Effects of other microbes and the host on the interaction and ecological function of Pseudomonas and Sphingomonas isolates with plants

德国西南部野生拟南芥植物叶片中最常见的细菌属是假单胞菌属和鞘氨醇单胞菌属。虽然有许多致病假单胞菌，但鞘氨醇单胞菌属病原体很少，如果有的话，但两个分类群都包括可以保护植物免受病原体影响的菌株。尽管这两个属的普遍存在，他们表现出不同的分布模式在野生A。Thaliana植物：鞘氨醇单胞菌种群在个体植物中的丰度非常均匀，而假单胞菌的丰度变化很大，并且只有假单胞菌是这些植物中总体微生物负荷的强预测因子。我们将调查简化的假单胞菌和鞘氨醇单胞菌群落，以了解植物体内假单胞菌和鞘氨醇单胞菌菌株之间的相互作用及其对宿主的影响。具体的问题，我们将问：（一）什么生态相关的基因基础植物保护的假单胞菌菌株？(ii)鞘氨醇单胞菌属菌株之间的性状、生态位和功能，包括与假单胞菌和简化的微生物群落的相互作用，有何不同？(iii)鞘氨醇单胞菌群落是如何建立的，它们的多样性和组成如何影响植物健康，以及它们如何与其他微生物相互作用？

The most common bacterial genera in leaves of wild Arabidopsis thaliana plants in Southwest Germany are Pseudomonas and Sphingomonas. While there are many pathogenic Pseudomonas, there are few, if any, Sphingomonas pathogens, but both taxa include strains that can protect plants from the effects of pathogens. Despite the ubiquity of both genera, they exhibit contrasting distribution patterns across wild A. thaliana plants: The abundances of Sphingomonas populations in individual plants are very uniform, whereas those of Pseudomonas greatly vary, and only Pseudomonas is a strong predictor of overall microbial load in these plants. We will investigate simplified Pseudomonas and Sphingomonas communities to learn about interactions between Pseudomonas and Sphingomonas strains inside plants and their effects on the host. Specific questions that we will ask are: (i) What ecologically relevant genes underlie plant protection by commensal Pseudomonas strains? (ii) How do traits, niches and functions, including interaction with Pseudomonas and a simplified microbial community, differ among individual Sphingomonas strains? (iii) How are Sphingomonas communities established, how do their diversity and composition affect plant health, and how do they interact with other microbes?