Ef7 Encodes an ELF3-like Protein and Promotes Rice Flowering by Negatively Regulating the Floral Repressor Gene Ghd7 under Both Short- and Long-Day Conditions
Ef7 Encodes an ELF3-like Protein and Promotes Rice Flowering by Negatively Regulating the Floral Repressor Gene Ghd7 under Both Short- and Long-Day Conditions
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DOI：
10.1093/pcp/pcs029
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发表时间：
2012-04-01
影响因子：
4.9
通讯作者：
Tanisaka, Takatoshi
中科院分区：
文献类型：
--
作者：
Saito, Hiroki;Ogiso-Tanaka, Eri;Tanisaka, Takatoshi
近年来，人们对水稻光周期开花的研究取得了很大进展，并对短日促进和长日抑制水稻成花的机理进行了深入的探讨。在这项研究中，我们确定和表征Ef7基因，拟南芥EARLY FLOWAR3（ELF3）的水稻直向同源物之一。ef7突变体HS276是由粳稻品种‘金宝津’经γ射线辐照诱导而成的，在SD和LD条件下均开花较晚。开花时间相关基因的表达分析表明，在SD和LD条件下，Ef 7负调节水稻开花光周期控制的抑制因子Ghd 7的表达，从而上调下游Ehd1和FT样基因的表达。非功能性Ghd7等位基因的遗传分析提供了进一步的证据，即ef7的延迟开花是通过Ghd7途径介导的。光诱导Ghd7表达的分析表明，ef7突变体比野生型植物对红光更敏感，但Ghd7表达的门没有改变。因此，我们的研究结果表明，Ef7功能作为一个花启动子抑制Ghd7在SD和LD条件下的表达。
Much progress has been made in our understanding of photoperiodic flowering of rice and the mechanisms underlying short-day (SD) promotion and long-day (LD) repression of floral induction. In this study, we identified and characterized the Ef7 gene, one of the rice orthologs of Arabidopsis EARLY FLOWERING 3 (ELF3). The ef7 mutant HS276, which was induced by gamma-irradiation of the japonica rice cultivar 'Gimbozu', flowers late under both SD and LD conditions. Expression analyses of flowering time-related genes demonstrated that Ef7 negatively regulates the expression of Ghd7, which is a repressor of the photoperiodic control of rice flowering, and consequently up-regulates the expression of the downstream Ehd1 and FT-like genes under both SD and LD conditions. Genetic analyses with a non-functional Ghd7 allele provided further evidence that the delayed flowering of ef7 is mediated through the Ghd7 pathway. The analysis of light-induced expression of Ghd7 revealed that the ef7 mutant was more sensitive to red light than the wild-type plant, but the gate of Ghd7 expression was unchanged. Thus, our results show that Ef7 functions as a floral promoter by repressing Ghd7 expression under both SD and LD conditions.