Search Results (434)

Lignin deposition in fruit trees represents a fundamental physiological trade-off: essential for structural integrity and stress adaptation, yet excessive or mistimed activation compromises fruit texture, palatability, and market value. This review synthesizes advances in lignin biosynthesis and its multilayered regulation in commercial fruit species. We describe how abiotic (drought, salinity, temperature extremes) and biotic (pathogens, pests) stresses trigger lignification through transcriptional, post-transcriptional, hormonal, and epigenetic mechanisms, centered on the conserved NAC-MYB cascade. This core module integrates WRKY/ERF transcription factors (TFs), microRNA networks, and hormone signaling. Transcriptional programs are further refined by microRNAs, alternative splicing, DNA methylation, histone acetylation, and phytohormone crosstalk (abscisic acid, ABA; jasmonic acid, JA; salicylic acid, SA; and brassinosteroids, BRs). We emphasize molecular crosstalk integrating abiotic and biotic stress signaling via shared TFs, reactive oxygen species (ROS), and epigenetic memory. We critically examine lignification’s dual nature during development and postharvest storage, contributing to desirable traits (stone formation and skin toughness) but also driving defects (stone cell gritty texture and chilling-induced wooliness). Finally, we propose a strategic framework leveraging molecular breeding, targeted gene editing, and precision horticulture to fine-tune lignification, enabling climate-resilient cultivars without compromising fruit quality. Full article

To clarify the photoacclimation and stress-resistance coupling strategies of maize (Zea mays L.) variety B73 under Ostrinia furnacalis (Guenée) herbivory, we compared herbivory with mechanical damage and exogenous salicylic acid (SA)/methyl jasmonate (MeJA) treatments, focusing on the relationship between photosynthesis and defense. Results showed that O. furnacalis herbivory significantly reduced chlorophyll fluorescence and gas-exchange parameters, impairing light energy capture and conversion, and induced a progressive shift in photosynthetic performance associated with dynamic changes in carbon acquisition and utilization. Although herbivory and MeJA elicitation induced similar phenotypic changes after 12 h, herbivory caused much stronger global downregulation of photosynthesis-related genes than mechanical damage and hormone treatments. All stress treatments increased total antioxidant capacity (T-AOC) and reactive oxygen species (ROS, H₂O₂ and O₂·⁻) levels; notably, soluble protein (SP) explained 30.09% of the variance in the trade-off between photosynthetic pigment degradation and stress tolerance. Network modeling of photosynthetic genes, chlorophyll fluorescence parameters, gas-exchange parameters, and resistance-defense traits demonstrated robust modular connectivity, identifying chlorophyll fluorescence and gas-exchange parameters as core modulators of the resistance-defense trade-off. Collectively, maize adapts to external stress by balancing photosynthetic downregulation and defense enhancement through coordinated regulation of photosynthetic performance, antioxidant capacity, and core photosynthetic gene expression. These findings provide new insights into the mechanisms underlying plant stress tolerance. Full article

Astragalus membranaceus is an important medicinal plant with considerable pharmacological and economic value; however, its growth and productivity are frequently threatened by drought stress. Basic leucine zipper (bZIP) transcription factors play crucial roles in plant growth, development, and abiotic stress responses, yet a comprehensive investigation of the bZIP gene family in A. membranaceus remains unavailable. In this study, 74 bZIP genes (AmbZIPs) were identified in the A. membranaceus genome and classified into 12 subfamilies based on phylogenetic relationships with Arabidopsis thaliana. Analyses of gene structure, conserved motifs, chromosomal distribution, and duplication events revealed high conservation within subfamilies and indicated that segmental duplication was the major driver of AmbZIP family expansion. Codon usage analysis showed that AmbZIP genes exhibited relatively weak codon usage bias, with codon preference predominantly shaped by natural selection rather than mutation pressure. A total of 23 optimal codons were identified, of which 91.3% were A/T-ending codons. Codon adaptability analysis further demonstrated that tobacco possessed the highest codon compatibility among five tested hosts, whereas Escherichia coli exhibited the lowest adaptability, suggesting that plant expression systems may be more suitable for functional studies of AmbZIP genes. Promoter analysis identified numerous cis-acting elements associated with phytohormone signaling and abiotic stress responses, particularly those related to abscisic acid, methyl jasmonate, salicylic acid, and drought responsiveness. Transcriptome analysis and quantitative real-time polymerase chain reaction (qRT-PCR) validation revealed that several AmbZIP genes were significantly induced under drought stress. Among them, AmbZIP46 displayed strong drought-responsive expression, transcriptional activation activity, and exclusive nuclear localization. These findings provide the first comprehensive characterization of the bZIP gene family in A. membranaceus and establish a valuable foundation for elucidating drought-tolerance mechanisms and facilitating molecular breeding in this medicinal plant. Full article

The Cysteine-rich Polycomb-like Protein (CPP) gene family is a class of transcription factors containing conserved CXC domains that are widely involved in the regulation of plant growth and development, cell division, and stress responses. Based on the ginseng genome and transcriptome database, all members of the PgCPP gene family in Panax ginseng were systematically identified, and comprehensive bioinformatics analyses, including phylogenetic, conserved domain, chromosomal localization and collinearity, cis-acting element, and expression pattern analyses, were conducted. In this study, we identified 44 PgCPP gene family members in ginseng, which were unevenly localized on multiple chromosomes. The phylogenetic tree divided them into three subfamilies, with members in the same subfamily being highly conserved. Conserved domain analysis revealed that all PgCPPs contain typical CXC motifs. Cis-acting elements were abundant in light response, hormone responses (abscisic acid, methyl jasmonate, salicylic acid), and stress response elements. Expression heatmaps demonstrated that different members have specific expression patterns across different ages, tissues, and species. After treatment with MeJA, transcriptional suppression of PgCPP03-4 and PgCPP03-13 was observed, and their expression levels demonstrated significant negative correlations with the contents of six protopanaxadiol-type ginsenosides. These findings suggest that PgCPP03-4 and PgCPP03-13 may act as negative regulators of protopanaxadiol-type ginsenoside biosynthesis within the MeJA signaling pathway. This systematic characterization and identification of the CPP gene family members in P. ginseng establishes a foundational framework for future functional validation and molecular breeding initiatives. Full article

Black tea quality is governed by aroma chemistry: terpene alcohols (linalool, geraniol, nerolidol), methyl salicylate, and short-chain aldehydes whose abundance and release kinetics from the polyphenol-rich leaf matrix shape perceived grade. Grade information lies not only in the average headspace concentration but in the temporal shape of volatile organic compound (VOC) release under controlled heating. Conventional electronic noses obscure this signal: they rely on multi-sensor arrays, compress each response into summary statistics, and report accuracy only at the level of individual measurements. Whether a single low-cost metal–oxide–semiconductor (MOS) gas sensor can recover grade-defining aroma chemistry, and whether waveform-level modeling can exploit it, was therefore investigated. A portable electronic nose built around a Bosch BME688 sensor recorded 90 time series, each comprising four directly measured channels (temperature, humidity, pressure, gas sensor resistance) and a derived indoor-air-quality (IAQ) proxy computed from them by the on-chip BSEC library, from 16 commercial Turkish black teas across three quality grades. Two representations were compared on the same data: a feature-based pipeline reducing 25 statistical descriptors to seven principal components for six classifiers (best F1-macro = 0.624, MLP), and a raw-waveform Multi-Scale 1D-CNN with Squeeze–Excitation and temporal self-attention (MS-CNN-Attention). Under product-grouped cross-validation, the deep model reached F1-macro = 0.811 (+30%) and graded 14 of 16 products correctly by majority vote, against 11 of 16 for the MLP, with the largest gain in the medium grade (F1: 0.52 → 0.79), where summary-statistic compression destroys the release-kinetic signal. The contributions are threefold: one programmable MOS sensor operated as a thermal-desorption profiler rather than a sensor array; a direct comparison of feature-based classical learning against raw-waveform deep learning on the same small, non-normally distributed dataset; and a product-level decision-consistency metric suited to batch screening. Pairing a low-cost MOS sensor with waveform-level modeling offers a rapid, non-destructive route to aroma-chemistry-based tea quality screening. Full article

This study investigated the influences of geographical origin, harvest season, and plucking position on the chemical composition and flavor characteristics of Hainan Dayezhong black tea. Systematic analysis of basic components, volatile profiles and metabolomes of tea samples collected under different pre-harvest conditions revealed significant variations in polyphenols, flavonoids and catechins, as well as distinct differences in volatile composition. Key aroma-active compounds identified were nerolidol, linalool, benzaldehyde, benzeneacetaldehyde and methyl salicylate, which were determined to be decisive for the characteristic aroma profile of Dayezhong black tea. Untargeted metabolomics further demonstrated that these factors do not merely alter individual metabolite levels, but also reprogram energy metabolism, carbon–nitrogen allocation, and secondary metabolic pathways, resulting in distinct metabolic signatures among samples. From a systematic chemical perspective, this study elucidates the metabolic basis of Hainan Dayezhong black tea quality formation and establishes a scientific foundation for targeted quality optimization through regulation of key components. Full article

Cold stress is a major environmental constraint limiting the growth, physiological performance, and productivity of African marigold (Tagetes erecta L.) under open-field conditions. This study evaluated the comparative effectiveness of salicylic acid (SA), silicon (Si), and methyl jasmonate (MeJA) in alleviating cold-induced damage and enhancing stress tolerance. Field experiments were conducted under naturally occurring cold stress using foliar applications of SA (0, 0.1, 0.5, and 1 mM), Si (0, 1, 5, and 10 mM), and MeJA (0, 10, and 50 µM) in a complete randomized block design with three replications. Moderate concentrations of all three regulators significantly (p < 0.05) improved plant growth and physiological stability relative to untreated controls. Salicylic acid at 0.5 mM produced the most consistent protective response, increasing biomass accumulation, chlorophyll content, and relative water content while reducing membrane damage, as indicated by a 42.3% decrease in leaf electrolyte leakage at 2 °C. Silicon at 10 mM enhanced membrane integrity, plant water status, and vegetative growth under low-temperature conditions, while methyl jasmonate at 10 µM mitigated cold-induced membrane damage and improved physiological tolerance, whereas higher concentrations (50 µM) were less effective. At their optimal doses, SA, Si, and MeJA increased plant dry mass by 39.7%, 30.1%, and 38.5%, respectively. Correlation analysis confirmed these results, revealing strong positive relationships among growth, chlorophyll, and relative water content. Conversely, electrolyte leakage was negatively correlated with biomass and water status, identifying membrane stability as a key determinant of cold tolerance. Overall, 0.5 mM SA, 5–10 mM Si, and 10 μM MeJA improved growth and key physiological responses in African marigold under cold stress under field conditions. Future studies should integrate mechanistic and economic analyses to refine growth-regulator-based cold-stress management strategies. Full article

Background: Grapevine leafroll-associated virus 3 (GLRaV-3) is a severe phloem-limited grapevine virus, meaning it is restricted to sugar-transporting vascular tissue, which helps explain its strong effects on leaf physiology and carbon transport. However, its impact on leaf oxidative status, phenolic composition, and volatile organic compounds (VOCs) remains insufficiently characterized. Methods: Virus-free and GLRaV-3-infected grapevine leaves were analyzed for photosynthetic pigments, oxidative stress markers, phenolic compounds, and VOCs using spectrophotometric assays, HPLC-DAD/FLD, and SPME-Arrow-GC/MS. Data were evaluated using one-way ANOVA, multiple testing correction, principal component analysis (PCA), and exploratory partial least squares-discriminant analysis (PLS-DA). Results: GLRaV-3-infected leaves showed lower chlorophyll a (576.75 vs. 657.85 mg 100 g⁻¹ DW), chlorophyll b (282.96 vs. 314.05 mg 100 g⁻¹ DW), and total carotenoids (125.89 vs. 154.65 mg 100 g⁻¹ DW), but higher malondialdehyde (11.91 vs. 8.73 nmol g⁻¹ DW), H₂O₂ (0.36 vs. 0.25 μmol g⁻¹ DW), and proline (8.83 vs. 7.98 μmol g⁻¹ DW). Phenolic profiling showed increased levels of several flavonols and hydroxycinnamic acids, including kaempferol-3-O-glucuronide (2.81-fold), myricetin-3-O-glucoside (1.75-fold), quercetin-3-O-glucuronide (1.48-fold), and caffeic acid (1.30-fold). VOC profiling revealed higher relative abundances of several green leaf volatile-related compounds and methyl salicylate, including 1-methoxy-2-propanol (1.85-fold), 1-penten-3-ol (1.58-fold), hexanal (1.42-fold), and methyl salicylate (1.37-fold). PCA summarized treatment-related differences, with the first two components explaining 63.73% of phenolic and 74.09% of VOC variability, while exploratory PLS-DA/VIP analysis further supported the identification of treatment-associated discriminant metabolic features. Conclusions: GLRaV-3 infection is associated with reduced pigment content, increased oxidative stress markers, and coordinated changes in phenolic and VOC profiles. These metabolite changes provide insight into grapevine responses to viral infection and highlight GLRaV-3-associated metabolic features for future targeted studies of grapevine leafroll disease. Full article

Scenting time is a critical parameter that not only shapes the aromatic characteristics of jasmine tea but also influences its processing strategies. This study aims to elucidate how scenting time influences the aroma quality of jasmine yellow tea (JYT) through the integration of sensory evaluation with volatile compound profiling and the use of multivariate analyses, including principal component analysis (PCA) and orthogonal partial least squares–discriminant analysis (OPLS-DA), alongside complementary analytical approaches. Results demonstrated that the optimal sensory aroma quality of JYT was achieved when the scenting duration ranged from 8 to 12 h. Three hundred volatile compounds were detected, fourteen of which were identified as key contributors to JYT’s distinctive aroma profile. These include indole, methyl anthranilate, methyl salicylate, and δ-Cadinene, all of which exerted a significant influence on the overall aroma quality score. The identification of these principal volatile components provides valuable insights for optimizing JYT manufacturing processes and offers a theoretical basis for establishing systematic aroma quality assessment protocols. Full article

Topical analgesics are increasingly recognised as an essential part of treatment for painful musculoskeletal conditions, valued for their localised effectiveness and safer profile compared to systemic options. Recent evidence suggests that the effects of topical analgesics go beyond simply alleviating pain from sports injuries; they also enhance sports performance immediately after application. We conducted a local survey of 141 adults engaging in exercise to gain insight into the use patterns and perceptions of topical analgesics; 102 reported using over-the-counter topical analgesics. Fisher–Freeman–Halton analyses confirmed that usage habits were similar between younger (21–30 years) and older (≥31 years) age groups, as well as between those exercising more frequently (≥3 times per week) and less frequently (once or twice per week). Participants typically employed topical analgesics to alleviate muscle aches, pain, or soreness (n = 92, 90.2%), relieve joint pain or discomfort (n = 57, 55.9%), and/or reduce muscle stiffness (n = 39, 38.2%). Most applied them at home as needed (n = 71, 69.6%), with some participants using them after exercise (n = 60, 58.8%). Regarding the frequency of topical analgesic use, most participants used analgesics fewer than five times a year (n = 54, 52.9%). Over half of the participants viewed topical analgesics as effective or very effective. To conclude, our survey revealed that adults engaging in exercise commonly used topical analgesics to relieve musculoskeletal pain or discomfort as needed. Full article

Phenolic compounds are vital bioactive constituents in fruits, yet modern strawberry breeding has often reduced their diversity. Here, we employed a multi-omics approach integrating UPLC-MS/MS-based metabolomics and RNA-seq transcriptomics to investigate the divergence in phenolic profiles and their transcriptional regulation between a wild strawberry (Fragaria nilgerrensis, HM) and three cultivated varieties (white ‘Danxue’ (DX), pink ‘Fenyu’ (FY), and red ‘Red Face 99’ (RF)). The wild HM genotype exhibited higher antioxidant activity and a significantly more complex phenolic profile, dominated by high-abundance galloylated and benzoylated glucosides (e.g., digallic acid methyl ester, salicylic acid-2-O-glucoside) that were largely absent or depleted in cultivated fruits. In contrast, the cultivated varieties displayed specialized yet simplified profiles: DX accumulated hydroxycinnamoyl galactonic acids, FY was enriched in feruloylated glucosides, and RF was characterized by coumaroyl-glucose derivatives. Transcriptomic analysis identified a set of MYB transcription factors (e.g., FxaYL_531g0581170, FxaYL_642g0175720) significantly upregulated in wild HM, with strong correlations to key bioactive phenolics such as 4-hydroxybenzoate and salicylic acid derivatives. These findings illustrate how selective breeding has reshaped phenolic composition through alterations in MYB regulatory networks. The wild strawberry germplasm thus represents a valuable natural reservoir for biofortification strategies aimed at restoring the nutritional and functional quality of modern strawberry cultivars. Full article

Jacalin-related lectins play crucial roles in plant adaptation to abiotic and biotic stresses. The rice genome encodes four putative jacalin-related lectin kinase genes (OsJacLKs), but their functions toward environmental stresses remain largely uncharacterized. This study demonstrates that a putative jacalin-related lectin kinase, OsJacLK1, conferred resistance to the rice blast fungus Magnaporthe oryzae rather than salt stress. OsJacLK1 protein exhibited agglutination activities and affinity toward chitin, fungal cell wall, and mannose. OsJacLK1 was transcriptionally activated by stress-related phytohormones salicylic acid (SA), methyl jasmonate (MeJA), abscisic acid (ABA), and indoleacetic acid (IAA), as well as salinity, chitin, and M. oryzae inoculation, suggesting its involvement in broad stress-responsive signaling pathways. Overexpression of OsJacLK1 in rice led to reduced susceptibility to rice blast disease, whereas loss-of-function osjaclk1 lines showed no significant phenotypic difference from wild-type plants upon infection. Enhanced resistance in OsJacLK1-overexpressing lines was associated with a stronger reactive oxygen species (ROS) burst and elevated hydrogen peroxide accumulation, accompanied by the up-regulation of defense-related genes (OsRac1, OsSGT1, OsMAPK6, OsPAL1, OsNAC4, OsPBZ1, OsAOS2, and OsJAZ8). Collectively, our findings establish that OsJacLK1 acts as a positive regulator of rice immunity against M. oryzae, modulating the cellular redox state, highlighting its potential as a candidate for genetic improvement of disease resistance in rice. Full article

Four sweet cherry cultivars (FuChen, Redlight, Huangmi, and Samituo) grown in northern China were used to produce sweet cherry wines with two alcohol levels. Physicochemical properties, antioxidant capacity, and volatile aroma compounds of the wines were systematically investigated. The results showed that wine from the Redlight cultivar with an alcohol content of 11.22 ± 0.17% contained the highest phenolic content and also exhibited the strongest antioxidant capacity as measured by DPPH and ABTS•⁺ assays. Meanwhile, wine from the FuChen cultivar with an alcohol content of 11.45 ± 0.03% had the highest anthocyanin content and showed the strongest FRAP antioxidant activity. Orthogonal partial least squares discriminant analysis (OPLS-DA) based on electronic nose data clearly distinguished the eight sweet cherry wine samples from different cultivars. A total of 58 volatile compounds were identified by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME-GC-MS). Both principal component analysis (PCA) and OPLS-DA revealed clear differences among the sweet cherry wines based on their volatile composition. Using variable importance in projection (VIP) scores > 1 and relative odor activity values (ROAVs), the key aroma compounds contributing to the characteristic aroma profiles of the eight sweet cherry wines were identified as ethyl butanoate, isoamyl acetate, isoamyl hexanoate, methyl decanoate, ethyl decanoate, ethyl benzoate, methyl salicylate, citronellol, and eugenol. These findings provide important guidance for the selection of raw materials to improve the production of sweet cherry wines with targeted alcohol levels. Full article

Plant volatiles are critical mediators of insect–plant interactions, guiding natural enemies to specific habitats and prey. The flower bug, Orius maxidentex Ghauri (Hemiptera: Anthocoridae), is a generalist predator that exhibits a specialized ecological association with the weed Celosia argentea L. (Caryophyllales: Amaranthaceae), utilizing the plant as a primary floral niche in Hainan Island. In this study, the attractiveness of C. argentea floral volatiles to O. maxidentex was confirmed using a Y-tube olfactometer. Solid-phase microextraction (SPME) combined with gas chromatography–mass spectrometry (GC-MS) was utilized to identify six compounds in the floral volatiles: 1,3-diethenylbenzene, trans-cinnamaldehyde, β-bisabolene, methyl salicylate, 3-ethylbenzaldehyde, and nonanal. Electroantennogram (EAG) assays revealed that O. maxidentex antennae showed significant physiological responses to these compounds, and the EAG relative values were positively correlated with concentration gradients. Furthermore, O. maxidentex exhibited significant orientation responses to 1,3-diethenylbenzene, trans-cinnamaldehyde, β-bisabolene, and methyl salicylate, whereas no behavioral response was observed for 3-ethylbenzaldehyde or nonanal. Further tests revealed that β-bisabolene elicited the highest attractiveness, comparable to a synthetic blend formulated to mimic the natural release ratio of the active semiochemicals. These findings reveal the hidden chemical cues mediating the interaction between a predator and its preferred habitat. Understanding this mechanism not only helps explain insect adaptation but also offers new strategies for using these plant volatiles to influence the behavior of this specific predator, potentially enhancing its targeted recruitment in agroecosystems. Full article

Acibenzolar-S-methyl (ASM), a salicylic acid (SA) analog, and jasmonic acid (JA) are chemical inducers of plant defenses, yet crosstalk between SA- and JA-associated pathways may result in antagonistic outcomes. Here, we assessed how ASM and JA, applied alone or in combination, are associated with rice blast severity and defense-related responses in an upland rice cultivar. Plants of rice (Oryza sativa L., cv. Primavera) were treated with JA, ASM or JA + ASM and subsequently challenged with Magnaporthe oryzae. ASM treatment was associated with reduced leaf blast severity (LBS), whereas JA treatment was associated with increased LBS. Antagonistic outcomes were observed in the combined treatment: LBS in JA + ASM plants was higher than in ASM-treated plants but lower than in JA-treated plants. Lipoxygenase (LOX) activity was induced by JA and positively correlated with LBS, indicating that higher LOX activity aligned with greater susceptibility under the tested conditions. In contrast, ASM-treated plants showed higher peroxidase (POX) activity, which was associated with lower LBS. Disease outcomes were also linked to secondary defense metabolism and phenylpropanoid-related components, including phenylalanine ammonia-lyase (PAL), salicylic acid (SA) and phenolic compounds (PC). Overall, these results provide an integrated biochemical profile of how ASM, JA and their combination are associated with contrasting blast outcomes in upland rice, consistent with antagonistic interactions between JA- and SA-associated defense responses. These findings may inform the use of defense inducers and the interpretation of defense markers in upland rice systems where blast management is a major constraint. Full article