Mechanisms linking nutrient acquisition and water-soaking during bacterial infection of plants

植物细菌感染期间养分获取和水浸泡的联系机制

• 批准号: 1953509
• 负责人: David Mackey
• 金额: $ 119.87万
• 依托单位: Ohio State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1953509&HistoricalAwards=false
• 关键词: Mechanisms; linking; nutrient; acquisition; water

Plant pathogens negatively affect production of food, fiber, biofuel and aesthetic crops. Water-soaking, which is the accumulation of fluid in extracellular spaces of infected plant tissues, is a hallmark symptom of diseases caused by pathogenic fungi, oomycetes and bacteria. Plant pathogens must also obtain nutrients from infected host tissues. Despite their central roles in pathogenesis, mechanistic explanations for how infecting microbes induce water-soaking and acquire nutrients are lacking. Bacterial pathogens that causes bacterial speck disease in tomato, the model plant Arabidopsis, and maize rely on a single, key virulence factor to induce water-soaking. In maize, the accumulating fluids are also rich in nutrients that support pathogen proliferation, indicating an inter-relationship in the key processes of water and nutrient acquisition. These findings along with identification of intracellular host targets of the virulence factor enable the proposed studies to elucidate molecular mechanisms underlying the liberation of water and nutrients from infected plant tissues. The acquired fundamental knowledge of this key step in pathogenesis will in turn enable breeding and biotechnological approaches for development of disease resistant plants. Because the key virulence factor is broadly conserved among diverse plant-pathogenic bacteria, these strategies will extend beyond tomato and maize to a multitude of agriculturally important plants.Prevailing speculation posits that pathogen-induced release of water and nutrients into extracellular spaces results from damage to plant cells. However, preliminary data indicate that Pseudomonas syringae pv. tomato (Pst) and Pantoea stewartii subsp. Stewartii (Pnss) deploy AvrE-family type III effector proteins that induce water-soaking and increase the extracellular abundance of nutritive metabolites prior to disrupting the integrity of infected plant cells. Additionally, pathogenicity of Pnss depends on AvrE-family effector induced perturbation of host phenylpropanoid metabolism, including accumulation of hydroxycinammic acid amides (HCAAs). Existing and newly generated mutant plants lacking AvrE-family effector targets, including plasma membrane-localized phosphatases, plasma membrane-spanning receptor-like kinases, and HCAA biosynthetic enzymes, will reveal the contribution of these host targets to effector-induced water and nutrient accumulation outside of intact plant cells. Comparisons of the plasma membrane (phospho)proteomes of wild-type plants with mutants that do not fully support the virulence activity of the AvrE-family effectors will enable identification of changes in protein phosphorylation or abundance that are genetically linked to these effector-induced perturbations of host physiology. These physiological, metabolomic, proteomic and genetic analyses will reveal mechanisms through which AvrE-family effectors regulate the movement of water and nutrients across the plasma membrane of host cells and place these mechanisms in the context of the disease state produced by Pst and Pnss in their dicot and monocot hosts, respectively. More generally, the findings will advance understanding of how plant pathogens induce water-soaked and nutritive extracellular spaces in their hosts.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.

植物病原体对粮食、纤维、生物燃料和观赏作物的生产产生不利影响。水浸，即液体在受感染植物组织的细胞外空间中的积累，是由病原真菌、卵菌和细菌引起的疾病的标志性症状。植物病原体还必须从受感染的宿主组织中获得营养。尽管它们在发病机制中起着中心作用，但缺乏对感染微生物如何诱导水浸泡和获得营养的机制解释。在番茄、模式植物拟南芥和玉米中引起细菌性斑点病的细菌病原体依赖于单一的关键毒力因子来诱导水浸。在玉米中，积累的液体也富含支持病原体增殖的营养物质，表明水分和营养物质获取的关键过程中存在相互关系。这些发现沿着鉴定了毒力因子的细胞内宿主靶点，使得拟议的研究能够阐明受感染植物组织释放水和营养物质的分子机制。获得发病机制中这一关键步骤的基础知识将反过来使育种和生物技术方法能够用于开发抗病植物。由于关键的毒力因子在不同的植物病原细菌中广泛保守，这些策略将从番茄和玉米扩展到许多农业上重要的植物。然而，初步数据表明，假单胞菌pv.番茄（Pst）和Pantoea stewartii subsp. Stewartii（Pnss）部署AvrE家族III型效应蛋白，其诱导水浸泡并在破坏受感染植物细胞的完整性之前增加营养代谢物的细胞外丰度。此外，Pnss的致病性取决于AvrE家族效应子诱导的宿主苯丙素代谢的扰动，包括羟基肉桂酸酰胺（HCAAs）的积累。现有的和新产生的突变体植物缺乏AvrE家族效应靶点，包括质膜定位磷酸酶，质膜跨受体样激酶和HCAA生物合成酶，将揭示这些宿主靶点对完整植物细胞外效应诱导的水分和养分积累的贡献。野生型植物的质膜（磷酸）蛋白质组与突变体的比较，不完全支持的毒力活性的AvrE家族效应子将能够识别蛋白质磷酸化或丰度的变化，遗传上与这些效应诱导的扰动宿主生理。这些生理学、代谢组学、蛋白质组学和遗传学分析将揭示AvrE家族效应物调节水和营养物质穿过宿主细胞质膜的运动的机制，并将这些机制分别置于由Pst和Pnss在其双子叶和单子叶宿主中产生的疾病状态的背景下。更广泛地说，这些发现将促进对植物病原体如何在其宿主中诱导水浸泡和营养细胞外空间的理解。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。

项目成果

Effect of Hydroxycinnamic Acid Amides, Coumaroyl Tyramine and Coumaroyl Tryptamine on Biotic Stress Response in Arabidopsis

• DOI: 10.1007/s12374-021-09341-2
• 发表时间: 2022-01-06
• 期刊: JOURNAL OF PLANT BIOLOGY
• 影响因子: 2.9
• 作者: Macoy, Donah Mary J.;Uddin, Shahab;Kim, Min Gab
• 通讯作者: Kim, Min Gab

Involvement of Arabidopsis Acyl Carrier Protein 1 in PAMP-Triggered Immunity

• DOI: 10.1094/mpmi-02-22-0049-r
• 发表时间: 2022-08-01
• 期刊: MOLECULAR PLANT-MICROBE INTERACTIONS
• 影响因子: 3.5
• 作者: Zhao，Zhenzhen;Fan，Jiangbo;Xia，Ye
• 通讯作者: Xia，Ye

Dynamic nutrient acquisition from a hydrated apoplast supports biotrophic proliferation of a bacterial pathogen of maize

• DOI: 10.1016/j.chom.2022.03.017
• 发表时间: 2022-04-13
• 期刊: CELL HOST & MICROBE
• 影响因子: 30.3
• 作者: Gentzel, Irene;Giese, Laura;Mackey, David
• 通讯作者: Mackey, David