The dominant rice blast resistance gene Pi54 cloned by map-based cloning approach from indica rice cultivar Tetep confers broad spectrum resistance to Magnaporthe oryzae. In this investigation, an orthologue of Pi54 designated as Pi54of was cloned from Oryza officinalis conferring high degree of resistance to M. oryzae and is functionally validated. We have also characterized the Pi54of protein and demonstrate its interaction with AVR-Pi54 protein. The Pi54of encoded ∼43 kDa small and unique cytoplasmic LRR family of disease resistance protein having unique Zinc finger domain overlapped with the leucine rich repeat regions. Pi54of showed Magnaporthe-induced expression. The phylogenetic and western blot analysis confirmed orthologous nature of Pi54 and Pi54of genes, whereas the identity of protein was confirmed through MALDI-TOF analysis. The in silico analysis showed that Pi54of is structurally more stable than other cloned Pi54 proteins. The molecular docking revealed that Pi54of protein interacts with AVR-Pi54 through novel non-LRR domains such as STI1 and RhoGEF. The STI1 and GEF domains which interact with AVR-Pi54 are also components of rice defensome complex. The Pi54of protein showed differential domain specificity while interacting with the AVR protein. Functional complementation revealed that Pi54of transferred in two rice lines belonging to indica and japonica background imparts enhanced resistance against three highly virulent strains of M. oryzae. In this study, for the first time, we demonstrated that a rice blast resistance gene Pi54of cloned from wild species of rice provides high degree of resistance to M. oryzae and might display different molecular mechanism involved in AVRPi54-Pi54of interaction.

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Priva cordifolia (Verbenaceae) is broadly dispersed all through India in states like Andhra Pradesh, Gujarat, Karnataka, Kerala and Tamil Nadu. The species of genus Priva are known for their rich composition of Phenolic compounds. Therefore, phytochemical properties and antioxidant potential of Priva cordifolia were evaluated in the present study. The ethanol extract of P.cordifolia [EEPC] was obtained by Soxhletion, with ethanol and was further processed for phytochemical screening, Total Phenol Content, Total Flavonoid Content and various in vitro antioxidant assays. The phytochemicals present in EEPC were Carbohydrates, Proteins, Steroids, Phenolic compounds, Flavonoids and Triterpenoids. The Total Phenolic and Flavonoid contents of EEPC were found to be 98.62 mg Gallic acid equivalents (GAE) per gram of dry extract and 49.76 mg Quercetin equivalents (QE) per gram of dry extract, respectively. In DPPH radical scavenging activity, EEPC exerted an inhibition of 71% and that of ascorbic acid was 79% at 500μg/ml. In the FRAP assay, the absorbance of EEPC clearly increased, due to the formation of the Fe2+-TPTZ complex with increasing concentration. Hydroxyl radical scavenging activity of the EEPC was 64% while ascorbic acid reached 73% at 500μg/ml. Superoxide radical scavenging activity of the EEPC was 79% while ascorbic acid reached 84% at 1000 μg/ml. Nitric oxide radical scavenging activity of the EEPC reached 54% while ascorbic acid reached 70% at 500μg/ml. The present study suggests that this plant could be of great importance for the treatment of free radical related diseases.