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.

植物可招募有益微生物以增强自身抵御病原物的能力。然而，相较于微生物招募过程受多种根系分泌物的合成所调控这一已知机制，由侵染性病原物引发的叶片代谢物变化是否能主动招募有益微生物并由此对抗叶部病原物，这一问题在很大程度上仍未得到充分探讨。本研究整合Illumina扩增子测序（Illumina amplicon sequencing）与液相色谱-质谱联用（LC-MS, Liquid Chromatography-Mass Spectrometry）分析，系统探究了两种海棠在受山田胶锈菌（G. yamadae）侵染后的6个时间点下，叶围（phyllosphere）真菌、细菌群落及关键叶片代谢物的动态变化。本研究旨在明确三方面内容：其一，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；其二，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；其三，受侵染叶片的代谢物如何调控叶围微生物组的组装模式及其共现关系。