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Swarnendu Chandra

Bio: Swarnendu Chandra is an academic researcher from University of Calcutta. The author has contributed to research in topics: Elicitor & Phenylalanine ammonia-lyase. The author has an hindex of 12, co-authored 26 publications receiving 458 citations. Previous affiliations of Swarnendu Chandra include Tea Board of India & Forest Research Institute.

Papers
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Journal ArticleDOI
TL;DR: The results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation.
Abstract: The immunomodulatory role of the natural biopolymer, chitosan, has already been demonstrated in plants, whilst its nanoparticles have only been examined for biomedical applications. In our present study, we have investigated the possible ability and mechanism of chitosan nanoparticles (CNP) to induce and augment immune responses in plants. CNP-treatment of leaves produced significant improvement in the plant's innate immune response through induction of defense enzyme activity, upregulation of defense related genes including that of several antioxidant enzymes as well as elevation of the levels of total phenolics. It is also possible that the extracellular localization of CNP may also play a role in the observed upregulation of defense response in plants. Nitric oxide (NO), an important signaling molecule in plant defense, was also observed to increase following CNP treatment. However, such CNP-mediated immuno-stimulation was significantly mitigated when NO production was inhibited, indicating a possible role of NO in such immune induction. Taken together, our results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation.

245 citations

Journal ArticleDOI
TL;DR: The results suggest that increased production of NO in chitosan-treated tea plants may play a critical role in triggering the innate defense responses effective against plant pathogens, including that causing the blister blight disease.

51 citations

Journal ArticleDOI
TL;DR: Observations indicate that Fa fraction of T. giganteum induces apoptogenic signal in EAC, which has also been confirmed by nuclear staining that demonstrated distinctive morphological features of apoptosis.
Abstract: This study explored the efficacy of Fa fraction of Tricholoma giganteum against Ehrlich’s ascites carcinoma (EAC). Mechanisms of apoptogenic effect of the fraction were delineated. The flow cytometric analysis of EAC cells, showed an increase in number of cells in sub-G0/G1 population and reduction in the G2/M phase due to the treatment thus suggesting apoptosis. The induction of apoptosis has also been confirmed by nuclear staining that demonstrated distinctive morphological features of apoptosis. Our data also revealed an increase in the expression of pro-apoptotic protein p53 in EAC and induced factors contributing to apoptosis. Pro-apoptotic gene Bax was up-regulated during p53-mediated apoptosis. No significant change in the expression of anti-apoptotic protein Bcl-2 was observed ensuing in decrease of the Bcl-2/Bax ratio. p53-mediated growth arrest involves p21 as a major effecter, which interestingly showed moderate elevation. All these observations indicate that Fa fraction of T. giganteum induces apoptogenic signal in EAC.

44 citations

Journal ArticleDOI
26 May 2017-PLOS ONE
TL;DR: The collected taxon was found to be unique with regard to its morphological as well as genetical features and introduced a potent therapeutic agent that could be explored for food and pharmaceutical purposes.
Abstract: Mushrooms have been prized by humankind as medicine and culinary wonder since antiquity. Though several species are ethnically valued; many prospective species are still being discovered. One such wild macrofungus has recently been discovered during subsequent field surveys in West Bengal, India which in turn exposed as a traditionally consumed popular myco-food. The collected taxon was found to be unique with regard to its morphological as well as genetical features. After detailed characterizations, the fungus was identified as a novel taxon belonging to the genus Russula (Russulaceae, Basidiomycota). Besides, the investigation was further extended in search of new functional ingredients and in this context, a water soluble crude polysaccharide rich extract (Rusalan) was isolated from dried basidiocarps. Accumulating evidences from GC-MS, HPTLC, FT-IR along with several spectrophotometric methods postulated that the fraction consisted mainly of carbohydrate in triple helical conformation, where glucose was the major monosaccharide mostly with β-type glycosidic linkage. Conversely, Rusalan showed pronounced antioxidant activity in six in vitro assay systems with EC50 value ranging from 190–1328 μg/ml concentration. The crude polysaccharide was also evaluated against six bacterial strains using microdilution method and the growth of Staphylococcus aureus and Bacillus subtilis were found to be inhibited effectively. In addition, immune-stimulatory assays demonstrated that Rusalan could evidently promote proliferation, induce phagocytosis, release NO, produce intracellular ROS and upregulate mRNA expression of iNOS, TNF-α, COX-2, as well as IL-6 genes in in mouse macrophage cells. Therefore, aim of the present study was not only to describe a new taxon to the world mycoflora but also to introduce a potent therapeutic agent that could be explored for food and pharmaceutical purposes. However, isolation of active component and in vivo studies need to be designed further.

29 citations

Journal ArticleDOI
TL;DR: The result suggested that CaCl2 induced an array of plant defense responses making this compound a potential phytosanitary product with a challenging issue and a rather attractive option for sustainable organic tea cultivation practice.
Abstract: Elicitor-induced natural defense machinery of plants could be proposed as an alternative, non-conventional, and ecologically-friendly approach for plant protection. In this work, the abiotic elicitor, calcium chloride (CaCl2), was used for inducing resistance in tea plants against blister blight disease caused by Exobasidium vexans. Foliar application of elicitor resulted in around 80 % disease inhibition over the control set, during the peak time of blister blight incidence at the experimental garden of Darjeeling Tea Research and Development Centre. A significant increase in the activities of defense enzymes like phenylalanine ammonia lyase (PAL), peroxidase, polyphenol oxidase, and β-1,3-glucanase along with higher accumulation of total phenolics was observed. Treated plants also had elevated transcript levels of thaumatin, catalase, PAL, cinnamate 4-hydroxylase, and flavonoid 3′-hydroxylase genes compared to control plants. Further, the treatment-induced nitric oxide (NO) production was confirmed by real-time visualization of the NO burst using a fluorescent probe and spectrophotometric analysis. The result suggested that CaCl2 induced an array of plant defense responses making this compound a potential phytosanitary product with a challenging issue and a rather attractive option for sustainable organic tea cultivation practice.

29 citations


Cited by
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Journal ArticleDOI
TL;DR: Chitosan is widely used in food and bioengineering industries for encapsulation of active food ingredients, enzyme immobilization, as a carrier for controlled drug delivery, in agriculture as a plant growth promoter and an antimicrobial agent.
Abstract: Shell fish processing industry is very common in coastal areas. While processing, only the meat is taken, the head and shells are discarded as waste. On an average, the sea food industry produces 80,000 tons of waste per year. The sheer amount of waste makes degradation a slow process causing accumulation of waste over a period of time. A very simple and effective solution to this environmental hazard is the recycling of shell waste to commercially viable products like chitin. Chitosan is the N-acetyl derivative of chitin obtained by N-deacetylation. Chitosan is widely used in food and bioengineering industries for encapsulation of active food ingredients, enzyme immobilization, as a carrier for controlled drug delivery, in agriculture as a plant growth promoter. Chitosan is also a defense elicitor and an antimicrobial agent. Chitosan has interesting properties such as biodegradability, biocompatibility, bioactivity, nontoxicity and polycationic nature. This review presents structural characteristics and physicochemical properties of chitosan. The methods of preparation of chitosan nanoparticles are detailed. Applications of chitosan nanoparticles are discussed. Applications include drug delivery, encapsulation, antimicrobial agent, plant growth-promoting agent and plant protector.

337 citations

Journal ArticleDOI
TL;DR: This review systematically summarizes the role of NMs in plants under abiotic stresses such as drought, salt, temperature, metal, UV-B radiation and flooding and suitable strategies adopted by plants under challenging environments are also being presented.

283 citations

Journal ArticleDOI
TL;DR: The results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation.
Abstract: The immunomodulatory role of the natural biopolymer, chitosan, has already been demonstrated in plants, whilst its nanoparticles have only been examined for biomedical applications. In our present study, we have investigated the possible ability and mechanism of chitosan nanoparticles (CNP) to induce and augment immune responses in plants. CNP-treatment of leaves produced significant improvement in the plant's innate immune response through induction of defense enzyme activity, upregulation of defense related genes including that of several antioxidant enzymes as well as elevation of the levels of total phenolics. It is also possible that the extracellular localization of CNP may also play a role in the observed upregulation of defense response in plants. Nitric oxide (NO), an important signaling molecule in plant defense, was also observed to increase following CNP treatment. However, such CNP-mediated immuno-stimulation was significantly mitigated when NO production was inhibited, indicating a possible role of NO in such immune induction. Taken together, our results suggest that CNP may be used as a more effective phytosanitary or disease control agent compared to natural chitosan for sustainable organic cultivation.

245 citations

Journal ArticleDOI
TL;DR: Divergence times as additional criterion in ranking provide additional evidence to resolve taxonomic problems in the Basidiomycota taxonomic system, and also provide a better understanding of their phylogeny and evolution.
Abstract: The Basidiomycota constitutes a major phylum of the kingdom Fungi and is second in species numbers to the Ascomycota. The present work provides an overview of all validly published, currently used basidiomycete genera to date in a single document. An outline of all genera of Basidiomycota is provided, which includes 1928 currently used genera names, with 1263 synonyms, which are distributed in 241 families, 68 orders, 18 classes and four subphyla. We provide brief notes for each accepted genus including information on classification, number of accepted species, type species, life mode, habitat, distribution, and sequence information. Furthermore, three phylogenetic analyses with combined LSU, SSU, 5.8s, rpb1, rpb2, and ef1 datasets for the subphyla Agaricomycotina, Pucciniomycotina and Ustilaginomycotina are conducted, respectively. Divergence time estimates are provided to the family level with 632 species from 62 orders, 168 families and 605 genera. Our study indicates that the divergence times of the subphyla in Basidiomycota are 406–430 Mya, classes are 211–383 Mya, and orders are 99–323 Mya, which are largely consistent with previous studies. In this study, all phylogenetically supported families were dated, with the families of Agaricomycotina diverging from 27–178 Mya, Pucciniomycotina from 85–222 Mya, and Ustilaginomycotina from 79–177 Mya. Divergence times as additional criterion in ranking provide additional evidence to resolve taxonomic problems in the Basidiomycota taxonomic system, and also provide a better understanding of their phylogeny and evolution.

233 citations

Journal ArticleDOI
Veysel Turan1
TL;DR: Results suggested that the CN2% treatment performed excellently in terms of reducing Ni concentrations in leaves and roots of lettuce plants along bioavailable Ni in the soil after plant harvest, whereas, application of BR at 2% could remarkably develop aforementioned parameters in lettuce plants.

223 citations