Publications by authors named "V Hallan"

Understanding the change in plant-associated microbial diversity and secondary metabolite biosynthesis in medicinal plants due to their cultivation in non-natural habitat (NNH) is important to maintain their therapeutic importance. Here, the bacterial endomicrobiome of Podophyllum hexandrum plants of natural habitat (NH; Kardang and Triloknath locations) and NNH (Palampur location) was identified and its association with the biosynthesis of podophyllotoxin (PTOX) was revealed. Rhizomes (source of PTOX) of plants of NH had highest endophytic bacterial diversity compared to NNH-plants.

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Plant protease inhibitors (PI's) inhibit the activity of gut proteases and thus provide resistance against insect attack. Previously we have published first report on cloning and characterization of a novel Bowman-Birk protease inhibitor gene (RbTI) from ricebean (Vigna umbellata). In this study, the RbTI gene was further characterized and validated as a potential candidate for transferring insect resistance in economically important crops.

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The estimation of relative levels of amino acids is crucial for understanding various biological processes in plants, including photosynthesis, stress tolerance, and the uptake and translocation of nutrients. A wide range of liquid chromatography (LC; HPLC/UHPLC)-based methods is available for measuring the quantity of amino acids in plants. Additionally, the coupling of LC with mass spectrometry (MS) significantly enhanced the robustness of existing chromatographic methods used for amino acid quantification.

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Pathogenesis-related proteins (PR), including osmotins, play a vital role in plant defense, being activated in response to diverse biotic and abiotic stresses. Despite their significance, the mechanistic insights into the role of osmotins in plant defense have not been extensively explored. The present study explores the cloning and characterization of the osmotin gene (WsOsm) from Withania somnifera, aiming to illuminate its role in plant defense mechanisms.

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Pathogenesis-related protein 1 (PR-1) is an antimicrobial protein involved in systemic acquired resistance (SAR) in plants, but its regulatory role and interactions with other pathways remain unclear. In this study, we functionally characterize WsPR-1 gene of Withania somnifera in Nicotiana tabacum to elucidate its role in plant defense, growth, and development. Interestingly, transgenic tobacco plants with increased levels of cytokinin (CK) and decreased gibberellins (GAs) exhibited stunted shoot growth, an underdeveloped root system, modified leaf morphology, reduced seed pod production, and delayed leaf senescence.

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