Arabidopsis ALS1 encodes a root tip and stele localized half type ABC transporter required for root growth in an aluminum toxic environment
Arabidopsis ALS1 encodes a root tip and stele localized half type ABC transporter required for root growth in an aluminum toxic environment
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DOI：
10.1007/s00425-006-0452-4
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发表时间：
2007-05-01
期刊：
影响因子：
4.3
通讯作者：
Ochoa, Vanessa
中科院分区：
文献类型：
--
作者：
Larsen, Paul B.;Cancel, Jesse;Ochoa, Vanessa
酸性土壤中的铝毒通过抑制根的生长，从而抑制新梢的发育，严重限制了作物的生产力。一些拟南芥突变体先前被确定为具有A1超敏反应的根，这表明这些代表有害的突变影响A1耐受性或抗性机制所需的基因。对于本报告，选择als 1 -1突变体进行进一步表征。als 1 -1的表型最明显地呈现在A1挑战的根中，如通过与wt相比，与A1响应基因的表达增加相结合的夸张的根生长抑制所证明的。使用基于图位的克隆方法，分离出als 1 -1突变，发现其代表了先前未表征的半型ABC转运蛋白At 5g 39040中的有害氨基酸取代，At 5g 39040在所有测试器官中以非A1依赖性方式表达。GUS依赖性分析表明，ALS 1的表达主要定位于根尖和整个植物的脉管系统。与此同时，ALS 1：GFP融合积累在液泡膜的根细胞，表明ALS 1可能是重要的细胞内运动的一些基板，可能螯合A1，作为A1隔离机制的一部分。
Aluminum toxicity in acid soils severely limits crop productivity through inhibition of root growth and, consequently, shoot development. Several Arabidopsis mutants were previously identified as having roots with A1 hypersensitivity, suggesting that these represent deleterious mutations affecting genes required for either A1 tolerance or resistance mechanisms. For this report, the als1-1 mutant was chosen for further characterization. The phenotype of als1-1 is most obviously presented in A1 challenged roots, as evidenced by exaggerated root growth inhibition in conjunction with increased expression of A1-responsive genes compared to wt. Using a map-based cloning approach, the als1-1 mutation was isolated and found to represent a deleterious amino acid substitution in a previously uncharacterized half type ABC transporter, At5g39040, which is expressed in a non-A1 dependent manner in all organs tested. GUS-dependent analyses revealed that ALS1 expression is primarily localized to the root tip and the vasculature throughout the plant. Concomitant with this, an ALS1: GFP fusion accumulates at the vacuolar membrane of root cells, indicating that ALS1 may be important for intracellular movement of some substrate, possibly chelated A1, as part of a mechanism of A1 sequestration.