Hepworth Jo, Antoniou-Kourounioti Rea L, Bloomer Rebecca H, Selga Catja, Berggren Kristina, Cox Deborah, Collier Harris Barley R, Irwin Judith A, Holm Svante, Säll Torbjörn, Howard Martin, Dean Caroline
John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
Department of Biology, Lund University, Sölvegatan 35, Lund, 223 62, Sweden.
Nat Commun. 2018 Feb 12;9(1):639. doi: 10.1038/s41467-018-03065-7.
Plants integrate widely fluctuating temperatures to monitor seasonal progression. Here, we investigate the temperature signals in field conditions that result in vernalisation, the mechanism by which flowering is aligned with spring. We find that multiple, distinct aspects of the temperature profile contribute to vernalisation. In autumn, transient cold temperatures promote transcriptional shutdown of Arabidopsis FLOWERING LOCUS C (FLC), independently of factors conferring epigenetic memory. As winter continues, expression of VERNALIZATION INSENSITIVE3 (VIN3), a factor needed for epigenetic silencing, is upregulated by at least two independent thermosensory processes. One integrates long-term cold temperatures, while the other requires the absence of daily temperatures above 15 °C. The lack of spikes of high temperature, not just prolonged cold, is thus the major driver for vernalisation. Monitoring of peak daily temperature is an effective mechanism to judge seasonal progression, but is likely to have deleterious consequences for vernalisation as the climate becomes more variable.
植物整合广泛波动的温度以监测季节进程。在此，我们研究了田间条件下导致春化作用的温度信号，春化作用是一种使开花与春季同步的机制。我们发现温度曲线的多个不同方面都对春化作用有贡献。在秋季，短暂的低温促进拟南芥开花位点C（FLC）的转录关闭，这与赋予表观遗传记忆的因素无关。随着冬季持续，表观遗传沉默所需的一个因子——春化作用不敏感3（VIN3）的表达通过至少两个独立的温度感应过程上调。一个过程整合长期低温，而另一个过程则要求每日温度不高于15°C。因此，缺乏高温峰值，而不仅仅是长期低温，才是春化作用的主要驱动因素。监测每日最高温度是判断季节进程的有效机制，但随着气候变得更加多变，这可能会对春化作用产生有害影响。
