铜在拔节期小麦中的亚细胞分布

Subcellular Distribution of Cu in Jointing Wheat

为了解小麦对Cu的解毒及耐性机制,通过盆栽试验并采用差速离心法研究了Cu在拔节期小麦根和叶片中的亚细胞分布。研究表明,在Cu胁迫下根和叶亚细胞组分中Cu含量随胁迫浓度的升高呈上升趋势,Cu主要富集在小麦根部,向地上叶片中输送较少,小麦根部Cu含量是叶片中的1.7~4.1倍。细胞质可溶性部分和细胞壁是Cu在小麦细胞内分布的主要位点,分别占总量的36%~81%和14%~48%,细胞器中分布较少,提高Cu胁迫浓度增强了细胞质可溶性部分对Cu的区隔化作用,减弱了细胞壁对Cu的固持作用,同时减少了Cu在细胞器中的分布;叶片细胞壁对Cu的固定作用较强,根部细胞质可溶性部分对Cu的区隔化作用较强。分析表明,细胞壁的沉淀和细胞质的区隔化作用对小麦对Cu的耐性起着重要的作用。

Using differential centrifugation technique,the subcellular distribution of Cu in roots and leaves of wheat at jointing stage were studied by pot experiment,to understand the tolerance and detoxification mechanism of Cu in wheat.Results showed that Cu content in the subcellular fractions of wheat roots and leaves under Cu stress increased with increasing Cu concentration.Cu mainly accumulated in wheat roots and accumulation amount in wheat leaves was less.36%～81% and 14%～48% of total Cu was bound to soluble fraction and cell wall respectively,and only a small quantity of Cu distributed in organelle fractions.Cu of different concentrations affected the effect of fractions of leaves and roots on Cu.Effect of leaves and roots on subcellular distribution of Cu were different.Cell wall binding and vacuolar compartmentalization in the soluble fraction are main tolerance mechanisms for Cu in wheat.