ABSTRACT
Drought-tolerant cultivars and their phytochemical composition, which has a role in providing drought tolerance are gaining importance. In this study, rice bran oil and semi-purified oryzanol (SPO) obtained from five rice (Oryza sativa L.) cultivars, namely P1401 and PB1 (drought-susceptible) and N22, PNR381 and APO (drought-tolerant) were analyzed for the γ-oryzanol content, an antioxidant present in considerable amount in the rice bran. The higher level of γ-oryzanol and its antioxidant activity was observed in drought-tolerant cultivars (N22, PNR381 and APO) as compared to drought-susceptible (PB1 and P1401), suggesting the role of γ-oryzanol in drought tolerance, as antioxidants are known to play an important role by scavenging free radicals. The total antioxidant activity of γ-oryzanol might be attributed to 24-methylene cycloartanyl ferulate, a major component of γ-oryzanol. By enhancing the level of active oryzanol components identified in this study by genetic and molecular means could impart increased drought tolerance.
Subject(s)
Antioxidants/metabolism , Droughts , Oryza/cytology , Oryza/metabolism , Oryza/physiology , Phenylpropionates/isolation & purification , Phenylpropionates/metabolism , Plant Oils/metabolismABSTRACT
An antibacterial metabolite extracted from Paenibacillus polymyxa HKA-15 showed strong inhibition against Xanthomonas campestris pv. phaseoli strains CP-1-1 and M-5. Minimum inhibitory concentration (MIC) of crude extract against strains CP-1-1 and M-5 was found to be 1.7 mg/ml and 1.52 mg/ml, respectively. In UV-Vis range, the absorption peak of crude extract was maximum at 240 nm. The compound is resilience to wide range of temperature, pH, surfactants and organic solvents. The complete loss of activity was observed when crude metabolite was treated with pepsin (400 unit / ml). Characterization of crude metabolite suggested its hydrophobic and peptide nature. Inhibition of Xanthomonas campestris pv. phaseoli by peptide like metabolite produced by Paenibacillus polymyxa strain HKA-15 under in vitro conditions showed ecological and biotechnological potential of strain HKA-15 to control common blight disease in beans.