缺铁水稻根细胞膜泡相关基因群的分析与电镜观察

Gene groups analysis relevant to membrane vesicles and electron microscopic observation of rice roots under Fe-deficiency condition

在缺铁固体培养基中,可清楚地观察到水稻根表面的分泌物和根的形态变化以及侧根增多。为了从分子水平深入了解水稻受缺铁胁迫后的反应机理,对缺铁水稻根进行了10531个EST芯片的微点阵分析,发现膜泡相关的基因群相对转录表达率最高。利用超薄切片技术,在透射电镜下观察了缺铁胁迫下水稻根尖细胞的结构变化。结果显示:缺铁根尖细胞中,膜泡好似起源于质膜和囊泡的组装,然后在质膜上凸起,并且是双方向性的。膜泡表面有衣被。虽然正常供铁情况下也有膜泡出现,但与缺铁比较有很大区别。缺铁根尖细胞的膜泡明显大,膜泡和凹陷泡上有较清晰的衣被。同时还观察到在单层膜的膜泡内有管状和圆球形的内含物质。内含物的来源有可能,至少是部分通过内吞作用来源于细胞外基质。

It was visualized that the secretory materials on the surface of rice roots and root morphological changes including more side roots with phytagel medium added iron-free nutrient solution. Micrearray methods were employed through the use of a EST collection representing 10531 individual gene sequences for understanding deeply the strategy responded to iron-lack stress. The highest ratio of - Fe/＋ Fe of transcripts relevant membrane vesicle were found among the whole up-regulated cDNAs . The vesicle changes of rice root apices under both Fe-deficiency and EDTA-Fe treatment were seen respectively using electron microscopy. It seems that the membrane vesicles originate from an assembly of membranes and vesicles, and then Protruded to the inside and outside of the plasma membrane. The coat appears to be present on all the above ground vesicles. Although membrane vesicle were also shown in rice root cells of ＋ Fe treatment, such a vesicles were quite distinguishable from in Fe-deficiency＇s because they were extensively involved with large, clearly detailed coat vesicles, and coated invaginations. The contents of single membrane-bound vesicles has two components, that is either tubular or solid and a fibrous or granular. The content material appears to be at least partially derived, via endocytosis, from extracellular matrix（ ECM）.