背景回顾：Plants have evolved a series of mechanisms to adapt to drought stress. Transcription factors are crucial for plant response to various environmental signals by modulating the expression of numerous stress-responsive genes. 

提出问题：However, how the crosstalk between different transcription factor families orchestrates to initiate the key transcriptional network responding to stress, and the role of posttranscriptional modification of transcription factors, especially in the cellular localization/trafficking of stress response in rice, are still largely unknown. 

结果1-突变体筛库：Here, we isolated an Osmybr57 mutant displaying a drought-sensitive phenotype in the genetic screening of drought stress. 

结果2-OsMYB57-OsbZIPs：We have found that OsMYBR57, an MYB-related protein, directly regulates several key drought-related OsbZIPs to respond to drought treatment. 

结果3-OsMYB57-OsHB22：Further studies reveal that OsMYBR57 interacts with a homeodomain transcription factor, OsHB22, which also plays a positive role in drought signaling. 

结果4-OsFTIP6-OsHB22：We further demonstrate that OsFTIP6 interacts with OsHB22 and promotes the nucleocytoplasmic translocation of OsHB22 into the nucleus, where OsHB22 cooperates with OsMYBR57 to regulate the expression of drought-related genes. 

结论：Our findings have revealed a mechanistic framework underlying the OsFTIP6-OsHB22-OsMYBR57 module mediating drought response in rice. The OsFTIP6-mediated OsHB22 nucleocytoplasmic shuttling and OsMYBR57-OsHB22 regulatory modes of OsbZIPs transcription ensure precise control of expression of OsLEA3 and Rab21, thereby regulating the response to water deficiency in rice. 

 摘 要 

植物已演化出一系列的机制以适应干旱胁迫。转录因子对于植物响应外界环境信号，从而调控胁迫响应基因的表达至关重要。但是，水稻中不同转录因子家族基因之间如何交互作用，从而启动植株响应胁迫的关键转录网络，以及转录因子的转录后修饰，尤其是转录因子的细胞定位和转运，这些都还不清楚。本文中，作者通过对干旱胁迫的遗传筛选中，鉴定到了一个Osmybr57突变体，该突变体表现出干旱敏感的表型。作者已发现OsMYBR57能够响应于干旱处理，直接调控干旱相关基因OsbZIPs的表达。进一步的研究发现，OsMYBR57能够与homeodomain转录因子OsHB22互作，后者同样也在干旱信号转导中发挥正调控作用。作者进一步揭示了OsFTIP6能够与OsHB22互作，促进OsHB22蛋白通过核质易位方式进入细胞核，从而与OsMYBR57共同作用于干旱相关基因的表达调控。本文的研究结果揭示了一个OsFTIP6-OsHB22-OsMYBR57分子模块，介导水稻的干旱响应。OsFTIP6介导的OsHB22核质穿梭以及OsMYBR57-OsHB22对OsbZIPs转录的调控模式确保了OsLEA3和Rab21基因表达的精确调控，从而调控水稻对缺水胁迫的响应。

 宋士勇