铝胁迫对小麦胚诱导及超微结构的影响

Effects of Aluminium Stress on Embryo Induction Frequency and Cell Ultra-structure of Wheats (Triticum aestivum)

目的：铝毒害在酸性土壤中普遍存在,已经成为影响小麦产量和品质的重要因素,因此小麦铝毒害与耐铝分子机制的研究逐渐成为了小麦抗逆研究的热点内容之一。从细胞水平上阐明铝毒害的机理。方法：设置了3种铝浓度梯度(100、200 300μmol/1),通过组织培养及透射电镜的方法观察了铝对铝敏感材料Scout66,耐铝材料Adas66及湖北主栽品种EM12胚发生阶段及超微结构的影响。结果：铝降低了胚的诱导率,抑制了胚的进一步分化,其中幼胚的诱导率从对照的94．0%降到了25．3% (300μmaol/1),成熟胚的诱导率从对照的75．0%降到了17．3%(300μtmol/1)；铝严重破坏了小麦根尖的超微结构,与对照相比,最明显的变化是细胞核结构变得不完整,同时空泡增多,线粒体数量增加,脊的结构变模糊甚至消失。结论：以上结果说明铝破坏了细胞的超微结构,特别是细胞核和线粒体结构的破坏阻止了细胞的进一步分裂和分化。

Objective：Aluminum toxicity in acidic soil is a serious problem worldwide, which results in poor quality and big loss of wheat production. Therefore, studies on the molecular mechanism of Aluminum tolerence has become one of the important tasks in wheat stress resistance research.Methods：In this study, hexaploid wheats Al- sensitive cultivar Scout66 , Al- tolerant cultivar Atlas66 and an elite wheat cultivar in Hebei province EM12 were analyzed embryo induction frequency and changes in cell ultra- structure under different concentrations of Aluminum ion stress by tissue culture method and transmission electron microscopy （TEM） method respectively.Results： The results showed that Al stress reduced the embryo induction frequency and restrained the differentiation of embryo （ immature embryo induction reduced from 94.0% to 25.3% ; mature embryo induction reduced from 75.0% to 17.3% ）; Al stress badly destroyed the ultra- structure d root tip cells, the nucleus changed uneven, the numbers of vacuole and mitochondria increased but cfista of mitochondria changed unclear and almost disappeared. Conclusion： Based on the above- result, the conclusion can be drawn out that Al damages the cell ultra- structure especially in nucleus and mitochondria, which implies that the damage of cell ultra- structure is probably the key factor in Al inhibition of cell differentiation and division.