Transcriptome Analysis Reveals Flower Development and the Role of Hormones in Three Flower Types of Grapevine

The molecular mechanism of flower development and sexual differentiation, which is an intricate process, still unclear in Vitis plants. In this study, we performed the transcriptome analysis by high-throughput sequencing to measure gene expression at three stages in male, female, and hermaphrodite grape flowers, and in combination with the fluctuation of hormones (ABA, IAA, BR, GA3, and JA) to understand the gene function and molecular basis of developmental processes in Vitis flowers. The results showed that more than 581 million clean reads were generated from all samples and average 83% reads were mapped on the Vitis vinifera genome. More, quite a large number of genes were differentially expressed between different stages within and across cultivars and various transcription factor families involved were identified in flower development. The genes belonging to MYB, bHLH, ERF, NAC, and WRKY have more numbers than other TF families. Furthermore, we analyzed the correlation of those hormones with 165 DEGs (including 36 TF genes). The results suggested that those genes might play important roles in sex differentiation during flower development and a unique opportunity to increase the efficiency of crossbreeding in Vitis plant.