Overexpression of the soybean (Glycine max) DRE-binding transcription factor GmDREB1 enhanced drought stress tolerance of transgenic wheat in the field.

Zhou Y, Chen M, Guo J, Wang Y, Min D, Jiang Q, Ji H, Huang C, Wei W, Xu H, Chen X, Li L, Xu Z, Cheng X, Wang C, Wang C, Ma Y.

J Exp Bot. 2019 Dec 26. pii: erz569. doi: 10.1093/jxb/erz569. [Epub ahead of print]

Abstract

DREB (drought response element binding) like transcription factors can significantly enhance plant tolerance to drought. However, most research on DREB-like proteins to date has been conducted in growth chambers or greenhouses, so there is very little evidence available to support the application of DREB-like proteins in the field. Here, we overexpressed GmDREB1 from soybean in two popular wheat varieties and conducted several drought tolerance experiments across a range of years, sites and drought-stress regimes. We found that these plants consistently exhibited significant improvements in yield performance and a variety of physiological traits over WT plants when grown under limited water conditions in the field, for example showing grain yield increases between 4.79-18.43%. Specifically, we found that the transgenic wheat plants had reduced membrane damage and enhanced osmotic adjustment as well photosynthetic efficiency compared to non-transgenic controls. Three enzymes from the biosynthetic pathway of the phytohormone melatonin were up-regulated in transgenic wheat, further supporting a role for melatonin in the observed drought tolerance, external application of melatonin improved drought tolerance performance. Collectively, our results convincingly demonstrate the utility of a transgenic overexpression strategy for using GmDREB1 to improve wheat drought tolerance in the field.

See https://academic.oup.com/jxb/advance-article/doi/10.1093/jxb/erz569/5687011

Figure 1: Overexpression of the known drought-resistance transcription factor GmDREB1 in wheat improved growth under drought stress. The germinated seedlings were grown to the three-leaf stage in soil with enough water; watering was then stopped for 21 days, followed by rehydration for 7 days, and the survival rates were determined. Water loss rates of leaves were investigated at the three-leaf stage. (A) Seedlings grown under normal conditions at the same time were used as controls. (B) Phenotypes of seedlings after cessation of watering for 7 days. (C) Phenotypes of the seedlings after rehydration for 7 days. (D) RTPCR for GmDREB1 expression in wheat. (E) qPCR analysis of the expression level of GmDREB1. (F) The survival rates of wheat seedlings. (G) Monitoring water loss rate of detached leaves for 8 hours. Data represent means ±SE of four replicates. Asterisks or letters indicate that the difference between the means of the transgenic lines and wild type was significant at the P < 0.05 (* or a, b, and c) and P < 0.01 (**, A, B, and C) level.