beta-Glucanase Family Genes Promote Resistance to Sheath Blight in Rice by Inhibiting the Permeability of Plasmodesmata

Rice sheath blight (ShB) caused by Rhizoctonia solani is one of the most serious diseases that threatens rice (Oryza sativa) production. However, the mechanisms of defense against ShB in rice remain largely unknown. In this study, we identified that the expression levels of beta-glucanase (OsBGL) family genes sensitively respond to infection by R. solani, and OsBGLs positively regulate rice resistance to ShB. In addition, OsBGL2 colocalized with AtPDCB1 at the plasmodesmata (PD) and limited the PD permeability. The level of callose accumulation in osbgls mutants and overexpressors was examined, and OsBGLs were found contribute to callose accumulation. Taken together, these data suggest that OsBGLs can regulate the deposition of callose at the PD to reduce its permeability to defend itself against ShB. Through the identification of these genes and the elucidation of their functions, this research fills the gap in the mechanism of PD permeability in rice ShB resistance.

Automated summary

Rice sheath blight is a serious disease that affects rice production, but the mechanisms of defense are poorly understood. This study found that the expression levels of beta-glucanase family genes are responsive to infection and positively regulate rice resistance to sheath blight. OsBGL2 was also found to co-localize with AtPDCB1 and limit the permeability of plasmodesmata. The identification and functional elucidation of these genes help fill the gap in understanding the mechanism of plasmodesmata permeability in rice sheath blight resistance.