Objective The role of MYB transcription factor family in the drought stress response of Phyllostachys edulis was analyzed to provide candidate genes for stress resistance improvement and molecular breeding of moso bamboo.

Method In this study, the gene sequence of PheMYB2R-4 was obtained from the genome database of Phyllostachys edulis, and the molecular characteristics of PheMYB2R-4 was analyzed by subcellular localization and transcriptional activity experiments. The function of PheMYB2R-4 was confirmed by qRT-PCR, phenotype analysis of transgenic Arabidopsis thaliana and determination of stress-related physiological and biochemical indicators.

Result PheMYB2R-4 encoded a protein with 305 amino acids, which had a conservative R2R3 domain in its N-terminal region and belonged to the R2R3-MYB subfamily. The expression of PheMYB2R-4 gene was significantly induced by drought and salt. PheMYB2R-4 was a nuclear localization protein and had transcriptional self-activation activity. The overexpression of PheMYB2R-4 increased the relative water content of Arabidopsis thaliana leaves under drought stress and decreased the relative conductivity and the accumulation of malondialdehyde, indicating that the overexpression of PheMYB2R-4 enhanced the drought tolerance of transgenic Arabidopsis thaliana by improving its water retention capacity and reducing oxidative damage. At the same time, under drought stress, AtRD22, AtRD29A, AtDREB2A and AtLEA were all up-regulated.

Conclusion PheMYB2R-4 has a positive regulatory role in the response to drought stress, which can improve the drought tolerance of plants and enhance the expression of drought response genes.