Factors affecting absorption and transport of potassium in maize roots

Before short-term absorption experiments, excised roots of young maize plants were differently treated to alter properties like membrane permeability and concentrations of organic and inorganic compounds. Subsequently, influx and efflux of potassium ions were estimated during the initial and the steady-state phase. In other experiments, absorption and translocation of K + were estimated simultaneously in excised roots of young plants and in decapitated roots of maize plants 5 weeks old. Absorption, accumulation and upward transport of potassium in maize roots were closely linked. Freshly absorbed potassium was accumulated initially but, with time, internal salt concentration, osmotic pressure and upward xylem transport (exudation) steadily increase. During the steady-state phage, rate of uptake and transport of K + to aerial parts were equal and K + did not accumulate in maize roots. Freshly absorbed K + was immediately transported upwards or exchanged with K + already present in the root cells and then temporarily accumulated in root cell vacuoles before being transported longitudinally