Nucleolar DEAD-Box RNA Helicase TOGR1 Regulates Thermotolerant Growth as a Pre-rRNA Chaperone in Rice

作者：Dong Wang, Baoxiang Qin, Xiang Li, Ding Tang, Yue Zhang, Zhukuan Cheng, Yongbiao Xue · 发表于：PLoS Genetics · 年份：2016 · DOI：10.1371/journal.pgen.1005844 · 被引用次数：145 · 研究领域：Plant Molecular Biology Research、Photosynthetic Processes and Mechanisms、RNA Research and Splicing

Plants have evolved a considerable number of intrinsic tolerance strategies to acclimate to ambient temperature increase. However, their molecular mechanisms remain largely obscure. Here we report a DEAD-box RNA helicase, TOGR1 (Thermotolerant Growth Required1), prerequisite for rice growth themotolerance. Regulated by both temperature and the circadian clock, its expression is tightly coupled to daily temperature fluctuations and its helicase activities directly promoted by temperature increase. Located in the nucleolus and associated with the small subunit (SSU) pre-rRNA processome, TOGR1 maintains a normal rRNA homeostasis at high temperature. Natural variation in its transcript level is positively correlated with plant height and its overexpression significantly improves rice growth under hot conditions. Our findings reveal a novel molecular mechanism of RNA helicase as a key chaperone for rRNA homeostasis required for rice thermotolerant growth and provide a potential strategy to breed heat-tolerant crops by modulating the expression of TOGR1 and its orthologs.