Overexpression of TaWRKY53 enhances drought tolerance in transgenic Arabidopsis plants

Abstract

The WRKY transcription factors are involved in plant response to multiple biotic and abiotic stress. However, the biological functions of WRKY in wheat are rarely studied. In this work, we isolated a WKRK transcription factor gene TaWRKY53 from wheat. The full-length cDNA of TaWRKY53 is 1436 bp, containing an open reading frame of 1323 bp which encodes a protein of 440 amino acids. TaWRKY53 was identified as part of the WRKY IIc group, and a phylogenetic tree analysis suggested that TaWRKY53 had a closer genetic relationship with the OsWRKY53 of Oryza sativa and ZmWRKY53 of Zea mays . Expression pattern analysis revealed that TaWRKY53 was regulated by various stresses, including drought, salt, cold, ABA and H2O2 treatments. The TaWRKY53 gene was overexpressed in Arabidopsis thaliana. Under drought stress, overexpression of TaWRKY53 plants increased germination rate, survival rate, and relative water content. In addition, overexpression of TaWRKY53 plants generally displayed lower malondialdehyde (MDA) and H2O2 contents, but higher peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities as well as higher chlorophyll content under drought stress. Our results indicate that TaWRKY53 is a Cd-inducible expansin gene, further providing valuable information for crop improvement.