Guangdong Provincial Key Laboratory of Plant Molecular Breeding, State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, South China Agricultural University, Guangzhou, 510640, China.
School of Integrative Plant Science, Plant Biology Section, Cornell University, Ithaca, NY, 14853, USA.
J Integr Plant Biol. 2023 Aug;65(8):1890-1903. doi: 10.1111/jipb.13498. Epub 2023 Jun 14.
Lipid droplet (LD) in vegetative tissues has recently been implicated in environmental responses in plants, but its regulation and its function in stress tolerance are not well understood. Here, we identified a Membrane Occupation and Recognition Nexus 1 (MORN1) gene as a contributor to natural variations of stress tolerance through genome-wide association study in Arabidopsis thaliana. Characterization of its loss-of-function mutant and natural variants revealed that the MORN1 gene is a positive regulator of plant growth, disease resistance, cold tolerance, and heat tolerance. The MORN1 protein is associated with the Golgi and is also partly associated with LD. Protein truncations that disrupt these associations abolished the biological function of the MORN1 protein. Furthermore, the MORN1 gene is a positive regulator of LD abundance, and its role in LD number regulation and stress tolerance is highly linked. Therefore, this study identifies MORN1 as a positive regulator of LD abundance and a contributor to natural variations of stress tolerance. It implicates a potential involvement of Golgi in LD biogenesis and strongly suggests a contribution of LD to diverse processes of plant growth and stress responses.
脂滴（LD）在营养组织中最近被牵涉到植物的环境响应中，但它的调控及其在胁迫耐受性中的功能还没有得到很好的理解。在这里，我们通过拟南芥的全基因组关联研究，鉴定出一个膜占领和识别连接蛋白 1（MORN1）基因为胁迫耐受性自然变异的贡献者。其功能丧失突变体和自然变异体的特征表明，MORN1 基因是植物生长、抗病性、耐寒性和耐热性的正调节剂。MORN1 蛋白与高尔基体有关联，也与 LD 部分有关联。破坏这些关联的蛋白截断使 MORN1 蛋白的生物学功能丧失。此外，MORN1 基因是 LD 丰度的正调节剂，其在 LD 数量调控和胁迫耐受性中的作用高度相关。因此，本研究将 MORN1 鉴定为 LD 丰度的正调节剂和胁迫耐受性自然变异的贡献者。它暗示了高尔基体在 LD 生物发生中的潜在作用，并强烈表明 LD 对植物生长和应激反应的多种过程有贡献。
