Mechanisms regulating plant immune homeostasis

植物免疫稳态调节机制

• 批准号: RGPIN-2016-04787
• 负责人: Monaghan, Jacqueline
• 金额: $ 6.7万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745820
• 关键词: Mechanisms; regulating; plant; immune; homeostasis

Plant diseases account for 15% of annual global crop losses (estimated worth of $100 billion) and currently require costly and environmentally unfriendly chemical treatments. Pathogens are capable of infecting crops and causing disease largely because they can suppress plant immune responses. Thus, only when we clearly understand the plant immune system will we be able to offer safe and sustainable solutions to diseases that affect our crops. Because pathogen responses necessarily re-direct plant energy away from growth, a major challenge is how to boost plant immunity without affecting yield.The long-term goal of my research program is to understand the molecular mechanisms that tailor plant immune signaling to maintain cellular homeostasis in the model plant Arabidopsis thaliana. I am particularly interested in how immune signaling enzymes are regulated by post-translational modifications and differential binding partners/substrates, and how positive and negative signaling cascades are established and controlled. The proposed research addresses the impact of immune signaling on plant homeostasis at the molecular level and integrates molecular and cell biology, biochemistry, and proteomics with forward- and reverse-genetics. Owing to the multi-disciplinary nature of our research program, lab personnel will be trained in a broad range of techniques spanning molecular biology, biochemistry, and plant genetics.Arabidopsis and other plants perceive pathogens via receptor kinases located at the cell surface. The kinase BIK1 is phosphorylated (and activated) by several receptors and is integral to plant immune signaling. Demonstrating its importance, BIK1 is the target of multiple unrelated pathogens to dampen immune signaling. We recently showed that plants maintain an optimal level of BIK1 through a process of continuous proteasomal degradation influenced by the kinase CPK28, which also interacts with and phosphorylates BIK1. Thus, it seems that BIK1 is both positively and negatively regulated by phosphorylation, raising the intriguing possibility that residue-specific or quantitative differences contribute to the two states. We will characterize phosphorylation and subsequent ubiquitination events on BIK1 and study how these events control its turnover. Furthermore, we will identify the E3 ligase(s) responsible for BIK1 degradation. To understand more about how CPK28 is regulated, will characterize CPK28-associated proteins that we recently identified by mass-spectrometry. Because of the need to identify novel proteins involved in plant immune signaling that may also be pathogen targets, we will also screen for such proteins using forward-genetics. My program provides an excellent training environment for HQP to make a high impact in plant molecular biology using state-of-the-art technologies that will inform agricultural practices in Canada and world-wide.

植物病害占全球每年作物损失的15%（估计价值1000亿美元），目前需要昂贵且对环境不友好的化学处理。病原体能够感染作物并导致疾病，主要是因为它们可以抑制植物的免疫反应。因此，只有当我们清楚地了解植物免疫系统时，我们才能够为影响作物的疾病提供安全和可持续的解决方案。由于病原体反应必然会将植物能量从生长中转移，因此一个主要的挑战是如何在不影响产量的情况下提高植物免疫力。我的研究计划的长期目标是了解调节植物免疫信号以维持模式植物拟南芥细胞内稳态的分子机制。我特别感兴趣的是免疫信号酶如何通过翻译后修饰和差异结合伴侣/底物进行调节，以及如何建立和控制正和负信号级联。拟议的研究在分子水平上解决了免疫信号对植物稳态的影响，并将分子和细胞生物学，生物化学和蛋白质组学与正向和反向遗传学相结合。由于我们的研究项目具有多学科性质，实验室人员将接受分子生物学、生物化学和植物遗传学等广泛技术的培训。拟南芥和其他植物通过位于细胞表面的受体激酶感知病原体。激酶BIK 1被几种受体磷酸化（和激活），是植物免疫信号传导的组成部分。BIK 1是多种不相关病原体抑制免疫信号传导的靶点，这证明了它的重要性。我们最近发现，植物通过受激酶CPK 28影响的连续蛋白酶体降解过程保持最佳水平的BIK 1，该激酶CPK 28也与BIK 1相互作用并使其磷酸化。因此，BIK 1似乎受到磷酸化的正向和负向调节，这提高了残基特异性或定量差异促成这两种状态的有趣可能性。我们将描述BIK 1的磷酸化和随后的泛素化事件，并研究这些事件如何控制其营业额。此外，我们将鉴定负责BIK 1降解的E3连接酶。为了更好地了解CPK 28是如何调节的，将描述我们最近通过质谱鉴定的CPK 28相关蛋白。由于需要鉴定参与植物免疫信号传导的新蛋白质，这些蛋白质也可能是病原体的靶标，我们还将使用正向遗传学筛选此类蛋白质。我的计划为HQP提供了一个良好的培训环境，使用最先进的技术在植物分子生物学方面产生重大影响，这些技术将为加拿大和世界各地的农业实践提供信息。