North Eastern Hill University

About: North Eastern Hill University is a education organization based out in Shillong, Meghalaya, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 2318 authors who have published 4476 publications receiving 48894 citations.

In Silico Identification of Mimicking Molecules as Defense Inducers Triggering Jasmonic Acid Mediated Immunity against Alternaria Blight Disease in Brassica Species.

Abstract: Alternaria brassicae and Alternaria brassicicola are two major phytopathogenic fungi which cause Alternaria blight, a recalcitrant disease on Brassica crops throughout the world, which is highly destructive and responsible for significant yield losses. Since no resistant source is available against Alternaria blight, therefore , efforts have been made in the present study to identify defense inducer molecules which can induce Jasmonic acid (JA) mediated defense against the disease. It is believed that JA triggered defense response will prevent necrotrophic mode of colonization of Alternaria brassicae fungus. The jasmonate receptor, COI1 is one of the potential targets for triggering jasmonic acid mediated immunity through interaction with jasmonate signal. In the present study, few mimicking compounds more efficient than naturally occurring jasmonic acid in terms of interaction with COI1 were identified through virtual screening and molecular dynamics simulation studies. A high quality structural model of COI1 was developed using the protein sequence of Brassica rapa . This was followed by virtual screening of 767 analogs of jasmonic acid from ZINC database for interaction with COI1. Two analogs viz. ZINC27640214 and ZINC43772052 showed more binding affinity with COI1 as compared to naturally occurring jasmonic acid. Molecular dynamics simulation of COI1and COI1-jasmonic acid complex, as well as best screened interacting structural analogs of jasmonic acid with COI1 was done for 50 ns to validate the stability of system. It was found that ZINC27640214 possesses efficient, stable, and good cell permeability properties. Based on the obtained results and its physicochemical properties, it is capable of mimicking jasmonic acid signalling and may be used as defense inducers for triggering JA mediated resistance against Alternaria blight, only after further validation through field trials.

Transverse thin cell layer ( t -TCL)-mediated improvised micropropagation protocol for endangered medicinal orchid Dendrobium aphyllum Roxb: an integrated phytomolecular approach

Abstract: Clonal propagation is an important biotechnological tool for the conservation of rare, endangered and threatened as well as commercially important plant species of which orchids are an important representative. In the present research, an attempt was made to develop a fast, clonally stable as well as phytochemically enriched regeneration protocol for propagating Dendrobium aphyllum, an important medicinal orchid using transverse thin cell layer (t-TCL) explants. Murashige and Skoog (MS) medium supplemented with 15 µM meta-topolin along with 10 µM TDZ and 10 µM AgNO3 was found to be most conducive for shoot proliferation. After 8 weeks of culture, an average of 39.41 shoots/explant proliferated; till date this is the best shooting frequency for D. aphyllum and one of the best amongst the orchids. The highest rooting frequency of 82.34% was accomplished in half-strength MS medium supplemented with 15 µM IBA. The plantlets were successfully acclimatized in greenhouse exhibiting normal developmental patterns and flowering occurred after 6 months of acclimatization with 3–4 flowers/stalk irrespective of the flowering season. The genetic homogeneity of the micropropagated plants was ascertained using IRAP and ISSR markers. A comparative assessment of the antioxidant activity (mother and micropropagated plant) was performed using DPPH and FRAP assays which was recorded to be higher amongst the in vitro-regenerated plants. A rapid, genetically stable regeneration protocol coupled with comprehensively higher phytochemical yield is reported in the present study on D. aphyllum. The results of this study confirm the use of in vitro propagation protocol for sustainable commercial utilization as well as conservation of medicinal orchid bio-resources within a limited time period.

Phyto-molecular profiling and assessment of antioxidant activity within micropropagated plants of Dendrobium thyrsiflorum: a threatened, medicinal orchid

Abstract: The escalating loss of biological diversity throughout the world has become a major concern for the conservation biologists Like other threatened plant species, the natural populations of the orchids are also severely threatened Dendrobium thyrsiflorum is one such representative of the family Orchidaceae whose natural populations are getting destroyed at an alarming rate and deserves special conservation attention Both direct shoot organogenesis (DSO) and indirect shoot organogensesis (ISO) pathways were experimented and the highest regeneration frequency for DSO and ISO pathways were found to be 862 and 96 % respectively The regenerated shoots were best rooted in half-strength MS medium supplemented with 1 mg/l indole butyric acid (IBA) and 05 mg/l phloroglucinol The genetic stability of the acclimatized plants derived from ISO and DSO pathways was assessed using Inter Simple Sequence Repeats (ISSR) and Start Codon Targeted (SCoT) molecular markers SCoT proved to be a superior marker over ISSR in detecting clonal variability The phytochemical analysis of the micropropagated plants also revealed a comprehensively higher yield of various secondary metabolites with significantly higher antioxidant potentials in both ISO- and DSO-derived plants over the mother plant However, the ISO-derived plants were more phytochemically enriched compared to the DSO-plants The rapid multiplication rate, higher genetic stability and secondary metabolite production ensures the utility of this micropropagation method for D thyrsiflorum in the ex situ conservation and commercial exploitation of other important orchid species