Subcellular distribution and chemical forms of Potentilla grifithii Hook

The differential centrifugation technique and sequential chemical extraction method were used to study the subcellular distribution and the chemical forms of Zn in the leaves,leafstalks and roots of Potentilla grifithii Hook.The result showed that most of Zn was bound to the cell wall in the plant under different Zn treatment levels,secondly was distributed in the soluble(including ribosome) and karyon fractionsl,ittle was found in the chloroplast and mitochondrion fractions.For the leavesi,ncreasing Zn supply reduced the proportion of Zn in the cell wall and soluble fractions,but increased the proportion of Zn in karyon fraction.For the leafstalks,increasing Zn supply increased the proportion of Zn in the soluble fraction.For the roots,however,Zn supply had no effects on the proportion of Zn in each fractions.For the chemical forms,NaCl and water-extractable Zn predominated in the plant.Increasing Zn supply obviously reduced the proportion of acetic acid-extractable Zn,and increased the proportion of water and ethanol-extractable Zn.Other forms such as HCl-extractable Zn and residual Zn were low.Cell wall and vacuole are important Zn combine sites where Zn maybe combines with water or ester soluble organic compound in Potentilla grifithii Hook