Dipartimento di Biologia, Università degli Studi di Milano, via Celoria 26, 20133 Milano, Italy.
Plant J. 2011 Sep;67(6):1006-17. doi: 10.1111/j.1365-313X.2011.04653.x. Epub 2011 Jul 1.
The floral transition is the switch from vegetative development to flowering. Proper timing of the floral transition is regulated by different pathways and is critical for the reproductive success of plants. Some of the flowering pathways are controlled by environmental signals such as photoperiod and vernalization, others by autonomous signals such as the developmental state of the plant and hormones, particularly gibberellin. SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1) acts in Arabidopsis as an integrative centre of these pathways, promoting the floral transition. In this work, we show that AGAMOUS-LIKE 42 (AGL42), AGAMOUS-LIKE 71 (AGL71) and AGAMOUS-LIKE 72 (AGL72), which encode MADS-box transcription factors phylogenetically closely related to SOC1, are also involved in the floral transition. They promote flowering at the shoot apical and axillary meristems and seem to act through a gibberellin-dependent pathway. Furthermore SOC1 directly controls the expression of AGL42, AGL71 and AGL72 to balance the expression level of these SOC1-like genes. Our data reveal roles for AGL42, AGL71 and AGL72 in the floral transition, demonstrate their genetic interactions with SOC1 and suggest that their roles differ in the apical and axillary meristems.
花发育转变是植物从营养生长向生殖生长的转变。花发育转变的适时发生受不同途径调控，对植物的生殖成功至关重要。一些开花途径受环境信号（如光周期和春化作用）控制，而另一些途径则受自主信号（如植物的发育状态和激素，特别是赤霉素）控制。拟南芥中的 CO 1 表达抑制子（SOC1）作为这些途径的整合中心，促进花发育转变。在这项工作中，我们表明，MADS 盒转录因子 AGAMOUS-LIKE 42（AGL42）、AGAMOUS-LIKE 71（AGL71）和 AGAMOUS-LIKE 72（AGL72），它们在系统发育上与 SOC1 密切相关，也参与花发育转变。它们在茎尖和腋芽分生组织中促进开花，并似乎通过赤霉素依赖途径发挥作用。此外，SOC1 直接控制 AGL42、AGL71 和 AGL72 的表达，以平衡这些 SOC1 样基因的表达水平。我们的数据揭示了 AGL42、AGL71 和 AGL72 在花发育转变中的作用，证明了它们与 SOC1 的遗传相互作用，并表明它们在茎尖和腋芽分生组织中的作用不同。
