biologia plantarum

Biologia plantarum 26:161, 1984 | DOI: 10.1007/BF02895040

The effect of some micronutrients and heavy metals on phosphate absorption by maize root cortex segments

Ivana Macháčková¹, Z. Zmrhal¹

¹ Department of Plant Nutrition, Institute of Crop Production, Praha 6, Czechoslovakia

The effect of salts (nitrates, chlorides, and sulfates) of microelements, Cd²⁺, Ni²⁺, and Co²⁺ and the effect of boric acid and ammonium molybdate on phosphate uptake by maize root cortex segments were tested.
Higher concentration (0.1 mM) of Cu²⁺ salts caused enhancement of phosphate efflux to the extent that efflux was higher than influx.
Inhibitory action on phosphate uptake by maize root cortex segments was exerted by following salts: 0.01 mM Cu²⁺ salts (20-30% inhibition), 0.5 mM ZnSO₄ (9.7%), 0.5 and 0.05 mM ZnCl₂ (34.3% and 20.8%), 0.1 mM salts of Cd²⁺, Ni²⁺, Co²⁺ (35-78%).
1 mM FeS_O4 had significant stimulatory effect (92%) on phosphate uptake. Much weaker stimulatory effect was exerted by 1 mM FeCl₃ (14%), 0.05 mM ZnS_O4 (9.6%), 0.005 mM ZnCla and ZnS_O4 (8.4 and 18.5%) and 0.001 mM CdCl2 and CdS_O4 (20.8 and 12.4%).
All other tested salts-salts of Mn²⁺ (0.1 and 0.01 mM), 0.01 and 0.001 mM salts of Co²⁺ and Ni²⁺, 0.001 mM salts of Cu²⁺, 0.001-10 mM boric acid, and 0.001-0.1 mM ammonium molybdate left phosphate uptake unaffected.

Received: March 30, 1983; Accepted: September 12, 1983; Published: May 1, 1984  Show citation