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

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 <i>GmWRKY12</i> based on RNA-Seq and qRT-PCR. <i>GmWRKY12</i>, which is 714 bp in length, encoded 237 amino acids and grouped into WRKY II. The promoter region of <i>GmWRKY12</i> included ABER4, MYB, MYC, GT-1, W-box and DPBF <i>cis</i>-elements, which possibly participate in abscisic acid (ABA), drought and salt stress responses. <i>GmWRKY12</i> was minimally expressed in different tissues under normal conditions but highly expressed under drought and salt treatments. As a nucleus protein, <i>GmWRKY12</i> was responsive to drought, salt, ABA and salicylic acid (SA) stresses. Using a transgenic hairy root assay, we further characterized the roles of <i>GmWRKY12</i> in abiotic stress tolerance. Compared with control (Williams 82), overexpression of <i>GmWRKY12</i> 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 <i>GmWRKY12</i> in abiotic stress responses in soybean.