Mutual interactions between biological timing and innate immunity in Arabidopsis

我们将研究两个不同的信号网络，都有助于植物性能的交错：内源性时钟系统用于最佳地调整植物生理学的周期性变化的光和暗的环境，并通过这些手段有助于植物的健身，和先天免疫系统提供的策略，植物对入侵病原体的自我防御。在哺乳动物和苍蝇中，已经报道了昼夜节律和先天免疫之间的相互作用的一些情况。我们最近的观察表明，拟南芥中的从属振荡器组件是先天免疫系统的一部分，这表明在高等植物中也存在密切的相互作用。此外，拟南芥的昼夜节律转录组包括参与病原体防御的基因。我们将从两个方向来解决这个功能连接。我们将研究病原体挑战对昼夜节律的影响。首先，我们将测试病原体相关的分子模式（PAMPs）的影响，随后细菌感染的影响，使用选定的时钟控制的转录物的振荡作为昼夜节律读数。相反，我们将分析受损的内源性定时系统对植物免疫反应的后果。一套突变体和转基因植物在选定的昼夜节律系统的组成部分中断将测试其对PAMPs的反应和疾病症状的发展和细菌感染后的生存。这些实验将提供见解，昼夜节律系统在多大程度上有助于植物免疫。这可能是一个完整的生物钟对植物性能的额外好处。

We will investigate the interdigitation of two distinct signaling networks that both contribute to plant performance: The endogenous clock system serves to optimally align plant physiology to the periodic changes of light and darkness in the environment and by these means contributes to fitness of the plant, and the innate immune system provides strategies to the plant for self-defense against invading pathogens. A few cases of mutual interactions between circadian rhythmicity and innate immunity have been reported in mammals and flies. Our recent observation that a slave oscillator component in Arabidopsis thaliana is part of the innate immune system suggests a close interaction also in higher plants. Moreover, the circadian transcriptome of Arabidopsis comprises genes involved in pathogen defense. We will address this functional connection from both directions. We will investigate the impact of pathogen challenge on circadian rhythms. First we will test the influence of pathogenassociated molecular patterns (PAMPs) and subsequently the effect of bacterial infection, using the oscillation of selected clock-controlled transcripts as a circadian readout. Conversely, we will analyse the consequences of an impaired endogenous timing system on plant immune responses. A suite of mutants and transgenic plants disrupted in selected components of the circadian system will be tested for their responses to PAMPs and for disease symptom development and survival upon bacterial infection. These experiments will provide insights to what extent the circadian system contributes to plant immunity. This may emerge as an additional benefit of an intact circadian clock for plant performance.