Browsing by Author "K.N. Tiwari"

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5-Amino uracil activated silver nano resonators for highly selective visual detection of dopamine and as an agonist towards BAP: Promoting shoot growth in Bacopa monnieri L.
(Elsevier B.V., 2024) Saumya Singh; Raksha Singh; Anurag Kumar Singh; Minu Yadav; S.K. Mishra; Jyoti Dixit; Pooja Verma; K.N. Tiwari; K.K. Upadhyay
Silver nanoparticles (AgNPs) with an average size of about 17.5 nm have been synthesized using 5-amino uracil as a reducing and capping agent. The concentration of these AgNPs was worked out to be 48 nM. These AgNPs served as a highly selective optical sensor against an important neurotransmitter like dopamine (DA) at its nano molar level (94 nM) with the linearity range of 1–5 µM. The quantification of DA in one of its injection sample was also achieved with a recovery of 91 %. Studies like FTIR, UV–Vis, XPS, SEM, TEM, EDX, DLS and Zeta potential measurements have supported our findings. Significant amplification in the Raman signal of DA was also observed upon its addition into as prepared AgNPs solution. Moreover, these AgNPs seemed to augment the activity of cytokinin (BAP) in synergistic fashion and enhanced in vitro high frequency shoots regeneration in B. monnieri L. and also led to increment in its antioxidant metabolite contents like phenol and flavonoid. © 2023 Elsevier B.V.
Comparative effect of different types of cytokinins for shoot formation and plant regeneration in endangered medicinal plantDesmodium Gangeticum
(2008) P. Ahuja; B.D. Singh; K.N. Tiwari
A mass in vitro propagation system for Desmodium gangeticum (L.) DC. (Leguminaceae), a medicinally important plant, has been developed. It is normally propagated through seeds but plant is in endangered category. Hence there is a need to develop an in vitro method. A range of cytokinins have been investigated for multiple shoot induction from nodal explants. Of the three cytokinins (6-benzyladenine, thidiazuron and kinetin) tested 6-benzyladenine (8.9 μM) and thidiazuron (6.8 υM) proved superior to other treatments. Differentiation of multiple shoots was initiated within 3 weeks of cultures. Optimal regeneration was achieved on medium containing 0.5 mg/l BA having 10.7 shoots/explant, 2mg/l TDZ having 7.4 shoots/explant and 5 mg/l KIN having 6.2 shoots/explant. The multiple shoots were elongated onto different media supplemented with low concentration (0.1-0.2 mg/l) GA3, Root induction was achieved on half-strength MS media by pulse treatment with 100 mg/l indole butyric acid (IBA) for 30 minutes. Rooted planlets were successfully acclimatized, with survival rate of 75-80%. The protocol developed for this study could be used for long-term conservation and mass propagation of this species.
Evaluation of cotyledonary node of Clitoria ternatea L. for high frequency in vitro axillary shoot proliferation
(Asian Network for Scientific Information, 2010) J. Singh; K.N. Tiwari
The objective of this study was to establish mass multiplication protocol for Clitoria ternatea. An efficient protocol for in vitro propagation of the valuable medicinal and forage plant aparajita (Clitoria ternatea L.) was developed through axillary shoot proliferation. Cotyledonary node having cotyledons or devoid of cotyledons were evaluated for axillary shoot development. The effect of cytokinins, sucrose concentrations and light-dark condition on axillary shoot regeneration was investigated. Cotyledonary node with cotyledons cultured on MS medium supplemented with 1.5 mg L-1 BAP yielded the maximum number (10.8) of shoots per explant. All media supplemented with 3% sucrose and incubated under 16 h light condition found most suitable for high frequency axillary shoot proliferation. Elongated shoots produced profuse rooting after transfer to half-strength MS medium supplemented with 0.2 mg L-1 IBA. The rooted plantlets were successfully acclimatized and exhibited 95% survival after transfer into the field. This protocol is suitable for large scale production of plantlets of C. ternatea. © 2010 Asian Network for Scientific Information.
Micropropagation and comparative phytochemical, antioxidant study of BacopaMonnieri (L.) Pennell
(Research Journal of Pharmaceutical, Biological and Chemical Sciences, 2015) S.K. Mishra; K.N. Tiwari; P.L. Shivna; A.B. Mishra
Bacopa monnieri an important medicinal plant of Scorphulariaceae family and is distributed in the wet and marshy lands throughout India, Nepal, Sri Lanka, China, Taiwan, and Hawaii. It shows the presence of various phytoconstituents namely, alkaloids, saponins, phenolics and flavonoids. These phytoconstituents are responsible for anti oxidant and various other activity of the plant. The protocols for tissue culture has been developed for regeneration of the BM plant from small part (nodal segment). The regenerated plant having the similar potential in terms of phytoconstituents and antioxidant activity. The In vitro (leaf and stem) regenerated plants have slightly less antioxidant activity as compared to the In vivo but comparable. The protocols (MS+BAP5μg/ml) may used for the clonal regeneration of plant on large scale through which it can be protected and preserved for long duration in small space. A good response was observed in a soil ratio 3:2:1 (Soil rite: red sand: garden soil) for acclamatization.
Pharmacognostic standardization of Asian folk medicinal plant Reinwardtia Indica Dumort
(BRNSS Publication Hub, 2018) Prabhat Upadhyay; Suresh Purohit; S.K. Mishra; K.N. Tiwari; G.P. Dubey; Harish Shah
Background: Recent scenario and global trends are moving toward the medicinal plant used as health-care product for the treatment of different disease or disorder, but the critical and essential issue to be considered in assuring the therapeutic efficacy and safety. Thus standardization of plant parts need to standardized according to the standard guideline for global acceptance of the product. Reinwardtia indica belongs to Linaceae family used as folk medicine in Asia in the treatment and management of boils, carbuncle, and as an antimicrobial agent in wound healing traditionally. Objective: The present study aimed at physicochemical standardization of R. indica leaves and stem part of the plant. Materials and Methods: In our investigation, leaves and stem part of R. indica were standardized based on microscopy, powder microscopy, physicochemical evaluations, extractive yields, and heavy metal analysis as per the International Regulatory Norms. Results: The results revealed that the pharmacognostic parameters have shown the leaves and stem part of the R. indica plant found within the standard limit as per regulatory norms. Conclusion: The data found after standardization can be adopted as a standard of the plant R. indica, and it can be used in the formulation of the health care product after pre-clinical and clinical investigations. © 2018 BRNSS Publication Hub. All rights reserved.
Role of secondary metabolites in plant defense mechanisms: a molecular and biotechnological insights
(Springer Science and Business Media B.V., 2024) R. Upadhyay; R. Saini; P.K. Shukla; K.N. Tiwari
The plants produce secondary metabolites (SMs) as defence compounds against both abiotic and biotic stresses. These stresses instigate the secretion and release of SMs by up or down-regulating the concerned genes involved in their synthesis. The secretion of SMs varies with the plant's genetic constitution and accordingly-they are susceptible or resistant. These metabolites mostly act as deterrents or antifeedants, allelochemicals, toxins or precursors of other metabolites that defend plants from stresses. However, some pathogens use these metabolites as a signal for host recognition or nutrition rather than using them as toxins or deterrents. The SMs activate different signalling pathways e.g. terpenoids modulate the calcineurin pathway, sesquiterpenoids modulate the jasmonic acid and salicylic acid pathway, polyphenols activate the jasmonic acid and phenylpropanoid pathway, and alkaloids activate the salicylic acid pathway to protect against pathogens and herbivores. Polyphenolic compounds provide resistance to different microbes by expressing different pathogenesis-proteins and hypersensitive reaction-mediated cell death and eliminate pathogens by altering the membrane permeability (inhibiting efflux pump), cell wall integrity, suppressing enzyme activity, free radicals’ generation, inhibiting protein biosynthesis, damaging DNA and reducing the expression of virulent genes. Flavonoids help plants sustain pathogen stresses through the changes in the auxin transport process. The pathogen exposure upregulate genes of alkaloid synthesis pathways such as tyrosine decarboxylase (TyDC), S-norcoclurine synthase (NCS), codeinone reductase 2-like (COR-2), and StWRKY8 transcription factors which in turn accumulate alkaloids in large amounts. Plant exposure to pathogens leads to hypersensitivity reactions and phytoalexin accumulation. The plant's treatment of salicylic acid and jasmonic acid upregulated downstream transcription factors, increased the expression of defence proteins, triggered the synthesis of SMs, and provided resistance against multiple pathogens. Pathogens and herbivores have also coevolved to cope with defence metabolites by detoxifying the toxic metabolites, converting toxins into useful products, evolving their food choice, fast digestive system, expulsion of toxins, and down-regulation of the gene-producing secondary metabolites. This review article gives a molecular insight into the genes and regulatory proteins controlling the synthesis of SMs, which may help decipher the role of the biosynthetic pathway intermediates and thereby scoring genes providing resistance to various stresses. The article comprehensively describes the roles of different SMs in plant defence and their molecular mechanisms of action. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.
Shoot regeneration from immature cotyledons of Cicer arietinum
(2001) K. Srivastava; K.N. Tiwari; R. Singh; B.D. Singh; H.K. Jaiswal
Shoot regeneration was achieved from immature cotyledons of five chickpea (Cicer arietinum L.) genotypes: C235, ICC4971, ICC11531, ICC12257 and ICC12873. The cotyledons cultured on Murashige and Skoog (MS) medium supplemented with 3 or 5 mg dm-3 zeatin with or without 0.04 mg dm-3 indole acetic acid (IAA) showed formation of cotyledon like structures (CLS) at their proximal ends. Subsequently, shoot regeneration took place in some of the CLS forming explants. CLS were also formed in cotyledons cultured on MS + 0.2 - 1 mg dm-3 thidiazuron (TDZ); direct shoot regeneration was observed in cotyledons cultured on 1 mg dm-3 TDZ. The shoot buds elongated on media containing indole butyric acid (IBA), benzylaminopurine (BAP) and gibberellic acid (GA3). Complete plantlets were obtained by rooting of shoots following pulse treatment with 200 mg dm-3 IBA for 5 min and culture on growth regulator free half-strength MS medium.
Synergistic effect of trimethoprim and bavistin for micropropagation of Bacopa monniera
(2012) K.N. Tiwari; V. Tiwari; J. Singh; B.D. Singh; P. Ahuja
A micropropagation protocol for Bacopa monniera (L.) Wettst., a medicinally important plant, has been developed. Direct organogenesis without callus formation was induced by culturing node, internode and leaf explants on growth regulator free Murashige and Skoog (MS) medium. MS medium supplemented with an antibiotic trimethoprim (TMP) and a fungicide bavistin (BVN) produced axillary shoots from node and adventitious shoot buds on the surface of all explants. The combination of 200 mg dm -3 TMP and 200 mg dm -3 BVN induced the optimum frequency of shoot formation as well as shoot number. Presence of both TMP and BVN induced multiple axillary shoot formation from the nodal segments and this ability was maintained for four subcultures. © 2012 Springer Science+Business Media B.V.