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 ZmWRKY114 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 ZmWRKY114 transgenic plants. Transcriptome and qRT-PCR analyses indicated that the expression of OsGA2ox4, 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 OsGA2ox4 promoter. Taken together, these results confirm that ZmWRKY114 is a GA-responsive gene and is participated in the regulation of plant height in rice.

摘要

WRKYs 代表了一个重要的转录因子家族，广泛参与植物发育、防御调节和应激反应。组成型表达ZmWRKY114的转基因水稻株高较短，对赤霉酸（GA ₃）的敏感性较低。进一步的研究证明，转基因水稻积累的生物活性 GAs 水平低于野生型植物。外源GA _{3的应用完全挽救了}ZmWRKY114转基因植物的半矮化表型。转录组和 qRT-PCR 分析表明OsGA2ox4的表达，编码 GA 生物合成的阻遏物显着增加。电泳迁移率变动分析和双荧光素酶报告基因分析表明 ZmWRKY114 直接与OsGA2ox4启动子中的 W-box 基序结合。总之，这些结果证实了ZmWRKY114是一个GA反应基因，参与了水稻株高的调控。