Genome-Wide Identification of BTB Domain-Containing Gene Family in Grapevine (Vitis vinifera L.)

BTB (broad-complex, tram track and bric-a-brac) proteins have broad functions in different growth processes and biotic and abiotic stresses. However, the biological role of these proteins has not yet been explored in grapevine, which draws our attention towards the BTB gene family. Herein, we identified 69 BTB genes (VvBTB) in the Vitis vinifera genome and performed comprehensive in silico analysis. Phylogenetic analysis classified VvBTB proteins into five groups, and further domain analysis revealed the presence of other additional functional domains. The majority of BTB proteins were localized in the nucleus. We also performed differential expression analysis by harnessing RNA- seq data of 10 developmental stages and different biotic and abiotic stresses. Our findings revealed the plausible roles of the BTB gene family in developmental stages; Fifty VvBTB were differentially expressed at different developmental stages. In addition, 47 and 16 VvBTB were responsive towards abiotic and biotic stresses, respectively. Interestingly, 13 VvBTB genes exhibited differential expression in at least one of the developmental stages and biotic and abiotic stresses. Further, miRNA target prediction of 13 VvBTB genes revealed that vvi-miR482 targets VvBTB56, and multiple miRNAs, such as vvi-miR172, vvi-miR169 and vvi-miR399, target VvBTB24, which provides an insight into the essential role of the BTB family in the grapevine. Our study provides the first comprehensive analysis and essential information that can potentially be used for further functional investigation of BTB genes in this economically important fruit crop.