Salicylic acid induces tolerance of Vitisriparia×V.labrusca to chilling stress by altered photosynthetic, antioxidant mechanisms and expression of cold stress responsive genes

The yield and quality of wine grapes are severely persecuted by low-temperaturestresses. Salicylic acid (SA) assists plants in coping with abiotic stresses such as drought, heavy metal toxicity, and osmotic stress. The objective of this study was to evaluate the effect of foliar spraying of different concentrations of SA on the mitigation of cold damage in grapes, which is useful for the cultivation of wine grapes.Vitisriparia×V.labruscaseedlings were treated with foliar-sprayedSA at concentrations of 0-2 mM and then subjected to chilling stress at 4°C for 2 or 4 days, while the expression of relevant physiological indicators and cold response genes (CBF1, CBF2, CBF3) were measured. The findings indicated that low temperature stresses markedly reduced chlorophyll content, and increased proline as well as soluble sugar content, enhanced superoxide dismutase (SOD) and peroxidase (POD) activities, decreased catalase (CAT) activity and inducedCBFgene expression in leaves. Physiologically, foliar spraying of different concentrations of SA greatly increased antioxidant enzyme activity (P < .05), soluble sugars, proline, and chlorophyll content of grapes leave under low temperature stress. With regard to gene expression, SA has significantly regulated the cold response genesCBF1, CBF2, andCBF3. Therefore, SA could reduce cold damage in grapevines under low-temperaturestress, and the effect of SA was most pronounced in the 1 and 2 mM concentrates.