Improved drought tolerance in wheat plants overexpressing a synthetic bacterial cold shock protein gene SeCspA

Tai-Fei Yu,Yan-Xia Wang,Jin-Kao Guo,Yong-Bin Zhou,Yong-Bin Zhou,Xiao Chen,Xiao Chen,You-Zhi Ma,You-Zhi Ma,Zhao-Shi Xu,Zhao-Shi Xu,Xing-Guo Ye,Xing-Guo Ye,Jin-Dong Fu,Jin-Dong Fu,Brian Abernathy,Brian Abernathy,Ming Chen,Ming Chen

doi:10.1038/srep44050

Abstract

Cold shock proteins (CSPs) enhance acclimatization of bacteria to adverse environmental circumstances. The Escherichia coli CSP genes CspA and CspB were modified to plant-preferred codon sequences and named as SeCspA and SeCspB. Overexpression of exogenous SeCspA and SeCspB in transgenic Arabidopsis lines increased germination rates, survival rates, and increased primary root length compared to control plants under drought and salt stress. Investigation of several stress-related parameters in SeCspA and SeCspB transgenic wheat lines indicated that these lines possessed stress tolerance characteristics, including lower malondialdehyde (MDA) content, lower water loss rates, lower relative Na+ content, and higher chlorophyll content and proline content than the control wheat plants under drought and salt stresses. RNA-seq and qRT-PCR expression analysis showed that overexpression of SeCsp could enhance the expression of stress-responsive genes. The field experiments showed that the SeCspA transgenic wheat lines had great increases in the 1000-grain weight and grain yield compared to the control genotype under drought stress conditions. Significant differences in the stress indices revealed that the SeCspA transgenic wheat lines possessed significant and stable improvements in drought tolerance over the control plants. No such improvement was observed for the SeCspB transgenic lines under field conditions. Our results indicated that SeCspA conferred drought tolerance and improved physiological traits in wheat plants.

Highlights

IntroductionWater-deficit stress has become a serious problem in global agriculture and severely affects the growth of crops; it is of particular concern in northern and northwestern China, where the main winter wheat production areas are located[17]
In media supplemented with 150 mM NaCl, the 35 S::SeCspA and 35 S::SeCspB transgenic Arabidopsis lines germinated at 70% and 56%, respectively, as compared with about 33% germination for the control plants
Cold shock domain (CSD) proteins in plants differ from the cold shock protein (CSP) identified in prokaryotes

Summary

Introduction

Water-deficit stress has become a serious problem in global agriculture and severely affects the growth of crops; it is of particular concern in northern and northwestern China, where the main winter wheat production areas are located[17]. In these areas, more than 70% of annual precipitation falls from June to September, whereas precipitation meets only 20 to 30% of the water requirement for winter wheat during the winter wheat growing season from February to the middle of June[18]. The study reported here was conducted with field experiments and showed that the 1000-grain weight and the grain yield of wheat was significantly increased in transgenic wheat expressing SeCspA under drought conditions, resulting in improved wheat drought tolerance

Methods

Results

Conclusion