Wang Mei, Wang Meng, Zhao Min, Wang Mengcheng, Liu Shupeng, Tian Yanchen, Moon Byeongho, Liang Chaochao, Li Chunlong, Shi Weiming, Bai Ming-Yi, Liu Shuwei, Zhang Wei, Hwang Inhwan, Xia Guangmin
The Key Laboratory of Plant Development and Environment Adaptation Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao, 266237, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
New Phytol. 2022 Oct;236(2):495-511. doi: 10.1111/nph.18340. Epub 2022 Jul 22.
Initially discovered in yeast, mitochondrial retrograde signalling has long been recognised as an essential in the perception of stress by eukaryotes. However, how to maintain the optimal amplitude and duration of its activation under natural stress conditions remains elusive in plants. Here, we show that TaSRO1, a major contributor to the agronomic performance of bread wheat plants exposed to salinity stress, interacted with a transmembrane domain-containing NAC transcription factor TaSIP1, which could translocate from the endoplasmic reticulum (ER) into the nucleus and activate some mitochondrial dysfunction stimulon (MDS) genes. Overexpression of TaSIP1 and TaSIP1-∆C (a form lacking the transmembrane domain) in wheat both compromised the plants' tolerance of salinity stress, highlighting the importance of precise regulation of this signal cascade during salinity stress. The interaction of TaSRO1/TaSIP1, in the cytoplasm, arrested more TaSIP1 on the membrane of ER, and in the nucleus, attenuated the trans-activation activity of TaSIP1, therefore reducing the TaSIP1-mediated activation of MDS genes. Moreover, the overexpression of TaSRO1 rescued the inferior phenotype induced by TaSIP1 overexpression. Our study provides an orchestrating mechanism executed by the TaSRO1-TaSIP1 module that balances the growth and stress response via fine tuning the level of mitochondria retrograde signalling.
线粒体逆行信号最初是在酵母中发现的，长期以来一直被认为是真核生物感知应激的关键因素。然而，在自然应激条件下如何维持其激活的最佳幅度和持续时间在植物中仍不清楚。在这里，我们表明，TaSRO1是面包小麦植株在盐胁迫下农艺性能的主要贡献者，它与一个含跨膜结构域的NAC转录因子TaSIP1相互作用，TaSIP1可以从内质网（ER）转运到细胞核并激活一些线粒体功能障碍刺激子（MDS）基因。在小麦中过表达TaSIP1和TaSIP1-∆C（一种缺乏跨膜结构域的形式）均损害了植株对盐胁迫的耐受性，突出了在盐胁迫期间精确调节这一信号级联的重要性。TaSRO1/TaSIP1在细胞质中的相互作用使更多的TaSIP1滞留在内质网膜上，而在细胞核中则减弱了TaSIP1的反式激活活性，从而减少了TaSIP1介导的MDS基因激活。此外，TaSRO1的过表达挽救了TaSIP1过表达诱导的不良表型。我们的研究提供了一种由TaSRO1-TaSIP1模块执行的协调机制，该机制通过微调线粒体逆行信号水平来平衡生长和应激反应。
