*Article* **The WRKY Transcription Factor GmWRKY12 Confers Drought and Salt Tolerance in Soybean**

**Wen-Yan Shi 1,2,†, Yong-Tao Du 2,†, Jian Ma 3,†, Dong-Hong Min <sup>1</sup> , Long-Guo Jin <sup>2</sup> , Jun Chen <sup>2</sup> , Ming Chen <sup>2</sup> , Yong-Bin Zhou <sup>2</sup> , You-Zhi Ma <sup>2</sup> , Zhao-Shi Xu 2,\* and Xiao-Hong Zhang 1,\***


Received: 14 November 2018; Accepted: 15 December 2018; Published: 17 December 2018

**Abstract:** WRKYs are important regulators in plant development and stress responses. However, knowledge of this superfamily in soybean is limited. In this study, we characterized the drought- and salt-induced gene *GmWRKY12* based on RNA-Seq and qRT-PCR. *GmWRKY12*, which is 714 bp in length, encoded 237 amino acids and grouped into WRKY II. The promoter region of *GmWRKY12* included ABER4, MYB, MYC, GT-1, W-box and DPBF *cis*-elements, which possibly participate in abscisic acid (ABA), drought and salt stress responses. *GmWRKY12* was minimally expressed in different tissues under normal conditions but highly expressed under drought and salt treatments. As a nucleus protein, *GmWRKY12* was responsive to drought, salt, ABA and salicylic acid (SA) stresses. Using a transgenic hairy root assay, we further characterized the roles of *GmWRKY12* in abiotic stress tolerance. Compared with control (Williams 82), overexpression of *GmWRKY12* enhanced drought and salt tolerance, increased proline (Pro) content and decreased malondialdehyde (MDA) content under drought and salt treatment in transgenic soybean seedlings. These results may provide a basis to understand the functions of *GmWRKY12* in abiotic stress responses in soybean.

**Keywords:** WRKY; stress responsive mechanism; drought tolerance; salt tolerance; transgenic hairy root assay; soybean
