Santelia Diana, Vincenzetti Vincent, Azzarello Elisa, Bovet Lucien, Fukao Yoichiro, Düchtig Petra, Mancuso Stefano, Martinoia Enrico, Geisler Markus
Zurich-Basel Plant Science Center, Institute of Plant Biology, Molecular Plant Physiology, University of Zürich, Switzerland.
FEBS Lett. 2005 Oct 10;579(24):5399-5406. doi: 10.1016/j.febslet.2005.08.061.
Previous data have suggested an involvement of MDR/PGP-like ABC transporters in transport of the plant hormone auxin and, recently, AtPGP1 has been demonstrated to catalyze the primary active export of auxin. Here we show that related isoform AtPGP4 is expressed predominantly during early root development. AtPGP4 loss-of-function plants reveal enhanced lateral root initiation and root hair lengths both known to be under the control of auxin. Further, atpgp4 plants show altered sensitivities toward auxin and the auxin transport inhibitor, NPA. Finally, mutant roots reveal elevated free auxin levels and reduced auxin transport capacities. These results together with yeast growth assays suggest a direct involvement of AtPGP4 in auxin transport processes controlling lateral root and root hair development.
先前的数据表明，多药耐药/类P-糖蛋白ABC转运蛋白参与植物激素生长素的运输，最近，已证明AtPGP1催化生长素的初级主动输出。在此，我们表明相关异构体AtPGP4主要在根早期发育过程中表达。AtPGP4功能缺失型植株表现出侧根起始增强和根毛长度增加，这两者均受生长素调控。此外，atpgp4植株对生长素和生长素运输抑制剂NPA的敏感性发生改变。最后，突变根显示游离生长素水平升高，生长素运输能力降低。这些结果与酵母生长试验共同表明，AtPGP4直接参与控制侧根和根毛发育的生长素运输过程。
