Ma Jing, Li Shuai, Wang Tengyue, Tao Zhen, Huang Shijie, Lin Ning, Zhao Yibing, Wang Chuanhong, Li Peijin
The National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, China.
Nat Commun. 2025 Jan 6;16(1):433. doi: 10.1038/s41467-025-55850-w.
Dissecting the mechanisms underlying heat tolerance is important for understanding how plants acclimate to heat stress. Here, we identify a heat-responsive gene in Arabidopsis thaliana, RNA-DIRECTED DNA METHYLATION 16 (RDM16), which encodes a pre-mRNA splicing factor. Knockout mutants of RDM16 are hypersensitive to heat stress, which is associated with impaired splicing of the mRNAs of 18 out of 20 HEAT SHOCK TRANSCRIPTION FACTOR (HSF) genes. RDM16 forms condensates upon exposure to heat. The arginine residues in intrinsically disordered region 1 (IDR1) of RDM16 are responsible for RDM16 condensation and its function in heat stress tolerance. Notably, RDM16 produces two alternatively spliced transcripts designated RDM16-LONG (RDL) and RDM16-SHORT (RDS). RDS also forms condensates and can promote RDL condensation to improve heat tolerance. Our findings provide insight into the cooperative condensation of the two RDM16 isoforms encoded by RDM16 splice variants in enhancing heat tolerance in Arabidopsis.
剖析耐热性的潜在机制对于理解植物如何适应热胁迫至关重要。在此，我们在拟南芥中鉴定出一个热响应基因，即RNA指导的DNA甲基化16（RDM16），它编码一种前体mRNA剪接因子。RDM16的敲除突变体对热胁迫高度敏感，这与20个热休克转录因子（HSF）基因中的18个基因的mRNA剪接受损有关。RDM16在受热时会形成凝聚物。RDM16内在无序区域1（IDR1）中的精氨酸残基负责RDM16的凝聚及其在耐热性中的功能。值得注意的是，RDM16产生两种可变剪接转录本，分别命名为RDM16长型（RDL）和RDM16短型（RDS）。RDS也会形成凝聚物，并能促进RDL凝聚以提高耐热性。我们的研究结果为RDM16剪接变体编码的两种RDM16异构体在增强拟南芥耐热性中的协同凝聚提供了见解。
