过量Fe^(2+)对大豆叶肉细胞超微结构的影响

Effect of excessive Fe2+ on leaf cells ultrastructure of soybean

研究了在过量Fe2+胁迫下,2个大豆[Glycine max(L.)Merrill]品种("浙春3号"和"1601")叶肉细胞超微结构的变化。观察发现,随着铁浓度的增加,"浙春3号"叶肉细胞超微结构损伤不断加重,叶绿体中出现巨型淀粉粒、被膜破损;线粒体嵴突减少或混乱,双层膜破裂;细胞质中液泡内含有膜系统片段;质膜向内折叠成波浪状。"1601"叶肉细胞在遭受低、中度铁毒时,叶绿体受损较轻,在高浓度铁毒下出现叶绿体被膜破裂、线粒体空泡化等现象。这些结果表明,过量Fe2+主要对细胞膜结构产生毒害作用;"浙春3号"对铁毒较为敏感。

The effect of excessive Fe2+ on plant growth and physiological characters were studied in our previous research. For a further investigation on the poisoning mechanism Fe2+ , the ultrastructure of the leave cells of Glycine max ( L. ) Merrill was observed in this paper. The change of ultrastructural under excessive Fe2 + stress for two soybean varieties, named as 'Zhechun No.3' and '1601' separately, was described. The results showed: with a increase of Fe2+ concentration, the ultrastructural damage on the 'Zhechun No. 3' leave cells unceasing aggravated; huge starch grains appeared in chloroplasts; granas became disordered; some cristae of mitochondria decreased or was chaos. As the results, the chloroplast and mitochondria membrane disrupted; and some fragments of membrane system were found in vacuoles of leaf cytoplasm. The plasmalemma folded entad forming wave shape. When leaf cells suffered low-middle degree Fe2+ poison, the concentration of Fe2+ being 100 mg/kg and 300 mg/kg, the chloroplast structure of '1601' was injured slightly. However, under high concentration Fe2+ poison, the accumulation of starch grains in the chloroplast, disruption of chloroplast membrane disrupted; disintegration of mitochondria cristae resulted in the vacuolization of mitochondria appeared in the leaf cells of '1601' . The results indicated that: excessive Fe2+ could injure the membranous structures of cells, among which the injury on chloroplast and mitochondria was more serious. Excessive Fe2+ caused the accumulation of starch grains in the chloroplast of leaf cells. The leaf cells ultrastructure of two soybean varieties had different response to Fe2+ poison, 'Zhechun No.3' soybean was more sensitive to Fe2+ .