Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan.
1] Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan [2] Graduate School of Science, Kobe University, 1-1 Rokkodai, Kobe 657-8501, Japan.
Nat Commun. 2014 Apr 22;5:3668. doi: 10.1038/ncomms4668.
Photoperiodic control of the phase transition from vegetative to reproductive growth is critical for land plants. The GIGANTEA (GI) and FLAVIN-BINDING KELCH REPEAT F-BOX1 (FKF1) protein complex controls this process in angiosperms. However, little is known about how plants evolved this regulatory system. Here, we report that orthologues of GI and FKF1 are present in a basal plant, the liverwort Marchantia polymorpha, and describe the molecular interaction between their products. Knockout of either the GI or FKF1 orthologue completely abolishes the long-day-dependent growth-phase transition in M. polymorpha. Overexpression of either gene promotes growth-phase transition, even under short-day conditions. Introduction of the GI orthologue partially rescues the late-flowering phenotype of the Arabidopsis thaliana gi mutant. Our findings suggest that plants had already acquired the GI-FKF1 system to regulate growth-phase transition when they colonized land, and that this system was co-opted from gametophyte to sporophyte generation during evolution.
光周期控制营养生长向生殖生长的转变是陆地植物生存的关键。在被子植物中，GI 和 FKF1 蛋白复合物控制着这一过程。然而，人们对植物如何进化出这种调控系统知之甚少。在这里，我们报告说，GI 和 FKF1 的同源物存在于一种基生植物——地钱中，并描述了它们产物之间的分子相互作用。GI 或 FKF1 同源物的敲除完全消除了地钱中长日依赖性的生长阶段转变。过表达任一基因，即使在短日条件下，也能促进生长阶段的转变。GI 同源物的引入部分挽救了拟南芥 gi 突变体的晚花表型。我们的研究结果表明，当植物在陆地上定殖时，它们已经获得了 GI-FKF1 系统来调节生长阶段的转变，并且在进化过程中，这个系统从配子体被共同进化到了孢子体世代。
