Expression profile and function characterization of the MYB type transcription factor genes in wheat (Triticum aestivum L.) under phosphorus deprivation

Abstract

MYB proteins constitute one of the largest transcription factor families in plants and play critical roles in mediating plant adaptation to diverse abiotic stresses. In this study, fourty two of the MYB genes in wheat were subjected to the expression profile and function characterization analysis under phosphorus (Pi) deprivation. The results indicated that twenty-one, eleven, five, two, and one of the wheat MYB genes share homologous partners in B. Distachyon, rice, maize, barley, and Arabidopsis, respectively. Phylogenetic analysis suggested that the wheat MYB genes have evolved from five evolutionary pathways. Based on a microarray analysis, the wheat MYB genes were found to exhibit different transcripts under normal condition and can be grouped into various categories according to expression level, including those of high (eight members), moderate (ten members), low (ten members), and very low (fourteen members), respectively. Under Pi deprivation, most of the MYB genes showed significantly modified transcripts, in which TaMYB1, TaMYB16, and TaMYB73;1 were upregulated, and TaMYB11, TaMYB12, TaMYB13-2;1, and TaMYB;6 were downregulated. Transgenic analysis of TaMYB1, one of the upregulated genes, confirmed that it played an important role in mediating plant tolerance to Pi deprivation. The transgenic plants overexpressing TaMYB1 displayed higher plant drymass and more P accumulation than wild type under Pi deprivation. Together, our investigation indicates that a subset of wheat MYB genes involves plant response to Pi deficiency in which TaMYB1 plays critical roles in mediating plant tolerance to the Pi-starvation stress.