Absorption of magnesium and chloride by excised corn root |
| |
| Authors: | Maas E V Ogata G |
| |
| Affiliation: | United States Salinity Laboratory, Soil and Water Conservation Research Division, Agricultural Research Service, United States Department of Agriculture, Riverside, California 92502. |
| |
| Abstract: | Absorption characteristics of Mg2+ and Cl− were investigated with 5-day-old excised corn (Zea mays) roots. Uptake from both 0.5 and 10 milliequivalents per liter MgCl2 solutions occurred at steady state rates for the first 6 hours. Inhibition by dinitrophenol and low temperatures established that absorption during this period was metabolically mediated in the absence and presence of Ca2+. Absorption isotherms indicated dual mechanisms of Mg2+ and Cl− absorption from solutions above 1 milliequivalent per liter. The effect of H+ on absorption of Mg2+ and Cl− was typical of that generally reported for other plant roots and other ions. In the physiological pH range, Ca2+ greatly suppressed the rate of Mg2+ absorption but had little effect on Cl−. The influence of Ca2+ on Mg2+ appeared to be noncompetitive and independent of its effect on membrane permeability. |
| |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ |
|
