RHO2 — Magnaporthe oryzae 70-15

Summary

MGG_02457 (MoRHO2) on chromosome 1 of Magnaporthe oryzae 70-15 encodes a small GTPase of the Rho family, possessing GTP-binding, GTPase, GDP-binding, protein serine/threonine kinase activator activity, and signaling adaptor activity. The gene is associated with positive regulation of 1,3-beta-D-glucan biosynthetic processes, formin-nucleated actin cable assembly, and primary cell septum biogenesis, as well as regulation of exocytosis, septum digestion after cytokinesis, and cell polarity. MoRHO2 is linked to rice blast disease, and its disruption is associated with absent spore germination and adhesion, delayed vegetative growth and protein secretion, decreased septum formation and cell fusion, abnormal nuclear fusion during mating, increased polyploidy, and loss of osmotic and alkaline pH resistance. The protein localizes to the hyphal tip, growing cell tip, bud, and 1,3-beta-glucan synthase complex. Studies of related genes in other species link the family to loss of pathogenicity.