Host induced gene silencing of Sclerotinia sclerotiorum effector genes for the control of white mold

Sclerotinia sclerotiorum (Lib.), the causal agent of white mold, is a necrotrophic fungus with worldwide distribution. This fungus can infect more than 600 agricultural crops, causing damage worth hundreds of millions of dollars annually. The control of white mold is usually performed using integrated management practices. Nevertheless, after the establishment of the disease, chemical compounds need to be used, increasing production costs and offering environmental risks. In this study, we used Host Induced Gene Silencing (HIGS) in an attempt to control white mold. Specific vectors were constructed to express a silencing hairpin (dsRNAs) of the pathogen effector genes Ss-caF1 (putative Ca2+ binding protein), SspG1d (endopolygalacturonase) and SsiTL (integrin). The results showed a reduction in the severity of the symptoms in Arabidopsis thaliana transgenic plants and a delay in the occurrence of early symptoms. The results obtained for the control of S. sclerotiorum support the potential of HIGS in the generation of plants resistant to phytopathogenic fungi. It is also possible to suggest that the effector genes Ss-caF1, SspG1d and SsiTL are not only involved in the interaction but also play important roles during the host colonization and infection process.