Identification of novel regulatory of flowering time using multiple mutants of rice(Oryza sativa L.)

为了鉴定控制水稻开花时间的新基因，对开花时间突变体进行了研究。高分辨率分子标记分析表明，早开花突变体HS112和HS254分别在第3染色体和第10染色体上携带一个突变基因Os03g0151300。这些基因参与控制植物开花时间的研究尚未见报道。因此，这些基因被认为是新的开花时间基因，称为Se 14和Se 15。表达分析表明，开花时间的基因，Ehd1，在长日照条件下，在这两个突变体的高度上调。这些结果表明，Se 14和Se 15在长日照条件下抑制Ehd1的表达。在已知突变株系的基础上获得了多个突变株系X61、HS169和这两个突变株系的双突变株系。从15000个株系中筛选出168株开花时间突变体。这些新的突变体将为我们了解如何控制水稻开花时间提供新的知识。

To identify novel genes controlling flowering time in rice, flowering time mutants were investigated. High resolution molecular marker analyses showed that an early flowering time mutant, HS112, harbored a mutation in the gene(Os03g0151300) in chromosome 3, and another early flowering time mutant, HS254, harbored a mutant gene in chromosome 10. It is not reported that these genes involve in controlling flowering time. Therefore, it is considered that these genes are novel flowering time genes, called Se14 and Se15. Expression analyses demonstrated that a flowering time gene, Ehd1, was highly up-regulated under long-day condition in both of these mutants. These results indicate that Se14 and Se15 repress the expression of Ehd1 under long-day condition. Multiple mutants based on known mutant lines, X61, HS169 and double-mutant line of these two lines, were obtained. In total 15, 000 lines, 168 plants were selected as flowering time mutants. These novel mutants will provide us new knowledge to understand how to control flowering time in rice.