A wheat gene encoding an aluminum-activated malate transporter
A wheat gene encoding an aluminum-activated malate transporter
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DOI：
10.1111/j.1365-313x.2003.01991.x
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发表时间：
2004-03-01
期刊：
影响因子：
7.2
通讯作者：
Matsumoto, H
中科院分区：
文献类型：
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作者：
Sasaki, T;Yamamoto, Y;Matsumoto, H
在酸性土壤中，植物生长的主要限制因素是有毒的铝（Al）阳离子的存在，它抑制根的伸长。一些小麦品种耐铝性的增强与苹果酸从根尖的铝依赖流出有关。苹果酸形成一个稳定的复合物与铝是无害的植物，因此，这种流出苹果酸的形式的基础上的一个假设来解释铝在小麦的耐受性。在这里，我们报告的克隆小麦基因，ALMT 1（铝激活的苹果酸转运蛋白），共分离与耐铝性的F-2和F-3群体来自近等基因小麦品系之间的杂交，不同的耐铝性。ALMT 1基因编码的膜蛋白，这是组成型表达在根尖的铝耐受线在更高的水平比近等基因，但铝敏感线。ALMT 1在非洲爪蟾卵母细胞，水稻和培养的烟草细胞中的异源表达赋予铝激活的苹果酸流出。此外，ALMT 1还提高了烟草细胞对铝处理的耐受性。这些研究结果表明，ALMT 1编码铝激活的苹果酸转运蛋白，能够赋予铝耐受植物细胞。
The major constraint to plant growth in acid soils is the presence of toxic aluminum (Al) cations, which inhibit root elongation. The enhanced Al tolerance exhibited by some cultivars of wheat is associated with the Al-dependent efflux of malate from root apices. Malate forms a stable complex with Al that is harmless to plants and, therefore, this efflux of malate forms the basis of a hypothesis to explain Al tolerance in wheat. Here, we report on the cloning of a wheat gene, ALMT1 (aluminum-activated malate transporter), that co-segregates with Al tolerance in F-2 and F-3 populations derived from crosses between near-isogenic wheat lines that differ in Al tolerance. The ALMT1 gene encodes a membrane protein, which is constitutively expressed in the root apices of the Al-tolerant line at greater levels than in the near-isogenic but Al-sensitive line. Heterologous expression of ALMT1 in Xenopus oocytes, rice and cultured tobacco cells conferred an Al-activated malate efflux. Additionally, ALMT1 increased the tolerance of tobacco cells to Al treatment. These findings demonstrate that ALMT1 encodes an Al-activated malate transporter that is capable of conferring Al tolerance to plant cells.