
Very few studies have investigated interactions at the plant surface and cellular levels for infection of Brassica napus by Sclerotinia sclerotiorum. Garg et al. demonstrate for the first time that resistance results from retardation of pathogen development on and within host tissues, and the mechanisms include impeded fungal growth, suppressed formation of appresoria and infection cushions, extrusion of hyphal protoplast, reduced calcium oxalate and starch deposits, and a hypersensitive reaction.