From the identification of new sources of resistance to late effectors to their introgression into modern oilseed rape varieties
Year: 2025
Type: conference-paper
Abstract: Leptosphaeria maculans is a phytopathogenic fungus being responsible for stem canker on Brassica napus. This disease is mainly controlled by plant genetic resistance: specific or quantitative resistance. During its long infectious cycle, alternating biotrophic, necrotrophic, and endophytic stages, L. maculans colonizes asymptomatically the stems of oilseed rape, producing specific late effectors. We hypothesized that quantitative resistance partly relies on gene-for-gene interactions, with fungal effectors produced during stem infection being recognized by resistance proteins. We exploited the repertoire of 'late' effectors to identify corresponding genes in Brassica that could contribute to quantitative disease resistance. Using an innovative strategy of early expression of late effector genes, we validated that the interaction between the late effector LmSTEE98 and the resistance RlmSTEE98 obeys a typical gene-for-gene interaction, occurring during the stem colonization by L. maculans, that contributes partly to quantitative resistance, in controlled conditions. We then used the same strategy to search for new sources of resistance after selecting ten of the most relevant late effectors. Our screening approach of 130 diversified genotypes of B. napus, allowed us to identify new sources of resistance, displaying diversified interaction phenotypes. Our results demonstrate the existence of unsuspected sources of resistance that are potentially more durable than the classic major genes expressed earlier in the fungal cycle. Now, the next steps of this project are further validation of their efficacy in the field by introgression into modern genotypes and validation of the quantitative resistance markers.
Source: HAL
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W7206708693