STOP1, a Cys2/His2 type zinc-finger protein, plays critical role in acid soil tolerance in Arabidopsis
STOP1, a Cys2/His2 type zinc-finger protein, plays critical role in acid soil tolerance in Arabidopsis
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DOI：
10.4161/psb.3.2.5037
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发表时间：
2008-01-01
影响因子：
2.9
通讯作者：
Kobayashi, Masatomo
中科院分区：
文献类型：
--
作者：
Iuchi, Satoshi;Kobayashi, Yuriko;Kobayashi, Masatomo
在酸性土壤条件下，铝和质子等根毒离子通过抑制根的生长和/或增强对干旱胁迫的敏感性，导致粮食和生物量生产的严重产量损失。因此，提高作物对根毒离子的耐受性将是作物育种的重要目标，而识别调控作物对铝和质子离子的耐性的关键基因将为解决这一限制提供解决方案。我们最近分离到了一个在根生长中对质子高度敏感的突变体，即stop1(对质子根毒性敏感)。通过测定低pH(pH 4.3)条件下的根生长，从甲烷磺酸乙酯诱变菌株中分离到stop1突变体。有趣的是，stop1对铝离子也表现出超敏反应，但对其他根毒害离子不敏感。STOP1基因的克隆表明，它编码一个Cys2/His2锌指型转录因子，并且该突变基因预测的氨基酸序列中保守的His残基被Tyr取代。这表明STOP1参与了质子和铝耐受的信号转导途径。事实上，在酸性条件下，stop1未能诱导编码铝耐受性的主要因素之一的AtALMT1基因。通过检索公共数据库，我们已经在水稻、玉米等植物中发现了与STOP1同源的基因。因此，STOP1家族基因可能是多种植物耐酸性的关键因素。
Under acid soil condition, rhizotoxic ions such as aluminum and protons cause severe yield loss in food and biomass production via inhibition of root growth and/or enhancement of sensitivity to drought stress. Therefore, improvement of crop tolerance to rhizotoxic ions would be an important target for crop breeding, and identification of key genes that regulate tolerance to both aluminum and proton ions should provide a solution to this limitation. We recently isolated a mutant that shows hyper-sensitivity to protons in root growth, namely stop1 (sensitive to proton rhizotoxicity). The stop1 mutant was isolated from an ethyl methanesulfonate mutagenized population by measuring root growth under low pH (pH 4.3). Interestingly, stop1 also shows hypersensitivity to aluminum ion, but not to other rhizotoxic ions. Cloning of the STOP1 gene revealed that it encodes a Cys2/His2 zinc-finger type transcription factor, and a conserved His residue was replaced with Tyr in the predicted amino acid sequence for the mutant gene. This indicates that STOP1 is involved in the signal transduction pathway of proton and aluminum tolerance. Indeed, under acidic condition, stop1 failed to induce the AtALMT1 gene, which encodes one of the major factors for aluminum tolerance. By searching a public database, we have identified genes homologous to STOP1 in rice, maize and some other plants. Thus, the STOP1 family genes may act as a key factor for acid tolerance in a wide variety of plants.