THE ACCUMULATION OF ZINC BY SUBCELLULAR FRACTIONS OF ROOTS OF <i>AGROSTIS TENUIS</i> SIBTH. IN RELATION TO ZINC TOLERANCE

Abstract

S ummary Zinc tolerance in the grass, Agrostis tennis Sibth., was investigated by comparing the uptake of radiozinc by the cell wall and mitochondrial fractions from the roots of sixteen different populations. Large differences in tolerance between populations were found. There was a significant correlation between zinc accumulation by each subcellular fraction and the index of zinc tolerance but the cell wall fraction accumulated a greater quantity of zinc. There was no correlation between the nitrogen content of the cell wall fraction and zinc tolerance. The importance of metal accumulation by the cell wall fraction is discussed and it is suggested that it is a major feature of the mechanism of tolerance to heavy metals in A. tenuis .