The interactome of soybean GmWRKY53 using yeast 2-hybrid library screening to saturation

Soybean GmWRKY53 functions in both biotic and abiotic stress signaling. Using GmWRKY53 as a bait yeast 2-hybrid library screening to saturation isolated multiple independent fragments for many interacting proteins, enabling delineation of minimal interacting domains and computation of a confidence score. Multiple independent clones coding for the LATE ELONGATED HYPOCOTYL clock protein GmLCL2 (MYB114) were isolated and the binding site for GmWRKY53 was mapped to 90 amino acids separate from the MYB domain. This suggests a direct input from the clock on GmWRKY53 activity. The GmWRKY53-interacting proteins also included 3 water stress-inducible AP2/ERF transcription factors. One of these (Glyma03g26310) is one of the most strongly water stress induced genes in soybean roots, suggesting that GmWRKY53/ERF complexes regulate water stress responses.

大豆GmWRKY53同时参与生物胁迫与非生物胁迫的信号传导通路。以GmWRKY53为诱饵蛋白开展饱和酵母双杂交（yeast 2-hybrid）文库筛选，成功分离得到多个互作蛋白的独立片段，由此可明确其最小互作结构域并计算置信度评分。研究共分离得到多个编码生物钟核心蛋白GmLCL2（MYB114）的独立克隆，且GmWRKY53的结合位点被定位在与MYB结构域（MYB domain）相互独立的90个氨基酸区域内，这表明生物钟可直接调控GmWRKY53的活性。与GmWRKY53互作的蛋白还包含3个水分胁迫诱导型AP2/ERF转录因子（AP2/ERF transcription factors），其中Glyma03g26310是大豆根系中受水分胁迫诱导表达最为显著的基因之一，这提示GmWRKY53与ERF蛋白形成的复合物可调控大豆的水分胁迫应答反应。