Study of Putative Pathogenesis-Associated Genes of Rhizoctonia solani AG1-IA Causal Agent of Rice Sheath Blight

Abstract

Rhizoctonia solani (Rs), the causal agent of rice sheath blight, is a notorious soil-borne disease prevalent in many rice-growing regions including in Indonesia. Although several studies of pathogenesis of Rs have been reported, there have been no reports describing the putative pathogenesis-associated genes of Rs AG1-IA in Indonesia.  Current study stated that there were 3942 genes that were identified unique to Rs  AG1-IA infecting rice. However, information on interaction and the pathogenicity genes of these Rs anastomosis groups during infection of rice is lacking. Therefore, this study is aims to do inceptive detection of putative pathogenesis-associated genes of Rs AG1-IA in Indonesia. Fifty Rs isolates were collected from thirteen districts of three rice producing provinces in Indonesia; DI Yogyakarta, Central Java, and South Sulawesi, and were identified as Rs AG1-IA based on the presence of 137-140 bp AG1-IA specific primers named Rs1F/Rs2R, also based on macroscopic and microscopic observation. Furthermore, the presence of the putative pathogenesis-associated genes were detected using primers Rga1, AG1_AP, AG1_PC and AG1_CFEM that were applied to selected isolates. The presence of a putative pathogenesis-associated genes was detected by the formation of amplicons at 172 bp using AG1_PC and 144 bp using primers AG1_CFEM. The associated bands showed 100% similarity to glycosyltransferase family 2 protein of Rs AG1-IA for AG1_PC primer and clathrin adapter complex small chain domain for AG1_CFEM primer after sequencing and analyzing by BLASTx tools. While primers Rga1 and AG1_PC didn’t show a specific band. Through the present study, pathogenicity genes were found specific to Rs AG1-IA. AG1_PC in MAG B2 and SPG A2 isolates; and AG1_CFEM in SPG A2, KLA D1, MAG B2 and SLE B1 isolates. These two primers can be used to next step study to better understand the molecular aspect of pathogenicity in Rs AG1-IA.