Calcium signalling induced by MAMPs (Microbe-associated molecular patterns) in Arabidopis thaliana

钙是普遍存在的信号转导的第二信使。与叶片中的flg22一样，Piriformospora indica的细胞壁提取物（CWE）可以模拟真菌的生长促进作用，诱导根中细胞质Ca2+ ([Ca2+]cyt)的快速和短暂增加。利用表达Ca2+传感器aequorin的转基因拟南芥，我们分离出了对根中CWE或茎中flg22的Ca2+响应受损的EMS突变体。除了完成两个MAMPs的突变体筛选外，延长期间的目标是：(a)表征鉴定的突变体，证明其特异性并分析突变体中mamp诱导的下游反应，(b)通过基于图谱的克隆鉴定选定数量的突变基因，(c)研究第二信使的作用，例如磷脂，作为两个系统中的[Ca2+]调节剂，以及(d)从籼菜CWE中纯化活性化合物。此外，cameleon系统将用于提高钙特征表征的分辨率。长期目标是将钙信号与下游反应联系起来，并填补目前关于植物与微生物相互作用过程中钙信号的知识空白。

Calcium is a universal signal transduction second messenger. Like flg22 in leaves, a cell wall extract (CWE) from Piriformospora indica, which mimics the growth promotion effects of the fungus, induces a rapid and transient increase in cytoplasmic Ca2+ ([Ca2+]cyt) elevation in the roots. Using transgenic Arabidopsis expressing the Ca2+ sensor aequorin, we have isolated EMS mutants impaired in their Ca2+ response to the CWE in roots or to flg22 in shoots. In addition to completing the mutant screen for the two MAMPs, the aims during the extension period are: (a) to characterize the identified mutants, demonstrate their specificity and analyse MAMP-induced downstream responses in the mutants, (b) to identify a selected number of mutated genes by map-based cloning, (c) to investigate the role of second messengers, e.g. phospholipids, as modulators of [Ca2+] in both systems, and (d) to purify the active compound from the P. indica CWE. Additionally, the cameleon system will be used to improve the resolution of calcium signature characterization. The long term goal is to link the calcium signature to downstream responses and to fill in gaps in current knowledge of calcium signalling during plant-microbe interactions.