Functional roles of Cercozoa in the rhizosphere and phyllosphere of plants (CERCOPLANT)

原生动物是陆生系统中主要的细菌食草动物，由于(1)消耗的细菌生物量释放出限制生长的营养物质和(2)细菌群落组成和功能的变化，通常对植物生长产生显著的积极影响。然而，关于特定土壤原生动物分类群的物种特征、多样性和功能作用差异的研究却非常缺乏。在土壤原生动物中，尾虫（Cercomonadida）是一个高度多样化的，可能是最多产的陆地鞭毛虫群。该项目旨在确定Cercozoa在植物根际和根层中的物种特征和量化多样性，并将Cercozoa的特定系统发育和表型特征与放牧引起的细菌群落组成和功能的时空变化联系起来。该项目将进一步研究植物根际中尾虫类群的功能冗余和互补性程度，以及它们对细菌多样性和植物生长性能的原位影响。在根层圈中，本项目将研究绒尾虫和不同根层圈细菌类群的空间元种群动态，并建立这些捕食-被捕食动态的时空动态模型，以表征其潜在机制，并确定绒尾虫和细菌的功能特征，这些特征决定了它们在根层圈群落动态中的核心作用。

Protozoa are the dominant bacterial grazers in terrestrial systems and often exert significant positive effects on plant growth, due to (1) the release of growth-limiting nutrients from consumed bacterial biomass and (2) changes in bacterial community composition and function. However, information on the species identity, the diversity and on differences in the functional roles of specific soil protozoan taxa is largely lacking. Among soil protozoa, the Cercozoa (Cercomonadida) are a highly diverse, and probably the most productive group of terrestrial flagellates. The project aims to determine the species identity and to quantify the diversity of Cercozoa in the rhizosphere and phyllosphere of plants and to link specific phylogenetic and phenotypic traits of the cercomonads to grazing-induced changes in bacterial community composition and function in space and time. The project will further investigate the degree of functional redundancy and complementarity of cercozoan taxa in the plant rhizosphere, and their in situ effects on the diversity of bacteria and on plant performance. In the phyllosphere, the project will investigate the spatial metapopulation dynamics of Cercozoa and different phyllosphere bacterial taxa and model the spatial and temporal dynamics of these predator-prey dynamics in order to characterize the underlying mechanisms and identify the functional traits of Cercozoa and bacteria that define their central role in phyllosphere community dynamics.