Overexpression of an auxilin-like gene (F9E10.5) can suppress Al uptake in roots of Arabidopsis
Overexpression of an auxilin-like gene (F9E10.5) can suppress Al uptake in roots of Arabidopsis
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DOI：
10.1093/jxb/erl221
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发表时间：
2007-02-01
影响因子：
6.9
通讯作者：
Nakashima, Susumu
中科院分区：
文献类型：
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作者：
Ezaki, Bunichi;Kiyohara, Hiroyuki;Nakashima, Susumu
从拟南芥增强子标记的突变体系中分离出抗铝胁迫的植物。与亲本Col-7对照相比，抗性候选系#355-2的F9 E10. 5基因（At 1g 75100）在第1染色体上的表达量较高，全根铝含量较低，根毛长度较短（约为30%）。铝流入和相关的氧化胁迫发生在根毛，以及在根尖的Col-7，然而，他们只看到在根尖#355-2。过量表达F9E10.5基因的转基因植株表现出比亲本对照（Ler）略高的抗铝性。F9E10.5基因编码一种生长素样蛋白，与胞吞作用中的网格蛋白脱壳过程有关。显微镜观察表明，与Col-7相比，#355-2系根毛细胞中的铝离子内流和内吞活性均较低。这些结果表明，这种生长素样蛋白的过表达抑制根毛细胞的内吞作用的运输系统的干扰，如在动物细胞中显示先前。这也表明，一部分铝流入发生在根毛细胞的内吞作用。因此，#355-2品系中的铝抗性可能是由于根毛区域中通过内吞作用的较低的铝吸收。
Plants resistant to aluminium (Al) stress were isolated from Arabidopsis thaliana enhancer-tagged mutant lines. Compared with the parental Col-7 control line, one of the resistant candidates, #355-2, showed a higher expression of the F9E10.5 gene (At1g75100) on chromosome 1, a lower Al content in whole roots, and a shorter root hair length (similar to 30%). Both Al influx and associated oxidative stress occurred in root hairs, as well as in root tips of Col-7; however, they were seen only in root tips of #355-2. Transgenic plants overexpressing the F9E10.5 gene showed a slightly higher Al resistance than their parental control line (Ler). The F9E10.5 gene encodes an auxilin-like protein related to the clathrin-uncoating process in endocytosis. Microscopic observation indicated that both Al ion influx and endocytosis activity were lower in root hair cells of the #355-2 line than in those of Col-7. These results suggested that overexpression of this auxilin-like protein inhibits endocytosis in root hair cells by a disturbance of the transport system as in animal cells shown previously. It was also suggested that a part of the Al influx occurred via endocytosis in root hair cells in Arabidopsis. The Al resistance in the #355-2 line may therefore be due to a lower Al uptake via endocytosis in the root hair region.