英国约翰英纳斯中心Martin Howard和Caroline Dean小组合作在研究中取得进展。他们的最新研究揭示温度依赖性生长有助于植物长期对寒冷的感知。这一研究成果于2020年7月15日在线发表在国际学术期刊《自然》上。
通过正向遗传筛选，研究人员发现了转录因子NTL8的两个显性突变，它们组成型激活了VERNALIZATION INSENSITIVE 3（VIN3）的表达并改变了VIN3的冷诱导曲线。在野生型植物中，NTL8蛋白在寒冷中缓慢积累，并直接上调VIN3转录。通过计算仿真和实验验证相结合的方法，研究人员证明这种缓慢累积的主要是由于在低温下条件下植物缓慢生长导致NTL8稀释度降低造成的。因此，通过蛋白质稀释来利用温度依赖性生长为VIN3上调提供了长期的热感信息。除直接热感外，在自然波动温度的长期感知中与温度依赖性生长有关的间接机制也可能参与其中。
据了解，温度是影响所有生物生长和发育的关键因素。植物必须感知每小时至每月时间范围内的温度波动，以使其生长和发育适应季节。关于植物如何应对急性热胁迫的研究很多，但是植物适应长期温度变化的机制仍然未知。VIN3是一种PHD蛋白，它在冬季缓慢上调，在春化过程中与多梳抑制复合物一起在表观遗传上沉默开花抑制基因（FLC），这对理解植物冬季进程至关重要。
附：英文原文
Title: Temperature-dependent growth contributes to long-term cold sensing
Author: Yusheng Zhao, Rea L. Antoniou-Kourounioti, Grant Calder, Caroline Dean, Martin Howard
Issue&Volume: 2020-07-15
Abstract: Temperature is a key factor in the growth and development of all organisms1,2. Plants have to interpret temperature fluctuations, over hourly to monthly timescales, to align their growth and development with the seasons. Much is known about how plants respond to acute thermal stresses3,4, but the mechanisms that integrate long-term temperature exposure remain unknown. The slow, winter-long upregulation of VERNALIZATION INSENSITIVE 3 (VIN3)5,6,7, a PHD protein that functions with Polycomb repressive complex 2 to epigenetically silence FLOWERING LOCUS C (FLC) during vernalization, is central to plants interpreting winter progression5,6,8,9,10,11. Here, by a forward genetic screen, we identify two dominant mutations of the transcription factor NTL8 that constitutively activate VIN3 expression and alter the slow VIN3 cold induction profile. In the wild type, the NTL8 protein accumulates slowly in the cold, and directly upregulates VIN3 transcription. Through combining computational simulation and experimental validation, we show that a major contributor to this slow accumulation is reduced NTL8 dilution due to slow growth at low temperatures. Temperature-dependent growth is thus exploited through protein dilution to provide the long-term thermosensory information for VIN3 upregulation. Indirect mechanisms involving temperature-dependent growth, in addition to direct thermosensing, may be widely relevant in long-term biological sensing of naturally fluctuating temperatures.
DOI: 10.1038/s41586-020-2485-4
Source: https://www.nature.com/articles/s41586-020-2485-4
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
