POWRE: Biological Role of Motility in Bacterial Wilt of Plants

POWRE：运动性在植物青枯病中的生物学作用

• 批准号: 9973372
• 负责人: Caitilyn Allen
• 金额: $ 7.49万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-15 至 2001-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9973372&HistoricalAwards=false
• 关键词: POWRE; Biological; Role; Motility; Bacterial

Many bacteria are able to move, using propeller-like structures called flagella. Although the ability to move towards or within a host confers a significant selective advantage on some animal pathogens, the role of bacterial motility in plant-associated microbes is not known. One motile plant pathogen, Ralstonia solanacearum, causes bacterial wilt disease of many diverse plant species. When R. solanacearum grows in laboratory culture, its cells are motile only at low cell densities, possibly corresponding to conditions the bacterium encounters in nature during the early stages of host plant invasion and colonization. The PI will test the hypothesis that motility contributes to the success of bacterial plant pathogens by creating a nonmotile mutant of R. solanacearum. Invasiveness of this nomnotile mutant will be quantified using a combination of realistic soil virulence assays, timed root dip assays, and microscopic analysis with marked mutant and wildtype strains. The hypothesis that this species is motile only during host plant invasion and early stages of colonization will be tested directly by assaying bacterial motility during growth in the plant xylem vessel and indirectly by measuring expression of motility genes during growth in the plant xylem vessel. This will determine whether R. solanacearum gene expression in culture reflects the behavior of the pathogen in its host. Measuring motility gene expression in two regulatory mutant backgrounds will determine how bacterial motility fits into R. solanacearum's complex gene expression network. This research will elucidate a critical stage in the life cycle of a cosmopolitan and flexible model pathogen.This proposal fits the POWRE Program guidelines in the following ways: a) it opens an entirely new line of research inquiry for the P.I.; b) the P.I. has substantial administrative responsibilities in the area of women and science (she is jointly appointed in the Plant Pathology and Women's Studies departments, and also serves as Faculty Director of the campus Women in Science and Engineering Program); and, c) the P.I. recently resumed her career after an interruption for family leave.

许多细菌能够使用称为鞭毛的螺旋桨状结构移动。尽管细菌向宿主移动或在宿主内移动的能力赋予了某些动物病原体显著的选择性优势，但细菌运动性在植物相关微生物中的作用尚不清楚。一种能动的植物病原体，青枯雷尔氏菌（Ralstonia solanacearum），引起许多不同植物物种的细菌性枯萎病。当R.青枯菌在实验室培养中生长，其细胞仅在低细胞密度下才能运动，这可能与该细菌在宿主植物入侵和定殖的早期阶段在自然界中遇到的条件相对应。PI将通过创建R的非运动突变体来检验运动性有助于细菌植物病原体成功的假设。青枯菌属将使用现实土壤毒力测定、定时根浸测定和标记突变体和野生型菌株的显微镜分析的组合来量化该无菌突变体的侵袭性。这一物种是能动的，只有在宿主植物入侵和早期阶段的殖民化的假设将直接测试通过测定细菌的运动性在植物木质部导管生长过程中，并间接通过测量运动基因在植物木质部导管生长过程中的表达。这将决定R.培养物中的青枯菌基因表达反映了病原体在其宿主中的行为。在两种调控突变体背景下测量运动基因表达将确定细菌运动性如何适应R。青枯菌复杂的基因表达网络。这项研究将阐明一个世界性的和灵活的模式病原体的生命周期中的一个关键阶段。这一建议符合POWRE计划的指导方针，在以下方面：a）它打开了一个全新的研究路线的研究调查的PI。B）P.I.在妇女和科学领域具有实质性的行政责任（她在植物病理学和妇女研究部门联合任命，并担任校园妇女科学和工程项目的系主任）;和，c）P.I.在因探亲假中断后，她最近重新开始了自己的职业生涯。