高等植物开花时程的基因调控（Ⅰ）

高等植物从营养生长向生殖生长及发育转变的时程具有重要意义，但是了解得很少。近6年来利用分子遗传学方法详细地分析了拟南芥中的这一转变的时程变化，为高等植物开花时程的基因调控提供了一个很好的模式。有关早期或晚期开花表现型的大量突变体及遗传变异得到了阐述。这里谈到的表现型对影响开花转变的环境及内部因子的控制有重大作用。通过分子生物学、遗传学和生理学分析已经鉴定了参与此过程的不同组分，如光识别和昼夜节律（circadian rhythm）因子。另外，通过克隆某些花诱导基因及其相应的靶基因已经对参与开花信号转导途径（signal transduction pathway）的相关因子进行了系统的鉴定，这些开创性工作大大促进了高等植物开花时程的基因表达调控研究及其机理的阐明。本实验室在以黄瓜、新红宝西瓜、西葫芦为材料所获得的部分结果基础上，主要以近六年来在拟南芥方面获得的进展为依据，对高等植物开花时程的基因调控作一系统的总结，并对其开花时程基因调控的机理提出可能的作用理论模型。

The Gene Control of Flowering Time in Higher Plants

The timing of the transition from vegetative to reproductive development in higher plants is of great importance, but is still poorly understood. Up to date, molecular-genetic approaches have been used to analyse the process in Arabidopsis thalian.The gentic variation present among a large number of mutants with early or late flowering phenotypes, affecting the control of environmental and endogenous factors that influence the transition to flowering, is discussed here. The analyses in genetics, molecular biology and physiology have led to the identification of different components involved, such as the elements of photoperception and circadian rhythm. By the cloning of some floral induction genes and their target genes some element involved in the signal transduction pathways to flowering have put forward a working moder for the explaination of the gene control of flowering time in higher plants.