The soybean gene, GmMYBJ2, encodes a R2R3-type transcription factor involved in drought stress tolerance in Arabidopsis thaliana

Abstract

MYB genes are extensively distributed in higher plants and constitute one of the largest transcription factors (TFs) families. These TFs have been proved to be implicated in the regulation of plant growth, development, metabolism, and multiple abiotic stress responses. In the present study, a new soybean MYB gene, denoted GmMYBJ2, was isolated and its function was characterized. The GmMYBJ2 cDNA is 1428 bp in length with an open reading frame (ORF) of 960 bp encoding 319 amino acids. Sequence and yeast one-hybrid analyses showed GmMYBJ2 contains two MYB domains and belongs to R2R3-MYB protein with transactivation activity. Transient expression analysis using the GmMYBJ2-GFP fusion gene in onion epidermal cells showed GmMYBJ2 protein is targeted to the nucleus. GmMYBJ2 was induced by drought, cold, salt, and exogenous abscisic acid (ABA). Arabidopsis overexpressing GmMYBJ2 exhibited a higher seed germination rates (GRs), a notable increase in the soluble sugar content under water-deficit stress, and a lower water loss rate (WLR) when water is sufficient. These results indicated the overexpression of GmMYBJ2 make transgenic Arabidopsis more tolerant to drought stress than wild-type (WT) plants, and GmMYBJ2 may be useful for improving drought stress tolerance in transgenic plant breeding.