Abstract
Potassium influx isotherms were obtained for 10 cultivars of barley using plants which had been grown with or without potassium (high K+ and low K+ plants, respectively), and the cultivars ranked with respect to Km or Vmax values for influx with a view to using these rankings as a predictive measure of long term performance under conditions of potassium-limited growth. Analyses of these rankings revealed significant differences between cultivars. Net uptake rates for low K+ plants, determined over a 24-hour period, confirmed the differences between upper (Herta) and lower (Conquest) ranked cultivars, and established similar differences in the rates of translocation to the shoot. Efflux analyses showed no differences in potassium efflux from the cytoplasm or from the vacuole for these cultivars. Growth rate studies under different conditions of potassium limitation indicated, with some exceptions, strong positive correlations between ranks accorded cultivars on the basis of influx kinetics and those based upon growth rates.
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- Cleland W. W. The statistical analysis of enzyme kinetic data. Adv Enzymol Relat Areas Mol Biol. 1967;29:1–32. doi: 10.1002/9780470122747.ch1. [DOI] [PubMed] [Google Scholar]
- Crowley P. H. Natural selection and the Michaelis constant. J Theor Biol. 1975 Apr;50(2):461–475. doi: 10.1016/0022-5193(75)90093-4. [DOI] [PubMed] [Google Scholar]
- Glass A. D. Regulation of potassium absorption in barley roots: an allosteric model. Plant Physiol. 1976 Jul;58(1):33–37. doi: 10.1104/pp.58.1.33. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pimentel D., Hurd L. E., Bellotti A. C., Forster M. J., Oka I. N., Sholes O. D., Whitman R. J. Food production and the energy crisis. Science. 1973 Nov 2;182(4111):443–449. doi: 10.1126/science.182.4111.443. [DOI] [PubMed] [Google Scholar]