Collaborative Research: Root-to-Shoot Communication via the bps Signal

合作研究：通过 bps 信号进行根与芽的通讯

• 批准号: 1755361
• 负责人: Leslie Sieburth
• 金额: $ 40.53万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1755361&HistoricalAwards=false
• 关键词: Collaborative; Research; Root; Shoot; Communication

Drought causes dramatic reductions in agricultural yields. An important step toward mitigating drought-associated losses is to fully understand how perception of drought causes reduced growth, and its associated impacts on agricultural production. The earliest perception of drought occurs as roots encounter dry soil, and the resulting whole-plant responses are believed to arise from a mobile chemical signal that moves from roots to shoots. The Sieburth lab has discovered a highly conserved gene family that regulates production of a root-to-shoot signal that is sufficient to induce drought responses. The goal of this research is to identify this signaling molecule. The Sieburth and Dilkes labs will use metabolomic, genetic, and gene expression based approaches. This combination of strategies should chemically identify the mobile signal and establish its relationship to other known components of root-to-shoot signaling. Knowing the chemical identity of the root-to-shoot signal could lead to development of new agricultural practices that promote greater food security.Plants drought responses include synthesis of abscisic acid (ABA) in the shoots, and decreased growth rates. Because most drought responses are measured in shoots, whereas the plant root is believed to initially detect drought conditions, scientists have long postulated a mobile root-to-shoot chemical signal that coordinates drought responses. The bypass1 (bps1) mutant of Arabidopsis has a growth-arrest phenotype caused by a graft-transmissible signal over-produced in bps1 roots. Transcriptomics and hormone measurements demonstrated that this mobile compound is sufficient to induce ABA synthesis in wild-type shoots, and genetic analyses demonstrated that growth arrest is independent of ABA. This project's goal is chemical identification of this over-produced compound. Experiments will use previously established extraction methods, fractionation by Ultra Performance Liquid Chromatography, and analysis by mass spec. Other experiments will use a labeled precursor and precursor analogs; these will clarify the structural components of the precursor that are required in the active product, and time-resolved assays using the labeled precursor should prove informative for its biosynthetic pathway. In addition, bps1 and wild type root transcriptomes will be compared, and reverse genetic analyses will be carried out to test whether differentially expressed genes are necessary to produce the mobile compound. Finally, bps1 mutants will be generated in another plant species, and its metabolome analyzed; this experiment will test the hypothesis that this drought-induced root-to-shoot compound is the same in different plant species. Diverse undergraduates and high-school students will be trained through this grant; broad outreach to under-represented groups includes interaction with local community colleges.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.

干旱导致农业产量急剧下降。减轻干旱相关损失的一个重要步骤是充分了解对干旱的认识是如何导致生长减少的，以及它对农业生产的相关影响。最早对干旱的感知发生在根系遇到干燥土壤的时候，而由此产生的整个植物的反应被认为是由一种从根到芽的移动化学信号引起的。Sieburth实验室发现了一个高度保守的基因家族，该基因家族调节着足以诱导干旱反应的根到茎信号的产生。本研究的目的是识别这种信号分子。Sieburth和Dilkes实验室将使用基于代谢组学、遗传学和基因表达的方法。这种策略的组合应该在化学上识别移动信号，并建立其与根到茎信号的其他已知成分的关系。了解从根到茎信号的化学特性可以促进新的农业实践的发展，从而促进更大程度的粮食安全。植物对干旱的反应主要表现在茎部脱落酸的合成和生长速率的降低。由于大多数干旱反应是在茎中测量的，而植物的根被认为是最初检测干旱条件的，科学家们长期以来一直假设有一种移动的根到茎的化学信号来协调干旱反应。拟南芥的bypass1 （bps1）突变体具有由bps1根中过量产生的移植物传递信号引起的生长停滞表型。转录组学和激素测量表明，这种可移动的化合物足以诱导野生型芽中的ABA合成，遗传分析表明生长停滞与ABA无关。这个项目的目标是对这种过量生产的化合物进行化学鉴定。实验将使用先前建立的提取方法，超高效液相色谱分离和质谱分析。其他实验将使用标记的前体和前体类似物；这将澄清活性产物中所需的前体的结构成分，并且使用标记前体的时间分辨分析应证明其生物合成途径的信息。此外，将比较bps1和野生型根转录组，并进行反向遗传分析，以测试是否需要差异表达基因来产生移动化合物。最后，在另一种植物中产生bps1突变体，并对其代谢组进行分析；这个实验将验证这样一个假设，即这种由干旱引起的从根到茎的化合物在不同的植物物种中是相同的。各类本科生和高中生将通过这项拨款得到培训；对代表性不足的群体的广泛拓展包括与当地社区大学的互动。该奖项反映了美国国家科学基金会的法定使命，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。