Background: GATA transcription factors are type IV zinc-finger proteins that play key roles in plant growth and responses to environmental stimuli. Although these proteins have been studied in model plants, the related studies of GATA gene family under abiotic stresses are rarely reported in grapevine (Vitis vinifera L.). Results: In the current study, a total of 23 VviGATA genes were identified in grapevine and classified into four groups (I, II, III, and IV), based on phylogenetic analysis. The proteins in the same group exhibited similar exon–intron structures and conserved motifs and were found to be unevenly distributed among the thirteen grapevine chromosomes. Accordingly, it is likely that segmental and tandem duplication events contributed to the expansion of the VviGATA gene family. Analysis of cis-acting regulatory elements in their promoters suggested that VviGATA genes respond to light and are influenced by multiple hormones and stresses. Organ/tissue expression profiles showed tissue specificity for most of the VviGATA genes, and five were preferentially upregulated in different fruit developmental stages, while others were strongly induced by drought, salt and cold stress treatments. Heterologously expressed VamGATA5a, VamGATA8b, VamGATA24a, VamGATA24c and VamGATA24d from cold-resistant V. amurensis ‘Shuangyou’ showed nuclear localization and transcriptional activity was shown for VamGATA5a, VamGATA8b and VamGATA24d. Conclusions: The results of this study provide useful information for GATA gene function analysis and aid in the understanding of stress responses in grapevine for future molecular breeding initiatives.

Grapevine leafroll-associated virus 3 (GLRaV-3) is one of the causal agents of grapevine leafroll disease (GLD), which severely impacts grapevine production in most viticultural regions of the world. The development of virus-resistant plants is a desirable strategy for the efficient control of viral diseases. However, natural resistant resources have not been reported in the genus Vitis, and anti-GLRaV-3 research has been quite limited in grapevine. In this study, by expressing FnCas9 and LshCas13a, we established a highly effective transgenic construct screening system via an optimized Agrobacterium-mediated transient delivery system in grapevine plantlets. Our study indicated that CRISPR/FnCas9 and LshCas13a caused GLRaV-3 inhibition. Moreover, three vectors—pCR01-CP, pCR11-Hsp70h and pCR11-CP—exhibited the most robust inhibition efficiency compared to those targeting other sites and could be further engineered to generate GLRaV-3-resistant grapevine. In addition, the viral interference efficiency of FnCas9 was dependent on its RNA binding activity. The efficiency of virus inhibition was positively correlated with the level of Cas gene expression. Importantly, we demonstrated that LshCas13a had better interference efficiency against viruses than FnCas9. In summary, this study confirmed that these two RNA-targeting CRISPR mechanisms can confer immunity against viruses in grapevine, providing new avenues to control GLRaV-3 or other RNA viruses in fruit crops.

Grapevine leafroll-associated virus (GLRaV) is a globally widespread disease that causes substantial economic losses in the wine industry. In severely affected vineyards, GLRaV can reduce grape yield by 20–40%. This study aimed to evaluate the effects of GLRaV infection on polyphenolic and volatile organic compound contents, as well as on the sensory profiles of the resulting wines. A comparative analysis was conducted between GLRaV-3-infected and healthy Cabernet Sauvignon grapes and their corresponding wines. Results show GLRaV-3 significantly alters grape and wine quality. In infected grapes, sugar content decreased while titratable acidity increased. Polyphenol composition was notably altered: phenolic acids and flavonols increased by 22.46% and 15.27%, respectively, whereas flavanols decreased by 17.86%. The levels of aldehydes and C₆ compounds also rose significantly in the berries. Wines produced from infected grapes showed lower alcohol content and reduced dry extract. Phenolic acids and flavanols were decreased, but total flavonols increased by 12.54%. Among volatile compounds, alcohols, phenols, and fatty acids were elevated, while esters declined by 13.36%. These chemical changes directly influenced sensory attributes. Compared with wines from healthy grapes, those from infected grapes exhibited improved tannin texture and longer aftertaste. However, they were inferior in color intensity, aroma intensity, body fullness, and varietal typicity.