Abstract
The rate of auxin transport in sunflower hypocotyls (Helianthus annuus L. cv `Russian mammoth') or corn coleoptiles (Zea mays L. cv `WF9 × 38') was less in seedlings grown in Ca-deficient medium than in controls. The rate of IAA transport depended on the concentration of Ca in the root medium up to 1 millimolar. Further increases in auxin transport were observed when the isolated segments were incubated in medium containing up to 30 millimolar Ca. We suggest that the rate of auxin transport in plant tissue is dependent on the pool of ionic Ca in the extracellular space.
Segments from Ca-deficient seedlings exhibited a high specific requirement for Ca2+ in auxin transport. Magnesium, strontium, and several other divalent cations tested for their ability to replace Ca2+ in restoring auxin transport showed no effect; partial replacement by lanthanum was observed.
Auxin transport, or auxin flux through the segment, which is the result of IAA secretion by individual cells, was reduced in the low Ca2+ segments due both to lowered velocity and to reduced capacity of transport. The requirement for Ca2+ in the secretion of auxin is believed to be equivalent to the phenomenon observed in animal cell secretion, where the influx of Ca2+ serves as a link between an external stimulus and the secretion response.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Cleland R. E., Prins H. B., Harper J. R., Higinbotham N. Rapid Hormone-induced Hyperpolarization of the Oat Coleoptile Transmembrane Potential. Plant Physiol. 1977 Mar;59(3):395–397. doi: 10.1104/pp.59.3.395. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cohen J. D., Nadler K. D. Calcium Requirement for Indoleacetic Acid-induced Acidification by Avena Coleoptiles. Plant Physiol. 1976 Mar;57(3):347–350. doi: 10.1104/pp.57.3.347. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DOUGLAS W. W., RUBIN R. P. The role of calcium in the secretory response of the adrenal medulla to acetylcholine. J Physiol. 1961 Nov;159:40–57. doi: 10.1113/jphysiol.1961.sp006791. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dela Fuente R. K., Leopold A. C. A role for calcium in auxin transport. Plant Physiol. 1973 May;51(5):845–847. doi: 10.1104/pp.51.5.845. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dieter P., Marmé D. Calmodulin activation of plant microsomal Ca uptake. Proc Natl Acad Sci U S A. 1980 Dec;77(12):7311–7314. doi: 10.1073/pnas.77.12.7311. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jacobs M., Gilbert S. F. Basal localization of the presumptive auxin transport carrier in pea stem cells. Science. 1983 Jun 17;220(4603):1297–1300. doi: 10.1126/science.220.4603.1297. [DOI] [PubMed] [Google Scholar]
- Marschner H., Handley R., Overstreet R. Potassium Loss and Changes in the Fine Structure of Corn Root Tips Induced by H-ion. Plant Physiol. 1966 Dec;41(10):1725–1735. doi: 10.1104/pp.41.10.1725. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Plattner H., Reichel K., Matt H. Bivalent-cation-stimulated ATPase activity at preformed exocytosis sites in Paramecium coincides with membrane-intercalated particle aggregates. Nature. 1977 Jun 23;267(5613):702–704. doi: 10.1038/267702a0. [DOI] [PubMed] [Google Scholar]
- Rehfeld D. W., Jensen R. G. Metabolism of Separated Leaf Cells: III. Effects of Calcium and Ammonium on Product Distribution During Photosynthesis with Cotton Cells. Plant Physiol. 1973 Jul;52(1):17–22. doi: 10.1104/pp.52.1.17. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williamson R. E., Ashley C. C. Free Ca2+ and cytoplasmic streaming in the alga Chara. Nature. 1982 Apr 15;296(5858):647–650. doi: 10.1038/296647a0. [DOI] [PubMed] [Google Scholar]
- de la Fuente R. K., Leopold A. C. Kinetics of polar auxin transport. Plant Physiol. 1966 Nov;41(9):1481–1484. doi: 10.1104/pp.41.9.1481. [DOI] [PMC free article] [PubMed] [Google Scholar]