A root trait accounting for the extreme phosphorus sensitivity of Hakea prostrata (Proteaceae)

Abstract

Proteaceae are adapted to acquire P from nutrient-impoverished soils; many function at very low leaf P levels, but are killed by P fertilization. Phosphorus toxicity develops at a remarkably low external P concentration. Previous studies have described P toxicity in Proteaceae, but the physiological basis for it remained unclear. The aim of the present study was to elucidate the physiological basis of P toxicity in Hakea prostrata R. Br. (Proteaceae). Triticum aestivum L. (Gramineae), Medicago truncatula Gaertn., Lupinus albus L. (both Fabaceae) and Hakea prostrata R.Br. were grown in solution at a range of P concentrations (0-1000 mmol P m-3), and determined net P-uptake rates at 5 (all spe..