Department of Plant Biotechnology, Hungarian University of Agriculture and Life Sciences, Genetics and Biotechnology Institute, Szent-Györgyi A. U. 4, Gödöllő, 2100, Hungary.
Biological Research Centre, Institute of Plant Biology, Szeged, Hungary.
Plant Cell Rep. 2024 Oct 10;43(11):260. doi: 10.1007/s00299-024-03345-1.
Barley reproductive fitness and efficient heat stress adaptation requires the activity of TFIIS, the elongation cofactor of RNAPII. Regulation of transcriptional machinery and its adaptive role under different stress conditions are studied extensively in the dicot model plant Arabidopsis, but our knowledge on monocot species remains elusive. TFIIS is an RNA polymerase II-associated transcription elongation cofactor. Previously, it was shown that TFIIS ensures efficient transcription elongation that is necessary for heat stress survival in A. thaliana. However, the function of TFIIS has not been analysed in monocots. In the present work, we have generated and studied independent tfIIs-crispr-mutant barley lines. We show that TFIIS is needed for reproductive development and heat stress survival in barley. The molecular basis of HS-sensitivity of tfIIs mutants is the retarded expression of heat stress protein transcripts, which leads to late accumulation of HSP chaperones, enhanced proteotoxicity and ultimately to lethality. We also show that TFIIS is transcriptionally regulated in response to heat, supporting a conserved adaptive function of these control elements for plant thermal adaptation. In sum, our results are a step forward for the better understanding of transcriptional machinery regulation in monocot crops.
大麦的生殖适应性和高效热应激适应需要 TFIIS 的活性，TFIIS 是 RNA 聚合酶 II 的延伸共因子。拟南芥作为双子叶模式植物，其转录机制的调控及其在不同应激条件下的适应作用已得到广泛研究，但单子叶物种的相关知识仍不清楚。TFIIS 是一种与 RNA 聚合酶 II 相关的转录延伸共因子。先前的研究表明，TFIIS 确保了热应激生存所必需的高效转录延伸。然而，在单子叶植物中，TFIIS 的功能尚未被分析。在本工作中，我们生成并研究了独立的 tfIIs-crispr 突变体大麦系。结果表明，TFIIS 是大麦生殖发育和热应激生存所必需的。tfIIs 突变体对热敏感的分子基础是热应激蛋白转录物的表达延迟，导致 HSP 伴侣的积累延迟，蛋白毒性增强，最终导致死亡。我们还表明，TFIIS 是转录调控响应热的，支持这些控制元件在植物热适应中的保守适应功能。总之，我们的结果为更好地理解单子叶作物中转录机制的调控迈出了一步。
