Physiological and transcriptome analysis of exogenous trehalose enhancing abiotic stress tolerance in grape

The role of trehalose in plant resistance to abiotic stress is well-established. However, the mechanism by which trehalose is involved in abiotic stress tolerance in grapevine is remains poorly understood. Therefore, our study aimed to compare the mechanism of trehalose in response to different abiotic stresses in grapevine cultivar (Thompson Seedless) by spraying with trehalose and combining physiological measurements and RNA-seq. Exogenous trehalose effectively alleviated the frostbitten wilting phenotype of grapevine leaves caused by cold stress and the leaf withering phenotype caused by salt and drought stress. Trehalose increased the soluble sugar content and reduced the contents of MDA and H 2 O 2 under three stresses. GO analysis of the transcriptome revealed that the differentially expressed genes (DEGs) are involved in defense responses. KEGG analysis revealed that the main pathways included phenylpropanoid biosynthesis, flavonoid biosynthesis, and plant hormone signal transduction. The DEGs under the three abiotic stresses included VvPALs, VvSTSs and VvPYL4 . Unlike those under cold stress, the types of DEGs under salt and drought stress were relatively consistent; moreover, the number of DEGs was greater under drought stress. In addition, trehalose may respond to abiotic stress by regulating soluble sugar-related genes in grapevine. Transcription factor analysis revealed that ERFs were differentially expressed under the three abiotic stresses, especially VvERF105s , which played an important role under salt and drought stress. Therefore, our study suggested that exogenous trehalose regulates the grapevine abiotic stress responses mainly through key genes associated with secondary metabolism, hormone and sugar signaling, and transcriptional cascades.