RoL: Control of trans-species microRNA expression

RoL：跨物种 microRNA 表达的控制

• 批准号: 2003315
• 负责人: Michael Axtell
• 金额: $ 83.17万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2003315&HistoricalAwards=false
• 关键词: RoL; Control; trans; species; microRNA

Parasitic plants can be noxious weeds that attack crops and affect agricultural productivity. The parasitic plant Dodder (genus Cuscuta) is widespread in the United States and is a problem on diverse crops. Strategies to control Dodders are limited. One way that Dodders affect their hosts is by injected short bits of genetic information, "microRNAs", into host stems. These "trans-species" microRNAs destroy certain target host genes. This process seems to allow the parasite to suppress the host's immune system. This project seeks to understand exactly how the Dodder trans-species microRNAs are activated and injected into the host plants. Understanding this process could lead to novel methods of control and thus would benefit agriculture. Other parasites and pathogens use trans-species microRNAs to manipulate their hosts. Thus, details learned from study of the Dodder trans-species microRNAs may inform research into a broader array of parasites and pathogens.Recent studies have shown that Dodder (Cuscuta) expresses many microRNAs which enter host plant tissues and target host mRNAs. These trans-species microRNAs are likely acting as virulence factors to shut down host mRNAs in order to benefit the parasite. Unlike canonical microRNAs, the Cuscuta trans-species microRNAs only accumulate at the interface between the host and parasite. The core promoters upstream of trans-species microRNA loci in the Cuscuta genome all have a common Upstream Sequence Element (USE) that is absent from canonical microRNAs and also absent from the promoters of Cuscuta mRNAs. The 10 base-pair USE sequence is identical to the USE element known to drive transcription of small nuclear RNAs (snRNAs) in all plants. It thus appears that Cuscuta trans-species microRNAs have co-opted a pre-existing, constitutive promoter element to drive a highly tissue-specific expression pattern. This project will seek to understand this process via two aims: Aim 1: Functional analyses of USE to determine its role in the transcription of Cuscuta trans-species microRNA precursors. Aim 2: Identification and functional analyses of the USE-binding factor(s).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.

寄生植物可能是有害杂草，会攻击农作物并影响农业生产力。寄生植物菟丝子（菟丝子属）在美国广泛分布，是多种作物的一个问题。控制菟丝子的策略是有限的。菟丝子影响宿主的一种方式是向宿主茎中注入短的遗传信息，即“微RNA”。这些“跨物种”microRNA破坏某些靶宿主基因。这一过程似乎使寄生虫能够抑制宿主的免疫系统。该项目旨在准确了解菟丝子跨物种microRNA是如何被激活并注入宿主植物的。了解这一过程可能会导致新的控制方法，从而有利于农业。其他寄生虫和病原体使用跨物种microRNA来操纵它们的宿主。因此，研究菟丝子跨物种microRNA的细节可以为更广泛的寄生虫和病原体的研究提供信息。最近的研究表明，菟丝子（Cuscuta）表达许多microRNA，这些microRNA进入宿主植物组织并靶向宿主mRNA。这些跨物种的microRNA可能作为毒力因子关闭宿主mRNA，以使寄生虫受益。与典型的microRNA不同，菟丝子跨物种microRNA仅在宿主和寄生虫之间的界面处积累。菟丝子基因组中跨物种microRNA基因座上游的核心启动子都具有共同的上游序列元件（USE），其不存在于典型microRNA中，也不存在于菟丝子mRNA的启动子中。10个碱基对的USE序列与已知在所有植物中驱动小核RNA（snRNA）转录的USE元件相同。因此，似乎菟丝子跨物种microRNA已经增选了一个预先存在的组成型启动子元件来驱动高度组织特异性的表达模式。本项目将通过两个目标来理解这一过程：目标1：USE的功能分析，以确定其在菟丝子跨物种microRNA前体转录中的作用。目标二：使用约束因素的识别和功能分析。该奖项反映了NSF的法定使命，并被认为值得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来支持。