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Gupta N.S.,University of Calcutta | Banerjee M.,West Bengal State Council of Science and Technology | Basu S.K.,University of Lethbridge | Acharya K.,University of Calcutta
Plant OMICS | Year: 2013

This study elucidates Alternaria alternata toxin induced defense enzyme activity and phenolics accumulation and its correlation with nitric oxide (NO) generation. Role of NO in plant defense signaling to biotic stress has been strongly established by earlier investigators. Here, in vitro treatment of Rauvolfia serpentina Benth. ex Kurz callus with A. alternata toxin induced a rapid production of NO at 50 mg L-1 toxin concentration. This increase in toxin induced NO production was further confirmed by real time visualization of NO burst using a fluorescent probe, 4, 5-diaminofluorescein diacetate (DAF-2DA) in cells of R. serpentina. Parallely, the same concentration of toxin also induced the production of peroxidase (PO), polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), β-1, 3 glucanase and phenolics accumulation in the callus tissue of R. serpentina. Further, inhibition of NO production by co-treatment with NO synthase inhibitor, NG -nitro-L-arginine-methyl ester (L-NAME) at 10 μM and NO scavenger, 2-(4- carboxyphenyl)- 4,4,5,5- tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) at 100 μM reduced the accumulation of all the defense enzymes and total phenols in the callus signifying the regulatory role of NO in the induction of defense enzyme and phenol accumulation. The effect of NO in host defense response was crosschecked further by sole application of NO donor sodium nitroprusside (SNP). Treatment of R. serpentina callus with 100 μM SNP showed the similar pattern of defense responses. So, the overall results demonstrated that increased production of NO in R. serpentina callus treated with fungal toxin, might act as an essential signaling molecule for triggering the activation of PO, PPO, PAL, β-1, 3 glucanase and phenolics accumulation.

Gupta S.,West Bengal State Council of Science and Technology | Sahu P.K.,Dr. C.V. Raman University
International Journal of Pharma and Bio Sciences | Year: 2014

Aloe vera (L.) Burm. f. commonly known as Ghritakumari which belongs to family Alliaceae or Asphodelaceae widely used in Ayurveda, as well as cosmetic industry and has as well as for its health benefits. In present work the cytological observation was performed. Fresh root tips from ex vitro plants were used for cytological study and different dividing stages were observed and photographed. The chromosome number was counted and a typical mitotic metaphase somatic cell contains 14 chromosomes (2n=14). The aim of the present work is to study the cytology of Aloe vera.

Hansda C.,Jadavpur University | Hansda C.,University of Burdwan | Dutta B.,Sammilani Mahavidyalaya | Chakraborty U.,Jadavpur University | And 5 more authors.
Journal of Luminescence | Year: 2016

This communication reports the fabrication of layer-by-layer electrostatic self-assembled films of an azo dye Chromotrope-2R (CH2R) and a Polycation poly(allylamine hydrochloride) (PAH) onto solid substrate. UV–vis absorption and steady state fluorescence emission spectroscopy successfully confirm the incorporation of dye molecules onto the PAH coated quartz substrate. The adsorption behavior of CH2R onto PAH backbone in LbL films highly depends upon the variation of the microenvironment namely pH of the dye solution from which the film was fabricated. PAH layer onto quartz substrate was able to swell sufficiently in the dye solution at very high pH. The Density functional theory was also utilized here to explain the origin of various spectral transitions from the ground electronic states for both in neutral and anionic form of CH2R. In LbL films the more closure association of dye molecules causes their aggregations which are reflected in their absorption and steady state fluorescence emission spectra when compared to those of pure dye solution. Atomic force microscopic images of LbL films assembled from CH2R aqueous solution at different pH clearly reveal the change in the surface morphology of the films and different degree of association of dye molecules in LbL films deposited at various pH of CH2R. © 2016 Elsevier B.V.

Banerjee M.,West Bengal State Council of Science and Technology | Gantait S.,West Bengal State Council of Science and Technology | Pramanik B.R.,West Bengal State Council of Science and Technology
Physiology and Molecular Biology of Plants | Year: 2011

An accelerated protocol for large-scale propagation of Dendrocalamus asper, an edible bamboo, has been described. Seven axillary shoots were induced in vitro from each excised tender node (15-20 mm in length) containing single axillary bud when nodal segments were inoculated in semisolid Murashige and Skoog (MS) medium fortified with 5 mg/l 6-benzylaminopurine (BAP). Maximum multiple shoot formation (14) was observed when in vitro generated axillary shoots were transferred to liquid MS medium containing 5 mg/l BAP and 40 mg/l adenine sulphate. A maximum of 93. 33 % shoots were effectively rooted when transferred to liquid MS medium supplemented with 1 mg/l indole-3-biutyric acid (IBA). A simple acclimatization procedure of 55 days, primarily in cocopeat for 20 days and finally in a blend of sand, soil and farm yard manure (1:1:1 v/v), ensured a very high survival rate within next 35 days. After acclimatization, rooted plantlets were further multiplied by splitting of rhizomes, formed in vivo within 90 days of growth. After 90 and 180 days of acclimatization, plants were successfully transferred to the field and maintained in an unirrigated condition with the initial supplementation of farm yard manure @ 10 kg/pit; where around 85 % survivability with 25 culms per bush attaining an average height of 4.5 m was recorded up to four years. © 2011 Prof. H.S. Srivastava Foundation for Science and Society.

Chakraborty N.,West Bengal State Council of Science and Technology | Chakraborty N.,University of Calcutta | Banerjee D.,West Bengal State Council of Science and Technology | Banerjee D.,University of Calcutta | And 6 more authors.
Physiology and Molecular Biology of Plants | Year: 2013

Withania somnifera (L.) Dunal, is an important medicinal plant being the source of extremely important compounds like withanolides and withaferin. Influence of different plant growth regulators (PGRs) were evaluated for induction of callus, callus mediated regeneration and production of secondary metabolites in them. Explants for callusing were collected from plants grown in vitro and maximum callusing (98 %) was obtained on MS medium supplemented with a combination of 2,4-dichlorophenoxy acetic acid (2,4-D) (0. 5 mg l-1) and kinetin (KN) (0. 2 mg l-1). Among different types of calli, best shoot regeneration was observed on green, compact calli produced on MS medium with a combination of 6-benzylamino purine (BAP) and indole butyric acid (IBA). MS medium supplemented with BAP (2 mg l-1) showed highest frequency (98 %) of shoot bud regeneration. The micro-shoots were efficiently rooted on MS media supplemented with 0. 5 mg l-1 IBA. Rooted plants were transferred to soil-vermi-compost (1:3; w/w) medium in greenhouse for acclimatization. Presence of withanolide A and withaferin A in calli was validated through high performance thin layer chromatography (HPTLC). It was interesting to observe that the PGRs showed significant influence on the secondary metabolites production in callus and 2,4-D having the least effect. Histological studies revealed the origin of shoot tip in the callus during regeneration. © 2012 Prof. H.S. Srivastava Foundation for Science and Society.

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