Regulation of plant cell-to-cell communication

胞间连丝是细胞质的一种通道，对植物的发育、逆境反应和病原体防御具有重要意义。它们也是植物病毒感染的渠道，而植物病毒是对全球农业经济产生影响的主要作物病原体。基于Tilsner实验室在了解胞间连丝结构和病毒运输方面的最新进展，以及Hemsley实验室开发的一种识别蛋白质-蛋白质相互作用的新方法，该项目将表征胞间连丝上的收缩机制，该机制被认为是调节植物细胞间通讯所必需的，并可能被用于病毒运输。一些肌动蛋白相关蛋白已定位于胞间连丝，并在某些情况下被证明参与调节植物细胞-细胞连接和病毒运输。该项目的目的是：分析胞间连丝中肌动蛋白相关蛋白之间的相互作用，确定推定的收缩结构的附加成分，测试单个和组合敲除突变对植物发育、细胞-细胞连接、病毒运输和胞间连丝超微结构的影响。该博士候选人将使用一种新的系统来检测体内蛋白质-蛋白质相互作用，以鉴定胞间连丝中与肌动蛋白相关的收缩系统的新成分。新候选的胞浆间质定位将通过荧光和电子显微镜确认。共同免疫沉淀和酵母双杂交测定将用于分析所有已知和新鉴定的成分之间的相互作用。这些蛋白之间的功能关系将通过拟南芥敲除系的杂交来探测，并将分析发育表型、病毒易感性和细胞间分子运输。该学生将前往合作实验室进行突变系间连丝形态的超微结构（电子断层扫描）分析。

Plasmodesmata are membrane-lined cytoplasmic channels which are of fundamental importance to plant development, stress responses and defence against pathogens. They also serve as conduits for infection by plant viruses, major crop pathogens with a global agro-economic impact. Building on recent advances in understanding plasmodesmata architecture and virus transport by the Tilsner lab, and a novel method for identifying protein-protein interactions developed by the Hemsley lab, this project will characterize a contractile machinery at plasmodesmata putatively required for the regulation of intercellular communication in plants, and likely co-opted for virus transport.Several actin-associated proteins have been localized to plasmodesmata and in some cases shown to be involved in regulation of plant cell-cell connectivity and virus transport. The aims of the project are: Analyse interactions between actin-related proteins at plasmodesmata Identify additional components of the putative contractile structure Test effects of individual and combined knock-out mutations on plant development, cell-cell connectivity, virus transport and plasmodesmata ultrastructure.The PhD candidate will use a novel system for detection of protein-protein interactions in vivo to identify new components of a putative actin-related contractile system at plasmodesmata. The plasmodesmal localization of new candidates will be confirmed by fluorescence and electron microscopy. Co-immunoprecipitation and yeast-two-hybrid assays will be used to analyse reciprocal interactions between all previously known and newly identified components. Functional relations between these proteins will be probed using crosses of Arabidopsis knock out lines, which will be analysed for developmental phenotypes, virus susceptibility and intercellular molecular transport. The student will travel to a collaborating lab for ultrastructural (electron tomography) analysis of plasmodesmata morphology in mutant lines.