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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。
In order to understand the mechanism of detoxification and tolerance of Cu to wheat, the subcellular distribution of Cu in root and leaf of wheat at jointing stage was studied by pot experiment and differential centrifugation. The results showed that the content of Cu in root and leaf sub-cellular components increased with the increase of stress concentration under Cu stress. Cu was mainly concentrated in the root of wheat and less in the above-ground leaves. Cu content in the root of wheat was 1.7 to 4.1 times. The soluble cytoplasm and the cell wall were the major sites for the distribution of Cu in wheat cells, accounting for 36% -81% and 14% -48% of the total, respectively, with less distribution in organelles. Increasing concentrations of Cu increased the soluble portion of cytoplasm The segregation of Cu weakens the retention of Cu on the cell wall and decreases the distribution of Cu in organelles. The immobilization of Cu on the cell wall is stronger, and the soluble part of the cytoplasm of the root has a stronger effect on the partition of Cu. The analysis shows that cell wall sedimentation and cytoplasmic compartmentation play an important role in the tolerance of Cu to Cu.