Related Experiment Video
Updated: Aug 8, 2026
13:14
Measuring Fluxes of Mineral Nutrients and Toxicants in Plants with Radioactive Tracers
Published on: August 22, 2014
Calcium uptake by excised maize roots and interactions with alkali cations
1Mineral Nutrition Laboratory, USDA, ARS, SWCRD, Beltsville, Maryland 20705.
Plant Physiology
|July 1, 1969
Summary
Calcium (Ca2+) uptake in maize roots is a metabolically driven process. Its rate is significantly affected by factors like counter-ions, pH, concentration, and other cations present.
Area of Science:
- Plant Physiology
- Root Biology
- Mineral Nutrition
Background:
- Calcium (Ca2+) is essential for plant cell wall structure and signaling.
- Understanding Ca2+ uptake mechanisms is crucial for optimizing plant growth and stress tolerance.
Purpose of the Study:
- To investigate the metabolic mediation of Ca2+ uptake in excised maize roots.
- To identify factors influencing the rate of Ca2+ absorption.
Main Methods:
- Short-term uptake experiments using 5-day-old excised maize roots.
- Assessing Ca2+ absorption under varying conditions (temperature, inhibitors, different salt solutions).
Main Results:
- Ca2+ uptake is an active, energy-dependent process, inhibited by dinitrophenol and low temperatures.
- Uptake rate is influenced by the counter-ion, with NO3- > Cl- = Br- > SO4(2-).
- Potassium (K+) and hydrogen (H+) ions significantly inhibit Ca2+ absorption, while Li+ and Na+ have minimal effects.
Conclusions:
- Ca2+ uptake in maize roots is a metabolically regulated process.
- Environmental factors and the presence of other cations critically modulate Ca2+ absorption efficiency.
- These findings have implications for understanding nutrient transport in plants.
Related Concept Videos
02:02Responses to Salt Stress
Salt stress—which can be triggered by high salt concentrations in a plant’s environment—can significantly affect plant growth and crop production by influencing photosynthesis and the absorption of water and nutrients.
02:34Water and Mineral Acquisition
Specialized tissues in plant roots have evolved to capture water, minerals, and some ions from the soil. Roots exhibit a variety of branching patterns that facilitate this process. The outermost root cells have specialized structures called root hairs that increase the root surface, thus increasing soil contact. Water can passively cross into roots, as the concentration of water in the soil is higher than that of the root tissue. Minerals, in contrast, are actively transported into root cells.
03:46Qualitative Analysis
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...