Comparative Physiological and Transcriptomic Analyses of Wheat (Triticum Aestivum L.) Seedlings under Salt Stress Reveal Salt Tolerance Mechanisms

Abstract

Liya Niu, Zhenjie Zhao, Jingwei Zou, Yujie Zhang, Chao Chen, Hefei Shi, Zhenghui Luo, Liang Yu, Weiwei Wang, Yufan Wang, Fengzhi Wang and Shuang Zhao

Wheat is an important food crop, and salt stress severely affects the growth and development of wheat; however, the salt tolerance mechanism of wheat is not understood. In this study, Cangmai6002 and Jimai22 were used as experimental materials, and the physiological and molecular mechanisms involved in the response to salt stress were analysed by high-throughput RNA sequencing technology. The results revealed that, compared with Jimai22, Cangmai600 maintained a greater germination rate, growth level and antioxidant enzyme activity under salt stress. Compared with Jimai22, Cangmai6002 presented lower Na+ influx and higher K+ influx with increasing salt concentration. RNA-seq revealed 9815 and 9595 differentially expressed genes (DEGs) in Cangmai6002 and Jimai22, respectively. These genes were enriched in pathways such as MAPK signalling pathway–plant, Glycolysis/Gluconeogenesis, Plant-pathogen interaction and Plant hormone signal transduction. We specifically highlight DEGs involved in reactive oxygen species (ROS) removal (POD, SOD, and CAT) and ion transport (HKT, KAT, and ATPase). These results preliminarily reveal the mechanism of wheat salt tolerance and provide transcriptomic resources for molecular breeding to improve wheat salt tolerance.