Differential biochemical response of rice (Oryza sativa L.) genotypes against rice blast (Magnaporthe oryzae)

Abstract

The disease-free (control) and blast infected leaf samples of 11 rice genotypes were evaluated for activity profile of defense-related and antioxidative enzymes. The amplification genomic DNA with two SSR markers RM124 and RM224 were also performed for identification of blast resistance and susceptible genotypes. The activity of chitinase, PAL and β-glucosidase of post pathogen-infected leaf samples increased significantly in all rice genotypes, thought the increase was comparable less in to blast susceptible genotypes Chimansal and EK-70. The activity of antioxidative enzymes was comparatively higher in the infected leaf of blast resistant genotypes recording highest increase in NLR-20104 and KJT-5. The activity of defense-related and antioxidative enzymes in the disease-free leaf samples differed among the genotypes and was even higher in the two blast susceptible genotypes. RM144 and RM224 SSR primers clearly amplified in blast resistant KJT-5, NLR-20104, KJT-2, Tetep genotypes whereas RM144 missing in susceptible Chimansal but prominently present in susceptible genotype EK-70. This study revealed that higher level of induction of defense-related and antioxidative enzymes and presence of specific amplified fragments with RM144 and RM224 could be useful for screening the resistant and susceptible rice genotypes against Magnaporthe oryzae.

Keywords:

• rice blast (M. oryzae)
• SSR marker
• defense-related enzymes
• antioxidants

Public Interest Statement

Rice blast disease is a serious fungal disease caused by Magnaporthe oryzae. The use of chemical is expensive and not environment-friendly; hence utilization of host resistance has been the best way to manage the disease. To identify biochemical and molecular markers selectively differentiating the germplasm which can be environmentally sustainable plan for developing rice resistant genotypes. In this report, disease-free and infected leaf samples of 11 rice genotypes were screened against fungal blast disease for biochemical analysis of some defense-related and antioxidative enzymes. Amplification genomic DNA with two SSR markers RM124 and RM224 were also performed for identification of blast resistance and susceptible genotypes. This study revealed that higher level of induction of defense-related and antioxidative enzymes and presence of specific amplified fragments with RM144 and RM224 could be useful for screening the resistant and susceptible rice genotypes against M. oryzae.

Additional information

Funding

Funding. The authors received no direct funding for this research.

Notes on contributors

P.U. Anushree

We at the department of Biochemistry are undertaking research work to identify biochemical and molecular markers to screen the available germplasm of crop plants for major abiotic and biotic stresses particularly in pigeon pea, chickpea for wilt and sterility mosaic, rice for blast and blight, sorghum for shoot fly. The work is also being undertaken for abiotic stresses particularly drought and salinity and also for combinational stress. The present work is similar attempt which was carried out in collaboration with rice pathologist working at ARS, Lonavala, India which is a hot spot for blast disease of rice. Disease-free and infected leaf samples of 11 rice genotypes were collected and biochemical analysis of some defense-related and antioxidative enzymes was carried out. Flanking markers RM144 and RM224 also amplified for validation of blast resistant and susceptible rice genotypes in the present study. These efforts are helping the plant breeder to understand breeding program and developing mapping population is being utilized for marker trait association.