植物开花受内在遗传因子和外部环境因子的调控，其中最主要的是受光周期的调控。长日照植物拟南芥开花调控的遗传机理目前研究的比较清楚，而短日照植物水稻开花调控的机制仍然有很多不清楚。我们在对水稻标签突变体进行筛选时，发现一个早花突变体，比对照日本晴早开花30天左右。遗传学分析与互补试验表明一个新的Tos17逆转座子插入OsEF1中，引起单基因隐性突变，从而导致该突变体的早花表型。OsEF1在小丽碗藓中的同源基因编码一个激酶配基，基因被破坏后，小立碗藓可以在低于正常光照的条件下仍然能正常产生孢子体，提示该基因在水稻中的功能可能是参与光周期控制的水稻开花过程。详细研究OsEF1基因的功能有助于阐明短日照植物水稻的开花机制，从分子水平上揭示水稻开花同光周期的内在关系。

Endogenous genetic factors and environmental signals controlled flowering time in plants. One of the environmental signals is photoperiod. Genetic mechanisms for the photoperiodic response of flowering of long-day plants (LDPs) have been extensively analyzed using Arabidopsis as a model plant. In contrast, mechanisms in short-day plants (SDPs) remain unclear. During field screening of rice mutant pool we found a mutant that flowers 30 days earlier than Nippon bare at normal condition. Molecular analysis shows taht a newly transposed Tos17 was inserted in a gene we named OsEF1, the homolog of Osk4 in moss (Physcomitrella patens) encoding a ligand of a kinase. Co-segregation and complementation analysis showed disruption of OsEF1 by Tos7 is directly related to early flowering phenotype. Functional analysis of OsEFl will contribute directly to reveal genetic mechanism of flowering time control in short day plants, especially in rice.