Directing floral timing through genetic variation in the plant circadian clock

点击翻译按钮获取中文摘要

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.