Real-time plant evolution in a multitrophic community

理解多营养群落的进化过程是进化生物学中一个基本而突出的挑战。在自然界中，植物受到食草动物的威胁，同时受到各种微生物的殖民。越来越多的证据表明，植物微生物群改变了宿主对食草动物的防御，并被食草动物改变。然而，在食草压力下，植物与其微生物群之间的相互作用在多大程度上影响植物进化的过程和轨迹仍然是未知的。本项目旨在通过实时研究食草驱动的植物进化过程和机制来填补这一知识空白。我们将使用生长最快的植物之一--大浮萍（Spirophilopolyrhiza）作为模型系统进行“选择和重排序”实验。我们将使用池螺（Stagnalis）对S施加食草压力。由150个代表本物种遗传多样性的自然加入物组成的多根种群。试验在田间条件下进行，历时6个月，相当于S.多根我们将量化草食动物驱动植物表型，等位基因频率和微生物群变化的程度。我们将进一步评估所观察到的植物性状和等位基因频率变化的适应性后果，并研究植物微生物群的变化是否以及如何改变对植物防御的草食性选择。利用实验进化和尖端的遗传和基因组工具相结合，这项研究将通过阐明植物防御进化的机制和过程，推动植物-草食动物相互作用领域的研究边界。该项目所产生的资源不仅将为植物实验进化开辟新的研究途径，而且还将加速浮萍的工业应用。

Understanding the process of evolution in multitrophic communities represents a fundamental and outstanding challenge in evolutionary biology. In nature, plants are threatened by herbivores and simultaneously colonized by diverse microorganisms. Accumulating evidence suggests that the plant microbiota changes the host’s defense against herbivores and is altered by herbivory. However, it remains unknown to what extent interactions between plants and their microbiota affect the process and trajectory of plant evolution under herbivore pressure.This project aims to close this knowledge gap by investigating the process and mechanism of herbivory-driven plant evolution in real-time. We will perform “selection and resequence” experiments using the giant duckweed (Spirodela polyrhiza), one of the fastest-growing plants, as a model system. We will use the pond snail (Lymnaea stagnalis) to impose herbivory pressure on S. polyrhiza populations consisting of 150 natural accessions that represent the majority of genetic diversity in this species. The experiment will be conducted under field conditions and last for 6 months, which corresponds to more than 30 generations for S. polyrhiza. We will quantify the extent to what herbivory drives changes in the plant phenotype, allele frequency, and microbiota. We will further assess the fitness consequences of the observed changes in plant traits and allele frequencies, and investigate whether and how changes in the plant microbiota alter the herbivory-imposed selection on plant defenses. Using a combination of experimental evolution and cutting-edge genetic and genomic tools, this research will push the research boundaries in the field of plant-herbivore interaction by elucidating the mechanisms and processes of plant defense evolution in a multitrophic community. The resources generated in this project will not only open new research avenues of plant experimental evolution, but will also accelerate the use of duckweeds for industrial applications.