Cloning and functional analysis of Phyllostachys edulis MYB transcription factor PeMYB2

Abstract

MYB-type transcription factor is one of the largest families in plants, which plays important roles in accepting stress signals from environment and regulating the expression of stress-tolerant genes. In this paper, using homologous cloning and RACE technology, a MYB-type transcription factor, designated PeMYB2, was cloned from Phyllostachys edulis. The results of bioinformatics showed that PeMYB2 is a typical R2R3-MYB. It contained two tandem repeats in its N-terminus, and a membrane protein DUF3651 in its C-terminus. In addition, phylogenetic analysis indicated that PeMYB2 shared the highest homology with 85.98% to OsMYB18 protein from Oryza sativa spp. Japonica. In addition, a yeast one-hybrid assay showed that PeMYB2 could activate the expression of downstream genes. After PeMYB2 was transformed into Arabidopsis thaliana, seven PeMYB2 transgenic Arabidopsis lines were obtained. Phenotypic analysis of the transgenic and wild-type Arabidopsis showed that over-expression of PeMYB2 caused delayed flower or dwarfism in transgenic Arabidopsis. Under the abiotic stress conditions, such as salt and cold stresses, the over-expression of PeMYB2 in Arabidopsis had higher survival rate than the wild-type Arabidopsis. Expression analysis of saline stress response marker genes in the transgenic and wild-type plants under the salt stress condition showed that PeMYB2 regulated the expression of NXH1, SOS1, RD29A, and COR15A. As the result, PeMYB2 might play an important role in various responses to abiotic stresses in P. edulis.

The R2R3MYB Gene Family in Phyllostachys edulis: Genome-Wide Analysis and Identification of Stress or Development-Related R2R3MYBs

“…Increasing amounts of research has indicated that MYB proteins play fundamental roles in the regulation of gene expression in response to environmental change, where they act as active players in abiotic stress signaling ( Ambawat et al, 2013 ; Li et al, 2015 ). In moso bamboo, the overexpression of PeMYB2 (named PheMYB2R-73 in our study) could strengthen the tolerance of the transgenic Arabidopsis lines under salt stress conditions ( Xiao et al, 2013 ). Moreover, “the MYB TFs might play crucial roles in regulating, acclimating, and modulating gene expression in photosynthetic processes in response to the high-light stress of moso bamboo” ( Zhao et al, 2016 ).…”

“…Moreover, they might be involved in drought-responsive and gibberellic acid (GA)-signaling pathways to improve stress resistance and further activate downstream genes to influence flowering transition ( Gao et al, 2014 ). Although many studies have emphasized the importance of MYB proteins and have facilitate a preliminary understanding of this large gene family, with the exception of PeMYB2 ( Xiao et al, 2013 ), few members of moso bamboo MYB genes have been well functional characterized, particularly in comparison with model plants. There is thus an urgent need to characterize the roles of MYB s in moso bamboo and to further our understanding of these genes.…”