MacGregor Dana R, Kendall Sarah L, Florance Hannah, Fedi Fabio, Moore Karen, Paszkiewicz Konrad, Smirnoff Nicholas, Penfield Steven
Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK; Department of Crop Genetics, John Innes Centre, Norwich Research Park, Colney Ln, Norwich, Norfolk, NR4, 7UH, UK.
New Phytol. 2015 Jan;205(2):642-52. doi: 10.1111/nph.13090. Epub 2014 Nov 20.
Environmental changes during seed production are important drivers of lot-to-lot variation in seed behaviour and enable wild species to time their life history with seasonal cues. Temperature during seed set is the dominant environmental signal determining the depth of primary dormancy, although the mechanisms though which temperature changes impart changes in dormancy state are still only partly understood. We used molecular, genetic and biochemical techniques to examine the mechanism through which temperature variation affects Arabidopsis thaliana seed dormancy. Here we show that, in Arabidopsis, low temperatures during seed maturation result in an increase in phenylpropanoid gene expression in seeds and that this correlates with higher concentrations of seed coat procyanidins. Lower maturation temperatures cause differences in coat permeability to tetrazolium, and mutants with increased seed coat permeability and/or low procyanidin concentrations are less able to enter strongly dormant states after exposure to low temperatures during seed maturation. Our data show that maternal temperature signalling regulates seed coat properties, and this is an important pathway through which the environmental signals control primary dormancy depth.
种子生产过程中的环境变化是批次间种子行为变异的重要驱动因素，使野生植物能够根据季节性线索来安排其生活史。结实期的温度是决定初级休眠深度的主要环境信号，尽管温度变化影响休眠状态的机制仍仅被部分理解。我们运用分子、遗传和生化技术来研究温度变化影响拟南芥种子休眠的机制。在此我们表明，在拟南芥中，种子成熟期间的低温导致种子中苯丙烷类基因表达增加，且这与种皮原花青素浓度升高相关。较低的成熟温度导致种皮对四唑的通透性存在差异，并且种皮通透性增加和/或原花青素浓度低的突变体在种子成熟期间暴露于低温后进入强休眠状态的能力较弱。我们的数据表明，母体温度信号调节种皮特性，这是环境信号控制初级休眠深度的一条重要途径。
