天女木兰是我国重点保护的集观赏、芳香和药用价值于一身的野生木本植物资源，有重要的分类地位和科学价值，具有广阔的开发应用前景。木兰科植物的种子绝大多数都具有形态生理休眠特性，发芽持续时间较长（3-5个月）。申请者前期研究发现：强光照可促进天女木兰种子快速萌发（40d发芽率可达80%）；转录组数据进一步证明光敏色素蛋白PHYs及不同光质响应基因随种子休眠解除及萌发大量上调；国内外研究也证明，PHYs蛋白促进种子萌发。基于上述证据，申请者拟从光敏色素信号转导途径起始蛋白PHYs入手，以天女木兰种子为研究对象，在生理生化、转录、翻译不同水平上，探究PHYs在加速种子休眠解除过程中的功能及其作用机制，为揭示具有形态生理休眠特性的种子种胚发育调控机制，丰富种子休眠解除机理提供科学的参考和证据，具有重要的科学意义。该研究结果也为加速木兰科植物种子发芽提出新策略和新选择。

Magnolia sieboldii K. Koch (Magnoliaceae) is the north boundary species of Magnoliaceae in China. It is a wild tree species resources which focus on ornamental, aromatic and medicinal value in oneself. It has important classification status and scientific value, and has broad development and application prospects.Seeds with Morphophysiological dormancy (MPD) usually germinated within3-5months. The applicant's previous study found that light can stimulation to promote seed germination (germination rate were 80% for 40 days). Transcriptome data further demonstrated that most PHYs and light response genes were considerably up-regulated during germination. At the same time, relevant studies had also proved that PHYs promotes seed germination by regulating endogenous hormones, nutrient metabolism and signal transduction. Therefore, based on the above evidence, the applicant intends to investigate the mechanisms of PHY regulates seed germination in the physiological and biochemical, transcription and translation by focusing on PHYs, which is the initial position of light signal. We will explore PHYs functions and mechanisms in the process of accelerating seed dormancy breaking in order to provide scientific reference and evidence for revealing MPD regulation mechanism.The results will have an important scientific significance by riching seed dormancy breaking mechanism and providing new strategies and options for accelerating the germination of Magnoliaceae seeds.