Influence of phosphate supply on aluminium toxicity in cereal species

Abstract

In acid soils, aluminium toxicity is the primary stress factor limiting the growth and yield of plants. The objective of this study was to examine the effects of aluminium (A1) and phosphate (P) treatments on the growth and potassium uptake of roots and transport toward the shoots in Al-sensitive and Al-tolerant cereal species. Seedlings were grown hydroponically at pH 4.1 in the presence and absence of A1 and P. A1 reduced root growth in the order of Al-tolerance (rye>triticale>common wheat>durum wheat) in the growth solution. Shoot growth was influenced (reduced) at 50 μM A1 concentration only in cultivars GK Betadur and Jubilejnaja 50. In the short-term (6h) K+(86Rb) uptake experiments, P reduced the specific stimulatory effect of A1 on K+(86Rb) influx anomaly of the roots, which indicates a definite Al-P interaction both in external and internal detoxification of AI. Results show that PO4-P in the growth solution enabled plants to overcome AI toxicity symptoms; however, different species respond differently to P-application.