VvGA2ox8-Likefrom grape confers drought tolerance by activating the antioxidant defense system

Drought stress severely limits grape productivity. Gibberellin (GA) metabolism is involved in drought responses, yet the role of specific GA catabolic genes remains unclear. In the present study, VvGA2ox8-Like, a member of the grape GA 2-β-dioxygenase (VvGA2ox) gene family, was identified to confer drought tolerance in Vitis vinifera cv. ‘Pinot Noir’. As a GA catabolic enzyme, VvGA2ox8-Like expression is significantly induced by drought stress. Transient transformation of ‘Pinot Noir’ grape leaves showed that VvGA2ox8-Like overexpression decreased H₂O₂ and MDA contents, while increasing proline content, antioxidant enzyme activities, and drought-responsive gene expressions; in contrast, virus-induced gene silencing (VIGS) of VvGA2ox8-Like exhibited opposite results. Furthermore, VvGA2ox8-Like overexpression in ‘Pinot Noir’ grape calli further confirmed its positive regulatory role in drought tolerance, whereas CRISPR-Cas9-edited VvGA2ox8-Like calli showed opposite phenotypes. A drought-responsive protein VvGRX-S7 was identified as an interacting partner of VvGA2ox8-Like via yeast two-hybrid (Y2H) assay. RNA-sequencing (RNA-seq) analysis revealed that VvGA2ox8-Like overexpression significantly affected the biosynthesis of secondary metabolites, phenylpropanoids, and flavonoids. In conclusion, VvGA2ox8-Like plays a key role in grape drought tolerance, providing theoretical support for elucidating the molecular mechanism of grape drought resistance.