PT - JOURNAL ARTICLE AU - Fredrik Dölfors AU - Louise Holmquist AU - Panagiotis N. Moschou AU - Christina Dixelius AU - Georgios Tzelepis TI - The <em>Rhizoctonia solani</em> LysM and RlpA-like effector proteins contribute to virulence suppressing chitin-triggered immunity and hypersensitive response AID - 10.1101/395582 DP - 2018 Jan 01 TA - bioRxiv PG - 395582 4099 - http://biorxiv.org/content/early/2018/08/22/395582.short 4100 - http://biorxiv.org/content/early/2018/08/22/395582.full AB - Rhizoctonia (in Greek “root-killer”) species and particularly R. solani attacks a broad range of plant species and crops. It belongs to Basidiomycota and is a soil-borne pathogen causing mainly damping-off in seedlings, although it can infect plants in any stage. It does not form any kind of asexual spores while the sexual form (Thanatephorus cucumeris) is extremely rare. However, it forms microsclerotia, able to survive in soil and plant debris for a long period and under harsh environmental conditions. Despite the severity of this disease, many aspects in R. solani infection biology still remain to be elucidated. In this study, we investigated the role of two effector candidates, derived from a R. solani AG2-2IIIB strain isolated from infected sugar beet plants. Gene expression analysis showed that genes encoding for a LysM effector and a RlpA-like protein were induced upon early infection stages, while their heterologous expression in Cercospora beticola contributed to virulence. Furthermore, the RsLysM effector showed chitin binding affinity, suppressing chitin-triggered immunity but could not protect hyphae from hydrolysis. The RlpA-like effector is homologous to a papain-like inhibitor and to a barwin-like endoglucanase, while our data showed that it was able to suppress hypersensitive response in Nicotiana bethamiana leaves. Overall, this study provides us with valuable information on R. solani infection biology towards understanding the molecular mechanisms in this pathosystem.