The BnALMT1 and BnALMT2 genes from rape encode aluminum-activated malate transporters that enhance the aluminum resistance of plant cells
The BnALMT1 and BnALMT2 genes from rape encode aluminum-activated malate transporters that enhance the aluminum resistance of plant cells
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DOI：
10.1104/pp.106.085233
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发表时间：
2006-11-01
期刊：
影响因子：
7.4
通讯作者：
Matsumoto, Hideaki
中科院分区：
文献类型：
--
作者：
Ligaba, Ayalew;Katsuhara, Maki;Matsumoto, Hideaki
植物根系释放的有机阴离子可以保护植物免受铝毒害，并帮助植物克服磷缺乏。我们以前的研究结果表明，铝处理诱导苹果酸和柠檬酸从油菜（甘蓝型油菜）根的流出，和磷缺乏没有引起的流出。由于这种反应是类似的苹果酸从小麦（小麦），是由TaALMT1基因控制的流出，我们调查是否同源TaALMT1存在于油菜和它们是否参与释放有机阴离子。我们从油菜中分离到两个TaALMT 1同源物，命名为BnALMT 1和BnALMT 2（B. napus A1激活的苹果酸转运蛋白）。这些基因的表达诱导根，而不是芽，铝处理，但磷缺乏没有影响。其他几种阳离子（镧、镱和铒）也增加了BnALMT1和BnALMT2在根中的表达。通过在培养的烟草（Nicotiana tabacum）细胞和非洲爪蟾卵母细胞中异源表达来研究BnALMT 1和BnALMT 2蛋白的功能。两种转染系统表现出增强的能力，苹果酸外排，但不是柠檬酸外排，当暴露于铝。较小的苹果酸通量也激活镱和铒治疗。转基因烟草细胞生长显着优于对照细胞铝处理18 h后，表明BnALMT1和BnALMT2的表达增加了这些植物细胞对铝胁迫的抗性。这份报告表明，同源的TaALMT1基因从小麦在其他物种中执行类似的功能。
The release of organic anions from roots can protect plants from aluminum (Al) toxicity and help them overcome phosphorus ( P) deficiency. Our previous findings showed that Al treatment induced malate and citrate efflux from rape ( Brassica napus) roots, and that P deficiency did not induce the efflux. Since this response is similar to the malate efflux from wheat ( Triticum aestivum) that is controlled by the TaALMT1 gene, we investigated whether homologs of TaALMT1 are present in rape and whether they are involved in the release of organic anions. We isolated two TaALMT1 homologs from rape designated BnALMT1 and BnALMT2 (B. napus Al-activated malate transporter). The expression of these genes was induced in roots, but not shoots, by Al treatment but P deficiency had no effect. Several other cations ( lanthanum, ytterbium, and erbium) also increased BnALMT1 and BnALMT2 expression in the roots. The function of the BnALMT1 and BnALMT2 proteins was investigated by heterologous expression in cultured tobacco ( Nicotiana tabacum) cells and in Xenopus laevis oocytes. Both transfection systems showed an enhanced capacity for malate efflux but not citrate efflux, when exposed to Al. Smaller malate fluxes were also activated by ytterbium and erbium treatment. Transgenic tobacco cells grew significantly better than control cells following an 18 h treatment with Al, indicating that the expression of BnALMT1 and BnALMT2 increased the resistance of these plant cells to Al stress. This report demonstrates that homologs of the TaALMT1 gene from wheat perform similar functions in other species.