Exploring virulence and mating in Colletotrichum lentis

探索 Colletotrichum lentis 的毒力和交配

• 批准号: RGPIN-2018-03768
• 负责人: Banniza, Sabine
• 金额: $ 2.91万
• 依托单位: University of Saskatchewan
• 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=687707
• 关键词: Exploring; virulence; mating; Colletotrichum; lentis

Colletotrichum lentis is a fungal pathogen that causes an important foliar disease on lentil. Infection, referred to as hemibiotrophic, is complex as C. lentis initially infects without being perceived by the plant (biotrophic phase) before aggressively killing host cells (necrotrophic phase). Understanding the biology of C. lentis in terms of its ecology and its interaction with lentil is the long-term objective of my research program. In the Canadian population, two races were described, the highly virulent race 0 and the weakly virulent race 1. In past research we succeeded in mating isolates of the two races and developed a large population of offspring isolates. The genome of C. lentis was sequenced and with the help of our population, we could arrange the genome into 12 linkage groups probably representing chromosomes. Based on subtle differences in the genetic make-up of the parents (molecular markers) across all chromosomes, we developed a genetic linkage map that can be used analogues to a road map for direction to identify genes involved in controlling traits such as virulence. Using our genetic map and our offspring population we associated differences in the presence of molecular markers among the individuals of the offspring with their virulence on a differential lentil variety. We also associated the markers with the ability to mate, as there are two mating groups in C. lentis, and only two individuals from different mating groups are fertile. We could thus identify one particular chromosomal region that is associated with virulence and another one associated with mating.****These regions consist of many genes and are referred to as quantitative trait loci or QTLs. Not every gene in the QTL will be involved in regulating the trait of interest, so further research is needed to identify those that are. The short-term objectives of my program are therefore to identify and characterize the genes associated with the mating incompatibility QTL and the virulence QTL, and to compare Canada lentil isolates with a Chinese vetch isolate, the first foreign isolate of this species, in terms of mating and virulence. Identification of genes will be achieved by comparing the structure of genes with those that have already been associated with our traits in other species based on conserved features across species. Experiments then will assess whether these genes are affecting the trait by determining whether the fungus “switches on or off” a particular gene when it is infecting a lentil plant, and/or by disabling the candidate gene and assessing changes in the trait, e.g. a prevention of infection by the fungus or two previously fertile isolates becoming infertile. Understanding these traits will enable us to breed for better resistance in lentil varieties because we know what “weapons” C. lentis uses to successfully infect, and what the evolutionary potential of the fungal population is based on its mating system.***

扁豆炭疽病菌是引起扁豆重要叶面病害的一种真菌病原体。被称为半生物营养的感染是复杂的，因为在积极杀死宿主细胞（坏死性营养期）之前，C. lentis最初在未被植物感知的情况下感染（生物营养期）。从生态学及其与扁豆的相互作用方面了解扁豆的生物学是我研究计划的长期目标。在加拿大人群中，描述了两个种族，高毒力的种族0和弱毒的种族1。在过去的研究中，我们成功地将两个种族的分离物交配，并开发了大量的后代分离物。我们对扁豆的基因组进行了测序，在种群的帮助下，我们可以将基因组排列成12个连锁群，可能代表染色体。基于所有染色体中亲本基因组成（分子标记）的细微差异，我们开发了一个遗传连锁图，可以类似于路线图，用于识别控制性状（如毒力）的基因。利用我们的遗传图谱和我们的后代种群，我们将后代个体之间分子标记的存在差异与不同扁豆品种的毒力联系起来。我们还将这些标记与交配能力联系起来，因为大扁豆有两个交配群体，只有来自不同交配群体的两个个体是可育的。因此，我们可以确定一个特定的染色体区域与毒性有关，另一个与交配有关。****这些区域由许多基因组成，被称为数量性状位点或qtl。并不是QTL中的每一个基因都参与调控感兴趣的性状，因此需要进一步的研究来确定那些参与调控的基因。因此，我的计划的短期目标是鉴定和表征与交配不相容QTL和毒力QTL相关的基因，并将加拿大小扁豆分离物与该物种的第一个外源分离物中国豇豆分离物在交配和毒力方面进行比较。基于物种间的保守特征，将基因结构与其他物种中已经与我们的特征相关的基因结构进行比较，从而实现基因鉴定。然后，实验将通过确定真菌在感染扁豆植物时是否“打开或关闭”特定基因，以及/或通过禁用候选基因并评估性状的变化，例如预防真菌感染或两个先前可育的分离株变得不育，来评估这些基因是否影响该性状。了解这些特性将使我们能够在扁豆品种中培育出更好的抗性，因为我们知道扁豆使用什么“武器”来成功感染，以及真菌种群的进化潜力基于其交配系统