Directing floral timing through genetic variation in the plant circadian clock

开花时间受昼夜节律钟的强烈调节，昼夜节律钟驱动光周期开花。我们最近在拟南芥中探索了时钟的自然等位基因多样性，并发现了对过程环境的“记忆”。此外，我们还发现，在田间条件下，时钟变化对花期的指导作用很大。一个昼夜节律数量性状位点的克隆揭示了开花时间基因早花3 （ELF3）的变异。在这里，我们将进一步探索时钟基因的等位基因变异，以确定直接光周期开花的关键位点。首先，我们将完成来自不同纬度地区的拟南芥重组自交系新群体的构建，并以千碱基分辨率绘制这些系的基因组图谱。这些种群将根据时钟和开花时间的变化进行评分；动态关联将被构建。总之，时钟基因变异下的组成部分，指导季节性开花将被确定。其次，我们将利用大麦ELF3现有和新产生的变异来研究单子叶大麦开花昼夜节律控制的分子遗传学。该基因可能是季节性基因座Ppd-H1的直接调节因子。第二个程序应该揭示双子叶/单子叶的时钟保守性，并确定生物钟基因ELF3的等位基因变异，这可以直接用于大麦育种程序。

Flowering time is strongly regulated by the circadian clock, which drives photoperiodic flowering. We recently explored natural allelic diversity of the clock in the dicot Arabidopsis and found a "memory" of the proceeding environment. Furthermore, we showed that clock variation has a large role in directing flowering time under field conditions. Cloning of one circadian quantitative trait locus revealed variation at the flowering-time gene EARLY FLOWERING 3 (ELF3). Here we will further explore allelic variation in clock genes to define key loci that direct photoperiodic flowering. Firstly, we will complete the construction of new Arabidopsis recombinant inbred populations derived from accessions originating from extremely differing latitudes, and map the genomes of these lines at kilobase resolution. These populations will be scored for variation in the clock and flowering time; dynamic correlations will be constructed. Together, components underling clock-gene variation that directs seasonal flowering will be identified. Secondly, we will examine the molecular genetics of circadian control of flowering in the monocot barley using existing and newly generated variation at barley ELF3. This gene is the likely direct regulator of the seasonality locus Ppd-H1. This second program should reveal dicot/monocot clock conservations and identify allelic variation at the circadian-clock gene ELF3 that could be directly used in barley breeding programs.