拟南芥PLM调控神经酰胺合成及胞间连丝通透性的机制研究

提高糖、蛋白质等营养物质在植物不同器官的定向运输效率可以促进生长和增产。由胞间连丝介导的共质体运输是植物体内物质转运和信号交流的重要途径。胞间连丝通透性受到动态调节，但其调控机制仍不清楚。申请人前期研究发现PLM基因功能缺失降低鞘脂分子超长链脂肪酸神经酰胺的含量，抑制胞间连丝形态转变，导致胞间连丝通透性和韧皮部同化物卸载增强。然而具体调控机制尚不明确。本项目拟通过细胞生物学、生物化学、分子生物学、组学分析等手段进一步研究 (1）PLM对神经酰胺合成的作用方式 (2）神经酰胺合成对胞间连丝结构组分的影响 (3）PLM-神经酰胺调控胞间连丝通透性与昼夜环境适应。研究结果有望阐明以PLM介导神经酰胺合成为核心的胞间连丝结构与功能调控和环境适应的机制，建立胞间连丝通透性调控研究的基础性工具和前沿性平台，为通过调节共质体运输来促进植物生长和抗逆提供新的思路。

Improving the transport efficiency of sugar, proteins and other nutritions between different parts of plants can promote crop growth and yield. Plasmodesmata-mediated symplastic transport acts as an important way of material and signal exchange in plants. The permeability of plasmodesmata is regulated dynamically, but its mechanism remains unclear. Our previous study proved that the absence of PLM significantly reduced the biosynthesis of ceramide containing very-long-chain fatty acids, a kind of sphingolipids, and inhibited the morphological transformation of plasmodesmata, resulting in enhanced permeability and phloem unloading. However, the regulatory mechanism is still not clear. In this project, we intend to further study (1) the regulation of ceramide synthesis by PLM (2) the alteration of plasmodesmal structural components by PLM-mediatd ceramide synthesis (3) the day-night environment adaptation of PLM-ceramide-mediated plasmodesmal permeability regulation by means of cell biology, biochemistry, molecular biology, proteomics and lipidomics. Our work will further elucidate the mechanism of structural and functional regulation and environmental adaptation of plasmodesmata with PLM-mediated ceramide synthesis as the core, and establish the basic tools and cutting-edge platforms for the study of plasmodesmata permeability regulation. It will also provide a new ideas for promoting plant growth and stress resistance by modulating symplastic transport.