锌在长柔毛委陵菜细胞内的分布和化学形态研究

采用差速离心技术和化学试剂逐步提取法研究了Zn在长柔毛委陵菜(Potentilla grifithii Hook)叶片、叶柄和根系中的亚细胞分布和赋存形态。研究表明,细胞壁是Zn在长柔毛委陵菜细胞内的主要分布位点,其次是含核糖体的可溶部分和细胞核部分,而在叶绿体和线粒体的分布很少。叶片中,提高Zn处理水平,Zn向细胞壁和可溶部分的分配减少,而在细胞核部分的分配增加;叶柄中,提高Zn处理浓度增加了Zn在可溶部分的分配;根系中,Zn在各组分中的分配不受Zn浓度影响。在Zn赋存形态上,植物体内以氯化钠提取态和水提取态为主导形态;提高Zn处理水平,醋酸提取态的分配明显减少,水和乙醇两种提取态的分配增加;而其他形态Zn在植物体内的分配则很少。显示细胞壁和液泡是Zn在长柔毛委陵菜细胞内的重要结合位点,且可能主要与水溶性和酯溶性的有机配位体结合。

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