Effect of P concentration on 65Zn uptake in Gaudinia fragilis.

COGLIATTI D; ALCOCER N; SANTA MARÍA G

JOURNAL OF PLANT NUTRITION

TAYLOR & FRANCIS INC

Lugar: Londres; Año: 1991 vol. 14 p. 443 - 452

0190-4167

Phosphorus-Zn interaction was studied in Gaudinia fragilis plants grown in culture solution. The effect of different P supplies on 65Zn uptake was measured in 21 days-old seedlings. Zinc as 65Zn absorbed during 24 h decreased when P concentration in the nutrient solution was increased from 0 to 10 mM. The longer the period in high P concentration, the stronger the 65Zn uptake inhibition. The time course of 65Zn uptake showed that both Zn-influx and net Zn-uptake were inhibited in 10 mM with respect to 0.1 mM P. The partitioning of the 65Zn absorbed between shoot and root was not affected by P supply. However total 65Zn transported to the shoot was higher in 0,1 than in 10 mM phosphate due to the higher 65Zn absorption. The time course of the inhibition of 65Zn influx by high P concentration showed a rapid initial decrease, probably due to a direct effect of external P concentration, followed by a slower decrease, which was attributed to the increase in the internal P concentration.