Pradhyumna Kumar Singh

National Botanical Research Institute - India, Lakhnau, Uttar Pradesh, India

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Publications (11)40.48 Total impact

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    ABSTRACT: Cypermethrin induces the slow and progressive degeneration of the nigrostriatal dopaminergic neurons in rats. Postnatal preexposure with low doses of cypermethrin is known to enhance the susceptibility of animals upon adulthood reexposure. The study was undertaken to delineate the role of mitochondria in cypermethrin-induced neurodegeneration. Indexes of dopaminergic neurodegeneration, microglial activation, and mitochondrial dysfunction and its proteome profile were assessed in controls and cypermethrin-treated rats. Cypermethrin increased nigral dopaminergic neurodegeneration and microglial activation while reduced mitochondrial membrane potential and complex I activity. Cypermethrin attenuated striatal dopamine content and differentially regulated the expressions of the nine striatal and ten nigral proteins. Western blot analyses showed that cypermethrin also increased c-Jun N-terminal kinase (JNK), caspase-3, tumor suppressor protein (p53), tumor necrosis factor-α (TNF-α), p38 mitogen-activated protein kinase (p38 MAPK), and heme oxygenase-1 (HO-1) expressions and reduced B cell lymphoma-2 protein (Bcl-2) expression. Syndopa and minocycline rescued from cypermethrin induced augmentation in microglial activation and reductions in mitochondrial membrane potential and complex I activity, striatal dopamine content, and degeneration of nigral dopaminergic neurons. Syndopa and minocycline, respectively, modulated the expressions of four and six striatal and four and seven nigral proteins. Furthermore, they reinstated the expressions of JNK, caspase-3, Bcl-2, p53, p38 MAPK, TNF-α, and HO-1. The study demonstrates that cypermethrin induces mitochondrial dysfunction and alters mitochondrial proteome leading to oxidative stress and apoptosis, which regulate the nigrostriatal dopaminergic neurodegeneration.
    Molecular Neurobiology 04/2014; · 5.47 Impact Factor
  • Harpal Singh, Sameer Dixit, Praveen Chandra Verma, Pradhyumna Kumar Singh
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    ABSTRACT: Tomatoes are one of the most consumed crops in the whole world because of their versatile importance in dietary food as well as many industrial applications. They are also a rich source of secondary metabolites, such as phenolics and flavonoids. In the present study, we described a method to produce these compounds from hairy roots of tomato (THRs). Agrobacterium rhizogenes strain A4 was used to induce hairy roots in the tomato explants. The Ri T-DNA was confirmed by polymerase chain reaction amplification of the rolC gene. Biomass accumulation of hairy root lines was 1.7-3.7-fold higher compared to in vitro grown roots. Moreover, THRs efficiently produced several phenolic compounds, such as rutin, quercetin, kaempferol, gallic acid, protocatechuic acid, ferulic acid, colorogenic acid, and caffeic acid. Gallic acid [34.02 μg/g of dry weight (DW)] and rutin (20.26 μg/g of DW) were the major phenolic acid and flavonoid produced by THRs, respectively. The activities of reactive oxygen species enzymes (catalase, ascorbate peroxidase, and superoxide dismutase) were quantified. The activity of catalase in THRs was 0.97 ± 0.03 mM H2O2 min(-1) g(-1), which was 1.22-fold (0.79 ± 0.09 mM H2O2 min(-1) g(-1)) and 1.59-fold (0.61 ± 0.06 mM H2O2 min(-1) g(-1)) higher than field grown and in vitro grown roots, respectively. At 100 μL/g concentration, the phenolic compound extract caused 53.34 and 40.00% mortality against Helicoverpa armigera and Spodoptera litura, respectively, after 6 days. Surviving larvae of H. armigera and S. litura on the phenolic compound extract after 6 days showed 85.43 and 86.90% growth retardation, respectively.
    Journal of Agricultural and Food Chemistry 03/2014; · 2.91 Impact Factor
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    ABSTRACT: BACKGROUND: Cotton (Gossypium hirsutum L.) is a major fiber crop that is grown worldwide; it faces extensive damage from sap-sucking insects, including aphids and whiteflies. Genome-wide transcriptome analysis was performed to understand the molecular details of interaction between Gossypium hirsutum L. and sap-sucking pests, namely Aphis gossypii (Aphid) and Bemisia tabacci (Whiteflies). Roche's GS-Titanium was used to sequence transcriptomes of cotton infested with aphids and whiteflies for 2 h and 24 h. RESULTS: A total of 100935 contigs were produced with an average length of 529 bp after an assembly in all five selected conditions. The Blastn of the non-redundant (nr) cotton EST database resulted in the identification of 580 novel contigs in the cotton plant. It should be noted that in spite of minimal physical damage caused by the sap-sucking insects, they can change the gene expression of plants in 2 h of infestation; further change in gene expression due to whiteflies is quicker than due to aphids. The impact of the whitefly 24 h after infestation was more or less similar to that of the aphid 2 h after infestation. Aphids and whiteflies affect many genes that are regulated by various phytohormones and in response to microbial infection, indicating the involvement of complex crosstalk between these pathways. The KOBAS analysis of differentially regulated transcripts in response to aphids and whiteflies indicated that both the insects induce the metabolism of amino acids biosynthesis specially in case of whiteflies infestation at later phase. Further we also observed that expression of transcript related to photosynthesis specially carbon fixation were significantly influenced by infestation of Aphids and Whiteflies. CONCLUSIONS: A comparison of different transcriptomes leads to the identification of differentially and temporally regulated transcripts in response to infestation by aphids and whiteflies. Most of these differentially expressed contigs were related to genes involved in biotic, abiotic stresses and enzymatic activities related to hydrolases, transferases, and kinases. The expression of some marker genes such as the overexpressors of cationic peroxidase 3, lipoxygenase I, TGA2, and non-specific lipase, which are involved in phytohormonal-mediated plant resistance development, was suppressed after infestation by aphids and whiteflies, indicating that insects suppressed plant resistance in order to facilitate their infestation. We also concluded that cotton shares several pathways such as phagosomes, RNA transport, and amino acid metabolism with Arabidopsis in response to the infestation by aphids and whiteflies.
    BMC Genomics 04/2013; 14(1):241. · 4.40 Impact Factor
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    ABSTRACT: Mitochondrial dysfunction is the foremost perpetrator of the nigrostriatal dopaminergic neurodegeneration leading to Parkinson's disease (PD). However, the roles played by majority of the mitochondrial proteins in PD pathogenesis have not yet been deciphered. Present study investigated the effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and combined maneb and paraquat on the mitochondrial proteome of the nigrostriatal tissues in the presence or absence of minocycline, levodopa and manganese (III) tetrakis (1-methyl-4-pyridyl) porphyrin (MnTMPyP). The differentially expressed proteins were identified and proteome profiles were correlated with the pathological and biochemical anomalies induced by MPTP and maneb and paraquat. MPTP altered the expression of twelve while combined maneb and paraquat altered the expression of fourteen proteins. Minocycline, levodopa and MnTMPyP, respectively, restored the expression of three, seven and eight proteins in MPTP and seven, eight and eight proteins in maneb- and paraquat-treated groups. Although levodopa and MnTMPyP rescued from MPTP- and maneb- and paraquat-mediated increase in the microglial activation and decrease in Mn-SOD expression and complex I activity, dopamine content and number of dopaminergic neurons, minocycline defended mainly against maneb- and paraquat-mediated alterations. The results demonstrate that MPTP and combined maneb and paraquat induce mitochondrial dysfunction and microglial activation and alter the expression of a bunch of mitochondrial proteins leading to the nigrostriatal dopaminergic neurodegeneration and minocycline, levodopa or MnTMPyP variably offset scores of such changes.
    Biochimica et Biophysica Acta 04/2013; · 4.66 Impact Factor
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    ABSTRACT: δ-Endotoxins produced by Bacillus thuringiensis (Bt) have been used as bio-pesticides for the control of lepidopteran insect pests. Garlic (Allium sativum L.) leaf agglutinin (ASAL), being toxic to several sap-sucking pests and some lepidopteran pests, may be a good candidate for pyramiding with δ-endotoxins in transgenic plants for enhancing the range of resistance to insect pests. Since ASAL shares the midgut receptors with Cry1Ac in Helicoverpa armigera, there is possibility of antagonism in their toxicity. Our study demonstrated that ASAL increased the toxicity of Cry1Ac against H. armigera while Cry1Ac did not alter the toxicity of ASAL against cotton aphids. The two toxins interacted and increased binding of each other to brush border membrane vesicle (BBMV) proteins and to the two important receptors, alkaline phosphatase (ALP) and aminopeptidase N (APN). The results indicated that the toxins had different binding sites on the ALP and APN but influenced mutual binding. We conclude that ASAL can be safely employed with Cry1Ac for developing transgenic crops for wider insect resistance.
    Applied Microbiology and Biotechnology 08/2011; 93(6):2365-75. · 3.69 Impact Factor
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    ABSTRACT: A gene from Withania somnifera (winter cherry), encoding a highly stable chloroplastic Cu/Zn superoxide dismutase (SOD), was cloned and expressed in Escherichia coli. The recombinant enzyme (specific activity of ~4,200 U mg(-1)) was purified and characterized. It retained ~90 and ~70% residual activities after 1 h at 80 and 95 °C, respectively. At 95 °C, thermal inactivation rate constant (K (d)) of the enzyme was 2.46 × 10(-3) min(-1) and half-life of heat inactivation was 4.68 h. The enzyme was stable against a broad pH range (2.5-11.0). It also showed a high degree of resistance to detergent, ethanol and protease digestion. This recombinant Cu/Zn SOD could therefore have useful applications.
    Biotechnology Letters 06/2011; 33(10):2057-63. · 1.85 Impact Factor
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    ABSTRACT: RNA interference (RNAi)-mediated gene silencing was explored for the control of sap-sucking pest Bemisia tabaci, commonly known as whitefly. dsRNAs and siRNAs were synthesized from five different genes - actin ortholog, ADP/ATP translocase, alpha-tubulin, ribosomal protein L9 (RPL9) and V-ATPase A subunit. A simplified insect bioassay method was developed for the delivery of ds/siRNA through the oral route, and efficacy was evaluated. ds/siRNA caused 29-97% mortality after 6 days of feeding. Each insect ingested nearly 150 nl of insect diet per day, which contained a maximum of 6 ng of RNA. Knocking down the expression of RPL9 and V-ATPase A caused higher mortality with LC50 11.21 and 3.08 microg/ml, respectively, as compared to other genes. Semi-quantitative PCR of the treated insects showed significant decrease in the level of RPL9 and V-ATPase A transcripts. siRNAs were found stable in the insect diet for at least 7 days at the room temperature. Phloem-specific expression of dsRNAs of RPL9 and V-ATPase A in transgenic plants for the protection against whiteflies might be an interesting application of this technology.
    Journal of Biosciences 03/2011; 36(1):153-61. · 1.76 Impact Factor
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    ABSTRACT: Allium sativum leaf agglutinin (ASAL) binds to several proteins in the midgut of Helicoverpa armigera and causes toxicity. Most of these were glycosylated. Six ASAL-binding proteins were selected for identification. PMF and MS/MS data showed their similarity with midgut aminopeptidase APN2, polycalins and alkaline phosphatase of H. armigera, cadherin-N protein (partial AGAP009726-PA) of Acyrthosiphon pisum, cytochrome P450 (CYP315A1) of Manduca sexta and alkaline phosphatase of Heliothis virescens. Some of the ASAL-binding midgut proteins were similar to the larval receptors responsible for the binding of δ-endotoxin proteins of Bacillus thuringiensis. Galanthus nivalis agglutinin also interacted with most of the ASAL-binding proteins. The ASAL showed resistance to midgut proteases and was detected in the larval hemolymph and excreta. Immunohistochemical staining revealed the presence of ASAL in the body tissue also.
    Proteomics 12/2010; 10(24):4431-40. · 4.43 Impact Factor
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    ABSTRACT: Flavonoids synthesized by the phenylpropanoid pathway participate in myriad physiological and biochemical processes in plants. Due to the diversity of secondary transformations and the complexity of the regulation of branched pathways, single gene strategies have not been very successful in enhancing the accumulation of targeted molecules. We have expressed an Arabidopsis (Arabidopsis thaliana) transcription factor, AtMYB12, in tobacco (Nicotiana tabacum), which resulted in enhanced expression of genes involved in the phenylpropanoid pathway, leading to severalfold higher accumulation of flavonols. Global gene expression and limited metabolite profiling of leaves in the transgenic lines of tobacco revealed that AtMYB12 regulated a number of pathways, leading to flux availability for the phenylpropanoid pathway in general and flavonol biosynthesis in particular. The tobacco transgenic lines developed resistance against the insect pests Spodoptera litura and Helicoverpa armigera due to enhanced accumulation of rutin. Suppression of flavonol biosynthesis by artificial microRNA reversed insect resistance of the AtMYB12-expressing tobacco plants. Our study suggests that AtMYB12 can be strategically used for developing safer insect pest-resistant transgenic plants.
    Plant physiology 02/2010; 152(4):2258-68. · 6.56 Impact Factor
  • Biotechnology Journal 04/2009; 4(3):319-28. · 3.71 Impact Factor
  • Raju Madanala, Vijayta Gupta, Pradhyumna Kumar Singh, Rakesh Tuli
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    ABSTRACT: Plastid transformation vectors are used for high-level expression of industrially important recombinant proteins in plants. In the present study, new vectors for plastid transformation were developed. One of these vectors targets transgenes at a new site in the chloroplast genome. Intergenic regions of trnfM-trnG, ndhB-trnL and rrn16-trnV were selected as sites for transgene insertion. Tobacco chloroplast was successfully transformed with designed vectors, and the transplastomic plants accumulated recombinant protein as high as 5–6% of total soluble protein which remained localized in the chloroplasts. Although the vectors were designed using the plastid genome of Nicotiana tabacum, flanking regions used in two vectors show a high level of homology with chloroplast genomes of other plant species, thus it might be possible to use them for the transformation of a wider range of plant species.
    Plant Biotechnology Reports 6(1). · 1.05 Impact Factor