Intracellular Localization of Lead in a Lead Tolerant and Sensitive Clone of Anthoxanthum odoratum

Abstract

Summary Tillers from lead tolerant and non-tolerant plants of Anthoxanthum odoratum were incubated in the presence of 30μM lead for 7 days then the root tips examined for the intracellular distribution of lead. Electron microscopy of sections of both chemically fixed and freeze dried sections of root tips showed an accumulation of electron dense material in the cell walls which was assumed to be lead. An X-ray probe analysis of sections of chemically fixed root tips from tolerant plants also showed lead to be present in the cell walls and excluded from the cytoplasm. Examination of the non-tolerant material by electron microscopy alone again showed electron dense material in the cell walls, and also in the cytoplasm. It was suggested that the tolerance mechanism for lead in A. odoratum was related to the capacity of the tolerant plants to restrict the lead to the cell walls.