Jiayu Dong
Southern Piedmont Agricultural Research and Extension Center, Virginia Tech, Blackstone, VA 23824 / School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061
Blacktone, Virginia, United States
David Haak
School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061
Blacksburg, Virginia, United States
Boris A. Vinatzer
Professor
School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061
Blacksburg, Virginia, United States
Song Li
School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061
Blacksburg, Virginia, United States
Thomas D. Reed
Southern Piedmont Agricultural Research and Extension Center, Virginia Tech, Blackstone, VA 23824 / School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061
Blackstone, Virginia, United States
Yuan Zeng
Assistant Professor
Southern Piedmont Agricultural Research and Extension Center, Virginia Tech, Blackstone, VA 23824 / School of Plant and Environmental Sciences, Virginia Tech, Blacksburg, VA 24061
Blackstone, Virginia, United States
Rhizoctonia solani is a soilborne fungus classified into 13 anastomosis groups (AGs) based on hyphal fusion compatibility. It causes diseases in crops like tobacco, potato, corn, rice, and forage crops, leading to significant yield losses. Understanding the genetic basis of pathogenicity and host specificity in R. solani is crucial for effective disease management. In this study, we performed a comparative genomic analysis of 16 R. solani isolates representing different AGs and host plants, with Ceratobasidium theobromae as an outgroup. A phylogenetic tree based on single-copy orthologs identified by OrthoFinder showed that isolates within the same AG clustered together, indicating close genetic relationships. Among AG-3 isolates, which are highly host-specific to potato and tobacco, we identified 38 single-copy orthologs, including one encoding a pectate lyase. Other pectate lyases appeared as multi-copy orthologs in all isolates. In addition, 24 single-copy orthologs were unique to the tobacco AG-3 isolate, including a ricin B-type lectin domain-containing (RBLD) protein and a stress-associated endoplasmic reticulum protein (SERP). Proteins associated with R. solani survival and pathogenicity were further analyzed for structure using AlphaFold3. These findings suggest that genes such as the single-copy pectate lyase, RBLD, or SERP, may contribute to host adaptation and pathogenicity in R. solani, offering potential targets for genetic studies on host specificity and virulence or for developing inhibitors for disease control in tobacco and potato.