Metabolites-Mediated Response of Phyllosphere Microbiota to Rust Infection in Leaves of two Malus Species

Plants can recruit beneficial microbes to enhance their ability to against pathogens. However, in contrast to that the recruitment of microbes is regulated by the production of multiple root exudates, it remains largely underestimated whether changes in leaf metabolites caused by infectious pathogens could actively recruit beneficial microbes and thus combat foliar pathogens. Here, we integrated the Illumina amplicon sequencing and LC-MS analysis to systematically explore the dynamics of phyllosphere fungal and bacterial communities and key leaf metabolites in two crabapple species at six stages after infection of G. yamadae. We aimed to assess how phyllosphere microbial communities responded to G. yamadae infection during the rust colonization from the spermogonial to aecial stages; the key metabolites with significantly differently abundance in G. yamdaea infected leaves; how metabolites in G. yamadae infected leaves shape phyllosphere microbiomes assemblies and the co-occurrence patterns.

植物可通过招募有益微生物来增强自身抵御病原菌的能力。然而，与微生物招募过程受多种根系分泌物合成调控的已有机制不同，由侵染性病原菌诱导的叶片代谢物变化是否能够主动招募有益微生物并对抗叶部病原菌，这一问题在很大程度上仍未得到充分关注。本研究整合Illumina扩增子测序与液相色谱-质谱联用（LC-MS）分析技术，系统探究了两个海棠物种在受山田胶锈菌（G. yamadae）侵染后的六个时间节点的叶围真菌、细菌群落动态，以及关键叶片代谢物的变化规律。本研究旨在明确三方面核心内容：一是在从性孢子器阶段到锈孢子器阶段的锈病定殖过程中，叶围微生物群落对山田胶锈菌侵染的响应模式；二是受山田胶锈菌侵染的叶片中丰度存在显著差异的关键代谢物；三是受侵染叶片的代谢物如何调控叶围微生物组的组装及其共现模式。