Functional use of core pathogenicity genes to develop mitigation strategies against blackleg of canola and FHB of wheat
Term: 3 years, beginning in 2023
Status: Ongoing
Researcher(s): Hossein Borhan, Agriculture and Agri-Food Canada
SaskCanola Investment: $79,853
Total Project Cost: $405,600
Funding Partners: TBC
Objectives
Define the core effector (pathogenicity) genes of F. graminearum and L. maculans.
Develop core effector deletion libraries from L. maculans and F. graminearum.
Assess functional diversity of core effectors of L. maculans and F. graminearum.
Identify conserved pathogen effectors as inducers of broad-spectrum resistance.
Project Description
This proposal aims to identify core pathogenicity factors (effectors) of Lm and Fg and determine their function. This information could be used to develop biological and chemical fungicides that target the effector gene expression or block the function of effector gene products. Core effectors could also be used to identify new R genes from Brassica and Triticum species. These resistant cultivars could be used by breeders to develop Lm resistant canola and Fg resistant wheat. R genes that are effective against core effectors of Lm and Fg will provide durable and broad-spectrum resistance against these two important pathogens and other taxonomically related pathogens. In addition, core effectors that are functionally confirmed as virulent factors could be used in future research to identify their host targets (susceptibility genes) to engineer novel resistance by deletion or suppression of the susceptibility genes. This approach could be applied to other important Canadian crops/pathogen systems. Resistance against core effector is often broad-spectrum and functions across multiple species. Another deliverable of this research project is to identify conserved effectors that trigger canola and wheat defense. Products of such effectors could be formulated as plant defense priming agents that, when applied to the plants, will boost canola and wheat immunity against Lm, Fg, and other pathogens.
The most desirable approach to protect crops against pathogens is to breed cultivars with disease resistance (R) genes. However, current methodologies to discover new R genes are labour intensive and are limited by germplasms that are effective against a single or a few isolates of a pathogen. This problem is exacerbated by an unintended consequence of crop domestication; the purging of genetic diversity in elite lines relative to older landraces and ancestral species, resulting in depauperate gene pools that lack the immunodiversity needed to respond to emerging pathogens. One of the solutions is to harness the natural immunodiversity of crop relatives and ancestral species to identify new R-genes. While this approach holds tremendous promise, it suffers from its challenge; how do you identify useful and deployable R-gene diversity from poorly studied species? This proposal uses an innovative, functional approach that harnesses the natural diversity of pathogen effectors to identify both resistance and susceptibility genes. Borhan and Subramaniam are co-PIs on a separate ADF project that is currently developing RNAi sprays for biofungicides.