BBSRC-NSF/BIO: Anatomy and functions of LTP interactomes and their relationship to small RNA signals in systemic acquired resistance

BBSRC-NSF/BIO：LTP 相互作用组的解剖和功能及其与系统获得性耐药中小 RNA 信号的关系

• 批准号: 2131400
• 负责人: Pradeep Kachroo
• 金额: $ 126.02万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2131400&HistoricalAwards=false
• 关键词: BBSRC; NSF; BIO; Anatomy; functions

Plants possess a unique form of immunity called systemic acquired resistance (SAR). SAR is highly desirable because it protects the whole plant against a wide range of pathogens and is long-lasting. When a primary pathogen infects the plant and activates SAR, mobile signals generated at the infection site travel to distal portions of the plant and prepare them to fend off future infections. Several SAR-inducing factors, including some that move systemically, have been discovered, though the identity of the early SAR signal has remained elusive. In a recent breakthrough, we identified RNA-based molecules that function within the early time frame of SAR. This collaborative project between laboratories at the University of Kentucky and University of Warwick will combine computational, biochemical, gentics and metabolomic analyses to generate a deep mechanistic understanding of these molecules. By facilitating the use of SAR in developing sustainable and environmentally friendly crop protection strategies, and its applicability to economically important crop species, this project will benefit US and UK agricultural economies. The knowledge gained could have rational applications in human health because the underlying components have conserved functions in mammalian physiology. The project will generate undergraduate research experiences for Kentucky students from primarily underserved backgrounds, middle-high school workshops via the Kentucky Youth Science Summit, Girl Scout’s GEMS program, Science on the Hill public engagement series and undergraduate research-based experiential learning coursework. This project will investigate early signals in Systemic Acquired Resistance (SAR). The production of the SAR mobile signal is thought to occur within 3 h of primary infection, and the infected leaf must remain attached for at least 4 h after inoculation for SAR to be induced, suggesting that the mobile signal is translocated during that early timeframe. We find that two phased 21 nucleotide RNA (tasi-RNA) derived from Trans-Acting Small Interfering RNA3a (TAS3a), are synthesized within 3 h of pathogen infection, move to distal leaves within 4 h and function as the elusive early mobile signal in SAR. TAS3a cleaves Auxin Response Factor (ARF) 3 and conversely increased ARF3 negatively regulates SAR. TAS3a positively regulates the expression of Lipid Transfer Proteins (LTP) 3, 4 and AZI1 and a novel protein A70. The LTPs form a complex and regulate SAR by promoting transport of tasi-ARFs. Systemic mobility of the LTPs further suggests that SAR activation is associated with the transport of a high molecular weight LTP-RNA complex. This project will characterize the LTP-RNA interactome and the dynamics of systemic activation of A70, and will compute how changes in these complexes regulate SAR. In addition, we will characterize ARF3 targets and SAR-associated components that function downstream of tasi-ARFs and A70. Research findings will be disseminated to the scientific community via traditional publication routes, presentations at conferences, and through outreach to US soybean, corn, wheat, and oat growers via annual meetings and grower-targeted publications, as well as with vegetable and protected crop growers and seed companies in the UK.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.

植物具有一种独特的免疫形式，称为系统获得性抗性（SAR）。SAR是非常理想的，因为它保护整个植物免受广泛的病原体的侵害，并且是持久的。当原生病原体感染植物并激活SAR时，在感染部位产生的移动的信号传播到植物的远端部分，并使它们做好抵御未来感染的准备。已经发现了几个SAR诱导因素，包括一些系统移动的因素，尽管早期SAR信号的身份仍然难以捉摸。在最近的一项突破中，我们确定了在SAR早期时间框架内发挥作用的基于RNA的分子。肯塔基州大学和沃里克大学实验室之间的这一合作项目将结合联合收割机计算，生物化学，遗传学和代谢组学分析，以产生对这些分子的深入机制的理解。通过促进SAR在制定可持续和环境友好型作物保护策略中的应用，以及其对经济上重要的作物物种的适用性，该项目将使美国和英国的农业经济受益。所获得的知识可以在人类健康中得到合理的应用，因为基本成分在哺乳动物生理学中具有保守的功能。该项目将产生本科生的研究经验，为肯塔基州学生从主要是服务不足的背景下，通过肯塔基州青年科学峰会，女童子军的GEMS计划，科学在山上公众参与系列和本科研究为基础的体验式学习课程高中讲习班。 该项目将研究系统获得性抗性（SAR）的早期信号。SAR移动的信号的产生被认为发生在初次感染的3小时内，并且感染的叶必须在接种后保持附着至少4小时以诱导SAR，这表明移动的信号在该早期时间段期间移位。我们发现，两个阶段的21个核苷酸的RNA（tasi-RNA）来自反式作用小干扰RNA 3a（TAS 3a），在病原体感染3小时内合成，4小时内移动到远端叶片和功能作为难以捉摸的早期移动的信号在SAR。TAS 3a切割生长素反应因子（ARF）3，相反，增加的ARF 3负调节SAR。TAS 3a正调节脂质转移蛋白（LTP）3、4和AZI 1以及一种新蛋白A70的表达。LTP形成复合体，通过促进tasi-ARF的运输来调节SAR。LTP的全身流动性进一步表明SAR活化与高分子量LTP-RNA复合物的转运相关。该项目将表征LTP-RNA相互作用组和A70系统激活的动力学，并将计算这些复合物的变化如何调节SAR。此外，我们还将表征在tasi-ARF和A70下游发挥作用的ARF 3靶标和SAR相关组分。研究结果将通过传统的出版途径、会议上的演讲以及通过年会和针对种植者的出版物向美国大豆、玉米、小麦和燕麦种植者传播，该奖项反映了NSF的法定使命，并通过使用基金会的学术价值和更广泛的影响审查标准。