcriptional responses associated with anthocyanin accumulation. The findings indicate that supplemental lighting significantly promoted fruit development, accelerated maturation, and increased fruit size, weight, sugar, vitamin C content and the antioxidant capacity of the fruits, especially the anthocyanin content. Transcriptomic analysis revealed that, during fruit ripening, the differentially up-regulated genes activated by supplemental lighting primarily involved transmembrane transport functions, membrane components, and redox enzyme activity. Conversely, the down-regulated genes were mainly involved in organic acid metabolism, photosynthesis and photosystem functions. Pathways associated with the up-regulated genes were largely connected to anthocyanin biosynthesis and galactose metabolism. Furthermore, the anthocyanin biosynthesis showed affiliations with several distinct genes (such as 4CL and UFGT) that were differentially up-regulated, along with the MYB transcription factor. Notably, in blueberries exposed to supplemental lighting, VcMYBPA1 showed a strong positive correlation with UFGT. Further investigations demonstrated that VcMYBPA1 was mainly localized in the nucleus, and its overexpression significantly increased the expression levels of AtDFR, AtANS, and AtUFGT in Arabidopsis. This study highlights the crucial role of supplemental lighting in enhancing blueberry yield and quality and provides an effective way to further improve the utilization of light-assisted agricultural technologies. Full article

Fruit ripening is accompanied by extensive reprogramming of secondary metabolism, which determines the antioxidant value of medicine-food homologous fruits. Ziziphus jujuba Mill. cv. ‘Junzao’ (Junzao) is a high-quality cultivar rich in bioactive compounds, yet its stage-dependent metabolite accumulation and the corresponding antioxidant capacity remain poorly resolved. In this study, widely targeted metabolomics was combined with the quantification of total phenolic (TPC), total flavonoid (TFC), and total triterpenoid (TTC) contents and with 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS) radical-scavenging assays to profile Junzao fruits at five developmental stages. A total of 2388 secondary metabolites were identified, with flavonoids and terpenoids representing the major classes. TPC and TFC were highest at the immature YG (young-fruit) stage, whereas TTC peaked at the BS (white-ripe) stage; all three decreased during subsequent ripening, consistent with the stronger DPPH and ABTS radical-scavenging activities observed in early-stage fruits. Multivariate analyses revealed distinct metabolic profiles among developmental stages, and 2111 differentially accumulated metabolites (DAMs) were identified. K-means clustering resolved nine temporal accumulation patterns, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment indicated dynamic regulation of flavonoid biosynthesis, phenylpropanoid metabolism, and triterpenoid-related pathways. Spearman correlation analyses further identified ten metabolites, comprising six flavonoids, three triterpenes, and one phenolic acid, that were strongly associated with antioxidant capacity (|r| ≥ 0.5, p < 0.05), highlighting their potential as biomarkers for quality evaluation. Overall, immature Junzao fruits exhibited superior antioxidant capacity, supporting their promise as functional-food ingredients and providing a basis for stage-specific harvesting and utilization. Full article

Tomato (Solanum lycopersicum L.) exhibits extensive cultivar diversity in fruit morphology, color, and bioactive compounds. These are closely associated with genetic background, ripening stage, and carotenoid metabolic regulation. Carotenoids, especially lycopene and β-carotene, are major determinants of tomato coloration and are also nutritionally and industrially important high-value-added antioxidants. Carotenoid profiles are regulated by changes in related biosynthetic pathways, including precursor supply, desaturation, isomerization, and cyclization. Key genes such as PSY1, CRTISO, LCY-B and LCY-E play central roles in carotenoid synthesis and accumulation, thereby determining color phenotypes. Mutations and genome-editing (CRISPR/Cas9) approaches can modify carotenoid metabolic flux and develop cultivars with improved nutritional traits. Furthermore, advanced and sustainable recovery strategies for carotenoids (ultrasound-, microwave-, enzyme-, high-pressure-, deep eutectic solvent-, and supercritical fluid-assisted extraction methods) have been developed for efficient pigment extraction. In this review, we compare the physiological and molecular characteristics of diverse cultivars and traits of advanced bioprocesses in terms of carotenoid extraction efficiency and solvent safety. Finally, we discuss various encapsulation techniques that improve product stability and storage performance in industrial applications. Taken together, we review practical strategies combining cultivar-based carotenoid production, sustainable recovery, and product stabilization. Full article

Fruit-specific promoters (FSPs) are a class of regulatory DNA sequences that direct transgene expression exclusively in fruit tissues or during specific stages of fruit development. They are indispensable molecular tools in modern agricultural biotechnology, with broad applications in fruit quality improvement, nutritional enhancement, and shelf-life extension. By functioning as precise molecular switches that regulate fruit-specific gene expression, FSPs overcome the limitations of constitutive promoters and facilitate precision molecular breeding for fruit quality improvement. This review systematically summarizes recent advances in FSP research. First, based on their spatiotemporal expression patterns, FSPs are classified into four categories: immature fruit-specific, fruit ripening-specific, whole fruit development stage-specific, and dual-stage (immature fruit/ripening) promoters. Their origins, expression characteristics, and key cis-regulatory elements are comprehensively summarized. Second, the complex transcriptional regulatory network governing FSP activity is discussed from the perspectives of cis-regulatory elements, major transcription factor families (such as MADS-box and NAC proteins), and epigenetic regulation, including DNA methylation and histone modifications. Furthermore, recent advances in key methodologies, including promoter cloning, functional characterization, and CRISPR/Cas9-mediated precise editing of cis-regulatory elements, are reviewed, together with their applications in crop genetic improvement, plant molecular farming, and fundamental molecular biology research. Finally, this review highlights the major challenges limiting the application of FSPs, including the relatively weak transcriptional activity of natural promoters, insufficient tissue specificity, and limited cross-species applicability. Future perspectives are discussed, emphasizing the integration of artificial intelligence-assisted promoter design, high-throughput screening, and single-cell omics technologies to develop finely tunable synthetic promoters. These advances are expected to provide both a theoretical foundation and technical support for precision molecular breeding in fruit crops. Full article

The lipoxygenase (LOX) pathway plays a crucial role in the biosynthesis of characteristic aroma compounds in fruit. Despite the progress in understanding the LOX pathway in model plants like tomato, the distinct roles of individual members within the LOX gene family in flavor formation in the complex octoploid strawberry are still not fully understood. In this study, we identified 13 LOX genes in the strawberry genome and focused on a specific lipoxygenase gene, designated FaLOX11, which exhibited the highest expression during fruit ripening. Spatiotemporal expression analysis revealed that FaLOX11 expression was significantly correlated with 3-hexenal accumulation, quantified via headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). Functional characterization via transient overexpression of FaLOX11 in strawberry fruits resulted in a significant increase in C6 volatile content, specifically a ~72% increase in 3-hexenal content. Conversely, RNA interference (RNAi)-mediated transient silencing of FaLOX11 significantly downregulated the expression of this gene and led to a marked reduction in the production of these key aroma compounds. Our findings demonstrate that FaLOX11 acts as a positive regulator of C6 aldehyde and alcohol biosynthesis, thereby playing a pivotal role in determining the characteristic aroma profile of strawberry fruit. This study provides new insights into the LOX pathway in strawberry and lays a solid molecular foundation for improving strawberry flavor quality. Full article

Abscisic acid (ABA) and ethylene are both essential regulators of strawberry fruit (Fragaria × ananassa Duch.) ripening. This study investigated the interplay between ABA and ethylene, revealing that ABA downregulates FaMADS1, thereby de-repressing ethylene biosynthesis genes. Functional validation via FaMADS1 silencing and over-expression confirmed that FaMADS1 acts as a negative regulator of ethylene biosynthesis key genes (FaSAMS1, FaACS1, and FaACO1). Furthermore, dual-luciferase assays demonstrated FaMADS1’s direct suppression of the promoters of key ethylene biosynthesis genes. Collectively, these results elucidated a novel mechanism wherein ABA and ethylene coordinate ripening via FaMADS1-mediated transcriptional repression. This ABA-FaMADS1-ethylene regulatory cascade provides a theoretical basis for targeted postharvest regulation of strawberry ripening, laying a foundation for developing low-cost, hormone-based preservation technologies and molecular breeding strategies to alleviate rapid quality deterioration and economic losses of harvested strawberry. Full article

Understanding the genetic basis of adaptation traits including chilling requirements, flowering and fruiting is essential for developing apricot cultivars adapted to changing climatic conditions and for extending the apricot production calendar. The objective of this study is to detect and finely identify marker−trait associations linked to these adaptation traits including chilling requirements in apricot, using an R-based workflow developed with agroclimatic functions. In this study, high-density GBS-based linkage maps previously developed for two biparental populations (‘Bergeron’ × ‘Currot’ and ‘Goldrich’ × ‘Currot’) were used to analyze the genetic basis of key adaptation traits, including chilling requirement (CR), blooming date (BD), fruit development period (FDP), and ripening time (RT), through Genome-Wide Association (GWAS) and Quantitative Trait Locus (QTL) analyses. Phenotypic evaluation over eight years revealed wide variability across genotypes and strong correlations between CR and BD, particularly when using Chill Portions as a metric. Genome-wide association and QTL mapping consistently identified major loci on linkage group (LG) 1 for BD and CR, and on LG4 for FDP and RT, explaining up to 59% of phenotypic variance. The candidate gene (qMD4.1 ANAC072), upon analysis, revealed the involvement of epigenetic regulators, cold-responsive proteins, and transcription factors, offering plausible functional links between genotype and phenotype. These findings provide novel insights into the genetic control of dormancy and phenological traits in apricot and represent a valuable genomic resource for marker-assisted breeding programs aimed at improving climatic resilience and extending the harvest. Full article

Fruit color is a key quality indicator for apples and directly influences their market value. The process of fruit ripening encompasses various physiological and biochemical changes, such as the breakdown of chlorophyll and the buildup of anthocyanins and carotenoids. This study investigated the mechanism of chlorophyll degradation in apple peels using ‘Granny Smith’ varieties. The experiments involving the treatment with methyl jasmonate (MeJA) indicated that a concentration of 10 µM MeJA led to a reduction in chlorophyll degradation, while a higher concentration of 1500 µM MeJA enhanced this degradation, which aligned with the variations observed in the expression of genes associated with chlorophyll degradation. The key chlorophyll degradation gene MdSGR1 was cloned and found to be induced by methyl jasmonate. MdSGR1 encodes a 283-amino-acid protein belonging to the stay-green superfamily. The promoter possesses inducible cis-acting elements that respond to methyl jasmonate, low temperature and light, while the protein is localized to chloroplasts. Overexpression and silencing vectors were constructed. Overexpression of MdSGR1 induced chlorosis in tobacco leaves and ‘Granny Smith’ apple peels, decreased chlorophyll content, and upregulated related gene expression. Conversely, silencing MdSGR1 produced opposite effects. Arabidopsis thaliana plants overexpressing MdSGR1 exhibited low chlorophyll content, reduced photosynthetic rate, upregulated expression of genes associated with chlorophyll degradation. The results of yeast one-hybrid and dual-luciferase reporter assays indicated that the MdMYC2 transcription factor interacts with the promoter region of MdSGR1. In conclusion, MdSGR1 is crucial for the degradation of chlorophyll in apple peel, and it is regulated both by the MdMYC2 transcription factor and different concentrations of MeJA. This study preliminarily elucidated the regulatory mechanism of methyl jasmonate on chlorophyll degradation in fruit peel, and these findings provide an important theoretical basis for controlling degreening and color quality in apple fruit. Full article

Selenium is an essential micronutrient for humans, underscoring its importance in enhancing the nutritional and physiological attributes of agricultural and horticultural crops through exogenous application. At low doses, selenium improves growth and development, and increases crop yield and quality, particularly under stress conditions. It is believed that abscisic acid and sucrose work together to regulate strawberry (Fragaria × ananassa Duch.) fruit ripening. This study aimed to provide comprehensive biochemical and molecular insights into the selenium mediated effects on ripening and quality changes in ‘Camarosa’ strawberry fruits. Selenium treatment increased chlorophyll levels in leaves, suggesting a positive impact on overall plant health. Foliar application of 1 mM selenium significantly accelerated ripening. Treated fruits exhibited higher levels of total soluble solids, along with a decrease in titratable acidity. About lipid peroxidation indices, foliar application of 1 mM selenium decreases hydrogen peroxide and malondialdehyde. Consistently, flavonoids, phenolic compounds, anthocyanins, ascorbic acid, and antioxidant capacity, as well as the activity of the enzymes SOD, CAT, APX and PAL, were increased by selenium treatment. Interestingly, the ABA content in strawberry fruits also increased with selenium treatment. The selenium treatment upregulated genes involved in abscisic acid biosynthesis, phenolic compound biosynthesis, and anthocyanin production, namely, FaNCED1, FaG2BD, FaCHS, FaPAL, and FaSUT1. This study highlights the potential of selenium as a biostimulant and quality-enhancing agent in strawberries, improving fruit biochemical composition and ripening dynamics while contributing to better nutritional value and market appeal. Full article

Background: Anthocyanin biosynthesis is tightly controlled by MYB transcription factors, yet the role of repressors, particularly those in the DIVARICATA-like (DIV) subfamily, remains poorly characterized. Methods: A genome-wide identification of MYB family members was performed in the mulberry (Morus atropurpurea) genome using a hidden Markov model and BLAST-based searches. Putative MYB genes were phylogenetically classified, and their expression profiles were analyzed across three fruit developmental stages. A DIV-like R2R3-MYB candidate, MaDIV, was functionally characterized via subcellular localization, quantitative real-time PCR, and heterologous overexpression in tobacco. Results: A total of 145 MaMYB genes were identified and classified into 31 distinct subfamilies. MaDIV expression showed a progressive decline during fruit ripening, which significantly correlated with increasing anthocyanin accumulation. Heterologous overexpression of MaDIV in tobacco led to a 42% reduction in floral anthocyanin content compared with wild-type plants. Concomitantly, the expression of the key anthocyanin biosynthetic gene NtDFR was strongly suppressed, whereas the flavonol synthase gene NtFLS1 was significantly upregulated. Conclusions: These findings point to a possible involvement of MaDIV in the regulation of anthocyanin biosynthesis and provide preliminary evidence for the functional diversification of the DIV-like MYB subfamily in plants. The results contribute to a better understanding of the transcriptional control of fruit pigmentation in mulberry and related species. Full article

Polygalacturonase (PG) is a key enzyme in cell wall metabolism and fruit ripening. Atemoya (Annona cherimola Mill. × A. squamosa L.) is a high-value tropical fruit that undergoes rapid postharvest softening at room temperature. However, the role of the atemoya PG gene family in this process remains unknown. This study determined that storing atemoya at 28 °C significantly reduced fruit firmness and the total pectin content but increased water-soluble pectin (WSP) and PG activity compared to storage at 15 °C. Genome-wide identification of the AaPG gene family in atemoya revealed that 40 AaPG genes were unevenly distributed across seven chromosomes. Nineteen genes were located within six tandem duplication clusters. AaPG proteins exhibited clade-specific differences: Clades B-E contained the polysaccharide lyase family 6 (PL-6) superfamily domain, while Clade A harbored the Aspergillus niger polygalacturonase 1 (Pgu1) domain and lacked several conserved motifs. Expression profiling and reverse transcription quantitative polymerase chain reaction (RT-qPCR) showed that AaPG19, AaPG21, AaPG23 and AaPG24 were specifically induced at 28 °C. Subcellular localization confirmed that these four proteins were located on the plasma membrane. These findings provide insights into the evolution and temperature-dependent regulation of the AaPG family, identifying candidate genes responsible for the rapid softening of atemoya fruit. Full article

RNA N⁶-methyladenosine (m⁶A) is a prevalent epitranscriptomic modification that governs plant growth, development, and environmental adaptation. This review synthesizes recent advances in understanding the molecular mechanisms and biological functions of m⁶A in plants. The m⁶A landscape is dynamically regulated by methyltransferases (writers), demethylases (erasers), and m⁶A-binding proteins (readers), which collectively influence mRNA stability, translation efficiency, alternative polyadenylation (APA), and chromatin crosstalk. Functionally, m⁶A integrates diverse developmental processes—including embryogenesis, organogenesis, flowering, fruit ripening, and leaf senescence—with abiotic stress responses such as salt, drought, cold, and heat. Notably, m⁶A modification exhibits remarkable species-, cultivar-, and tissue-specific plasticity, enabling precise spatiotemporal gene regulation. Recent breakthroughs have revealed bidirectional crosstalk between m⁶A and histone modifications, forming a multi-layered regulatory network, while emerging concepts including phase separation, RNA structure dynamics, and stress memory further expand the functional repertoire of m⁶A. Despite significant progress, plant epitranscriptomics remains mechanistically underexplored, with critical gaps persisting in our understanding of translation initiation mechanisms, upstream regulatory signals controlling writers/erasers activities, and the functional significance of individual m⁶A sites. This review provided systematic insights into the complexity and specificity of m⁶A regulation in plants, offering a theoretical foundation for future efforts to decipher and ultimately manipulate this epitranscriptional layer for crop improvement. Full article

Background/Objectives: At present, there are only a few studies on characteristic changes in polyphenols and cell wall polysaccharides and their correlations in Z. mioga flower buds during development. Methods: Polyphenols were analysed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Content and enzyme activities of cell wall components were examined using a microplate reader. Expression of genes related to these components was detected using de novo-Seq. Results: Most polyphenols accumulated significantly, with the highest levels being found in cyanidin-3-O-glucoside and epicatechin. PCA results show that changes in polyphenols were largely dependent on the germination and ripening stage, which might represent its specific period. Additionally, the increased flavonoid and anthocyanin fractions might be due to the up-regulated expression of DFR1/2, ANS and BZl. During development, PME, PG and β-galactosidase synergistically break down protopectin to soluble pectin; PME coordinates with cellulase in cellulose degradation, while xylanase dominates hemicellulose degradation. Lac collaborated with PME, PG and cellulase to regulate lignin synthesis. Key upregulated genes driving cell wall polysaccharide alterations include PME35, PG and GAUT7 for pectin metabolism, CESA2/3 for cellulose synthesis, and Lac25, POD6/7/47/52 and CCR6 for lignin synthesis. Correlation analysis revealed that the synergistic effects of p-coumaric acid, chlorogenic acid, epicatechin, cyanidin-3-O-glucoside, peonidin-3-O-glucoside, protopectin, pectin, lignin and cellulose might be responsible for the sensory quality formation in Z. mioga. Conclusions: This study further investigates the binding mode of polyphenols and cell wall polysaccharides, providing a theoretical basis for understanding the development of sensory qualities in Z. mioga flower buds during growth and maturation. Full article

Fruit softening, an irreversible ripening process that causes postharvest losses, is mainly attributed to cell wall disassembly, rendering cell-wall-modifying genes critical targets for genetic improvement. However, the molecular mechanism by which expansins loosen the cell wall via the nonenzymatic mechanism, thereby affecting fruit softening, remains largely unknown. In this study, HSM (melting peach, MF) fruits exhibited a rapid decline in firmness, accompanied by more extensive cell wall disassembly and larger intercellular spaces compared with CN14 (non-melting peach, NMF) during the fruit development process. The expression of PpEXPA13, an expansin gene, was significantly higher in HSM than in CN14 during fruit softening. Virus-induced gene silencing in peach delayed firmness loss, while the overexpression of PpEXPA13 in tomato accelerated it. PpEXPA13-OE fruits displayed enlarged intercellular spaces and upregulated expression of multiple cell-wall-modifying genes. Furthermore, a yeast one-hybrid assay identified the transcription factor PpMYC2 as an upstream regulator of PpEXPA13. PpMYC2 specifically binds to the MYC box (CACGTG) in the PpEXPA13 promoter. These findings reveal that PpMYC2 activates PpEXPA13 expression, which might lead to cell wall disassembly and promote peach fruit softening. Full article

Low-light (LL) stress is a major abiotic limiting factor in protected cherry tomato production, adversely affecting vegetative growth, inducing oxidative damage, and disrupting fruit sugar metabolism. To clarify the regulatory role of exogenous abscisic acid (ABA) in mitigating LL stress, we examined the effects of varying ABA concentrations on plant growth, antioxidant capacity, and fruit sugar metabolism in cherry tomatoes under low-light conditions. A two-factor randomized complete block design, with two light regimes—normal light (NL, 100% natural sunlight) and low light (LL, 25% natural sunlight)—and three ABA concentrations (CK: 0 mg·L⁻¹, T1: 10 mg·L⁻¹, T2: 20 mg·L⁻¹). Fruits were sampled at three typical ripening stages (green mature, breaker, and red ripe) to evaluate vegetative and reproductive physiological responses. The results showed that exogenous ABA application effectively suppressed LL-induced excessive stem elongation and alleviated LL-caused reductions in stem diameter and biomass accumulation. ABA treatment significantly increased peroxidase (POD) activity and reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) accumulation, thereby relieving LL-triggered oxidative damage. In addition, ABA regulated key sugar-metabolizing enzymes (soluble acid invertase (SAI), sucrose synthase (SS), sucrose phosphate synthase (SPS), and amylase (Amy)) and the transcript levels of related functional genes (HXK1, SPS, SS, AI), thereby mediating stage-dependent fruit sugar metabolism under LL stress. In conclusion, exogenous ABA effectively modulates vegetative growth, antioxidant homeostasis, and stage-specific fruit sugar metabolism, ultimately alleviating low-light stress damage in cherry tomato. Among the tested treatments, 20 mg·L⁻¹ ABA exhibited the most pronounced mitigation effects, which can be recommended as an optimal foliar application concentration for cherry tomato cultivation in low-light protected facilities. Full article