Molecular mechanisms that boost systemic immunity in plants

增强植物系统免疫力的分子机制

• 批准号: 2026368
• 负责人: Mary Beth Mudgett
• 金额: $ 97.5万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2026368&HistoricalAwards=false
• 关键词: Molecular; mechanisms; boost; systemic; immunity

Plants are sessile organisms that lack circulating immune cells. To fight bacterial infections, plants use small, mobile metabolites that travel throughout their vascular system to turn on defenses at sites of attack and throughout the plant body. By activating defenses in uninfected tissues, plants exist in a heightened immune state that limits new pathogen infections. This immune response is known as defense priming or systemic acquired resistance. Recent research identified an amino acid derivative called N-hydroxy-pipecolic acid (NHP) that is the bioactive metabolite required to turn on defense priming. There is sparse information for how NHP affects plant defense and development. Notably, watering or injecting plants with NHP is sufficient to induce defense priming and protect against bacterial and fungal infections. These findings suggest that altering NHP levels in plants or providing NHP to plants to enhance their defense responses may be effective strategies to enhance disease resistance in plants used in agriculture and horticulture. This project will study important aspects of NHP biology. Key questions include: (1) How long does the NHP defense signal last? (2) How is the defense signal turned off? (3) How does NHP signaling impact normal growth and development? (5) Do pathogens manipulate NHP biology to turn off this plant defense system? These questions will be answered by using chemical biology and functional genomic approaches with tomato, an important crop plant. The long-term goal is to investigate possible chemical applications and/or engineering efforts to enhance defense priming in plants to improve plant health. This study will provide intensive research training at the graduate, undergraduate and high school level with special consideration of women, underrepresented minorities, and those from under-resourced backgrounds. The research and outreach activities will also provide hands-on teaching and mentorship training for Stanford graduate and postgraduate students. Systemic acquired resistance (SAR) is a global plant immune response induced at the site of pathogen infection that triggers long-lasting and broad-spectrum disease resistance throughout the plant. A single small metabolite, N-hydroxy-pipecolic acid (NHP), is necessary and sufficient for initiation of this heightened immune state, even in the absence of an initial infection. Interestingly, NHP and its derivatives appear to be mobile metabolites, illuminating the chemical nature of the signals that are required to initiate and amplify defense responses over long distances within the plant body. Moreover, overexpression of the NHP biosynthetic pathway in local tissues alone can protect distal tissues from pathogen infection. These data thus highlight the intriguing possibility for translating a chemical or metabolic engineering approach to prime and/or enhance disease resistance under pathogen pressure. Currently, there is sparse information available regarding the regulation of NHP biosynthesis, dynamics of NHP signaling, and universal impact of this defense priming mechanism on plant growth and health. The goal of this research is to elucidate the temporal dynamics of NHP chemical defense and its effectiveness in protecting important crop plants under native and engineered conditions. This study will test the hypothesis that the regulation of NHP biosynthesis and the duration of the NHP bioactive signal can be titrated to increase disease resistance without compromising plant fitness. The model vegetable tomato, Solanum lycopersicum, will be used to elucidate fundamental aspects of NHP. This research will provide insight to the dynamics of NHP signaling and growth-defense associated with altered NHP production.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.

植物是无柄生物，缺乏循环免疫细胞。为了对抗细菌感染，植物使用小的、移动的代谢物，这些代谢物穿过它们的脉管系统，在攻击部位和整个植物体开启防御。通过激活未受感染组织中的防御，植物处于增强的免疫状态，限制了新的病原体感染。这种免疫反应被称为防御启动或系统获得性抗性。最近的研究发现了一种名为N-羟基-哌啶酸（NHP）的氨基酸衍生物，它是开启防御启动所需的生物活性代谢物。关于NHP如何影响植物防御和发育的信息很少。值得注意的是，用NHP浇灌或注射植物足以诱导防御引发并防止细菌和真菌感染。这些发现表明，改变植物中的NHP水平或向植物提供NHP以增强其防御反应可能是增强农业和园艺植物抗病性的有效策略。该项目将研究NHP生物学的重要方面。关键问题包括：（1）NHP防御信号持续多长时间？(2)防御信号是如何关闭的？(3)NHP信号如何影响正常生长和发育？(5)病原体是否操纵NHP生物学来关闭这种植物防御系统？这些问题将通过使用化学生物学和功能基因组学方法与番茄，一种重要的作物植物来回答。长期目标是研究可能的化学应用和/或工程努力，以增强植物的防御引发，以改善植物健康。这项研究将在研究生、本科生和高中一级提供密集的研究培训，特别考虑到妇女、代表性不足的少数民族和来自资源不足背景的人。研究和推广活动还将为斯坦福大学的研究生和研究生提供实践教学和导师培训。系统获得性抗性（systemic acquired resistance，SAR）是植物在病原菌感染部位诱导的一种全局性免疫反应，它能在整个植物中引发持久的广谱抗病性。一个单一的小代谢产物，N-羟基-哌啶酸（NHP），是必要的，足以启动这种提高免疫状态，即使在没有初始感染。有趣的是，NHP及其衍生物似乎是移动的代谢物，阐明了在植物体内长距离启动和放大防御反应所需的信号的化学性质。此外，局部组织中NHP生物合成途径的过表达可以保护远端组织免受病原体感染。因此，这些数据突出了将化学或代谢工程方法转化为在病原体压力下引发和/或增强抗病性的有趣的可能性。目前，关于NHP生物合成的调节、NHP信号传导的动力学以及这种防御引发机制对植物生长和健康的普遍影响的信息很少。本研究的目的是阐明NHP化学防御的时间动态及其在天然和工程条件下保护重要作物的有效性。这项研究将测试的假设，NHP生物合成的调节和NHP生物活性信号的持续时间可以滴定，以提高抗病性，而不损害植物的健身。模式蔬菜番茄，番茄，将被用来阐明NHP的基本方面。这项研究将为NHP信号的动态和与改变NHP生产相关的生长防御提供洞察力。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。