Objective
- The Clubroot Susceptibility 1 (CS1) genes have been identified in Brassica napus and edited with CRISPR/Cas9 gene editing technology. Homozygous single/double-gene mutants and transgene-free lines will be developed in this objective.
- The disease resistance of all cs1 mutant lines characterized from Obj1 will be evaluated in controlled-environment conditions following inoculation with different Pb pathotypes found in western Canada.
- cs1 mutant lines will be evaluated to determine if CS1 genes are involved in disease susceptibility to additional canola diseases that are prevalent in western Canada, including blackleg, verticillium stripe, and sclerotinia stem rot.
Project Description
Growing clubroot resistant (CR) varieties in diverse rotations remains the most effective strategy for long-term management of this disease. However, current available CR varieties carry race-specific, dominant R genes that can be broken by shifts in the pathogen population. For instance, many new pathotypes identified in Alberta appeared capable of overcoming all first-generation sources of CR in commercial canola varieties. Even worse, some fields with second-generation CR canola have started to show symptoms of clubroot disease in recent years. Hence, there is an urgent need to explore new CR sources to effectively combat this rapidly evolving pathogen.
Different from R-gene mediated disease resistance, a novel strategy based on susceptibility (S) genes has emerged, offering the potential for enhanced durability of performance in the field. The S genes can either act as negative regulators of immunity or are considered host compatible factors for the successful pathogen infection. While R genes are dominant, the disease resistance provided by manipulation of S genes is mostly recessive. Therefore, broad-spectrum and durable disease resistance can be readily conferred by disrupting S genes via precise genome-editing tools.
