Zinc finger protein STOP1 is critical for proton tolerance in Arabidopsis and coregulates a key gene in aluminum tolerance
Zinc finger protein STOP1 is critical for proton tolerance in Arabidopsis and coregulates a key gene in aluminum tolerance
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DOI：
10.1073/pnas.0700117104
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发表时间：
2007-06-05
影响因子：
11.1
通讯作者：
Kobayashi, Masatomo
中科院分区：
文献类型：
--
作者：
Iuchi, Satoshi;Koyama, Hiroyuki;Kobayashi, Masatomo
由于铝（Al 3+）等离子的根毒性，酸性土壤综合症会导致各种农作物的严重产量损失。虽然质子（H+）也可能是某些土壤类型中的主要根毒物质，但其耐受性的分子机制尚未确定。从甲基磺酸乙酯诱变的种子中分离到一个对H+根毒高度敏感的突变体，该突变体位于第1染色体上。基因组序列分析后的定位克隆显示，预测的CY 5（2）His（2）型锌指蛋白中锌指结构域的错义突变，即对质子根毒性敏感（STOP）1，是对H+根毒性超敏反应的原因。STOP 1蛋白属于锌指蛋白的一个功能未鉴定的亚家族，基于Blast搜索，该亚家族由拟南芥中的两个成员组成。stop 1突变对镉、铜、镧、锰和氯化钠的敏感性没有影响，但对Al ~（3+）的根毒性产生超敏反应。该突变体stop 1缺乏编码苹果酸转运蛋白的AtALMT 1基因的诱导，该基因伴随着Al诱导的苹果酸分泌。Al ~（3+）处理对stop 1突变体的AtALMT 1没有诱导作用。这些结果表明，STOP 1在拟南芥对酸性土壤中主要胁迫因子的耐受性中起着关键作用。
Acid soil syndrome causes severe yield losses in various crop plants because of the rhizotoxicities of ions, such as aluminum (Al3+). Although protons (H+) could be also major rhizotoxicants in some soil types, molecular mechanisms of their tolerance have not been identified yet. One mutant that was hypersensitive to H+ rhizo-toxicity was isolated from ethyl methanesulfonate mutagenized seeds, and a single recessive mutation was found on chromosome 1. Positional cloning followed by genomic sequence analysis revealed that a missense mutation in the zinc finger domain in a predicted CY5(2)His(2)-type zinc finger protein, namely sensitive to proton rhizotoxicity (STOP)1, is the cause of hypersensitivity to H+ rhizotoxicity. The STOP1 protein belongs to a functionally unidentified subfamily of zinc finger proteins, which consists of two members in Arabidopsis based on a Blast search. The stop1 mutation resulted in no effects on cadmium, copper, lanthanum, manganese and sodium chloride sensitivitities, whereas it caused hypersensitivity to Al3+ rhizotoxicity. This stop1 mutant lacked the induction of the AtALMT1 gene encoding a malate transporter, which is concomitant with Al-indluced malate exudation. There was no induction of AtALMT1 by Al3+ treatment in the stop1 mutant. These results indicate that STOP1 plays a critical role in Arabidopsis tolerance to major stress factors in acid soils.