To investigate the effects of straight-line-shape (SL) and inverted-umbrella-shape (IU) training systems on sugar accumulation and metabolism in ‘Kyoho’ grape berries in Fujian, this study used 16-year-old ‘Kyoho’ grapevines trained in the two systems. Fruit samples were collected from 45 to 95 days after flowering (DAF) to measure soluble sugar content. Transcriptome sequencing was performed to analyze the differential expression of sugar metabolism-related genes, combined with KEGG enrichment analysis and RT-qPCR validation of key genes. The results showed that, at the same stage, the soluble sugar content in berries under the SL training system was significantly higher than that under the IU training system, especially from 45 to 65 DAF, where sugar accumulation was faster. Transcriptome analysis revealed that the SL training system showed 6274, 5597, and 2064 differentially expressed genes at 45, 65, and 95 DAF, respectively. Key sugar metabolism-related genes, such as fructokinase (FK), phosphofructokinase (PFK), and sucrose phosphate synthase (SPS), exhibited significantly higher expression levels in the SL training system than in the IU training system. KEGG enrichment analysis indicated that the SL training system significantly enriched sugar metabolism and transport pathways during the early fruit ripening stage. RT-qPCR validation confirmed that genes related to sugar metabolism and transport (such as FK7, SUS3, SPP1) were expressed at significantly higher levels in the SL training system than in the IU training system. In conclusion, the SL training system significantly promoted soluble sugar accumulation and accelerated fruit ripening in ‘Kyoho’ grapes by regulating the expression of sugar metabolism and transport-related genes, providing a theoretical basis for promoting the SL training system in production.

MeJA (Methyl jasmonate) acts as a crucial regulatory phytohormone that mediates plant responses to biotic and abiotic stresses. Nevertheless, systematic studies on the effects and underlying regulatory mechanisms of MeJA on the postharvest quality of table grapes during low-temperature storage remain limited. In this study, physiological measurements combined with transcriptomic data demonstrated that MeJA treatment effectively maintained the postharvest quality of ‘Kyoho’ grapes under low-temperature storage. Physiological results showed that MeJA significantly enhanced the activities of antioxidant enzymes, inhibited the activities of cell wall softening-related enzymes PG and PE, promoted lignin accumulation, and delayed cellulose degradation. Furthermore, transcriptomic analysis verified that MeJA markedly upregulated the expression of genes associated with lignin biosynthesis. Collectively, MeJA maintains the postharvest quality of ‘Kyoho’ grapes during low-temperature storage by modulating antioxidant metabolism and cell wall metabolism, exhibiting great potential as an effective postharvest regulatory technique.

Grapes are among the most widely cultivated fruit crops globally, yet their growth and yield are severely compromised by Colletotrichum viniferum, which causes a devastating disease that affects grape berries. The wall-associated kinase (WAK) gene family, a unique subfamily of receptor-like-kinases (RLKs), plays important roles in mediating plant responses to both abiotic and biotic stresses. However, the expression patterns and biological functions of grape WAKs in response to C. viniferum infection remain largely uncharacterized. In this study, a total of 57 VdWAK genes were identified and phylogenetically classified into twelve subgroups. Chromosomal localization and collinearity analyses further revealed that tandem duplication and segmental duplication events contributed to the expansion of the VdWAK gene family. Transcriptomic profiling identified VdWAK19 as a key responsive gene. It was predominantly expressed in mature berries but transcriptionally repressed upon C. viniferum infection. Virus-induced gene silencing assays in grape berries demonstrated that knockdown of VdWAK19 significantly reduced fruit resistance to C. viniferum infection. Overall, these findings advance our understanding of the functional roles of VdWAK genes during C. viniferum infection and provide a theoretical basis for the potential application of VdWAK19 in breeding grape varieties with enhanced resistance to ripe rot.

Cadmium (Cd), a highly toxic and mobile heavy metal, has emerged as a severe environmental concern in global agroecosystems, posing a substantial threat to human health. Although prior studies have established that ZAT6 and ZAT10 positively regulate Arabidopsis tolerance to Cd toxicity, the underlying molecular mechanisms remain largely elusive. The present study provides evidence that a class I TCP transcription factor, TCP9, significantly enhances Arabidopsis tolerance to Cd toxicity through the direct activation of ZAT6 and ZAT10 expression. The real-time quantitative PCR (RT-qPCR) analysis indicates that the expression of TCP9 was induced under Cd toxicity. Meanwhile, the tcp9 mutant exhibited heightened sensitivity to Cd toxicity, accompanied by elevated Cd accumulation in both shoots and roots. Notably, the complemented lines exhibited phenotypic characteristics analogous to those observed in the wild-type (WT) plants. Further physiological and biochemical analyses revealed that, in comparison to WT, the tcp9 mutant displayed elevated hydrogen peroxide (H₂O₂) accumulation and reduced contents of catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) under Cd toxicity. Furthermore, TCP9 directly interacted with the promoters of ZAT6 and ZAT10 in vitro, facilitating their transcription and consequently enhancing plant tolerance to Cd toxicity. Overall, our findings showed that TCP9 enhances Cd tolerance via modulating ZAT6 and ZAT10, thereby identifying TCP9 as a potential key target for improving plant tolerance to Cd toxicity.