Gamma-irradiated fenugreek extracts mediates resistance to rice blast disease through modulating histochemical and biochemical changes.

The impact of gamma radiation on the activation of rice innate immunity to blast disease caused by Magnaporthe oryzae is described. In the present study, fenugreek seed extracts radiated with different doses of gamma rays viz. 5Gy, 10Gy, 15Gy, 20Gy and 25Gy were examined for their presence of biocompounds as well as for its ability to induce plant growth promotion and resistance against rice blast disease. The results of GC-MS analysis detected antimicrobial properties in methanolic extract. Enhanced germination (97%) and vigor (2718) was noticed in seeds pretreated with 20 Gy of gamma radiation in comparison with non-irradiated controls. Under greenhouse conditions, a significant disease protection of 56.7% on 3rd and 4th day after inoculation against rice blast was observed in 15Gy-irradiated rice plants challenge-inoculated with M. oryzae. Further, a significant increase in the hydrogen peroxide, phenol and lignin deposition was noticed in 20Gy-irradiated rice plants. Additionally, rice plants pretreated with 15Gy induced maximum activities of peroxidase (POX) and polyphenol oxidase (PPO) compared to untreated control plants. These findings revealed that rice plants-pretreated with gamma radiation elicit resistance against rice blast disease as well as strengthening the growth parameters by modulating cellular and biochemical defense system.

Bioactive compounds guided diversity of endophytic fungi from Baliospermum montanum and their potential extracellular enzymes.

Baliospermum montanum (Willd.) Muell. Arg, a medicinal plant distributed throughout India from Kashmir to peninsular-Indian region is extensively used to treat jaundice, asthma, and constipation. In the current study, 203 endophytic fungi representing twenty-nine species were isolated from tissues of B. montanum. The colonization and isolation rate of endophytes were higher in stem followed by seed, root, leaf and flower. The phytochemical analysis revealed 70% endophytic isolates showed alkaloids and flavonoids, 13% were positive for phenols, saponins and terpenoids. Further, these endophytes produced remarkable extracellular enzymes such as amylase, cellulase, phosphates, protease and lipase. The most promisive three endophytic fungi were identified by ITS region and secreted metabolites were identified by gas chromatography-mass spectrometry (GC-MS/MS). The GC-MS profile detected twenty-five bioactive compounds from ethyl acetate extracts. Among endophytic fungi, Trichoderma reesei isolated from flower exhibited nine bioactive compounds namely, 2-Cyclopentenone, 2-(4-chloroanilino)-4-piperidino, Oxime-methoxy-Phenyl, Methanamine N-hydroxy-N-methyl, Strychane, Cyclotetrasiloxane, Octamethyl and 1-Acetyl-20a-hydroxy-16-methylene. The endophyte, Aspergillus brasiliensis isolated from root and Fusarium oxysporum isolated from seed produced nine and seven bioactive compounds, respectively. Overall, a significant contribution of bioactive compounds was noticed from the diverse endophytic fungi associated with B. montanum and could be explored for development of novel drug with commercial values.