How does the circadian clock regulate disease resistance?

本项目研究植物的生物钟（分子钟）如何在一天的不同时间改变对感染的易感性。这是一个令人兴奋的机会，在一个新的领域工作，学习一系列现代实验和计算技能，并加入一个积极，热情的研究小组。该研究将涉及遗传学、分子生物学、蛋白质组学、高通量酵母双杂交、转录组学、病原体感染检测、基因组学、基因编辑和计算生物学。几乎所有的生物体，从蓝藻到植物和动物，都拥有生物钟。生物钟产生一个约24小时的节律，这是由每天的光和温度周期设定的。这使生物体能够预测日常事件，如黎明和黄昏。对于不能移动的植物来说，生物钟对于使其新陈代谢与环境同步尤为重要。最近发现，生物钟也影响植物的免疫力;在一天中的不同时间接种的植物对病原体表现出不同的敏感性。我们证明，与夜间接种相比，在黎明接种后，拟南芥植物对灰葡萄孢（一种真菌病原体）表现出更大的抗性（Ingle et al. 2015 Plant Journal）。植物在黎明或夜晚接种时的易感性差异是由植物的生物钟驱动的。植物免疫反应涉及由调控网络内的转录因子调控的基因表达的显着变化。在黎明接种后，这种防御网络被激活得更快，从而对病原体产生更有效的抵抗力。令人难以置信的是，防御反应失活的四小时差异导致疾病进展的显着差异。时机就是一切！我们发现激素（茉莉酸）信号通路中的一种蛋白质控制着白天疾病易感性的变化。这种蛋白质JAZ 6通过靶向转录因子发挥作用。我们现在想知道生物钟是如何通过JAZ 6控制抗病性的？JAZ 6依赖的抗病性有多广泛？JAZ 6靶向调控网络中的哪些转录因子？防御网络的变化是如何导致抗病能力增强的？JAZ 6活动的时间是什么？关键的是，我们想研究我们是否可以改变作物中的JAZ 6，以更快地激活防御网络并增强抗病性。JAZ 6的直系同源物存在于芸苔属、莴苣和番茄（所有受B.cinerea感染的作物）中，我们将使用基因编辑来测试JAZ 6是否是这些作物中的时钟免疫调节剂。

This project investigates how a plant's circadian clock (molecular clock) altersits susceptibility to infection at different times of the day. It is an excitingopportunity to work in a new field, learn a range of modern experimental andcomputational skills and join an active, enthusiastic research group. Theresearch will involve genetics, molecular biology, proteomics, high-throughputyeast-2-hybrid, transcriptomics, pathogen infection assays, genomics, geneediting and computational biology.Almost all living organisms ranging from cyanobacteria to plants and animalspossess a circadian clock. The circadian clock generates an ~24 h rhythm that isset by daily cycles of light and temperature. This enables organisms toanticipate regular daily events such as dawn and dusk. For plants, which cannotmove, the circadian clock is particularly important to synchronise itsmetabolism with the environment. Recently it was discovered that the clockalso impacts plant immunity; plants inoculated at different times of the dayshow differing susceptibility to pathogens. We demonstrated that Arabidopsisplants showed greater resistance to Botrytis cinerea, a fungal pathogen, afterinoculation at dawn compared to inoculation during the night (Ingle et al. 2015Plant Journal). The difference in susceptibility when the plants are inoculated atdawn or night is driven by the plant circadian clock.The plant immune response involves significant changes in gene expressionregulated by transcription factors within a regulatory network. Afterinoculation at dawn this defence network is activated faster leading to moreeffective resistance against the pathogen. Incredibly a four-hour difference inactivation of the defence response leads to a dramatic difference in diseaseprogression. Timing is everything! We have found that a single protein in ahormone (jasmonic acid) signaling pathway controls the change in diseasesusceptibility during the day. This protein, JAZ6, works by targetingtranscription factors.We now want to ask how does the clock via JAZ6 control disease resistance?How broad is JAZ6-dependent disease resistance? What transcription factors inthe regulatory network does JAZ6 target? How do changes in the defencenetwork cause increased disease resistance? What is the timing of JAZ6activity?Critically we want to investigate whether we can alter JAZ6 in crop plants toactivate the defence network faster and enhance disease resistance. JAZ6orthologues are present in Brassica, lettuce and tomato (all crops infected by B.cinerea) and we will use gene editing to test whether JAZ6 is a clock-immunityregulator in these crops.