Regulation of calcium signal and signaling in plant immunity by BON1 associated proteins in Arabidopsis

由多种病原体引起的植物病害严重降低作物产量，威胁全球粮食安全。增强植物对各种病原体的天然免疫是防御植物感染和预防作物流行病的最有效方法之一。在分子水平上理解植物天然免疫是实现和加速具有增强的抗病性的植物的育种和生产的关键。在过去的三十年里，人们对植物天然免疫系统在分子和细胞水平上的认识有了巨大的增长。植物除了利用现有的物理屏障外，还利用诱导反应来阻止病原体入侵。已知钙作为信号和信使介导免疫应答的这种诱导。细胞内钙离子的水平、形状、幅度和频率等对外界刺激的响应特征可能携带刺激信息并引起不同的反应。钙信号是如何响应病原体而产生的，以及它如何转化为响应尚不清楚。该项目将研究几种蛋白质的功能，这些蛋白质对在植物-病原体相互作用模型系统中产生钙信号很重要。本研究将揭示钙信号和信号传导如何参与植物先天免疫应答。此外，该项目还将培训研究生、博士后研究员和本科生，使他们成为基础科学和农业部门的下一代科学家。它还将提供关于作物抗病性、农业和气候变化的公共教育。 最近的研究揭示了进化上保守的BON蛋白在拟南芥和水稻的抗病性中的调节作用。拟南芥BON 1与自抑制性钙ATP酶ACA 10/8和钙依赖性蛋白激酶CPK 3密切合作，调节拟南芥中的钙信号和信号转导。初步研究还表明，钙转运蛋白包括ACA 10/8，CCX 4和GLR 2作为CPK 3的目标，在钙信号的反馈调节。本研究的目的是鉴定植物免疫中钙信号产生分子及其受BON 1和CPK 3的调控。四个具体目标是：1）确定ACA 10/8、CCX 4和GLR 2对防御反应和钙信号的影响，2）研究BON 1对ACA 10/8的调节作用，3）研究防御反应中CPK 3对ACA 10/8的潜在调节，以及4）鉴定与CPK 3平行作用的抑制防御反应的组分。该研究将揭示植物免疫的新的调控机制。该奖项将获得有关钙信号对细菌病原体的响应特征、产生钙信号的钙转运分子以及钙信号的调节机制及其在防御反应中的解码的新信息。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估而被认为值得支持。

Plant diseases caused by diverse pathogens severely reduce crop yields and threaten global food security. Enhancing plant innate immunity against various pathogens is one of the most effective ways to defend plants against infection and prevent epidemics in crops. Understanding plant innate immunity at the molecular level is the key to enable and accelerate breeding and production of plants with enhanced disease resistance. The past three decades have seen a tremendous increase of knowledge on plant innate immunity systems at the molecular and cellular levels. Plants utilize induced responses in addition to existing physical barriers to deter pathogen invasion. It is known that calcium acts as a signal and messenger to mediate such an induction of immune responses. Specific features of calcium ion in the cell, such as its level, shape, amplitude, and frequency, in response to environment may carry stimulus information and induce distinct responses. How the signal of calcium is generated in response to pathogen and how it translates into responses are not understood. The project will investigate the function of several proteins that are important to generate calcium signals in a model plant-pathogen interaction system. The investigation will reveal how calcium signal and signaling contribute to plant innate immune response. Additionally, this project will train graduate students, postdoc fellows and undergraduate students and prepare them to become next-generation scientists in basic science and agriculture sectors. It will also provide public education on crop disease resistance, agriculture and climate change. Recent studies have revealed a regulatory role of evolutionarily conserved BON proteins in disease resistance of both Arabidopsis and rice. The Arabidopsis BON1 is found to work closely with auto-inhibitory calcium ATPases ACA10/8 and a calcium dependent protein kinase CPK3 to modulate calcium signature and signaling in Arabidopsis. Preliminary study also implicates calcium transport proteins including ACA10/8, CCX4 and GLR2 as CPK3 target in a feedback regulation of calcium signaling. This study aims to identify calcium signal generating molecules and their regulation by BON1 and CPK3 in plant immunity. Four specific aims are to: 1) determine the impact of ACA10/8, CCX4 and GLR2 on defense responses and calcium signature, 2) investigate the regulatory role of BON1 on ACA10/8, 3) investigate the potential regulation of ACA10/8 by CPK3 in defense response, and 4) identify components acting in parallel with CPK3 in dampening defense responses. This study will reveal new regulatory mechanisms in plant immunity. Novel information will be obtained on characteristics of calcium signatures in response to bacterial pathogens, calcium transport molecules for generating calcium signature, as well as regulatory mechanisms of calcium signature and its decoding in defense responses.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.