Cations, in plants

The first step in the concentrations of cations in plant roots is the transfer of the cations across the plasmalemma of the epidermal cells, and although the subsequent transfer of ions to the xylem is fairly clear (99), it is this transport across the cell membranes of the epidermis where the uncertainty occurs. Studies of the uptake of 46Sc3+ into barley roots have demonstrated that there is no significant uptake beyond the epidermis and first rank of cortical roots of the seminal roots (100). Presumably other polyvalent cations will be immobilised at the same place. 

Determination of Cations in Plant Materials, Vegetables and Fruit... 

Most of the work published on the determination of cations in plant material is of course concerned not with the analysis of single elements present in the sample but instead a range of elements present in the sample. 

Calcium transport in mitochondria Transport of the IIA cations in microbes- Sporulation Transport of the IIA cations in plants... 

Here, the mode of Zn action against the REE-induced OXB was assessed with Lineweaver-Burk kinetics and possible eco-physiological roles for Zn in interaction with other metal cations in plants are discussed. 

Potassium, sodium, and ammonium ions are the important members of this group. K+ is the predominant cation in plants, being essential for growth. In muscle tissue K+ is bound to muscle proteins and is involved in stabihzing myosin. Furthermore, it has been known for some time that cells selectively absorb and acciunulate K+ from an ionic environment low in K while sodium remains in the external environment. In addition K enhances glycolysis. Thus, yeast fermentation is more vigorous in the presence of 0.01 M K+. Rb+ replaces K+ to about an equal extent, but Na+ is far less effective and Li+ is ineffective. K+ in 0.0025 M concentration increases tumor glycolysis, whereas Na+ is inhibitory. 

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