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1

Osmotic stress induced-capsaicin production in suspension cultures of Capsicum chinense Jacq.cv. Naga King Chili

100%
Kehie M., Kumaria S., Tandon P.
Acta Physiologiae Plantarum
|
2012
|
tom 34
|
nr 5
The influence of osmotic stress on capsaicin production was investigated in cell suspension cultures of Capsicum chinense Jacq.cv. Naga King Chili, a chili species native to Northeastern India. The sterilized seeds were germinated in Murashige and Skoog medium. Two-weekold hypocotyls were excised from in vitro germinated seedlings and implanted in MS medium containing 2, 4-dichlorophenoxyacetic acid (2 mg/l), and Kinetin (0.5 mg/l) for callus induction. Capsaicin production in the suspension cultures was significantly affected using sucrose, mannitol, and NaCl in the medium. Stoichiometric analysis with different combinations of sucrose and nonsugar osmotic agent (NaCl) showed that osmotic stress was an important factor for enhancing capsaicin production in cell suspension cultures of C. chinense. The capsaicin content of 1,644.1 µg g⁻¹ f.wt was recorded on day 15 in cultures grown in MS medium containing 87.64 mM sucrose in combination with 40 mM NaCl. However, osmotic stress treatment at 160 mM NaCl with sucrose resulted in lowering capsaicin accumulation and separation of cell wall from their cytoplasm, under microscopic observation.
2

Comparative study of key phosphorus and nitrogen metabolizing enzymes in mycorrhizal and non-mycorrhizal plants of Dendrobium chrysanthum Wall. ex Lindl.

100%
Hajong S., Kumaria S., Tandon P.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 07
The role of mycorrhizal fungi in overcoming nutrient limitation to plant growth by enhancing nutrient acquisition, especially phosphorus (P) and nitrogen (N), is well documented. However, in orchids, the importance of mycorrhizal fungi in nutrient acquisition is not as extensively studied as in other plants. Therefore, an in vitro culture system to study the effects of mycorrhizal association on P and N metabolizing enzymes, viz., acid phosphatase, alkaline phosphatase, nitrate reductase (NR), nitrite reductase (NiR) and glutamine synthetase (GS) in Dendrobium chrysanthum was developed. After 90 days of mycorrhizal treatment, activities of acid phosphatase, alkaline phosphatase, NR, NiR and GS were higher in mycorrhizal plantlets than in control plantlets. The hardened plantlets that were initially treated with mycorrhiza under in vitro conditions also showed higher activities of the enzymes investigated. These mycorrhizal plantlets showed higher survival (96.33 %), shoot length (3.7 cm) and shoot fresh weight (0.359 g) as compared to control after 120 days of hardening. The results presented in this study suggest that mycorrhizal association might have increased the assimilation of P and N in D. chrysanthum plantlets, indicating the importance of mycorrhiza in orchids.
3

Transverse thin cell layer (t-TCL)-mediated improvised micropropagation protocol for endangered medicinal orchid Dendrobium aphyllum Roxb: an integrated phytomolecular approach

100%
Bhattacharyya P., Paul P., Kumaria S., Tandon P.
Acta Physiologiae Plantarum
|
2018
|
tom 40
|
nr 08
4

Comparative study on the changes of proteins and oxidative enzymes occurring in protocorms and protocorm-like bodies systems of development in the orchid Dendrobium hookerianum

100%
Paul S., Kumaria S., Tandon P.
Acta Physiologiae Plantarum
|
2014
|
tom 36
|
nr 08
Proteins and activities of antioxidant enzymes, including polyphenol oxidase (PPO), peroxidase (POX) and catalase (CAT), were evaluated in Dendrobium hookerianum during different stages of development of both protocorms and protocorm-like bodies (PLB) derived from seeds and axillary buds, respectively. The changes in the protein contents and the enzyme activities along with their isozyme patterns were compared between these two culture systems. It was found that the protein contents and the enzyme activities increased steadily over time during different stages of development in both the systems. Protein contents (4.57 mg/g fresh wt.) and activities of POX (21.9 U/mg protein), CAT (9.86 U/mg protein) were observed to be higher in PLB system as compared to protocorm system at stage IV of development. However, although the PPO activity increased gradually till the third stage of development, a decline was observed at stage IV wherein the activity was recorded to be more or less same in both the systems. Also, few proteins (~61, 50, 46, 32, 25, 16, 6 kDa) and new isozymes (POX 7, 8; CAT 2) were expressed only in PLB system of development. In general, high protein content and enzyme activities were detected in PLB system as compared to protocorm system. The results of the present study indicate that few proteins and isozymes could be regarded as specific biochemical markers for different stages of development of this medicinally important orchid.
5

Cryopreservation of pharmaceutically important orchid Dendrobium chrysanthum Wall. ex Lindl. using vitrification based method

100%
Mohanty P., Das M. C., Kumaria S., Tandon P.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 04
Our present study constitutes the successful and efficient protocol for cryopreservation of Dendrobium chrysanthum. D. chrysanthum Wall. ex Lindl. is a pharmaceutically valuable, ornamental epiphytic orchid of temperate and subtropical regions. On account of excellent herbal medicinal value and horticultural importance, D. chrysanthum is becoming rare due to over exploitation. For long-term conservation of this orchid, protocorm-like bodies of D. chrysanthum were excised and used for cryopreservation by encapsulation–vitrification. In this cryogenic procedure, PLBs were initially osmoprotected with a mixture of 0.4 M sucrose and 2 M glycerol, incorporated in the encapsulation matrix (comprising of 3 % (w/v) sodium alginate and 0.1 M CaCl2). Encapsulated protocorm-like bodies (PLBs) were then precultured on MS liquid medium supplemented with different concentrations of sucrose (0.06, 0.3, 0.5, 0.7 M), and loaded in a loading solution (comprised of 2 M glycerol and 0.4 M sucrose) for different duration to make the precultured PLBs tolerant to plant vitrification solution 2 (PVS2). Subsequently, the PLBs were subjected to PVS2 (Sakai et al. 1990) treatment at different time of exposure (minutes) and temperatures (0 C and 25 C). Encapsulated–vitrified PLBs were plunged directly into liquid nitrogen and stored for 1 h. Optimum result (survival 63.2 % and regrowth 59.9 %) was obtained when the beads treated with loading solution for 80 min followed by PVS2 treatment for 100 min. Regenerated plants showed normal morphology as that of control plants.
6

In vitro propagation and assessment of clonal fidelity of Nepenthes khasiana Hook. f.: a medicinal insectivorous plant of India

100%
Devi S. P., Kumaria S., Rao S. R., Tandon P.
Acta Physiologiae Plantarum
|
2013
|
tom 35
|
nr 09
An efficient in vitro protocol for large-scale multiplication of Nepenthes khasiana, a threatened insectivorous plant of India, has been developed from nodal stem segments. The highest shoot proliferation of 19.16 ± 0.23 shoots/explant was recorded in half-strength Murashige and Skoog (MS) medium supplemented with 2.5 mg/l kinetin, 2.0 mg/l 6-benzyl aminopurine, 3 % sucrose and 0.8 % agar. The best rooting was achieved in half-strength MS medium supplemented with 2.0 mg/l a-naphthalene acetic acid with an average of 9.04 ± 0.46 roots/shoot. The plantlets were successfully transferred to the greenhouse with survival rate of 92 %, exhibiting normal development. Cytological and random amplified polymorphic DNA (RAPD) analyses were carried out to assess the genetic integrity of the regenerated plantlets. Cytological analysis revealed no change in chromosome number with cells studied showing 2n = 80. Of the 80 primers screened for RAPD analysis, 14 primers resulted in clear and scorable bands. A total of 72 amplification products were obtained out of which only 4.1 % bands were polymorphic. Cluster analysis of the RAPD profile revealed an average similarity coefficient ranging from 0.98 to 1.0, thus suggesting genetic stability in the micropropagated plants of N. khasiana.
7

Phenotype of parvalbumin nullmutant mice

76%
Schwaller B., Villa A., Tetko I. V., Hunziker W., Tandon P., Silveira D. C., Celio M. R.
Acta Neurobiologiae Experimentalis
|
1999
|
tom 59
|
nr 3
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