Clock-Controlled and FLOWERING LOCUS T (FT)-Dependent Photoperiodic Pathway in Lotus japonicus I: Verification of the Flowering-Associated Function of an FT Homolog
Clock-Controlled and FLOWERING LOCUS T (FT)-Dependent Photoperiodic Pathway in Lotus japonicus I: Verification of the Flowering-Associated Function of an FT Homolog
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DOI：
10.1271/bbb.120871
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发表时间：
2013-04
期刊：
影响因子：
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通讯作者：
T. Yamashino;Saori Yamawaki;Emi Hagui;H. Ueoka‐Nakanishi;Norihito Nakamichi;S. Ito;T. Mizuno
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文献类型：
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作者：
T. Yamashino;Saori Yamawaki;Emi Hagui;H. Ueoka‐Nakanishi;Norihito Nakamichi;S. Ito;T. Mizuno
近十年来，拟南芥研究在确定植物生物钟响应光周期变化调控开花时间的分子机制方面取得了重大进展。一般认为，在高等植物中，包括拟南芥（a.thaliana）和水稻（Oryza sativa），光周期控制开花时间的外部巧合机制是由时钟控制的CONSTANS (CO)-开花位点T （FT）介导的。然而，也有人认为这种机制在物种之间的细节上有很大的不同。本研究对模式豆科植物荷花（Lotus japonicus）与拟南芥（a.t aliana）的生物钟控制CO-FT通路进行了比较。L. japonicus至少有一个FT同源基因（命名为LjFTa），该基因在长日特异性诱导，与拟南芥FT基因的突变病变形成互补。然而，我们推测该豆科植物可能缺乏上游正调节因子CO。我们利用日本l.a japonicus phyB突变体植物，发现光受体突变体由于LjFTa的表达增强而表现出提前开花的表型，这表明LjFTa参与了日本l.a japonicus开花的促进。这些结果是在当前的背景下讨论开花作物豆科植物，如大豆和豌豆。
During the last decade, significant research progress in the study of Arabidopsis thaliana has been made in defining the molecular mechanism by which the plant circadian clock regulates flowering time in response to changes in photoperiod. It is generally accepted that the clock-controlled CONSTANS (CO)-FLOWERING LOCUS T (FT)-mediated external coincidence mechanism underlying the photoperiodic control of flowering time is conserved in higher plants, including A. thaliana and Oryza sativa. However, it is also assumed that the mechanism differs considerably in detail among species. Here we characterized the clock-controlled CO-FT pathway in Lotus japonicus (a model legume) in comparison with that of A. thaliana. L. japonicus has at least one FT orthologous gene (named LjFTa), which is induced specifically in long-days and complements the mutational lesion of the A. thaliana FT gene. However, it was speculated that this legume might lack the upstream positive regulator CO. By employing L. japonicus phyB mutant plants, we showed that the photoreceptor mutant displays a phenotype of early flowering due to enhanced expression of LjFTa, suggesting that LjFTa is invovled in the promotion of flowering in L. japonicus. These results are discussed in the context of current knowledge of the flowering in crop legumes such as soybean and garden pea.