Research Objective

• Study the importance of and how the S. sclerotiorum proteins induce death in canola
• Study effectors (secreted proteins and RNA) that S. sclerotiorum uses to break down plant defenses
• Exploit these effectors to identify resistant B. napus cultivars

Project Description

The fungus Sclerotinia sclerotiorum causes sclerotinia stem rot in canola which leads to severe yield losses. Above average rainfall over the past several years, while necessary for a good crop, has also greatly increased stem rot incidence in many areas. While the timely use of fungicides in combination with new tolerant (though not resistant) canola varieties can reduce the impact of this disease, full and lasting resistance has not yet been achieved. This project will attempt to simplify the identification of Brassica napus (canola) lines with tolerance to this disease. Uncharacterized substances (proteins) called effectors that are produced by stem rot cause the characteristic brown, dead lesions on the plant and compromise the ability of the plant to defend itself against attack. These effectors of the fungus will be identified and used to find B. napus lines from collections at plant genetic resources centers that are most tolerant or resistant to these specific substances (proteins). It is complex to create resistant varieties because many genes are needed to combat stem rot, because it is such a violent attacker, releasing acids, enzymes, and toxins. The resistant plant will need to have several genes in play that help to strengthen plant tissues, neutralize the acids from stem rot, and inhibit its "eating-away" ability. By studying exactly how the pathogen attacks the plant, highly specific methods can be developed to identify B. napus lines that are resistant to the most important aspects of the disease. In this way, we hope to advance the development of B. napus varieties with better tolerance to this difficult-to-control disease.