Rana Priyanshi, Edathil Kadangodan Anjana, Koley Paulami, Ghosh Riya, Pullagurla Naga Jyothi, Naik Hemant Chandru, Mondal Padmabati, Gayen Srimonta, Laha Debabrata
Department of Biochemistry, Indian Institute of Science (IISc), Bengaluru, India.
Department of Developmental Biology and Genetics, IISc, Bengaluru, India.
Nat Chem Biol. 2025 Jul 31. doi: 10.1038/s41589-025-01961-w.
DELLA proteins integrate external and internal cues into a signaling network critical for land plant survival. In flowering plants, gibberellins (GAs) induce DELLA recognition to its receptor GID1, resulting in the polyubiquitylation and degradation of DELLA repressors. Notably, bryophytes lack the canonical GA receptor, despite the presence of genes encoding DELLA in these nonvascular land plants. Consequently, the underlying molecular mechanisms of DELLA regulation in bryophytes have remained largely elusive. Here, we report that MpVIH, responsible for the synthesis of inositol pyrophosphate messenger InsP, negatively regulates DELLA in the liverwort Marchantia polymorpha to promote cell division and thallus development. Mechanistically, we elucidate that MpVIH-derived InsP binds to MpDELLA, promoting polyubiquitination and proteasomal degradation of the repressor. Lastly, our study provides evidence for the conservation of inositol pyrophosphate-controlled DELLA degradation in angiosperms. We, thus, identify a 'noncanonical' type of DELLA regulation by the inositol pyrophosphate messengers in land plants.
DELLA蛋白将外部和内部信号整合到一个对陆地植物生存至关重要的信号网络中。在开花植物中，赤霉素（GAs）诱导DELLA被其受体GID1识别，导致DELLA阻遏蛋白的多聚泛素化和降解。值得注意的是，苔藓植物缺乏典型的GA受体，尽管这些非维管陆地植物中存在编码DELLA的基因。因此，苔藓植物中DELLA调控的潜在分子机制在很大程度上仍然不清楚。在这里，我们报告说，负责肌醇焦磷酸信使InsP合成的MpVIH对地钱（Marchantia polymorpha）中的DELLA起负调控作用，以促进细胞分裂和叶状体发育。从机制上讲，我们阐明了MpVIH衍生的InsP与MpDELLA结合，促进阻遏蛋白的多聚泛素化和蛋白酶体降解。最后，我们的研究为被子植物中肌醇焦磷酸控制的DELLA降解的保守性提供了证据。因此，我们在陆地植物中确定了一种由肌醇焦磷酸信使介导的“非典型”DELLA调控类型。
