Poplar FT2 shortens the juvenile phase and promotes seasonal flowering
Poplar FT2 shortens the juvenile phase and promotes seasonal flowering
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DOI：
10.1105/tpc.106.041038
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发表时间：
2006-08-01
期刊：
影响因子：
11.6
通讯作者：
Yuceer, Cetin
中科院分区：
文献类型：
--
作者：
Hsu, Chuan-Yu;Liu, Yunxia;Yuceer, Cetin
许多木本多年生植物，如杨树，在其生活史的头几年不能形成花芽。它们必须经历从幼年阶段到生殖阶段的过渡，才能有能力产生花蕾。在这一过渡之后，树木开始在每个生长季的春天形成花蕾。在杨树中，控制花启动、结束幼虫阶段的遗传因素是未知的。调节季节性花蕾形成的因素也是未知的。在这里，我们报道了杨树开花基因T2(FT2)，它是拟南芥开花时间基因FT的近缘基因，控制着杨树的第一次开花和季节性开花。在杨树幼龄期，FT2转录本是罕见的。用FT2转化杨树幼树，提高转录量，可在1年内诱导开花。在成熟树营养生长向生殖生长过渡的过程中，在长日照条件下的生殖生长过程中，FT2转录本含量较高。随后，花分生组织出现在腋生花序的侧枝上。这些发现表明，FT2是杨树开花途径的一部分，在调节与杨树多年生生长习性相结合的季节性花起始方面起着额外的作用。
Many woody perennials, such as poplar (Populus deltoides), are not able to form flower buds during the first several years of their life cycle. They must undergo a transition from the juvenile phase to the reproductive phase to be competent to produce flower buds. After this transition, trees begin to form flower buds in the spring of each growing season. The genetic factors that control flower initiation, ending the juvenile phase, are unknown in poplar. The factors that regulate seasonal flower bud formation are also unknown. Here, we report that poplar FLOWERING LOCUS T2 (FT2), a relative of the Arabidopsis thaliana flowering-time gene FT, controls first-time and seasonal flowering in poplar. The FT2 transcript is rare during the juvenile phase of poplar. When juvenile poplar is transformed with FT2 and transcript levels are increased, flowering is induced within 1 year. During the transition between vegetative and reproductive growth in mature trees, FT2 transcripts are abundant during reproductive growth under long days. Subsequently, floral meristems emerge on flanks of the axillary inflorescence shoots. These findings suggest that FT2 is part of the flower initiation pathway in poplar and plays an additional role in regulating seasonal flower initiation that is integrated with the poplar perennial growth habit.