RESEARCH-PGR: QTL Analyses Identify Genetic Components Regulating the Interactions between Plants, Pathogens and the Environment in the Face of Climate Change

有机体对环境做出反应的能力是其生存的基础。当感兴趣的生物体参与宿主-病原体的相互作用时，“环境”变得复杂，不仅包括外力，还包括相互作用的伙伴强加的条件。还有两个基因组在起作用，每个基因组都会影响两种生物的行为。此外，外部环境力量会带来额外的压力，每个基因组都会影响双方的反应。这个项目研究了寄主基因组在改变寄主和病原体在环境胁迫下的行为中所起的作用。它利用了一个与农业相关的系统--番茄线虫感染。寄生线虫每年造成全球约1250亿美元的农作物损失，其中番茄的产量损失超过80%。可供选择的控制措施有限，而且农业中一个新出现的担忧加剧了这种情况：夜间气温变暖的影响。这一史无前例的趋势正在给农作物带来严峻的挑战。这项工作的更广泛的未来影响包括开发新的方法来检查宿主-病原体的相互作用以及它们如何受到外部条件的影响。这将导致鉴定出对非生物和生物胁迫都更具弹性的植物品系。重要的是，通过阐明寄生虫对WNT下这些植物的反应背后的分子生物学，这项研究将不仅仅是识别相关的寄主基因，还将为这些基因改变线虫生物学的机制提供新的见解。除了了解植物外，了解线虫还为直接针对寄生虫进行作物改良铺平了道路。这个项目的目标与遗传学中的一个首要问题一致：识别影响个人对环境反应的DNA变异。这里，“个人”和“环境”的概念是复杂的。一个物种中的DNA变异将被识别出来，这些变异与外部环境条件一起影响另一个相互作用的物种的反应。考虑的环境背景是变暖的夜间温度(WNT)，这是一个关键的、高度相关的和当前的环境问题。来自栽培品系和野生品系杂交的遗传变异番茄植株将被一种遗传同质的寄生线虫菌株感染。还将对未受感染的植物进行对照实验。这些早期、后期和对照实验将在两种温度条件下进行：正常夜间温度和WNT。对于每个处理组合，将收集与感染和植物健康相关的表型，以及植物和线虫的基因表达数据。通过这种设计，将在番茄基因组中的DNA变异与线虫和植物的分子反应之间建立联系，并通过一系列遗传作图实验揭示WNT对这些联系的影响。利用以这种方式确定的连接，随后可以推断更复杂的基因-表达-表型途径，从而提供对WNT植物-寄生虫相互作用反应的分子生物学的详细视图。它还将精确定位有希望的候选基因，这些基因将得到功能验证。所有项目成果将通过出版物和将数据和资源存放在长期储存库中向公众公布。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

An organism’s ability to respond to its environment is fundamental to its survival. When the organism of interest is involved in a host-pathogen interaction, “the environment” becomes complex, including includes not only external forces, but also the conditions imposed by the interacting partner. There are also two genomes at play, each of which affects the behavior of both organisms. In addition, external environmental forces impose additional pressures, and each genome can affect how both partners respond. This project examines the role the host genome plays in altering behavior of both host and pathogen under environmental stress. It leverages an agriculturally relevant system, nematode infection of tomato. Parasitic nematodes are responsible for around $125 billion in annual crop loss worldwide with yield loss upwards of 80% for tomato. Limited control options are available, and the situation is exacerbated by an emerging concern in agriculture: the effect of warming nighttime temperatures (WNT). This unprecedented trend is causing critical challenges to crops. Broader, future impacts of this work include the development of novel approaches to examine host-pathogen interactions and how they are affected by external conditions. This then will lead to the identification of plant lines that are more resilient to both abiotic and biotic stresses. Importantly, by elucidating the molecular biology behind the parasite response to those plants under WNT, this study will go beyond merely identifying relevant host genes to contribute new insight into the mechanisms by which those genes alter the nematode biology. Understanding the nematode in addition to the plant paves the way towards targeting the parasite directly for crop improvement.The goals of this project align with an overarching concern in genetics: to identify DNA variants that influence how individuals respond to their environment. Here, the concept of “individuals” and “environment” are complex. DNA variants in one species will be identified that, in tandem with external environmental conditions, affect how another, interacting species responds. The environmental context considered is warming nighttime temperatures (WNT), a critical, highly relevant, and current environmental concern. Genetically variable tomato plants derived from a cross between a cultivated line and a wild line will be infected with a genetically homogeneous strain of parasitic nematodes. A control experiment will also be performed with uninfected plants. These early, late, and control experiments will be carried out under two temperature regimes: normal nighttime temperatures and WNT. For each treatment combination, phenotypes related to infection and plant health will be collected, along with gene expression data for both plant and nematode. With this design, connections between DNA variants in the tomato genome and molecular responses of the nematode as well as the plant will be made, and the effect of WNT on these connections will be uncovered through via a series of genetic mapping experiments. Leveraging the connections identified in this way, more complex genotype-expression-phenotype pathways can subsequently be inferred, providing a detailed view of the molecular biology of the plant-parasite interaction response to WNT. It will also pinpoint promising candidate genes, which will be functionally validated. All project outcomes will be made publicly accessible through publications and deposition of data and resources in long-term repositories.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.