Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan.
J Plant Res. 2012 Sep;125(5):643-51. doi: 10.1007/s10265-012-0477-7. Epub 2012 Feb 4.
The phytohormone auxin plays a pivotal role in various developmental aspects in land plants. However, little is known of the auxin response and distribution in non-vascular plants. In this study, we made transgenic plants of the liverwort Marchantia polymorpha which express the uidA (GUS) reporter gene under control of the soybean auxin-inducible promoter, ProGH3, and used it to indirectly monitor auxin-mediated transcriptional activation in planta. Transgenic plants carrying ProGH3:GUS showed GUS activity in an auxin-dependent manner. Histochemical GUS staining was observed at the bottom of gemma cups in the process of vegetative propagation. Significant GUS activity was also detected around the gametophyte-sporophyte junction as well as the developing sporophyte after fertilization. These results suggest that the activity of auxin is crucial in both gametophyte and sporophyte development in M. polymorpha, and that the mechanism for auxin-mediated transcriptional activation had already been established when plants emerged on the terrestrial environment.
植物激素生长素在陆生植物的各种发育方面发挥着关键作用。然而，对于非维管束植物中的生长素反应和分布知之甚少。在这项研究中，我们构建了表达 uidA（GUS）报告基因的地钱 Marchantia polymorpha 转基因植物，该基因受大豆生长素诱导启动子 ProGH3 的控制，并将其用于间接监测植物体内生长素介导的转录激活。携带 ProGH3:GUS 的转基因植物以生长素依赖的方式表现出 GUS 活性。在营养繁殖过程中，在芽杯的底部观察到组织化学 GUS 染色。在配子体-孢子体交界处以及受精后发育的孢子体周围也检测到显著的 GUS 活性。这些结果表明，生长素的活性在 M. polymorpha 的配子体和孢子体发育中都至关重要，并且当植物出现在陆地环境中时，生长素介导的转录激活机制已经建立。
