OsABCB14 functions in auxin transport and iron homeostasis in rice (Oryza sativa L.).
OsABCB14 functions in auxin transport and iron homeostasis in rice (Oryza sativa L.).
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DOI：
10.1111/tpj.12544
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发表时间：
2014-07
期刊：
影响因子：
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通讯作者：
Yanxia Xu;Saina Zhang;Haipeng Guo;Suikang Wang;Ligen Xu;Chuanyou Li;Q. Qian;Fan Chen;Markus Geisler;Yanhua Qi;D. Jiang
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文献类型：
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作者：
Yanxia Xu;Saina Zhang;Haipeng Guo;Suikang Wang;Ligen Xu;Chuanyou Li;Q. Qian;Fan Chen;Markus Geisler;Yanhua Qi;D. Jiang
ATP 结合盒 B/多药耐药/P-糖蛋白 (ABCB/MDR/PGP) 亚家族的成员主要在水稻生长素运输中发挥作用；然而，尚未对任何水稻 ABCB 转运蛋白进行功能表征。在这里，我们描述了 OsABCB14 的敲低会导致生长素浓度和极性生长素转运速率降低，从而对 2,4-二氯苯氧基乙酸 (2,4-D) 和吲哚-3-乙酸 (IAA) 不敏感。 OsABCB14 在由水稻敲低等位基因制备的酵母和原生质体中表现出增强的特定生长素流入活性。 OsABCB14 定位于质膜，表明生理条件下具有重要的方向性。令人惊讶地发现 osabcb14 突变体对缺铁治疗 (-Fe) 不敏感。与野生型水稻（Nipponbare，NIP）相比，osabcb14 突变体中铁浓度更高，铁缺乏反应基因的上调更低。综上所述，我们的结果强烈支持 OsABCB14 作为参与 Fe 稳态的生长素流入转运蛋白的作用。 OsABCB14 的功能表征为单子叶植物生长素转运及其与铁营养的关系提供了见解。
Members of the ATP Binding Cassette B/Multidrug-Resistance/P-glyco-protein (ABCB/MDR/PGP) subfamily were shown to function primarily in Oryza sativa (rice) auxin transport; however, none of the rice ABCB transporters have been functionally characterized. Here, we describe that a knock-down of OsABCB14 confers decreased auxin concentrations and polar auxin transport rates, conferring insensitivity to 2,4-dichlorophenoxyacetic acid (2,4-D) and indole-3-acetic acid (IAA). OsABCB14 displays enhanced specific auxin influx activity in yeast and protoplasts prepared from rice knock-down alleles. OsABCB14 is localized at the plasma membrane, pointing to an important directionality under physiological conditions. osabcb14 mutants were surprisingly found to be insensitive to iron deficiency treatment (-Fe). Their Fe concentration is higher and upregulation of Fe deficiency-responsive genes is lower in osabcb14 mutants than in wild-type rice (Nipponbare, NIP). Taken together, our results strongly support the role of OsABCB14 as an auxin influx transporter involved in Fe homeostasis. The functional characterization of OsABCB14 provides insights in monocot auxin transport and its relationship to Fe nutrition.