Improving grapevine (Vitis vinifera L., cv. Superior Seedless) drought tolerance with cerium oxide nanoparticles: Agronomic and molecular insights

Abstract

Drought stress poses a significant threat to global food security, impacting grapevine growth and development through physiological, biochemical, and molecular alterations. Cerium oxide nanoparticles (CeO2 NPs) have recently gained attention as a potential solution to environmental challenges, yet their application in grapevines remains understudied. This study examined the interaction between foliar-applied CeO2 NPs (at concentrations of 0, 5, 50, and 500 mg L−1) and drought stress (at 30% and 70% of field capacity humidity) in grapevine saplings. Among the different concentrations tested, 50 mg L−1 CeO2 NPs significantly improved the agronomic traits (e.g., shoot length, leaf area, shoot and root dry weights), photosynthetic parameters (stomatal conductance, chlorophyll a and chlorophyll b) and RWC of the grapevine saplings under drought stress. In parallel, CeO2 NPs significantly induced the activity of compatible solutes and SOD, CAT and APX under drought stress conditions. Moreover, the availability of CeO2 NPs alleviated drought stress-induced damage in grapevine saplings, as evidenced by decreased H2O2 (32.63%), EL (40.35%) and MDA (50.63%) levels. The molecular results revealed that CeO2 NPs caused significant changes in gene expression under drought stress by reducing the expression of the VvCLH1, VvCu/ZnSOD, VvRD29A and VvRBOHA genes by 4.54-fold, 27.73-fold, 14.6-fold and 46.12-fold, respectively. These findings suggest that CeO2 NPs applied via leaves enhance grapevine sapling resistance to drought-induced oxidative stress through cooperative enzymatic and nonenzymatic antioxidant mechanisms, influencing gene regulation. As a result, these findings revealed that CeO2 NPs could be promising elicitor candidates for alleviating drought stress in grapevines.