The Soybean Gene J Contributes to Salt Stress Tolerance by Up-Regulating Salt-Responsive Genes.

Qun Cheng,Zhuoran Gan,Fanjiang Kong,Haiyang Li,Baohui Liu,Zhihong Hou,Yanping Wang,Sijia Lu,Hongtao Xiang,Lidong Dong

doi:10.3389/fpls.2020.00272

Abstract

Soybean [Glycine max (L.) Merr.] is an important crop for oil and protein resources worldwide, and its farming is impacted by increasing soil salinity levels. In Arabidopsis the gene EARLY FLOWERING 3 (ELF3), increased salt tolerance by suppressing salt stress response pathways. J is the ortholog of AtELF3 in soybean, and loss-of-function J-alleles greatly prolong soybean maturity and enhance grain yield. The exact role of J in abiotic stress response in soybean, however, remains unclear. In this study, we showed that J expression was induced by NaCl treatment and that the J protein was located in the nucleus. Compared to NIL-J, tolerance to NaCl was significantly lower in the NIL-j mutant. We also demonstrated that overexpression of J increased NaCl tolerance in transgenic soybean hairy roots. J positively regulated expression of downstream salt stress response genes, including GmWRKY12, GmWRKY27, GmWRKY54, GmNAC, and GmSIN1. Our study disclosed a mechanism in soybean for regulation of the salt stress response. Manipulation of these genes should facilitate improvements in salt tolerance in soybean.

Highlights

Soybean [Glycine max (L.) Merr.] is classified as a moderately salt-sensitive crop, and salt stress has negatively affected soybean yields (Parker et al, 1983; Ashraf, 1994; Munns and Tester, 2008)
To understand whether J was involved in the response to NaCl stress in soybean, we first investigated the expression of J in soybean seedlings exposed for 2 weeks to NaCl (200 mM)
In this study we investigated the potential role and mechanism for one such candidate, named J, for which the Arabidopsis-ortholog AtELF3 may be involved in stress responses (Lu et al, 2017)

Summary

Introduction

Soybean [Glycine max (L.) Merr.] is classified as a moderately salt-sensitive crop, and salt stress has negatively affected soybean yields (Parker et al, 1983; Ashraf, 1994; Munns and Tester, 2008). Improving salt tolerance in soybean is essential to ensure future soybean yields. A major salt-tolerant QTL located on Chr. (linkage group N) has been identified repeatedly using different soybean-mapping populations (Lee et al, 2004; Hamwieh and Xu, 2008; Hamwieh et al, 2011; Ha et al, 2013).

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Results

Conclusion