Methyl jasmonate (MeJA) plays a vital role in plant disease resistance and also induces the expression of disease resistance genes in plants. In this study, a transcriptome analysis was performed on grapevine leaves after 12, 24 and 48 h of MeJA-100 μM treatment. A total of 1242 differentially expressed genes (DEGs) were identified from the transcriptome data, and the analysis of the DEGs showed that genes related to phytohormone signal transduction, jasmonic acid-mediated defense, Mitogen-activated protein kinase (MAPK), and flavonoid biosynthetic pathways were upregulated. As Pathogenesis-related gene 1 (PR1) is an important marker gene in plant defense also upregulated by MeJA treatment in RNA-seq data, the VvPR1 gene was selected for a promoter analysis with β-glucuronidase (GUS) through transient expression in tobacco leaves against abiotic stress. The results showed that the region from −1837 bp to −558 bp of the VvPR1 promoter is the key region in response to hormone and wound stress. In this study, we extended the available knowledge about induced defense by MeJA in a grapevine species that is susceptible to different diseases and identified the molecular mechanisms by which this defense might be mediated.

Grapes are grown extensively around the world and play a crucial role in overall fruit production globally. The quality of the grape is largely determined by the texture of the flesh, making it a key focus for grape breeders. Our study was conducted on 437 grape accessions using a puncture method to analyze berry texture characteristics. The results reveal strong correlations among the five texture parameters of grape accessions. Following the GWAS analysis using 2,124,668 population SNPs, 369 significant SNP locations linked to the grape berry texture were discovered. Through the process of gene annotation and expression analysis in the localization regions, several genes potentially linked to berry texture were identified, including E13A, FIS1A, CML35, AGL2, and AGL62. E13A, FIS1A, and CML35 were identified as potentially more relevant to grape berry texture based on gene expression analysis. Further investigation through transient transformation demonstrated that overexpressing E13A and CML35 resulted in notable changes in grape pulp texture. During this study, the berry textures of 437 grape accessions were comprehensively evaluated, and several important candidate genes were screened based on GWAS and analysis of gene function. This discovery paves the way for future research and breeding initiatives related to grape berry texture.

Grape production in China is significantly impacted by white rot disease, which is caused by Coniella diplodiella (Speg.) Sacc. This study analyzes the differences in leaf transcriptomes and phenotypes of two grape species, ‘Manicure Finger (Vitis vinifera L.)’ and ‘0940 (Vitis davidii Foex)’, following inoculation with C. diplodiella. Leaf anatomy and H₂O₂ content confirm the greater resistance of '0940' to C. diplodiella compared to 'Manicure Finger.' Comparative transcriptome analysis reveals that the defense mechanism of '0940' against C. diplodiella involves sesquiterpenoid and triterpenoid biosynthesis, plant-pathogen interactions, sulfur relay systems, suberin and wax biosynthesis, monoterpenoid biosynthesis, as well as flavonoid and flavonol biosynthesis pathways. Using Weighted Gene Co-expression Network Analysis (WGCNA), we identified three modules highly correlated with C. diplodiella resistance and 125 candidate genes, including resistant genes (R genes), pattern-recognition receptors (PRRs), and pathogenesis-related proteins genes (PR genes), which may play important roles in grape resistance to this disease.

In this study, the aroma of 182 table grapes was detected using a PEN3.5 electronic nose in order to explore the aroma components of table grape berries and provide a reference for aroma evaluation and quality improvements. Table grape varieties from the Zhengzhou Fruit Research Institute of the Chinese Academy of Agricultural Sciences were used as research materials. All of them were harvested in fruit trees over 10 years old from August to October 2023, which provided a reference for aroma evaluation and quality improvement of the table grapes. Radar analysis, correlation analysis, principal component (PCA) analysis, cluster analysis, and difference analysis were used to study these aroma substances. The results show that the sensor contribution rate from high to low is W5S (nitrogen oxides), W2S (alcohols and some aromatic compounds), W1S (alkanes), and W2W (sensor contribution rate from high to low). Cluster analysis can distinguish the varieties of table grapes a with common aroma content, and the varieties with a higher content are in the second category (II). PCA showed that the contribution rate of the first and second principal components of the three main sensors was 97.6% and 2.3%, respectively, and the total contribution value was 99.9%. The contribution rates of the first and second principal components of the three aromatic sensors are 79.5% and 15.9%, respectively, and the total contribution value is 95.4%. The results showed that there were significant differences in the content and composition of aroma substances in different grape varieties. Eight special germplasm with strong aroma (organic compounds of nitrogen oxides, alcohols, alkanes and sulfur) were selected: ‘Spabang’, ‘Neijingxiang’, ‘Zaotian Muscat’, ‘Jinmeigui’, ‘Zhengguo 6’, ‘Muscat Angel’, ‘Zizao’, and ‘Qiumi’. This study confirmed that electronic nose technology can effectively distinguish different varieties of table grapes. This study not only provides a scientific basis for the variety selection for the table grape processing industry, but it can also be used for male or female grape hybridization, which provides valuable data resources for table grape breeding.

‘Queen Nina’ is a popular grape variety, but the fruit flavor profile and its evolution and regulatory mechanism remain unclear. The flavor profile of ‘Queen Nina’ was systematically investigated by analyzing the soluble sugars, organic acids, free amino acids, and aroma volatiles at 6 different stages. A total of 55 aroma volatiles were identified, with esters being the predominant volatiles in mature berries. The flavor profile of ‘Queen Nina’ was elucidated by constructing a flavor radar chart based on the results of OAV, which identified 5 volatiles as reliable indicators of berries ripening. Additionally, we identified 29 genes associated with esters metabolism and reported for the first time the involvement of the CXE gene family in aroma esters decomposition in grapes. The results contribute to a more comprehensive understanding of the dynamics underlying the flavor profile of ‘Queen Nina’, thereby providing novel insights into enhancing the grape aroma.