渗透胁迫下群众杨根细胞中的K+累积效应

群众杨插条苗经 PEG渗透胁迫处理后,取根部样品,经过快速冷冻、冷冻干燥、乙醚真空渗透及塑料包埋后,用透射电镜 X-射线能谱微区分析技术,对根表皮层、皮层及中柱薄壁组织细胞的细胞壁、细胞质和液泡中的 K+含量与分布进行了测定。结果表明,在渗透胁迫下,在根各部位组织细胞的细胞壁、细胞质和液泡中,K+含量都有不同程度的增加,增加的 K+主要积累在液泡中。渗透胁迫所促进的 K+吸收可被蛋白质合成抑制剂环己酰亚胺所抑制。

K+- Accumulation in Poplar Roots Induced by Osmotic Stress

Cuttings of Populus × xiaozhuanica W.Y.Hsu et Liang cv.‘ Popularis ’ 35 44 were treated with PEG solution. After fast freezing,freeze-drying,pressure infiltration with ether and embedding in plastic,K+ content were measured by X ray microanalysis in cell wall,cytoplasm and vacuole of rhizodermis, cortex and stelar parenchyma cells of roots. Compared to the controls,K+ content in all root tissues were increased by osmotic stress.In particular,the increasing K+ was largely accumulated in vacuole. The K+ accumulation induced by osmotic stress could be inhibited completely by cycloheximide.