Biocontrol pseudomonads: interaction with the plants they protect and grazing predators that threaten their existence

生物防治假单胞菌：与它们保护的植物和威胁其生存的食肉动物相互作用

• 批准号: RGPIN-2017-04970
• 负责人: Dekievit, Teresa
• 金额: $ 2.91万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=687561
• 关键词: Biocontrol; pseudomonads; interaction; plants; they

For the past 15 years, research ongoing in my lab has focused on a biocontrol strain, Pseudomonas chlororaphis PA23, which is able to protect canola from sclerotinia stem rot caused by the fungal pathogen Sclerotinia sclerotiorum (Ss). Application of PA23 to the aerial surfaces of canola inhibits Ss directly through antibiosis and indirectly through priming of the plant defense response. In the first aim of the proposed research, we will shift our attention below ground and explore how the presence of PA23 in the rhizosphere influences plant physiology. PA23 colonization and gene expression on the plant roots will be investigated together with PA23-mediated changes in canola gene expression using RNA sequencing (RNAseq). In aim 2, the role of PA23 antifungal metabolites in the interaction with the grazing predator Acanthamoeba castellani (Ac) will be explored. Co-culturing will enable us to profile the bacterial response to predator exposure through RNAseq. Aim 3 builds upon our recent discovery that PA23 not only protects plants from fungal attack but also promotes plant growth. The impact of PA23 and protozoan grazing on canola root architecture and gene expression will be revealed. Additionally, metagenomic analysis will be employed to elucidate how the presence of Ac affects PA23 persistence and the composition of the soil community as a whole. Collectively, findings from the proposed studies will provide an unprecedented understanding of how PA23 in the rhizosphere impacts canola gene expression and susceptibility to Ss infection in the phyllosphere. We will reveal for the first time the effect of Ac grazing on PA23 gene expression and plant physiology when one or both organisms are present in the rhizosphere. This research will provide graduate and undergraduate students training in a wide breadth of areas including next generation sequencing, bioinformatics, confocal microscopy and tissue culture. Such opportunities will ensure trainees are well prepared and in high demand for both the discovery and applied science job sectors. The impact of this work will be realized by scientists investigating trans-kingdom signaling in complex prokaryotic-eukaryotic interactions, growers in the form of increased crop yields and society as a whole in our quest for safe, sustainable strategies for nourishing the ever-increasing number of humans on the planet.*****

在过去的15年里，我的实验室一直在研究一种生物防治菌株，绿假单胞菌PA23，它能够保护油菜免受由菌核菌（Ss）引起的菌核病茎腐病的侵害。在油菜气表面施用PA23可以通过直接的抗菌作用和间接的启动植物防御反应来抑制Ss。在本研究的第一个目标中，我们将把注意力转移到地下，探索根际中PA23的存在如何影响植物生理。利用RNA测序技术（RNAseq）研究PA23在植物根部的定殖和基因表达，以及PA23介导的油菜基因表达变化。目的2将探讨PA23抗真菌代谢物在与放牧捕食者棘阿米巴（Acanthamoeba castellani, Ac）相互作用中的作用。共培养将使我们能够通过RNAseq分析细菌对捕食者暴露的反应。Aim 3建立在我们最近发现的PA23不仅保护植物免受真菌攻击，而且促进植物生长的基础上。揭示PA23和原生动物放牧对油菜根构型和基因表达的影响。此外，宏基因组分析将用于阐明Ac的存在如何影响PA23的持久性和整个土壤群落的组成。总的来说，这些研究的结果将提供一个前所未有的了解根际中PA23如何影响油菜籽基因表达和对根际中Ss感染的易感性。本研究首次揭示了当根际有一个或两个微生物存在时，Ac放牧对PA23基因表达和植物生理的影响。这项研究将为研究生和本科生提供包括下一代测序、生物信息学、共聚焦显微镜和组织培养在内的广泛领域的培训。这样的机会将确保受训者为发现和应用科学工作部门做好充分的准备和高需求。这项工作的影响将通过科学家研究复杂的原核-真核相互作用中的跨界信号，种植者以增加作物产量的形式，以及整个社会在我们寻求安全，可持续的战略来滋养地球上不断增长的人类数量来实现。*****