The evolution and pathogenic mechanisms of the rice sheath blight pathogen

Abstract

Rhizoctonia solani is a major fungal pathogen of rice (Oryza sativa L.) that causes great yield losses in all rice-growing regions of the world. Here we report the draft genome sequence of the rice sheath blight disease pathogen, R. solani AG1 IA, assembled using next-generation Illumina Genome Analyser sequencing technologies. The genome encodes a large and diverse set of secreted proteins, enzymes of primary and secondary metabolism, carbohydrate-active enzymes, and transporters, which probably reflect an exclusive necrotrophic lifestyle. We find few repetitive elements, a closer relationship to Agaricomycotina among Basidiomycetes, and expand protein domains and families. Among the 25 candidate pathogen effectors identified according to their functionality and evolution, we validate 3 that trigger crop defence responses; hence we reveal the exclusive expression patterns of the pathogenic determinants during host infection. The rice sheath blight pathogen, Rhizoctonia solani, is an important fungal pathogen that can devastate rice and maize crops. Zheng and colleagues sequence and assemble the R. solani AG1 IA genome—the first to be sequenced from the Rhizoctoniagenus—using Illumina sequencing technology.