Systemic phloem signals for compatibility or defence in response to fungal infections in Zea mays and Hordeum vulgare

本项目的目标是捕获韧皮部传递的信号，负责系统诱导敏感性（SIS）和病原体攻击时的代谢重定向。直接收集韧皮部样品可能是发现这些未知化合物的一种有希望的方法。根据文献资料和一系列初步实验，我们得出结论，钙可能是长途信号传递中被忽视的必需元素。在本研究中，将提高韧皮部汁液微采样的产量，并采用适应不同病理系统的采集方法。将筛选韧皮部汁液在感染和未感染的亲和株系之间的成分变化。植物/真菌系统将是玉米/玉米黑穗病菌、玉米/玉米炭疽菌、普通玉米/谷物蓝孢菌和普通玉米/印度梨孢菌。在寻找候选信号的过程中，我们将首先关注Ca2+共轭物和茉莉酸及其近亲。在第二波分析中，将测试筛管液的糖、氧自由基和氧化还原状态。最后的分析部分将包括大分子的检测，如蛋白质、蛋白质复合物和几种rna形式。有了手头的技术，我们也许能够通过同一组实验来追踪具有相容性和抗性的化合物。

Goal of this project is to catch phloem-borne signals responsible for systemic induced susceptibility (SIS) and metabolic redirection upon pathogen attack. Direct collection of phloem samples may be one promising approach to find these unknown compounds. Based on literature data and a series of preliminary experiments, we reached the conclusion that calcium may be a neglected essential element in longdistance signalling. In this study, the yield of micro-sampling of phloem sap will be improved and the collection methods adapted to the pathosystems. The phloem sap will be screened for shifts in composition between infected and non-infected compatible plant lines. Plant/fungus systems will be Zea mays/Ustilago maydis, Zea mays/Colletotrichum graminicola, Hordeum vulgare/ Blumeria graminis and Hordeum vulgare/Piriformospora indica. In the chase for candidate signals, we will first focus on Ca2+-conjugates and jasmonic acid and its relatives. In a second wave of analyses, sugars, oxygen radicals and the redox state of the sieve tube sap will be tested. The last analytical part will include the detection of macromolecules such as proteins, protein complexes and several RNA-forms. With the techniques at hand, we may be able to trace compounds responsible for both compatibility and resistance by the same set of experiments.