Abstract
The endogenous gibberellin (GA) content of spinach (Spinacia oleracea) was reinvestigated by combined gas chromatography-mass spectrometry analysis. The 13-hydroxy GAs: GA53, GA44, GA19, GA17, GA20, GA5, GA1, GA29, and GA8; the non-3, 13-hydroxy GAs: GA12, GA15, GA9, and GA51; and the 3β-hydroxy GAs: GA4, GA7, and GA34, were identified in spinach extracts by comparing full-scan mass spectra and Kovats retention indices with those of reference GAs. In addition, spinach plants contained GA7-isolactone, 16,17-dihydro-17-hydroxy-GA53, GA29-catabolite, 3-epi-GA1, and 10 uncharacterized GAs with mass spectra indicative of mono- and dihydroxy-GA12, monohydroxy-GA25, dihydroxy-GA24, and dihydroxy-GAg. The effect of light-dark conditions on the GA levels of the 13-hydroxylation pathway was studied by using labeled internal standards in selected ion monitoring mode. In short day, the GA levels were higher at the end of the light period than at the end of the dark period. Levels of GAs at the end of each short day were relatively constant. During the first supplementary light period of long day treatment, GA53 and GA19 declined dramatically, GA44 and GA1 decreased slightly, and GA20 increased. During the subsequent high-intensity light period, the GA20 level decreased and the levels of GA53, GA44, GA19, and GA1 increased slightly. Within 7 days after the beginning of long day treatment, similar patterns for GA53 and GA19 occurred. Furthermore, when these plants were transferred to darkness, an increase in the levels of GA53 and GA19 was observed. These results are compatible with the idea that in spinach, the flow through the GA biosynthetic pathway is much enhanced during the high-intensity light period, although GA turnover occurs also during the supplementary period of long day, both effects being responsible for the increase of GA20 and GA1 in long day.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Albone K. S., Gaskin P., Macmillan J., Phinney B. O., Willis C. L. Biosynthetic Origin of Gibberellins A(3) and A(7) in Cell-Free Preparations from Seeds of Marah macrocarpus and Malus domestica. Plant Physiol. 1990 Sep;94(1):132–142. doi: 10.1104/pp.94.1.132. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Croker S. J., Hedden P., Lenton J. R., Stoddart J. L. Comparison of gibberellins in normal and slender barley seedlings. Plant Physiol. 1990 Sep;94(1):194–200. doi: 10.1104/pp.94.1.194. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fujioka S., Yamane H., Spray C. R., Gaskin P., Macmillan J., Phinney B. O., Takahashi N. Qualitative and Quantitative Analyses of Gibberellins in Vegetative Shoots of Normal, dwarf-1, dwarf-2, dwarf-3, and dwarf-5 Seedlings of Zea mays L. Plant Physiol. 1988 Dec;88(4):1367–1372. doi: 10.1104/pp.88.4.1367. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fujioka S., Yamane H., Spray C. R., Phinney B. O., Gaskin P., Macmillan J., Takahashi N. Gibberellin A(3) Is Biosynthesized from Gibberellin A(20) via Gibberellin A(5) in Shoots of Zea mays L. Plant Physiol. 1990 Sep;94(1):127–131. doi: 10.1104/pp.94.1.127. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gianfagna T., Zeevaart J. A., Lusk W. J. Effect of photoperiod on the metabolism of deuterium-labeled gibberellin a(53) in spinach. Plant Physiol. 1983 May;72(1):86–89. doi: 10.1104/pp.72.1.86. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gilmour S. J., Zeevaart J. A., Schwenen L., Graebe J. E. Gibberellin metabolism in cell-free extracts from spinach leaves in relation to photoperiod. Plant Physiol. 1986 Sep;82(1):190–195. doi: 10.1104/pp.82.1.190. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Metzger J. D., Zeevaart J. A. Effect of Photoperiod on the Levels of Endogenous Gibberellins in Spinach as Measured by Combined Gas Chromatography-selected Ion Current Monitoring. Plant Physiol. 1980 Nov;66(5):844–846. doi: 10.1104/pp.66.5.844. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Metzger J. D., Zeevaart J. A. Identification of six endogenous gibberellins in spinach shoots. Plant Physiol. 1980 Apr;65(4):623–626. doi: 10.1104/pp.65.4.623. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Talon M., Koornneef M., Zeevaart J. A. Endogenous gibberellins in Arabidopsis thaliana and possible steps blocked in the biosynthetic pathways of the semidwarf ga4 and ga5 mutants. Proc Natl Acad Sci U S A. 1990 Oct;87(20):7983–7987. doi: 10.1073/pnas.87.20.7983. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Talon M., Zeevaart J. A. Gibberellins and Stem Growth as Related to Photoperiod in Silene armeria L. Plant Physiol. 1990 Apr;92(4):1094–1100. doi: 10.1104/pp.92.4.1094. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zeevaart J. A. Effects of photoperiod on growth rate and endogenous gibberellins in the long-day rosette plant spinach. Plant Physiol. 1971 Jun;47(6):821–827. doi: 10.1104/pp.47.6.821. [DOI] [PMC free article] [PubMed] [Google Scholar]
