1
|
Nandi SK, Chatterjee N, Roychowdhury T, Pradhan A, Moiz S, Manna K, Sarkar DK, Dhar P, Dutta A, Mukhopadhyay S, Bhattacharya R. Kaempferol with Verapamil impeded panoramic chemoevasion pathways in breast cancer through ROS overproduction and disruption of lysosomal biogenesis. Phytomedicine 2023; 113:154689. [PMID: 36921428 DOI: 10.1016/j.phymed.2023.154689] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 01/07/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Reactive oxygen species (ROS) at low level promotes cell survival through lysosome induced autophagy induction. Glucose stress induced acidosis, hypoxia, ROS, upregulates markers related to cancer stemness and multidrug resistance. Also, lysosomal upregulation is proposed to be one of the important indicators of cell survival under ROS induced stress. Studies supported that, stimulation of Lysosome-TFEB-Ca2+ cascade has important role in induction of chemoresistance and survival of cancerous cells. PURPOSE To observe the effect of synergistic drug combination, Kaempferol and Verapamil on markers regulating chemoevasion, tumor stemness & acidosis as well as lysosome upregulation pathways, under low as well as high glucose conditions. HYPOTHESIS Based on our earlier observation as well as previous reports, we hypothesized, our drug combination Kaempferol with Verapamil could attenuate markers related to chemoevasion, tumor stemness & acidosis as well as lysosome-TFEB-Ca2+ pathway, all of which have indispensable association and role in chemoresistance. METHODS RNA and protein expression of candidate genes, along with ROS production and Ca2+ concentrations were measured in ex vivo models in altered glucose conditions upon treatment with KV. Also, computational approaches were utilized to hypothesize the mechanism of action of the drug combination. PCR, IHC, western blotting and molecular docking approaches were used in this study. RESULTS The overproduction of ROS by our candidate drugs KV, downregulated the chemoresistance and tumor acidosis markers along with ATP1B1 and resulted in lysosomal disruption with reduction of Ca2+ release, diminishing TFEB expression under low glucose condition. An anomalous outcome was observed in high glucose conditions. We also observed KV promoted the overproduction of ROS levels thereby inducing autophagy-mediated cell death through the upregulation of LC3-II and p62 in low glucose conditions. The ex vivo studies also corroborate with in silico study that exhibited the parallel outcome. CONCLUSION Our ex-vivo and in-silico studies revealed that our candidate drug combination KV, could effectively target several pathways regulating chemoresistance, that were not hitherto studied in the same experimental setup and thus may be endorsed for therapeutic purposes.
Collapse
Affiliation(s)
- Sourav Kumar Nandi
- Department of Molecular Biology, Netaji Subhas Chandra Bose Cancer Research Institute, 3081 Nayabad, Kolkata-700094, India
| | - Niloy Chatterjee
- Centre for Research in Nanoscience & Nanotechnology, University of Calcutta, JD 2, Sector III, Salt Lake City, Kolkata 700 098, West Bengal, India
| | - Tanaya Roychowdhury
- Cancer Biology and Inflammatory Disorder Division, Indian Institute of Chemical Biology, 4, Raja S. C. Mullick Road, Kolkata-700032, India
| | - Ayan Pradhan
- Department of General Surgery, Institute of Post graduate Medical Education &Research and SSKM Hospital, 244B AJC Bose Road Kolkata-700020, India
| | - Sumaiya Moiz
- Department of Molecular Biology, Netaji Subhas Chandra Bose Cancer Research Institute, 3081 Nayabad, Kolkata-700094, India
| | - Krishnendu Manna
- Department of Food and Nutrition, University of Kalyani, Kalyani, West Bengal, 741235, India
| | - Diptendra Kumar Sarkar
- Department of General Surgery, Institute of Post graduate Medical Education &Research and SSKM Hospital, 244B AJC Bose Road Kolkata-700020, India
| | - Pubali Dhar
- Laboratory of Food Science and Technology, Food and Nutrition division, University of Calcutta, 20B Judges Court Road. Kolkata 700027, West Bengal, India
| | - Amitava Dutta
- Department of Pathology, Netaji Subhas Chandra Bose Cancer Research Institute, 3081 Nayabad, Kolkata-700094
| | - Soma Mukhopadhyay
- Department of Molecular Biology, Netaji Subhas Chandra Bose Cancer Research Institute, 3081 Nayabad, Kolkata-700094, India
| | - Rittwika Bhattacharya
- Department of Molecular Biology, Netaji Subhas Chandra Bose Cancer Research Institute, 3081 Nayabad, Kolkata-700094, India.
| |
Collapse
|
2
|
Nandi SK, Pradhan A, Das B, Das B, Basu S, Dutta A, Sarkar DK, Mukhopadhyay A, Mukhopadhyay S, Bhattacharya R. Kaempferol attenuates viability of ex-vivo cultured post-NACT breast tumorexplants through downregulation of p53 induced stemness, inflammation and apoptosis evasion pathways. Pathol Res Pract 2022; 237:154029. [DOI: 10.1016/j.prp.2022.154029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/15/2022] [Accepted: 07/16/2022] [Indexed: 01/15/2023]
|
3
|
Nandi SK, Basu S, Bhattacharjya A, Ghosh RD, Bose CK, Mukhopadhyay S, Bhattacharya R. Interplay of gut microbiome, fatty acids and the endocannabinoid system in regulating development, progression, immunomodulation and chemoresistance of cancer. Nutrition 2022; 103-104:111787. [DOI: 10.1016/j.nut.2022.111787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 05/17/2022] [Accepted: 06/25/2022] [Indexed: 11/25/2022]
|
4
|
Abstract
The animal model deals with the species other than the human, as it can imitate the disease progression, its’ diagnosis as well as a treatment similar to human. Discovery of a drug and/or component, equipment, their toxicological studies, dose, side effects are in vivo studied for future use in humans considering its’ ethical issues. Here lies the importance of the animal model for its enormous use in biomedical research. Animal models have many facets that mimic various disease conditions in humans like systemic autoimmune diseases, rheumatoid arthritis, epilepsy, Alzheimer’s disease, cardiovascular diseases, Atherosclerosis, diabetes, etc., and many more. Besides, the model has tremendous importance in drug development, development of medical devices, tissue engineering, wound healing, and bone and cartilage regeneration studies, as a model in vascular surgeries as well as the model for vertebral disc regeneration surgery. Though, all the models have some advantages as well as challenges, but, present review has emphasized the importance of various small and large animal models in pharmaceutical drug development, transgenic animal models, models for medical device developments, studies for various human diseases, bone and cartilage regeneration model, diabetic and burn wound model as well as surgical models like vascular surgeries and surgeries for intervertebral disc degeneration considering all the ethical issues of that specific animal model. Despite, the process of using the animal model has facilitated researchers to carry out the researches that would have been impossible to accomplish in human considering the ethical prohibitions.
Collapse
Affiliation(s)
- P Mukherjee
- Department of Veterinary Clinical Complex, West Bengal University of Animal and Fishery Sciences, Mohanpur, Nadia, India
| | - S Roy
- Department of Veterinary Clinical Complex, West Bengal University of Animal and Fishery Sciences, Mohanpur, Nadia, India
| | - D Ghosh
- Department of Veterinary Surgery and Radiology, West Bengal University of Animal and Fishery Sciences, Kolkata, India
| | - S K Nandi
- Department of Veterinary Surgery and Radiology, West Bengal University of Animal and Fishery Sciences, Kolkata, India.
| |
Collapse
|
5
|
Guchhait KC, Manna T, Barai M, Karmakar M, Nandi SK, Jana D, Dey A, Panda S, Raul P, Patra A, Bhattacharya R, Chatterjee S, Panda AK, Ghosh C. Antibiofilm and anticancer activities of unripe and ripe Azadirachta indica (neem) seed extracts. BMC Complement Med Ther 2022; 22:42. [PMID: 35152903 PMCID: PMC8843028 DOI: 10.1186/s12906-022-03513-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 01/07/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Antibiotic resistances of pathogens and breast cancer warrant the search for new alternative strategies. Phytoextracts can eradicate microbe-borne diseases as well as cancer with lower side effects compared to conventional antibiotics. AIM Unripe and ripe Azadirachta indica (neem) seed extracts were explored as potential antibiofilm and anticancer agents in combating multidrug-resistant infectious bacteria as well as anticancer agents against the MDR breast cancer cell lines. METHODS Shed-dried neem seeds (both unripe and ripe) were pulverized and extracted using methanol. The chemical components were identified with FTIR and gas chromatography - mass spectrometry. Antibiofilm activity of neem seed extracts were assessed in terms of minimum biofilm inhibitory concentration (MBIC), minimum biofilm eradication concentration (MBEC), and fluorescence microscopic studies on Staphylococcus aureus and Vibrio cholerae. Bacterial cells were studied by fluorescence microscopy using acridine orange/ethidium bromide as the staining agents. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were evaluated to observe the antibacterial activities. Cytotoxicity of the extracts against human blood lymphocytes and the anticancer activity against drug-resistant breast cancer cell lines were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and fluorescence-activated cell sorting (FACS) studies. RESULTS 4-Ethyl-2-hydroxy-2-cyclopentene-1-one, phthalic acid, and 2-hexyl-tetrahydro thiophane were the major compounds in unripe neem seed, whereas 3,5-dihydroxy-6-methyl-2,3-dihydro-4-H-pyran-4-one and 4-ethylbenzamide were predominant in ripe neem seed. Triazine derivatives were also common for both the extracts. MBIC values of unripe and ripe neem seed extracts for S. aureus are 75 and 100 µg/mL, respectively, and for V. cholerae, they are 100 and 300 µg/mL, respectively. MBEC values of unripe and ripe seed extracts are 500 and 300 µg/mL, respectively for S. aureus and for V. cholerae the values are 700 and 500 µg/mL, respectively. Fluorescence microscopic studies at 16 and 24 h, after bacterial culture, demonstrate enhanced antibiofilm activity for the ripe seed extract than that of the unripe seeds for both the bacteria. MTT assay reveals lower cytotoxicity of both the extracts towards normal blood lymphocytes, and anticancer activity against breast cancer cell line (MDA-MB-231) with superior activity of ripe seed extract. FACS studies further supported higher anticancer activity for ripe seed extract. CONCLUSIONS Methanolic extract of neem seeds could substantially inhibit and eradicate biofilm along with their potent antibacterial and anticancer activities. Both the extracts showed higher antibiofilm and antibacterial activity against S. aureus (gram-positive) than V. cholerae (gram-negative). Moreover, ripe seed extract showed higher antibiofilm and anticancer activity than unripe extracts.
Collapse
Affiliation(s)
- Kartik Chandra Guchhait
- Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Tuhin Manna
- Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Manas Barai
- Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Monalisha Karmakar
- Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Sourav Kumar Nandi
- Department of Molecular Biology, Netaji Subhas Chandra Bose Cancer Research Institute, 3081 Nayabad, Kolkata, 700094, West Bengal, India
| | - Debarati Jana
- Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Aditi Dey
- Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Suman Panda
- Department of Biophysics, Bose Institute, P-1/12 CIT Road, Scheme VIIM, Kankurgachi, Kolkata, 700054, West Bengal, India
| | - Priyanka Raul
- Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India
| | - Anuttam Patra
- Chemistry of Interfaces Group, Luleå University of Technology, SE- 97187, Luleå, Sweden
| | - Rittwika Bhattacharya
- Department of Molecular Biology, Netaji Subhas Chandra Bose Cancer Research Institute, 3081 Nayabad, Kolkata, 700094, West Bengal, India
| | - Subhrangsu Chatterjee
- Department of Biophysics, Bose Institute, P-1/12 CIT Road, Scheme VIIM, Kankurgachi, Kolkata, 700054, West Bengal, India
| | - Amiya Kumar Panda
- Department of Chemistry, Vidyasagar University, Midnapore, 721102, West Bengal, India.,Sadhu Ram Chand Murmu University of Jhargram, Jhargram, 721507, West Bengal, India
| | - Chandradipa Ghosh
- Department of Human Physiology, Vidyasagar University, Midnapore, 721102, West Bengal, India.
| |
Collapse
|
6
|
Vos M, Grande PL, Venkatachalam DK, Nandi SK, Elliman RG. Oxygen self-diffusion in HfO2 studied by electron spectroscopy. Phys Rev Lett 2014; 112:175901. [PMID: 24836258 DOI: 10.1103/physrevlett.112.175901] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Indexed: 06/03/2023]
Abstract
High-resolution measurement of the energy of electrons backscattered from oxygen atoms makes it possible to distinguish between (18)O and (16)O isotopes as the energy of elastically scattered electrons depends on the mass of the scattering atom. Here we show that this approach is suitable for measuring oxygen self-diffusion in HfO2 using a Hf(16)O2 (20 nm)/Hf(18)O2 bilayers (60 nm). The mean depth probed (for which the total path length equals the inelastic mean free path) is either 5 or 15 nm in our experiment, depending on the geometry used. Before annealing, the elastic peak from O is thus mainly due to electrons scattered from (16)O in the outer layer, while after annealing the signal from (18)O increases due to diffusion from the underlying Hf(18)O2 layer. For high annealing temperatures the observed interdiffusion is consistent with an activation energy of 1 eV, but at lower temperatures interdiffusion decreases with increasing annealing time. We interpret this to be a consequence of defects, present in the layers early on and enhancing the oxygen diffusivity, disappearing during the annealing process.
Collapse
Affiliation(s)
- M Vos
- Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - P L Grande
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia and Instituto de Física, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, Rio Grande do Sul, Brazil
| | - D K Venkatachalam
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| | - S K Nandi
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia and Research School of Astronomy and Astrophysics, The Australian National University, Canberra, Australian Capital Territory 2611, Australia and Department of Physics, University of Chittagong, Chittagong 4331, Bangladesh
| | - R G Elliman
- Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
| |
Collapse
|
7
|
Nandi SK, Roy S, Mukherjee P, Kundu B, De DK, Basu D. Orthopaedic applications of bone graft & graft substitutes: a review. Indian J Med Res 2010; 132:15-30. [PMID: 20693585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023] Open
Abstract
Treatment of delayed union, malunion, and nonunion is a challenge to the orthopaedic surgeons in veterinary and human fields. Apart from restoration of alignment and stable fixation, in many cases adjunctive measures such as bone-grafting or use of bone-graft substitutes are of paramount importance. Bone-graft materials usually have one or more components: an osteoconductive matrix, which acts as scaffold to new bone growth; osteoinductive proteins, which support mitogenesis of undifferentiated cells; and osteogenic cells, which are capable of forming bone in the appropriate environment. Autologous bone remains the "gold standard" for stimulating bone repair and regeneration, but its availability may be limited and the procedure to harvest the material is associated with complications. Bone-graft substitutes can either substitute autologous bone graft or expand an existing amount of autologous bone graft. We review the currently available bone graft and graft substitutes for the novel therapeutic approaches in clinical setting of orthopaedic surgery.
Collapse
Affiliation(s)
- S K Nandi
- Department of Veterinary Surgery & Radiology, West Bengal University of Animal & Fishery Sciences, Kolkata, India.
| | | | | | | | | | | |
Collapse
|
8
|
Nadeem M, Palni LMS, Kumar A, Nandi SK. Podophyllotoxin content, above- and belowground biomass in relation to altitude in Podophyllum hexandrum populations from Kumaun region of the Indian Central Himalaya. Planta Med 2007; 73:388-91. [PMID: 17394102 DOI: 10.1055/s-2007-967154] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The morphological features of Podophyllum hexandrum Royle, a 'critically endangered' medicinal herb and a source of podophyllotoxin, were studied in populations growing in different parts of the Kumaun region of the Indian Central Himalaya. Plant growth performance in terms of biomass accumulation and podopyllotoxin levels in the rhizomes collected from eleven natural populations (P1 to P11, altitude ranging from 2740 to 3350 m) were analyzed. Morphological features, e. g., plant height, stem diameter and leaf area were, in general, negatively correlated with an increase in the altitude. Maximum aboveground (8.46 g/individual) and belowground (48.18 g/individual) biomass values were recorded from a population (P9) at the lowest altitude (2740 m) and, in general, the species was found to perform better at the lower altitudes. The podophyllotoxin content of rhizomes ranged between 0.36-1.08% (on dry wt. basis) in different populations, and a positive correlation was observed between podophyllotoxin content and an increase in the altitude.
Collapse
Affiliation(s)
- M Nadeem
- G.B. Pant Institute of Himalayan Environment & Development, Kosi-Katarmal, Almora, Uttaranchal, India.
| | | | | | | |
Collapse
|
9
|
Abstract
Taxol content in the bark of Taxus baccata trees growing in a homogenous (uniform) environment at Jageshwar, District Almora in Central Himalaya has been quantified. The average taxol concentration in the bark of sampled trees was 0.0558+/-0.008% (of dry wt.) and was about 64% higher for male plants (averaged across tree age) in comparison to female trees. Maximum taxol content was recorded in the bark samples collected from trees of >110 yrs age. ANOVA indicates a significant difference in the taxol content of bark from trees of different ages, however, differences were not significant between sexes. Taxol was quantified by HPLC using a standard curve prepared with authentic taxol; the identification of bark taxol was confirmed by UV and mass spectrometry. The total taxol content of the bark of Taxus trees across an age series was found to range between 0.064 to 8.032 g/tree, and a tree of about 100 yrs age can yield 5.74 kg dry bark.
Collapse
Affiliation(s)
- M Nadeem
- G.B. Pant Institute of Himalayan Environment & Development, Kosi-Katarmal, Almora-263 643, India
| | | | | | | | | |
Collapse
|
10
|
Abstract
An efficient protocol for in vitro propagation of Thamnocalamus spathiflorus (Trin.) Munro, an evergreen temperate bamboo, through multiple shoot formation from zygotic embryos excised from germinating seeds, as well as from nodal explants taken from a 2-year-old plant has been developed. Multiple shoot formation was standardized in both the cases on Murashige and Skoog (MS) medium supplemented with 5.0 µM 6-benzylaminopurine (BAP) and 1.0 µM indole-3-butyric acid (IBA). Clumps of three to four microshoots when transferred to plant growth regulator-free medium following 14 days' initial culture on medium supplemented with 150.0 µM IBA, resulted in 100% rooting with five to 12 roots per rooted plant. Then, 18 months following the transfer of in vitro propagated plants into earthen pots containing soil and growth under outdoor conditions, gas and water vapour exchange rates were measured at different light levels (0, 100, 500, 1000, 1500, 2000 µmol(-2) s(-1)), and compared with seedlings of the same age. Light optima for photosynthesis were recorded approximately 1000 µmol m(-2) s(-1) in in vitro propagated plants as well as seedlings. Water use efficiency increased with increase in the light intensity up to 1000 µmol m(-2) s(-1) and then decreased subsequently at higher light intensities. Stomatal conductance and transpiration also increased with the increase in light intensity up to 2000 µmol(-2) s(-1). Intercellular CO(2) concentration (C(i)) and the ratio of intercellular CO(2) concentration to ambient CO(2) (C(i)/C(a)) decreased with the increase in light intensity up to 500 µmol(-2) s(-1) and then reached nearly constant levels at higher light intensities. The results show that in vitro propagated and hardened plants of T. spathiflorus are morphologically as well as functionally comparable to seed raised plants of the same age, within the limits of this study.
Collapse
Affiliation(s)
- N Bag
- G.B. Pant Institute of Himalayan Environment and Development, Kosi-Katarmal, 263 643, U.P., Almora, India
| | | | | | | |
Collapse
|
11
|
Nandi SK, Palni LM, Parker CW. Dynamics of Endogenous Cytokinins during the Growth Cycle of a Hormone-Autotrophic Genetic Tumor Line of Tobacco. Plant Physiol 1990; 94:1084-9. [PMID: 16667800 PMCID: PMC1077345 DOI: 10.1104/pp.94.3.1084] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The profile of endogenous cytokinins in a genetic tumor line of tobacco, namely, Nicotiana glauca (Grah.) x Nicotiana langsdorffii (Weinm.), following 1 to 10 weeks of growth on solid medium was determined by radioimmunoassay. (3)H-labeled cytokinins of high specific activity were added during tissue extraction to correct for the purification losses. Following subculture (of 4-week-old tissues when their cytokinin content is high) onto fresh medium the total cytokinin content continued to be high during the first week (1470 picomoles per gram fresh weight) when the tissue fresh weight remained essentially unchanged (lag phase). The cytokinin levels then declined by about half in 2- and 3-week-old tissues (626 and 675 picomoles per gram fresh weight, respectively), a period when rapid increase in tissue fresh weight was recorded. Increments of 840% and 2780% over initial fresh weight were obtained in 2- and 3-week-old cultures, respectively. The cytokinin content then increased to initial high levels in 4-week-old tissues (1384 picomoles per gram fresh weight) after which it gradually declined with tissue age. The lowest cytokinin levels (432 picomoles per gram fresh weight) were observed in 10-week-old tissues. Maximal tissue fresh weight (4030% increase over initial fresh weight) was recorded in 5-week-old cultures after which it decreased slowly to 77.5% of the highest tissue fresh weight in 10-week-old cultures. Zeatin appeared to be the dominant endogenous cytokinin in tissues of all ages. Other cytokinins quantified were dihydrozeatin, zeatin riboside, and dihydrozeatin riboside; the values may include contributions from aglucones derived from the hydrolysis of corresponding O-glucosides, since the entire basic fraction was treated with beta-glucosidase before analysis. In addition the levels of isopentenyladenine, isopentenyladenosine, and the nucleotides of zeatin riboside, dihydrozeatin riboside, and isopentenyladenosine were also determined.
Collapse
Affiliation(s)
- S K Nandi
- Plant Cell Biology Group, Research School of Biological Sciences, The Australian National University, G.P.O. Box 475, Canberra, ACT 2601, Australia
| | | | | |
Collapse
|