Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany.
Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Seeland, Germany.
Mol Biol Evol. 2024 Oct 4;41(10). doi: 10.1093/molbev/msae205.
Plants have evolved mechanisms to anticipate and adjust their growth and development in response to environmental changes. Understanding the key regulators of plant performance is crucial to mitigate the negative influence of global climate change on crop production. EARLY FLOWERING 3 (ELF3) is one such regulator playing a critical role in the circadian clock and thermomorphogenesis. In Arabidopsis thaliana, ELF3 contains a prion-like domain (PrLD) that acts as a thermosensor, facilitating liquid-liquid phase separation at high ambient temperatures. To assess the conservation of this function across the plant kingdom, we traced the evolutionary emergence of ELF3, with a focus on the presence of PrLDs. We found that the PrLD, primarily influenced by the length of polyglutamine (polyQ) repeats, is most prominent in Brassicales. Analyzing 319 natural A. thaliana accessions, we confirmed the previously described wide range of polyQ length variation in AtELF3, but found it to be only weakly associated with geographic origin, climate conditions, and classic temperature-responsive phenotypes. Interestingly, similar polyQ length variation was not observed in several other investigated Bassicaceae species. Based on these findings, available prediction tools and limited experimental evidence, we conclude that the emergence of PrLD, and particularly polyQ length variation, is unlikely to be a key driver of environmental adaptation. Instead, it likely adds an additional layer to ELF3's role in thermomorphogenesis in A. thaliana, with its relevance in other species yet to be confirmed.
植物已经进化出了机制，以预测和调整其生长和发育，以适应环境变化。了解植物表现的关键调节因子对于减轻全球气候变化对作物生产的负面影响至关重要。EARLY FLOWERING 3（ELF3）就是这样一个调节因子，它在生物钟和热形态发生中起着关键作用。在拟南芥中，ELF3 含有一个类朊病毒结构域（PrLD），作为热感受器，在环境温度较高时促进液-液相分离。为了评估这个功能在植物界中的保守性，我们追踪了 ELF3 的进化出现，重点关注 PrLD 的存在。我们发现，PrLD 主要受多聚谷氨酰胺（polyQ）重复长度的影响，在芸薹科中最为突出。分析了 319 个自然的拟南芥品系，我们证实了先前描述的 AtELF3 中 polyQ 长度变化范围很广，但发现它与地理起源、气候条件和经典的温度响应表型只有微弱的关联。有趣的是，在其他几个研究的芸薹科物种中没有观察到类似的 polyQ 长度变化。基于这些发现、可用的预测工具和有限的实验证据，我们得出结论，PrLD 的出现，特别是 polyQ 长度的变化，不太可能是环境适应的关键驱动因素。相反，它可能在拟南芥中为 ELF3 在热形态发生中的作用增加了一个额外的层次，而其在其他物种中的相关性还有待证实。
