Molecular Ecology of Flowering Regulation Pathways: Flowering Regulation in the Natural Conditions

环境温度和光周期是植物感知季节的主要信号。与日历上光周期的可预测性相反，温度的季节性模式只是作为一种长期趋势出现。因此，植物需要一个对温度变化的长期趋势敏感但对短期波动敏感的分子系统。在这里，我们证明了聚梳组(PcG)蛋白介导的转录因子花序C(FLC)是多年生植物生活史中环境温度波动的长期整合的关键机制。我们量化了自然生长植物叶片中FLC的表达，每隔大约一周在多年生拟南芥自然种群中表达一年。发菜属植物。与一年一度的A.thaliana所知相反，FLC抑制的重置发生在多年生生活史中没有经过世代的情况下。FLC水平与一年中过去约5周的温度变化高度相关，FLC的抑制和增加都是温度相关的。FLC表达的季节模式不仅与营养-生殖转换的时间相对应，而且也与反向转换的时间相对应。我们的结论是，FLC不是对冬季的记忆，而是更具包容性地作为长期温度波动的定量示踪剂，用于在多年生生命周期中控制季节相位。

Ambient temperature and photoperiod are known to be the major cues for plants to sense seasons. Contrary to the predictable nature of photoperiod along the calendar, the seasonal pattern of temperature only appears as a long-term trend. Therefore, plants require a molecular system that is sensitive to the long-term trend of temperature change but to the short-term fluctuations. Here we show that the Polycomb group (PcG) protein mediated transcription factor, FLOWERING LOCUS C (FLC), serves as a key mechanism for long-term integration of fluctuating ambient temperature in the perennial life cycle. We quantified FLC expression in leaves of naturally growing plants for a year at ca. one week intervals in a natural population of the perennial Arabidopsis halleri ssp. gemmifera. Contrary to what is known in the annual A. thaliana, reset of FLC repression occurs without passing generation in the perennial life cycle. FLC levels were highly associated with temperature regimes for past ca. 5 weeks throughout the year, and both suppression and increment of FLC were temperature-dependent. The seasonal pattern in FLC expression corresponded not only to the timing of vegetative-reproductive transition but also to the timing of the reverse transition. We concluded that FLC is not mealy a memory of winter but have more inclusive role as a quantitative tracer of long-term temperature fluctuation for seasonal phase control in the perennial life-cycle.