Rapid Auxin-induced Decrease in Free Space pH and Its Relationship to Auxin-induced Growth in Maize and Pea
- 1 August 1976
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 58 (2), 203-209
- https://doi.org/10.1104/pp.58.2.203
Abstract
A pH microelectrode has been used to investigate the auxin effect on free space pH and its correlation with auxin-stimulated elongation in segments of pea (Pisum sativum) stem and maize (Zea mays var. Bear Hybrid) coleoptile tissue. Auxin induces a decrease in free space pH in both tissues. In maize coleoptiles, free space pH begins to fall within about 12 minutes of exposure to auxin and decreases by about 1 pH unit by approximately 30 minutes. In pea, pH begins to decrease within an average of 15 to 18 minutes of exposure to auxin and falls by about 0.9 pH unit by approximately 40 minutes. Auxin-stimulated elongation, measured in the same two tissues similarly prepared, appears in maize at the earliest 18 minutes after auxin application, while in pea it appears at the earliest 21 to 24 minutes after auxin application. The auxin analogs p-chlorophenoxyisobutyric acid and phenylacetic acid do not stimulate elongation above control levels in maize or pea tissue segments and do not cause a decrease in free space pH in either tissue. These findings are consistent with the acid secretion theory of auxin action.Keywords
This publication has 10 references indexed in Scilit:
- Kinetics of Hormone-induced H+ ExcretionPlant Physiology, 1976
- Stoichiometric Correlation of Malate Accumulation with Auxin-dependent K+-H+ Exchange and Growth in Avena Coleoptile SegmentsPlant Physiology, 1975
- Promotion of Xyloglucan Metabolism by Acid pHPlant Physiology, 1975
- Dark CO2 Fixation in Gladiolus Cormels and Its Regulation during the Break of DormancyPlant Physiology, 1975
- Separation of two responses to auxin by means of cytokinin inhibition.Proceedings of the National Academy of Sciences of the United States of America, 1975
- Growth Rate and Turgor PressurePlant Physiology, 1974
- Auxin Does Not Alter the Permeability of Pea Segments to Tritium-labeled WaterPlant Physiology, 1974
- Auxin-Induced Hydrogen Ion Excretion from Avena ColeoptilesProceedings of the National Academy of Sciences of the United States of America, 1973
- Effect of pH and surface charge on cell uptake of auxin.1973
- Enhancement of Wall Loosening and Elongation by Acid SolutionsPlant Physiology, 1970