Identification and expression analysis of Trehalose-6-phosphate phosphatase (VvTPP) genes in grape and function of the VvTPPA gene in salt stress response

Trehalose is widely involved in the processes of plant development and in defense against stress. To date, the role of the trehalose-6-phosphate phosphatase (TPP) genes in grapevine subjected to abiotic stress remains unreported. Here, seven VvTPPs were identified in grape (Vitis vinifera), all of which contained the TPP domain. Synteny analysis revealed two gene pairs with grape and four gene pairs between grape and Arabidopsis. Phylogenetic analysis showed that VvTPPs were distributed in Class Ⅰ, Class ⅡⅠ, and Class IV. The VvTPP proteins were highly conserved in both their distribution pattern and the number of conserved motifs. The VvTPPs contained a large number of introns and exons. The VvTPP promoter sequences contained numerous cis-acting elements associated with stress and hormonal responses. Tissue-specific analysis revealed that VvTPPA was highly expressed in all grape tissues. RT-qPCR analysis indicated that seven VvTPPs were induced by at least one of the cold, drought, and salt stresses. Finally, VvTPPA overexpression enhanced salt tolerance in grape callus and Arabidopsis thaliana. Based on expression and functional analyses of VvTPPs in grape, the role of VvTPPA in salt stress response was elucidated, identifying it as a key gene for raising stress resistant grape plants in future through breeding programs.