Plant growth promoting rhizobacteria mediated induced defence proteins in rice plants against the sheath rot pathogen.

摘要

Twenty-four strains of plant growth-promoting rhizobacterial (PGPR) isolated from different agro-ecosystems of Tamil Nadu, India, and were tested for their efficacy against the sheath rot pathogen Sarocladium oryzae in vitro, in glasshouse and field during 2011-12. Vigour index was used to assay the growth promotion and antagonistic activity of Pseudomonas strains against S. oryzae in vitro. The results revealed promising antagonistic action by strains Pf1, TDK1 and TV5 compared to other strains. Further, the combination of Pseudomonas strains Pf1, TDK1 and TV5 was more effective in reducing sheath rot disease in rice plants compared to individual strains under glasshouse and field conditions. Quantitative and native polyacrylamide gel electrophoresis (PAGE) analysis of peroxidase (PO), polyphenol oxidase (PPO) and chitinase activity in rice plants showed an increased accumulation of defence enzymes in the treatment with a combination of Pf1, TDK1 and TV5 compared to the treatment with individual strains and untreated controls. The present study revealed the probable influence of antagonism, plant growth promotion and induced systemic resistance (ISR) by the mixture of Pseudomonas bioformulations in enhancing resistance in rice plants against sheath rot disease. Proteomics analysis revealed the functional analysis of the differential proteins were reported to be directly or indirectly involved in the growth promotion in plants.