Characterization and transgenic study of CONSTANS-LIKE8 (COL8) gene in Arabidopsis thaliana: expression of 35S:COL8 delays flowering under long-day conditions
Characterization and transgenic study of CONSTANS-LIKE8 (COL8) gene in Arabidopsis thaliana: expression of 35S:COL8 delays flowering under long-day conditions
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DOI：
10.5511/plantbiotechnology.11.0823b
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发表时间：
2011-01-01
影响因子：
1.6
通讯作者：
Kiyosue, Tomohiro
中科院分区：
文献类型：
--
作者：
Takase, Tomoyuki;Kakikubo, Yoshihiro;Kiyosue, Tomohiro
CONSTANS（CO）是光周期开花的调节因子，其激活拟南芥中的成花基因FLOWERLOCUS T（FT）的转录。CO属于CO/CONSTANS-LIKE（COL）蛋白家族，其由17种蛋白质组成，并被细分为三组。在这里，我们表征了II组成员之一COL 8的基因。COL 8 mRNA在种子、叶片、花和角果中积累。将GUS报告基因转入拟南芥中，在叶片中表现出较强的GUS活性。瞬时和稳定产生的荧光标记的COL 8蛋白定位在细胞核中。转基因拟南芥植物COL 8 cDNA驱动的花椰菜花叶病毒（CaMV）35 S启动子没有显示任何改变昼夜节律在恒定光照条件下，但在长日照条件下表现出晚开花表型。在这些转基因植物中，CO mRNA并没有减少从zeitgeber时间（ZT）12到ZT 16，而FT mRNA减少从ZT 8到ZT 24。讨论了CaMV 35 S启动子驱动COL 8植物晚花表型的可能机制。
CONSTANS (CO) is a regulator of photoperiodic flowering that activates the transcription of a florigen gene, FLOWERING LOCUS T (FT), in Arabidopsis. CO belongs to the CO/CONSTANS-LIKE (COL) protein family, which consists of 17 proteins and is subclassified into three groups. Here, we characterized the gene for one of the group II members, COL8. The COL8 mRNA accumulated in seeds, leaves, flowers, and siliques. Transgenic Arabidopsis plants with a beta-glucuronidase (GUS) reporter gene driven by a 3-kb COL8 promoter displayed strong GUS activity in leaves. Both transiently and stably produced fluorescence-tagged COL8 proteins were localized in the nucleus. Transgenic Arabidopsis plants possessing COL8 cDNA driven by a cauliflower mosaic virus (CaMV) 35S promoter did not show any altered circadian rhythm under constant light conditions, but showed a late-flowering phenotype under long-day conditions. In these transgenic plants, CO mRNA did not decrease from zeitgeber time (zt) 12 to zt 16, whereas FT mRNA decreased from zt 8 to zt 24. The possible mechanisms for the late-flowering phenotype of the COL8 plants driven by the CaMV 35S promoter are discussed.