Transcription Factor OsWRKY53 Positively Regulates Brassinosteroid Signaling and Plant Architecture
Transcription Factor OsWRKY53 Positively Regulates Brassinosteroid Signaling and Plant Architecture
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转录因子 OsWRKY53 积极调节油菜素类固醇信号传导和植物结构
DOI：
10.1104/pp.17.00946
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发表时间：
2017-11-01
期刊：
影响因子：
7.4
通讯作者：
Bu, Qingyun
中科院分区：
文献类型：
--
作者：
Tian, Xiaojie;Li, Xiufeng;Bu, Qingyun
类甾醇（BRs）是一类调节植物生长、发育和适应多个方面的类固醇激素。相对于在拟南芥中的广泛研究，水稻中BR信号转导的机制还不太清楚。在这里，我们确定OsWRKY 53，一个转录因子参与防御反应，作为一个重要的调节器水稻BR信号。表型分析表明，OsWRKY 53过表达导致叶片角度增大，籽粒增大，而OsWRKY 53突变体叶片直立，籽粒较小。此外，OsWRKY 53表现出降低的BR敏感性，而OsWRKY 53过表达植株对BR高度敏感，表明OsWRKY 53正调控水稻BR信号传导。此外，我们发现OsWRKY 53可以与OsMAPKK 4-OsMAPK 6级联反应相互作用并被其磷酸化，该磷酸化是OsWRKY 53调节BR反应的生物学功能所必需的。此外，我们发现BR促进OsWRKY 53蛋白的积累，但抑制OsWRKY 53转录水平。综上所述，本研究揭示了OsWRKY 53作为水稻BR信号转导调节剂的新作用，也表明OsWRKY 53在介导激素与其他信号转导途径之间的串扰中的潜在作用。
Brassinosteroids (BRs) are a class of steroid hormones regulating multiple aspects of plant growth, development, and adaptation. Compared with extensive studies in Arabidopsis (Arabidopsis thaliana), the mechanism of BR signaling in rice (Oryza sativa) is less understood. Here, we identified OsWRKY53, a transcription factor involved in defense responses, as an important regulator of rice BR signaling. Phenotypic analyses showed that OsWRKY53 overexpression led to enlarged leaf angles and increased grain size, in contrast to the erect leaves and smaller seeds in oswrky53 mutant. In addition, the oswrky53 exhibited decreased BR sensitivity, whereas OsWRKY53 overexpression plants were hypersensitive to BR, suggesting that OsWRKY53 positively regulates rice BR signaling. Moreover, we show that OsWRKY53 can interact with and be phosphorylated by the OsMAPKK4-OsMAPK6 cascade, and the phosphorylation is required for the biological function of OsWRKY53 in regulating BR responses. Furthermore, we found that BR promotes OsWRKY53 protein accumulation but represses OsWRKY53 transcript level. Taken together, this study revealed the novel role of OsWRKY53 as a regulator of rice BR signaling and also suggested a potential role of OsWRKY53 in mediating the cross talk between the hormone and other signaling pathways.