Two Genes Encoding a Bacterial-Type ATP-Binding Cassette Transporter are Implicated in Aluminum Tolerance in Buckwheat
Two Genes Encoding a Bacterial-Type ATP-Binding Cassette Transporter are Implicated in Aluminum Tolerance in Buckwheat
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DOI：
10.1093/pcp/pcy171
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发表时间：
2018-12-01
影响因子：
4.9
通讯作者：
Ma, Jian Feng
中科院分区：
文献类型：
--
作者：
Che, Jing;Yamaji, Naoki;Ma, Jian Feng
荞麦（Fagopyrum esculentum Moench）对铝毒具有较强的耐受性，但其耐铝的分子机制尚不清楚。在这里，我们功能上的特点是两个基因（FeSTAR 1和FeSTAR 2），这两个基因分别编码一个核苷酸结合域和一个膜结构域，细菌型ATP结合盒（ABC）转运蛋白。FeSTAR 1和FeSTAR 2在根和叶中的表达均受Al诱导，但在根中的表达量较高。空间和组织特异性表达分析表明，铝诱导的这两个基因在根尖和根基部均有表达，在根外细胞层表达量较高。表达既不诱导其他金属，包括镉和镧，也不诱导低pH和缺磷。FeSTAR 1和FeSTAR 2在水稻和拟南芥中均以单拷贝存在，但铝诱导的FeSTAR 1和FeSTAR 2转录本拷贝数远高于其同源基因。FeSTAR 1和FeSTAR 2在洋葱表皮细胞中共表达时形成复合物。将FeSTAR 1和FeSTAR 2分别导入拟南芥突变体atstar 1和als 3/atstar 2中，可以挽救突变体对铝的敏感性。综上所述，我们的研究结果表明FeSTAR 1和FeSTAR 2参与了荞麦的铝耐性，它们的高表达水平可能有助于荞麦的高铝耐性。
Buckwheat (Fagopyrum esculentum Moench) shows high tolerance to aluminum (Al) toxicity, but the molecular mechanisms underlying its high Al tolerance are poorly understood. Here, we functionally characterized two genes (FeSTAR1 and FeSTAR2), which encode a nucleotide-binding domain and a membrane domain, respectively, of a bacterial-type ATP-binding cassette (ABC) transporter. The expression of FeSTAR1 and FeSTAR2 was induced by Al in both roots and leaves with higher expression in the roots. Spatial and tissue-specific expression analysis showed that the Al-induced expression of these two genes was found in both the root tips and basal root regions with higher expression in the root outer cell layers. The expression was neither induced by other metals including Cd and La nor by low pH and phosphorus-deficiency. FeSTAR1 and FeSTAR2 were present in a single copy in the genome, but the Al-induced transcript copy number of FeSTAR1 and FeSTAR2 was much higher than their homologous genes in rice and Arabidopsis. FeSTAR1 and FeSTAR2 form a complex when co-expressed in onion epidermal cells. Introduction of FeSTAR1 and FeSTAR2 into Arabidopsis mutants atstar1 and als3/atstar2, respectively, rescued the sensitivity of the mutants to Al. Taken together, our results indicate that FeSTAR1 and FeSTAR2 are involved in Al tolerance and that their high expression level may contribute to high Al tolerance in buckwheat.