8月17日，期刊《PLoS ONE》在线发表有关水稻开花基因OsELF3-1的成功克隆的研究成果。在题为“OsELF3-1, an Ortholog of Arabidopsis EARLY FLOWERING 3, Regulates Rice Circadian Rhythm and Photoperiodic Flowering”论文中，研究人员确定了水稻中两个同源基因OsELF3-1 和 OsELF3-2功能作用，完善了水稻光周期开花的机理。

水稻开花（抽穗期）对于水稻的生殖发育是极为重要的，同时开花机理的研究有利于育种家控制不同水稻的开花时间，利于杂交水稻的制种过程。另外，开花时间也直接影响水稻的产量。OsELF3-1参与调控水稻的生物节律系统。同时参与调控水稻光周期途径，在短日照条件下OsELF3-1直接激活开花的正调控因子Ehd1，Hd3a的表达诱导开花；在长日照条件下，OsELF3-1抑制开花的负调控因子Ghd7的表达，从而促进水稻在长日照条件下的开花。该基因的克隆直接证明了水稻生物节律基因参与调控水稻光周期开花，完善了水稻光周期开花的机理；并为水稻育种过程中调节开花时间提供了新的途径。

论文摘要：

Arabidopsis thaliana EARLY FLOWERING 3 (ELF3) as a zeitnehmer (time taker) is responsible for generation of circadian rhythm and regulation of photoperiodic flowering. There are two orthologs (OsELF3-1 and OsELF3-2) of ELF3 in rice (Oryza sativa), but their roles have not yet been fully identified. Here, we performed a functional characterization of OsELF3-1 and revealed it plays a more predominant role than OsELF3-2 in rice heading. Our results suggest OsELF3-1 can affect rice circadian systems via positive regulation of OsLHY expression and negative regulation of OsPRR1, OsPRR37, OsPRR73 and OsPRR95 expression. In addition, OsELF3-1 is involved in blue light signaling by activating EARLY HEADING DATE 1 (Ehd1) expression to promote rice flowering under short-day (SD) conditions. Moreover, OsELF3-1 suppresses a flowering repressor GRAIN NUMBER, PLANT HEIGHT AND HEADING DATE 7 (Ghd7) to indirectly accelerate flowering under long-day (LD) conditions. Taken together, our results indicate OsELF3-1 is essential for circadian regulation and photoperiodic flowering in rice.

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