Kinmonth-Schultz Hannah, Lewandowska-Sabat Anna, Imaizumi Takato, Ward Joy K, Rognli Odd Arne, Fjellheim Siri
Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, United States.
Research Support Office, Norwegian University of Life Sciences, Ås, Norway.
Front Plant Sci. 2021 Nov 1;12:747740. doi: 10.3389/fpls.2021.747740. eCollection 2021.
Temperate species often require or flower most rapidly in the long daylengths, or photoperiods, experienced in summer or after prolonged periods of cold temperatures, referred to as vernalization. Yet, even within species, plants vary in the degree of responsiveness to these cues. In , () and () genes are key to photoperiod and vernalization perception and antagonistically regulate () to influence the flowering time of the plants. However, it is still an open question as to how these genes vary in their interactions among wild accessions with different flowering behaviors and adapted to different microclimates, yet this knowledge could improve our ability to predict plant responses in variable natural conditions. To assess the relationships among these genes and to flowering time, we exposed 10 winter-annual accessions from throughout Norway, ranging from early to late flowering, along with two summer-annual accessions to 14 weeks of vernalization and either 8- or 19-h photoperiods to mimic Norwegian climate conditions, then assessed gene expression levels 3-, 5-, and 8-days post vernalization. and explained both levels and flowering time (days) but not rosette leaf number at flowering. The correlation between and flowering time increased over time. Although vernalization suppresses , was high in the late-flowering accessions. Across accessions, was expressed only at low levels and did not respond to in the late-flowering accessions. We proposed that may only be expressed below a threshold value of and demonstrated that these three genes correlated to flowering times across genetically distinct accessions of .
温带物种通常在夏季经历的长日照或光周期下，或者在经历长时间低温（即春化作用）后，最需要或开花最快。然而，即使在同一物种内，植物对这些信号的响应程度也有所不同。在拟南芥中，FT（FLOWERING LOCUS T）、SOC1（SUPPRESSOR OF CONSTANS1）和FLC（FLOWERING LOCUS C）基因是光周期和春化作用感知的关键基因，它们相互拮抗地调节FT，以影响植物的开花时间。然而，这些基因在具有不同开花行为并适应不同微气候的野生材料之间的相互作用如何变化，仍然是一个悬而未决的问题，但这些知识可以提高我们预测植物在多变自然条件下反应的能力。为了评估这些基因与开花时间之间的关系，我们将来自挪威各地、从早花到晚花的10个一年生冬性拟南芥材料，以及两个一年生夏性拟南芥材料，置于14周的春化处理和8小时或19小时的光周期下，以模拟挪威的气候条件，然后在春化处理后的第3天、第5天和第8天评估基因表达水平。FT和SOC1解释了基因表达水平和开花时间（天数），但没有解释开花时的莲座叶数量。FT与开花时间之间的相关性随时间增加。尽管春化作用抑制了FLC，但在晚花材料中FLC表达量很高。在所有材料中，FLC仅在低表达水平下表达，并且在晚花材料中对春化作用没有反应。我们提出FLC可能仅在FT的阈值以下表达，并证明这三个基因与不同遗传背景的拟南芥材料的开花时间相关。
