Factors Necessary for Mineral Absorption
Following are the plant factors and environmental factors contribute to the effective mineral absorption.
Plant Root System
The water and mineral elements are present in the soils. To absorb both water and mineral elements from the soil depends upon their capacity to develop an extensive root system. Plant roots grow continuously and root growth and development depends upon soil environment. In moist and fertile soils the roots proliferate extensively. If water is available deep in the ground, roots grow deep as well. The root hairs also contribute to absorption of ions and water, e.g., in lye plant the root hairs contribute about 67% of the total root surface area.
Mycorrhizae (myco=fungi + rhiza=root)
The fungi receive organic nutrients from the plant and in turn improve the mineral salts and water absorbing of the roots. The mycorrhizae help increase the capacity of the root system to absorb nutrients such as phosphorus and trace element like zinc and copper.
Movement of Nutrients within Soil
Within the soil, nutrient movement to the root surface can occur both by bulk flow and by diffusion. Bulk flow occurs when nutrients are carried in the flow of water moving through the soil towards the root. The bulk flow is effective when concentration of nutrients in the soil solution is high and rate of water flow through the plant is greater. Diffusion occurs when mineral nutrients move from a region of higher concentration to a region of lower concentration.
Nature of the Membranes
Plasma-lemma and tonoplast are biological membranes involved in ion transport. These membranes consist largely of proteins and lipids.
The proteins are usually about one-half to two-third of the membrane dry weight. Some of the hydrophobic proteins called integral proteins penetrate deeply into lipid-rich interior whereas some extend all the way through the bilayer. The proteins in membranes are of three types:
Catalytic Proteins (Enzymes): These usually catalyze hydrolysis of Nu to ADP and I-12P01. These are called ATPases. All membranes of all organisms have at least one kind of ATPase.
Transporters: Several kinds of proteins called carrier or transporters, each of which combines with and transport a different ion or molecules across the membrane.
Structural Proteins: These proteins contribute to structure only but it is difficult to prove that these contribute to structure only.