季节性抗寒是温带木本植物为了生存而进化出的适应性机制。对树木低温适应性分子机制的深入研究，提高植物的抗寒性，培育抗寒农林品种对于农林的发展具有重要的意义。前期研究发现杨树PttGIs-PttCDFs不仅是调控杨树季节性休眠的关键元件，也是参与杨树季节性抗寒的重要候选基因。本项目将利用遗传学、植物生理学等手段证实PttGIs-PttCDFs在杨树生长与季节性抗寒中的功能；通过分子生物学、生物信息学等方法深入解析PttCDF-PttGI复合体在杨树生长与抗寒过程中的分子机理。本项目的成功实施将使我们在分子层面了解木本植物季节性抗寒的适应机制；其次，如何平衡植物生长发育与提高逆境抗性一直是植物逆境基因工程研究的瓶颈，本研究中的CDF家族基因是能够平衡生长发育与抗性的重要候选基因，深入解析杨树PttCDFs在抗寒中的分子机制，将为培育既抗寒又高产的林木基因工程提供新的思路与方法。

Seasonal cold hardiness is an adaptive growth habit of temperate woody plants. Deeply understand the molecular mechanism on how plants adapt to low temperature and improve plants cold hardiness will have great meanings for the development of agriculture and forestry. Previous studies have found that PttGIs-PttCDFs regulon is not only a key component regulating seasonal dormancy, but also an important candidate involved in seasonal cold hardiness in poplar. In this project, we will characterize PttGIs-PttCDFs regulon functions in poplar growth and seasonal cold hardiness by using genetics and plant physiology methods. The molecular mechanisms on how PttCDFs-PttGIs complex regulate cold hardiness will be further deeply investigated through molecular biology, bioinformatics etc. The successful implementation of this project will enable us to understand the adaptation mechanism of seasonal cold hardiness in woody plants at the molecular level. On the other hand, how to improve plant stress resistance without affecting plant growth and development has always been the bottleneck for genetic engineering. Interestingly, previous studies have shown that CDF family genes are good candidates for balanced plant growth development and stress resistant. Understanding the function and molecular mechanism of PttCDFs in poplar will provide new ideas and methods for breeding both cold resistant and high-yielding trees.