OsMADS51 is a short-day flowering promoter that functions upstream of Ehd1, OsMADS14, and Hd3a1[W][OA]
OsMADS51 is a short-day flowering promoter that functions upstream of Ehd1, OsMADS14, and Hd3a1[W][OA]
复制标题
DOI：
10.1104/pp.107.103291
复制
发表时间：
2007-12-01
期刊：
影响因子：
7.4
通讯作者：
An, Gynheung
中科院分区：
文献类型：
--
作者：
Kim, Song Lim;Lee, Shinyoung;An, Gynheung
虽然拟南芥（Arabidopsis thaliana）的开花调控机制已被广泛研究，但在其他物种中的开花调控机制尚未得到很好的阐明。本研究以水稻为材料，研究了Ⅰ型MADS-box基因OsMADS 51在水稻短日照促进途径中的作用。在SDs中，OsMADS 51无效突变体开花比正常情况晚2周，而在长日照中，OsMADS 51的缺失对开花几乎没有影响。在这些突变体中，三个开花调节因子Ehd 1，OsMADS 14和Hd 3a的转录水平降低，而OsGI和Hd 1的转录水平不变。OsMADS 51的异位表达仅在SD中使开花提前约7 d。在异位表达株系中，Ehd 1、OsMADS 14和Hd 3a的转录水平增加，但OsGI和Hd 1的转录水平保持不变。这些结果表明OsMADS 51是开花启动子，特别是在SD中，并且该基因在Ehd 1、OsMADS 14和Hd 3a的上游起作用。为了进一步研究与其他开花启动子的关系，我们产生了Ehd 1或OsGI表达被抑制的转基因植物。在Ehd 1 RNA干扰植物中，OsMADS 51的表达没有受到影响，支持我们的结论，MADS-box基因的功能上游Ehd 1。然而，在OsGI反义植物中，OsMADS 51转录水平降低。此外，该MADS盒基因的昼夜表达模式与OsGI相似。这些结果表明OsMADS 51在OsGI下游发挥功能。综上所述，OsMADS 51是一个新的开花启动子，它将SD启动信号从OsGI传递到Ehd 1。
Although flowering regulatory mechanisms have been extensively studied in Arabidopsis (Arabidopsis thaliana), those in other species have not been well elucidated. Here, we investigated the role of OsMADS51, a type I MADS-box gene in the short-day (SD) promotion pathway in rice (Oryza sativa). In SDs OsMADS51 null mutants flowered 2 weeks later than normal, whereas in long days loss of OsMADS51 had little effect on flowering. Transcript levels of three flowering regulators-Ehd1, OsMADS14, and Hd3a - were decreased in these mutants, whereas those of OsGI and Hd1 were unchanged. Ectopic expression of OsMADS51 caused flowering to occur about 7 d earlier only in SDs. In ectopic expression lines, transcript levels of Ehd1, OsMADS14, and Hd3a were increased, but those of OsGI and Hd1 remained the same. These results indicate that OsMADS51 is a flowering promoter, particularly in SDs, and that this gene functions upstream of Ehd1, OsMADS14, and Hd3a. To further investigate the relationship with other flowering promoters, we generated transgenic plants in which expression of Ehd1 or OsGI was suppressed. In Ehd1 RNA interference plants, OsMADS51 expression was not affected, supporting our conclusion that the MADS-box gene functions upstream of Ehd1. However, in OsGI antisense plants, the OsMADS51 transcript level was reduced. In addition, the circadian expression pattern for this MADS-box gene was similar to that for OsGI. These results demonstrate that OsMADS51 functions downstream of OsGI. In summary, OsMADS51 is a novel flowering promoter that transmits a SD promotion signal from OsGI to Ehd1.