Sidler M, Hassa P, Hasan S, Ringli C, Dudler R
Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland.
Plant Cell. 1998 Oct;10(10):1623-36. doi: 10.1105/tpc.10.10.1623.
In the dark, plant seedlings follow the skotomorphogenetic developmental program, which results in hypocotyl cell elongation. When the seedlings are exposed to light, a switch to photomorphogenetic development occurs, and hypocotyl cell elongation is inhibited. We have manipulated the expression of the AtPGP1 (for Arabidopsis thaliana P glycoprotein1) gene in transgenic Arabidopsis plants by using sense and antisense constructs. We show that within a certain light fluence rate window, overexpression of the AtPGP1 gene under the control of the cauliflower mosaic virus 35S promoter causes plants to develop longer hypocotyls, whereas expression of the gene in antisense orientation results in hypocotyls shorter than those occurring in the wild type. In the dark, hypocotyls of transgenic and wild-type plants are indistinguishable. Because the AtPGP1 gene encodes a member of the superfamily of ATP binding cassette-containing (ABC) transporters, these results imply that a transport process is involved in a hypocotyl cell elongation pathway active in the light. The AtPGP1 transporter is localized in the plasmalemma, as indicated by immunohistochemical techniques and biochemical membrane separation methods. Analysis of the AtPGP1 expression pattern by using reporter gene constructs and in situ hybridization shows that in wild-type seedlings, AtPGP1 is expressed in both the root and shoot apices.
在黑暗中，植物幼苗遵循暗形态建成发育程序，这会导致下胚轴细胞伸长。当幼苗暴露于光照下时，会发生向光形态建成发育的转变，下胚轴细胞伸长受到抑制。我们通过使用正义和反义构建体来操纵转基因拟南芥植物中AtPGP1（拟南芥P糖蛋白1）基因的表达。我们发现，在一定的光通量率窗口内，在花椰菜花叶病毒35S启动子控制下AtPGP1基因的过表达会使植物发育出更长的下胚轴，而反义方向的基因表达则导致下胚轴比野生型的更短。在黑暗中，转基因植物和野生型植物的下胚轴没有区别。由于AtPGP1基因编码含ATP结合盒（ABC）转运蛋白超家族的一个成员，这些结果表明，一种转运过程参与了在光照下起作用的下胚轴细胞伸长途径。免疫组织化学技术和生化膜分离方法表明，AtPGP1转运蛋白定位于质膜。通过使用报告基因构建体和原位杂交分析AtPGP1的表达模式表明，在野生型幼苗中，AtPGP1在根和茎尖均有表达。
