Wang Wentao, Lu Yue, Li Junjie, Zhang Xinran, Hu Fangfang, Zhao Yu, Zhou Dao-Xiu
National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan 430070, China.
Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, China.
Plant Cell. 2021 Dec 3;33(12):3721-3742. doi: 10.1093/plcell/koab224.
Plant SNF1-Related Kinase1 (SnRK1) is an evolutionarily conserved energy-sensing protein kinase that orchestrates transcriptional networks to maintain cellular energy homeostasis when energy supplies become limited. However, the mechanism by which SnRK1 regulates this gene expression switch to gauge cellular energy status remains largely unclear. In this work, we show that the rice histone H3K27me3 demethylase JMJ705 is required for low energy stress tolerance in rice plants. The genetic inactivation of JMJ705 resulted in similar effects as those of the rice snrk1 mutant on the transcriptome, which impairs not only the promotion of the low energy stress-triggered transcriptional program but also the repression of the program under an energy-sufficient state. We show that the α-subunit of OsSnRK1 interacts with and phosphorylates JMJ705 to stimulate its H3K27me3 demethylase activity. Further analysis revealed that JMJ705 directly targets a set of low energy stress-responsive transcription factor genes. These results uncover the chromatin mechanism of SnRK1-regulated gene expression in both energy-sufficient and -limited states in plants and suggest that JMJ705 functions as an upstream regulator of the SnRK1α-controlled transcriptional network.
植物蔗糖非发酵-1-相关蛋白激酶1（SnRK1）是一种进化上保守的能量感应蛋白激酶，当能量供应受限，它会协调转录网络以维持细胞能量稳态。然而，SnRK1调节这种基因表达开关以评估细胞能量状态的机制仍不清楚。在这项研究中，我们表明水稻组蛋白H3K27me3去甲基化酶JMJ705是水稻植株耐低能量胁迫所必需的。JMJ705的基因失活对转录组产生了与水稻snrk1突变体类似的影响，这不仅损害了低能量胁迫触发的转录程序的促进作用，还损害了能量充足状态下该程序的抑制作用。我们发现OsSnRK1的α亚基与JMJ705相互作用并使其磷酸化，从而刺激其H3K27me3去甲基化酶活性。进一步分析表明，JMJ705直接靶向一组低能量胁迫响应转录因子基因。这些结果揭示了植物在能量充足和受限状态下SnRK1调节基因表达的染色质机制，并表明JMJ705作为SnRK1α控制的转录网络的上游调节因子发挥作用。
