RESUMEN
ß-glucosidase is an enzyme that has ability to cleave ß-glycosidic bonds present in oligosaccharides and glycoconjugates. They are known to be present across all domains of living organism and have important roles in many biological processes including plant defense mechanism. In the present study, a ß-glucosidase enzyme identified from seeds of Sechium edule was characterized using various bioinformatics tools. A homology model (SeBG) was generated using a ß-glucosidase crystal structure from Oryza sativa (PDB ID: 3PTK) as template. In silico structural binding studies on putative ß-glucosidase protein revealed a stable and strong interaction indicative of higher GOLD fitness score with the substrates: p-nitrophenyl-ß-d-glucopyranoside (pNPG), laminarin, chitotriose, N-acetylglucosamine and N-acetylmuramic acid suggesting its possible role in broad spectrum antifungal and antimicrobial activity. Assessment of the in vitro enzyme activity with pNPG showed a Km and Vmax values of 2.7 mM and 22 µMmin-1mL-1mg-1, respectively. While, the in vitro enzyme activity with laminarin showed a Km and Vmax values of 0.31 mM and 0.043 µMmin-1mL-1mg-1. The broad spectrum activity of the protein shown in our result indicates SeBG as a promising biocontrol agent against phytopathogens.Communicated by Ramaswamy H. Sarma.
Asunto(s)
Cucurbitaceae , beta-Glucosidasa , Antifúngicos , Simulación por Computador , Cucurbitaceae/metabolismo , Estabilidad de Enzimas , Concentración de Iones de Hidrógeno , Cinética , Modelos Moleculares , Especificidad por Sustrato , beta-Glucosidasa/metabolismoRESUMEN
Rice bean [Vigna umbellate (Thumb.) Ohwi and Ohashi] is an underutilized crop believed to be domesticated in the Myanmar-Thailand region of Asia. In India, rice bean is mainly cultivated in the North-Eastern Hills, which is a hotspot for biological diversity. A 5' anchored PCR was used to develop microsatellite markers in rice bean. Twenty-eight specific primer pairs were designed and employed to characterize sixty five ricebean accessions collected from North East India. A total of 179 alleles were amplified with an average of 6.393 alleles per locus. The gene diversity was high (mean 0.534) in the accessions collected from Darjeeling, Nagaland and Manipur, which are bordering areas with East Nepal and Myanmar, respectively. Exceptionally high outcrossing rate was observed in the entire population. Population structure analysis identified three distinct clusters in which accessions collected from areas bordering Myanmar and East Nepal grouped separately. Using a combination of STRUCTURE and Principal Coordinate Analysis, relative affinity of the intermediate accessions could be established. However, differences in allelic counts among populations were non-significant. The results showed that there is a high level of genetic diversity within the accessions, with high outcrossing rate.