Overexpression of the maize <i>WRKY114</i> gene in transgenic rice reduce plant height by regulating the biosynthesis of GA

Abstract

WRKYs represent an important family of transcription factors that are widely involved in plant development, defense regulation and stress response. Transgenic rice that constitutively expressed <i>ZmWRKY114</i> had shorter plant height and showed less sensitivity to gibberellic acid (GA₃). Further investigation proved that transgenic rice accumulated lower levels of bioactive GAs than that in wild-type plants. Application of exogenous GA₃ fully rescued the semi-dwarf phenotype of <i>ZmWRKY114</i> transgenic plants. Transcriptome and qRT-PCR analyses indicated that the expression of <i>OsGA2ox4</i>, encoding the repressor of GA biosynthesis, was markedly increased. Electrophoretic mobility shift assay and dual-luciferase reporter assay indicated that ZmWRKY114 directly binds to a W-box motif in the <i>OsGA2ox4</i> promoter. Taken together, these results confirm that <i>ZmWRKY114</i> is a GA-responsive gene and is participated in the regulation of plant height in rice.