Deciphering the guard cell metabolome in plant pathogen defense

解读植物病原体防御中的保卫细胞代谢组

• 批准号: 1758820
• 负责人: Sixue Chen
• 金额: $ 9.13万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1758820&HistoricalAwards=false
• 关键词: Deciphering; guard; cell; metabolome; plant

Crops are constantly challenged by bacterial pathogens, which cause huge losses in yield and economical value every year. The pathogens enter the plant body through wounds and through tiny pores on leaf surfaces. These pores are called stomata, and are formed by highly specialized cells called guard cells. Stomatal opening mediated by the guard cells allows carbon dioxide uptake. After uptake, carbon dioxide is captured by photosynthesis, generating organic materials such as carbohydrates; therefore stomatal opening is critical for agricultural yield and bioenergy production. However, the open stomatal pores also allow water vapor loss, and create entries for pathogens, which are liabilities for plants. It is known that when guard cells sense pathogens, they close stomata within an hour as an immune response. However, subsequently, the stomata open again and pathogens go in. This project aims to elucidate how lipids and fatty acids function in regulating the stomatal closure and opening during pathogen infection. This research will enable scientists to gain an in-depth understanding of guard cell lipid metabolites important for pathogen triggered stomatal closing and opening. The outcome of the research has broad societal impact, e.g., for informing rational crop breeding to enhance pathogen defense and crop yield. The results will be made available to the public via community repositories and no-cost publications (e.g. Metabolight, the Plant Journal). The project will also enable cross-disciplinary training of students at different levels, including women and under-represented students. Training the next generation of scientists and citizens has far-reaching positive impacts for society and the world.The Chen lab has observed significant lipid metabolite changes in guard cells in response to treatment with a bacterial elicitor comprised of the flagellin N-terminal 22 amino acid peptide (flg22). The Assmann lab has previously demonstrated the effect of the lipid metabolite sphingosine-1-phosphate (S1P) as a component of abscisic acid signaling. However, the roles of S1P and other lipids and fatty acids in stomatal immunity against Pseudomonas syringe pv. tomatao (Pst DC3000) are not known. Here the hypothesis is that lipid metabolites function as important regulators of guard cell pathogen signaling. The goals are to: 1) determine dynamic changes of lipids and fatty acids in guard cells during Pst DC3000 triggered stomatal movement; 2) determine stomatal movement triggered by Pst DC3000 in relevant mutants of lipid biosynthesis and metabolism implicated from the lipidomics analyses, and characterize the effects of lipid metabolites as signaling molecules in triggering stomatal movement. Approaches to be used include lipidomics, cell biology, genetics and biochemistry. This focused project specially targets the functions of lipids and fatty acids in stomatal immunity against Pst DC3000. The results are expected to reveal novel lipid metabolite functions, boost understanding of molecular mechanisms that underlie stomatal immunity, and illustrate the power of integrated approaches involving lipidomics to reveal novel biological mechanismsThis 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.

农作物不断受到细菌病原体的挑战，每年造成产量和经济价值的巨大损失。病原体通过伤口和叶面的微小孔隙进入植物体。这些孔称为气孔，由高度特化的细胞（称为保卫细胞）形成。由保卫细胞介导的气孔打开允许二氧化碳的吸收。吸收后，二氧化碳通过光合作用捕获，生成碳水化合物等有机物质；因此，气孔开放对于农业产量和生物能源生产至关重要。然而，开放的气孔也会导致水蒸气流失，并为病原体创造入口，这对植物来说是不利的。众所周知，当保卫细胞感知到病原体时，它们会在一小时内关闭气孔作为免疫反应。然而，随后，气孔再次打开，病原体进入。该项目旨在阐明脂质和脂肪酸如何在病原体感染期间调节气孔的关闭和打开。这项研究将使科学家能够深入了解对于病原体触发气孔关闭和打开很重要的保卫细胞脂质代谢物。该研究的成果具有广泛的社会影响，例如，为合理的作物育种提供信息，以增强病原体防御和作物产量。结果将通过社区存储库和免费出版物（例如 Metabolight、植物杂志）向公众提供。该项目还将为不同级别的学生提供跨学科培训，包括女性和代表性不足的学生。培训下一代科学家和公民对社会和世界具有深远的积极影响。Chen 实验室观察到，在使用由鞭毛蛋白 N 末端 22 个氨基酸肽 (flg22) 组成的细菌激发子处理后，保卫细胞中的脂质代谢发生了显着变化。 Assmann 实验室此前已经证明了脂质代谢物 1-磷酸鞘氨醇 (S1P) 作为脱落酸信号传导成分的作用。然而，S1P 和其他脂质和脂肪酸在针对注射器假单胞菌的气孔免疫中的作用。 tomatoo (Pst DC3000) 未知。这里的假设是脂质代谢物充当保卫细胞病原体信号传导的重要调节剂。目标是：1）确定 Pst DC3000 触发气孔运动期间保卫细胞中脂质和脂肪酸的动态变化； 2) 确定脂质组学分析涉及的脂质生物合成和代谢相关突变体中 Pst DC3000 触发的气孔运动，并表征脂质代谢物作为信号分子在触发气孔运动中的作用。使用的方法包括脂质组学、细胞生物学、遗传学和生物化学。该重点项目专门针对脂质和脂肪酸在针对 Pst DC3000 的气孔免疫中的功能。研究结果预计将揭示新的脂质代谢功能，促进对气​​孔免疫分子机制的理解，并说明涉及脂质组学的综合方法揭示新生物机制的力量。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，被认为值得支持。