Abstract
The profile of endogenous cytokinins in a genetic tumor line of tobacco, namely, Nicotiana glauca (Grah.) × Nicotiana langsdorffii (Weinm.), following 1 to 10 weeks of growth on solid medium was determined by radioimmunoassay. 3H-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 β-glucosidase before analysis. In addition the levels of isopentenyladenine, isopentenyladenosine, and the nucleotides of zeatin riboside, dihydrozeatin riboside, and isopentenyladenosine were also determined.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Badenoch-Jones J., Letham D. S., Parker C. W., Rolfe B. G. Quantitation of cytokinins in biological samples using antibodies against zeatin riboside. Plant Physiol. 1984 Aug;75(4):1117–1125. doi: 10.1104/pp.75.4.1117. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cohen J. D., Baldi B. G., Slovin J. P. C(6)-[benzene ring]-indole-3-acetic Acid: a new internal standard for quantitative mass spectral analysis of indole-3-acetic Acid in plants. Plant Physiol. 1986 Jan;80(1):14–19. doi: 10.1104/pp.80.1.14. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nishinari N., Syōno K. Changes in endogenous cytokinin levels in partially synchronized cultured tobacco cells. Plant Physiol. 1980 Mar;65(3):437–441. doi: 10.1104/pp.65.3.437. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Palni L. M., Summons R. E., Letham D. S. Mass spectrometric analysis of cytokinins in plant tissues : v. Identification of the cytokinin complex of datura innoxia crown gall tissue. Plant Physiol. 1983 Jul;72(3):858–863. doi: 10.1104/pp.72.3.858. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Palni L. M., Tay S. A., Macleod J. K. Determination by Gas Chromatography-Mass Spectrometry of [N(5)]Adenine Incorporation into Endogenous Cytokinins and the Effect of Tissue Age on Cytokinin Biosynthesis in Datura innoxia Crown Gall Tissue. Plant Physiol. 1987 Aug;84(4):1158–1165. doi: 10.1104/pp.84.4.1158. [DOI] [PMC free article] [PubMed] [Google Scholar]