Induction of resistance to rice leaf blast by avirulent isolates of Magnaporthe oryzae

Rice blast (Magnaporthe oryzae) disease can cause losses of up to 100% in grain production. A sustainable management should consider alternative control measures. In the present work, biotic resistance induction to blast disease was studied by comparing disease severity and quantifying some pathogenesis-related proteins (PRPs). Rice plants of cultivars Metica-1 and Cica-8 were sprayed with biotic resistance inducers (incompatible isolates of M. oryzae) 48 h before inoculation with challenging isolates (compatible isolates of M. oryzae) under greenhouse conditions. For both cultivars, Metica-1 and Cica-8, the area under the disease progress curve was reduced by more than 80% when plants were induced with avirulent isolates of Magnaporthe oryzae. The biotic inducers also promoted an increase in the activity of peroxidase (POX), -1.3-glucanase (GLU), chitinase (CHI), and phenylalanine ammonia-lyase (PAL). Systemic expression of resistance was also observed.