Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
College of Biological Science and Engineering, Hebei University of Economics and Business, Shijiazhuang 050061, China.
Plant Cell. 2019 Oct;31(10):2353-2369. doi: 10.1105/tpc.19.00519. Epub 2019 Jul 29.
Although much is known about plant responses to heat shock (HS), how plants sense high temperature and the primary HS signal transduction pathway leading to HS-regulated gene expression are still poorly understood. To identify primary transcription factors that mediate HS-regulated gene expression and their target genes, RNA sequencing was performed to detect genes whose expression is rapidly altered by HS in Arabidopsis (). The results showed several genes were induced after only 5 min of HS treatment, suggesting that HS signaling occurs very rapidly. Analysis of the -elements in the promoters of genes upregulated by 10 min of HS treatment identified HEAT SHOCK FACTOR A1s (HSFA1s) and circadian clock proteins REVEILLE4 (RVE4) and RVE8 as essential transcription factors that independently mediate early HS-induced gene expression. Using and mutants, we identified subsets of HSFA1s- or RVE4/8-dependent early HS-induced genes and showed RVE4/8 regulate plant thermotolerance partially by regulating the expression of downstream transcription factors () and , specifically around noon. These findings reveal a potential transcriptional regulatory hierarchy governing the first wave of HS-induced gene expression. They also provided important insight into the mechanism by which the circadian clock gates thermotolerance and prepares plants for exposure to high temperatures during the day.
虽然人们对植物的热激反应（HS）有了很多了解，但植物如何感知高温以及导致 HS 调节基因表达的主要 HS 信号转导途径仍知之甚少。为了鉴定介导 HS 调节基因表达的主要转录因子及其靶基因，我们对拟南芥中的基因进行了 RNA 测序，以检测在 HS 处理后迅速改变表达的基因。结果表明，在 HS 处理仅 5 分钟后，就有几个基因被诱导，这表明 HS 信号发生得非常快。对 HS 处理 10 分钟后上调基因的启动子中的 -元件进行分析，鉴定出热休克因子 A1s（HSFA1s）和生物钟蛋白 REVEILLE4（RVE4）和 RVE8 作为必需的转录因子，它们独立地介导早期 HS 诱导的基因表达。使用和 突变体，我们鉴定了 HSFA1s 或 RVE4/8 依赖的早期 HS 诱导基因的子集，并表明 RVE4/8 通过调节下游转录因子（）和 ，特别是在中午左右，部分调节植物的耐热性。这些发现揭示了一个潜在的转录调控层次，用于调控第一波 HS 诱导基因表达。它们还为生物钟调控耐热性并为植物在白天暴露于高温做好准备的机制提供了重要的见解。
