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sharmila chattopadhyay

    sharmila chattopadhyay

    Objective: Glutathione (GSH) is well-known to play a crucial role in imparting resistance against various pathogen invasions. Nevertheless, the role of GSH in regulating miRNA mediated defence response is yet to be explored. Results: To... more
    Objective: Glutathione (GSH) is well-known to play a crucial role in imparting resistance against various pathogen invasions. Nevertheless, the role of GSH in regulating miRNA mediated defence response is yet to be explored. Results: To decipher the GSH mediated regulation of miRNA expression during necrotrophic infected Arabidopsis thaliana, wild-type Col-0 and AtECS1, the transgenic line exhibiting enhanced GSH content, was infected with necrotrophic pathogen Alternaria brassicicola. AtECS1 plants exhibited enhanced resistance as compared to wild-type. MiRNA next generation sequencing (NGS) was performed to compare the miRNA expression in Col-0 and AtECS1 leaves. Under control condition, differentially expressed 96 known miRNAs and 17 novel miRNAs viz. ath-miR8167f, ath-miR1886.3, ath-miR3932b-5p, etc were identified. Whereas, under infected condition, 73 known and 43 novel differentially expressed miRNAs viz. ath-miR5652, ath-miR160b, ath-miR865-5p, etc. were identified. Function...
    The contribution of glutathione (GSH) in combating environmental stress in the plant system has long been known. Previous reports also pointed towards the involvement of GSH in inducing various heat shock proteins (HSPs). However, the... more
    The contribution of glutathione (GSH) in combating environmental stress in the plant system has long been known. Previous reports also pointed towards the involvement of GSH in inducing various heat shock proteins (HSPs). However, the molecular mechanism is yet to be explored. Here, we investigate how GSH induces the expression of important HSPs in Arabidopsis thaliana. Expressions of HSPs like BiP3, HSP70B and HSP90.1 were positively regulated by GSH. Promoter activation assay suggested the role of GSH in inducing these HSPs. Less expressions of BiP3 and HSP70B in GSH-fed Atmyb21 mutant and HSP90.1 in GSH-fed Atbzip10 mutant in comparison to GSH-fed Col-0 revealed the role of GSH in inducing these HSPs genes by activating their promoters through MYB21 and BZIP10 transcription factors (TFs). Co-transfection of TF mutant's protoplasts with TF constructs and HSPs promoter reconfirmed the results. Comparative proteomics also revealed proteins whose expressions were controlled by MY...
    The involvement of ethylene and abscisic acid in providing stress tolerance and defence response to plants is widely recognized. However, little is known about the cross-talk between glutathione with ethylene and abscisic acid to combat... more
    The involvement of ethylene and abscisic acid in providing stress tolerance and defence response to plants is widely recognized. However, little is known about the cross-talk between glutathione with ethylene and abscisic acid to combat stress in planta. Here, transcriptome analysis of combined cold and osmotic stress treated Arabidopsis mutants were carried out to elucidate the crosstalk between the abscisic acid, ethylene and glutathione. Microarray experiment revealed the differential regulation of about 2313 and 4131 transcripts in ein2 (ethylene insensitive mutant) and aba1.6 (abscisic acid mutant) respectively. Functional analysis exposed common down-regulated stress and defence, secondary metabolite biosynthesis viz. phenylpropanoid, lignin and flavonols, redox and transcription factors related genes in ein2, aba1.6 and pad2.1 (glutathione mutant) in response to combined stress treatment. The reduced glutathione content was less in stress treated mutants in comparison to Col-...
    Page 1. GENETIC TRANSFORMATION Genetic transformation of a hepatoprotective plant, Phyllanthus amarus Anindita Banerjee & Sharmila Chattopadhyay Received: 31 August 2007 /Accepted: 5 September 2008 /Published ...
    A rapid micropropagation system was developed for Mucuna pruriens f. pruriens using explants from 1-week-old aseptically grown seedlings. Multiple shoot regeneration occurred following an initial callus growth on Revised Tobacco (RT)... more
    A rapid micropropagation system was developed for Mucuna pruriens f. pruriens using explants from 1-week-old aseptically grown seedlings. Multiple shoot regeneration occurred following an initial callus growth on Revised Tobacco (RT) medium supplemented with 2.7 μM NAA and 9.8 μM 2iP. Maximum number of shoot regeneration was achieved only from seedling explant 6 to 7 days old. More than 90% of the regenerated shoots could be rooted on half-strength liquid RT medium supplemented with 2.7 μM NAA. Plantlets readily adopted to greenhouse conditions. This system provides a new tool for micropropagation of Mucuna pruriens f. pruriens, an important medicinal plant.
    The leaf spot disease of Mentha arvensis, caused by Alternaria alternata, is a devastating foliar disease worldwide and leads to considerable economic losses. In this investigation, two-dimensional gel electrophoresis (2-DE) was used to... more
    The leaf spot disease of Mentha arvensis, caused by Alternaria alternata, is a devastating foliar disease worldwide and leads to considerable economic losses. In this investigation, two-dimensional gel electrophoresis (2-DE) was used to identify the membrane proteins potentially involved in M. arvensis - A. alternata interaction. Membrane proteins, isolated from leaves of control and infected plants, were analyzed by 2-DE and identified using mass spectrometry (MALDI TOF-TOF MS/MS). Our analysis identified 21 differentially expressed membrane proteins including several interesting receptors and channel proteins. Of these identified proteins, 34% were found to be involved in plant defense responses. Leucine-rich repeat family protein/protein kinase family protein which plays critical role in stress response and nucleotide-binding site-leucine-rich repeat (NBS-LRR) which is involved in detecting the advent of pathogen on plant surface were identified to be up-regulated in our study. I...
    Bioactivity-guided fractionation has led to the successful isolation of calceolarioside A ( 1) from the methanolic extract of night jasmine leaves. The in vitro antileishmanial activity of compound 1 was determined (IC (50) = 20... more
    Bioactivity-guided fractionation has led to the successful isolation of calceolarioside A ( 1) from the methanolic extract of night jasmine leaves. The in vitro antileishmanial activity of compound 1 was determined (IC (50) = 20 microg/mL). Its IN VIVO efficacy was noted at 20 mg/kg body weight when it reduced the hepatic and splenic parasite burden by 79 and 84 %, respectively, in an established model of L. donovani Ag83 infected golden hamster. Furthermore, synergistic potentiations of compound 1 at 20 mg/kg body weight and SAG at 5 mg/kg body weight showed a significant reduction of hepatic and splenic parasite burden. No cytotoxicity was observed against the U937 cell line. This is the first report describing the isolation of compound 1 from N. arbor-tristis L. and the first demonstration of its potent activity against visceral leishmaniasis.
    The involvement of glutathione (GSH) in plant defense against pathogen invasion is an established fact. However, the molecular mechanism conferring this tolerance remains to be explored. Here, proteomic analysis of pad2-1, an Arabidopsis... more
    The involvement of glutathione (GSH) in plant defense against pathogen invasion is an established fact. However, the molecular mechanism conferring this tolerance remains to be explored. Here, proteomic analysis of pad2-1, an Arabidopsis thaliana GSH-depleted mutant, in response to Pseudomonas syringae infection has been performed to explore the intricate position of GSH in defense against biotrophic pathogens. The pad2-1 mutant displayed severe susceptibility to P. syringae infection compared to the wild-type (Col-0) thus re-establishing a fundamental role of GSH in defense. Apart from general up-accumulation of energy metabolism-related protein-species in both infected Col-0 and pad2-1, several crucial defense-related protein-species were identified to be differentially accumulated. Leucine-rich repeat-receptor kinase (LRR-RK) and nucleotide-binding site-leucine-rich repeat resistance protein (NBS-LRR), known to play a pioneering role against pathogen attack, were only weakly up-accumulated in pad2-1 after infection. Transcriptional and post-transcriptional regulators like MYB-P1 and glycine-rich repeat RNA-binding protein (GRP) and several other stress-related protein-species like heat shock protein 17 (HSP17) and glutathione-S-transferase (GST) were also identified to be differentially regulated in pad2-1 and Col-0 in response to infection. Together, the present investigation reveals that the optimum GSH-level is essential for the efficient activation of plant defense signaling cascades thus conferring resistance to pathogen invasion.
    The contribution of glutathione (GSH) in stress tolerance, defense response and antioxidant signaling is an established fact. In this study transcriptome analysis of pad2.1, an Arabidopsis thaliana mutant, after combined osmotic and cold... more
    The contribution of glutathione (GSH) in stress tolerance, defense response and antioxidant signaling is an established fact. In this study transcriptome analysis of pad2.1, an Arabidopsis thaliana mutant, after combined osmotic and cold stress treatment has been performed to explore the intricate position of GSH in the stress and defense signaling network in planta. Microarray data revealed the differential regulation of about 1674 genes in pad2.1 amongst which 973 and 701 were significantly up- and down-regulated respectively. Gene enrichment, functional pathway analysis by DAVID and MapMan analysis identified various stress and defense related genes viz. members of heat shock protein family, peptidyl prolyl isomerase (PPIase), thioredoxin peroxidase (TPX2), glutathione-S-transferase (GST), NBS-LRR type resistance protein etc. as down-regulated. The expression pattern of the above mentioned stress and defense related genes and APETALA were also validated by comparative proteomic a...
    A comparative analysis of earthworm communities was carried out in the rubber plantations (Hevea brasiliensis) of different age groups in West Tripura to understand the impact of such exotic and monoculture plantation in biodiversity... more
    A comparative analysis of earthworm communities was carried out in the rubber plantations (Hevea brasiliensis) of different age groups in West Tripura to understand the impact of such exotic and monoculture plantation in biodiversity conservation. Earthworm communities were studied on monthly basis over a period of one year (2006-2007) in the 3, 10, 14, 20 and 25 year-old plantations. Among twelve earthworm species collected from the studied sites, six species belonged to Octochaetidae [Eutyphoeus assomensis Stephenson, Eutyphoeus comillahnus Michaelsen, Lennogaster chittagongensis (Stephensen), Octochaetona beatrix Gates, Dichogaster offinis Michaelsen, Lennogaster yeicus (Stephensen)], two species each to Megascolecidae [Metaphire houlleti (Perrier), Konchurio sp. 1] and Moniligastridae [Drowida nepalensis Michaelsen, Drawida papillifer papillifer Stephenson], one species each to Glossoscolecidae [Pontoscolex corethrurus (Muller)] and Ocnerodrilidae [Gordiodrilus elegans Beddard]....
    The elaborate networks and the crosstalk of established signaling molecules like salicylic acid (SA), jasmonic acid (JA), ethylene (ET), abscisic acid (ABA), reactive oxygen species (ROS) and glutathione (GSH) play key role in plant... more
    The elaborate networks and the crosstalk of established signaling molecules like salicylic acid (SA), jasmonic acid (JA), ethylene (ET), abscisic acid (ABA), reactive oxygen species (ROS) and glutathione (GSH) play key role in plant defense response. To obtain further insight into the mechanism through which GSH is involved in this crosstalk to mitigate biotic stress, transgenic Nicotiana tabacum overexpressing Lycopersicon esculentum gamma-glutamylcysteine synthetase (LeECS) gene (NtGB lines) were generated with enhanced level of GSH in comparison with wild-type plants exhibiting resistance to pathogenesis as well. The expression levels of non-expressor of pathogenesis-related genes 1 (NPR1)-dependent genes like pathogenesis-related gene 1 (NtPR1), mitogen-activated protein kinase kinase (NtMAPKK), glutamine synthetase (NtGLS) were significantly enhanced along with NtNPR1. However, the expression levels of NPR1-independent genes like NtPR2, NtPR5 and short-chain dehydrogenase/reductase family protein (NtSDRLP) were either insignificant or were downregulated. Additionally, increase in expression of thioredoxin (NtTRXh), S-nitrosoglutathione reductase 1 (NtGSNOR1) and suppression of isochorismate synthase 1 (NtICS1) was noted. Comprehensive analysis of GSH-fed tobacco BY2 cell line in a time-dependent manner reciprocated the in planta results. Better tolerance of NtGB lines against biotrophic Pseudomonas syringae pv. tabaci was noted as compared to necrotrophic Alternaria alternata. Through two-dimensional gel electrophoresis (2-DE) and image analysis, 48 differentially expressed spots were identified and through identification as well as functional categorization, ten proteins were found to be SA-related. Collectively, our results suggest GSH to be a member in cross-communication with other signaling molecules in mitigating biotic stress likely through NPR1-dependent SA-mediated pathway.
    Bioactivity-guided fractionation has led to the successful isolation of calceolarioside A ( 1) from the methanolic extract of night jasmine leaves. The in vitro antileishmanial activity of compound 1 was determined (IC (50) = 20... more
    Bioactivity-guided fractionation has led to the successful isolation of calceolarioside A ( 1) from the methanolic extract of night jasmine leaves. The in vitro antileishmanial activity of compound 1 was determined (IC (50) = 20 microg/mL). Its IN VIVO efficacy was noted at 20 mg/kg body weight when it reduced the hepatic and splenic parasite burden by 79 and 84 %, respectively, in an established model of L. donovani Ag83 infected golden hamster. Furthermore, synergistic potentiations of compound 1 at 20 mg/kg body weight and SAG at 5 mg/kg body weight showed a significant reduction of hepatic and splenic parasite burden. No cytotoxicity was observed against the U937 cell line. This is the first report describing the isolation of compound 1 from N. arbor-tristis L. and the first demonstration of its potent activity against visceral leishmaniasis.
    Production of L-DOPA was studied in cell suspension culture of Mucuna pruriens f. pruriens. Suspension culture was established in MSI medium composed of half concentration of Murashige and Skoog's salts and 2% sucrose. A two-stage... more
    Production of L-DOPA was studied in cell suspension culture of Mucuna pruriens f. pruriens. Suspension culture was established in MSI medium composed of half concentration of Murashige and Skoog's salts and 2% sucrose. A two-stage cell suspension culture was developed for enhanced accumulation of L-DOPA. In the first stage, the culture system was composed of MSI medium without CaCl, which was suitable for cell growth and in the second stage MSI medium containing 42.5 mg.l(-1) KH2PO4 and 4% sucrose favoured L-DOPA production. A discernible higher production of L-DOPA was obtained in this two-stage cell suspension culture in comparison to single stage culture.
    A rapid micropropagation system was developed for Mucuna pruriens f. pruriens using explants from 1-week-old aseptically grown seedlings. Multiple shoot regeneration occurred following an initial callus growth on Revised Tobacco (RT)... more
    A rapid micropropagation system was developed for Mucuna pruriens f. pruriens using explants from 1-week-old aseptically grown seedlings. Multiple shoot regeneration occurred following an initial callus growth on Revised Tobacco (RT) medium supplemented with 2.7 μM NAA and 9.8 μM 2iP. Maximum number of shoot regeneration was achieved only from seedling explant 6 to 7 days old. More than 90% of the regenerated shoots could be rooted on half-strength liquid RT medium supplemented with 2.7 μM NAA. Plantlets readily adopted to greenhouse conditions. This system provides a new tool for micropropagation of Mucuna pruriens f. pruriens, an important medicinal plant.
    The genus Mentha has been widely used in food, flavor, culinary, cosmetic and pharmaceutical industries. Substantial damage to this crop happened regularly due to environmental stresses like metal toxicity and pathogen attack. Here, an... more
    The genus Mentha has been widely used in food, flavor, culinary, cosmetic and pharmaceutical industries. Substantial damage to this crop happened regularly due to environmental stresses like metal toxicity and pathogen attack. Here, an approach has been taken to raise transgenic mint over-expressing γ-glutamyl-cysteine synthetase (γ-ECS), the rate-limiting enzyme of GSH biosynthesis, resulted enhanced GSH content and its in planta expression confers significant tolerance towards abiotic/biotic stresses viz. metal toxicity - Cd, Zn as well as against infection of Alternaria alternata and Rhizoctonia solani. A differential proteomic analysis through 2-DE and MALDI TOF-TOF MSMS was performed to focus on the altered abundance of functionally important protein species in control and infected transgenic mint. Results showed a significant variation in the protein profile of the infected transgenic plant as compared to the wild/control transgenic counterpart. In addition to protein species related to stress and defense, redox regulation, transcription factors and energy & metabolism, protein species related to signaling and gene regulation as well as cell division also showed differential accumulation in infected transgenic. Hence, proteomics can be used as a tool to decipher the mechanism of action of GSH in providing tolerance against a necrotrophic fungus, A. alternata in transgenic mint. The reported work describes a comparative proteomics of non-model unsequenced plants like Mentha. There is a comparative protein profile between transgenic and its wild counterparts under control and infected condition. The work has an impact in crop proteomics and also tries to explain the application of proteomic approach to decipher the mechanism by which a foreign metabolite mediates stress tolerance in plant under control and infected condition. This article is part of a Special Issue entitled: Translational Plant Proteomics.
    The role of glutathione (GSH) in plant defense is an established fact. However, the association of GSH with other established signaling molecules within the defense signaling network remains to be evaluated. Previously we have shown that... more
    The role of glutathione (GSH) in plant defense is an established fact. However, the association of GSH with other established signaling molecules within the defense signaling network remains to be evaluated. Previously we have shown that GSH is involved in defense signaling network likely through NPR1-dependent salicylic acid (SA)-mediated pathway. In this study, to gain further insight, we developed chloroplast-targeted gamma-glutamylcysteine synthetase (γ-ECS) overexpressed transgenic Nicotiana tabacum (NtGp line) and constructed a forward subtracted cDNA (suppression subtractive hybridization (SSH)) library using NtGp line as a tester. Interestingly, in addition to SA-related transcripts like pathogenesis-related protein 1a (PR1a) and SAR8.2 m/2l, 1-aminocyclopropane-1-carboxylate oxidase (ACC oxidase), a key enzyme of ethylene (ET) biosynthesis, was identified in the SSH library. Besides, transcription factors like WRKY transcription factor 3 (WRKY3), WRKY1 and ethylene responsive factor 4 (ERF4), associated with SA and ET respectively, were also identified thus suggesting an interplay of GSH with ET and SA. Furthermore, proteomic profiling of NtGp line, performed by employing two-dimensional gel electrophoresis (2-DE), corroborated with the transcriptomic profile and several defense-related proteins like serine/threonine protein kinase, and heat shock 70 protein (HSP70) were identified with increased accumulation. Fascinatingly, induction of 1-aminocyclopropane-1-carboxylate synthase (ACC synthase) was also noted thus demonstrating the active involvement of GSH with ET. Protein gel blot analysis confirmed the enhanced accumulation of ACC oxidase in NtGp line. Together, our data revealed that GSH is involved in the synergistic multiple steps crosstalk through ET as well as SA to combat environmental stress.
    Page 1. GENETIC TRANSFORMATION Genetic transformation of a hepatoprotective plant, Phyllanthus amarus Anindita Banerjee & Sharmila Chattopadhyay Received: 31 August 2007 /Accepted: 5 September 2008 /Published ...
    Pudina extract (Mentha spicata Linn.) used as flavoring in culinary preparation throughout the plains of India was examined for its DNA damage protecting activity and antioxidant potential. n-Butanol soluble fraction (PE) derived from... more
    Pudina extract (Mentha spicata Linn.) used as flavoring in culinary preparation throughout the plains of India was examined for its DNA damage protecting activity and antioxidant potential. n-Butanol soluble fraction (PE) derived from methanol extract of Mentha spicata ...