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

为了寻找控制水稻开花时间的新基因，对水稻开花时间突变体进行了研究。高分辨分子标记分析表明，早花突变体HS112在3号染色体上含有一个基因(Os03g0151300)突变，另一个早花突变体HS254在10号染色体上含有一个突变基因。因此，这些基因被认为是新的开花时间基因，称为SE14和SE15。表达分析表明，在这两个突变体中，开花时间基因Ehd1在长日照条件下都高度上调。这些结果表明，SE14和SE15在长日照条件下抑制Ehd1的表达。在已知突变株系X61、HS169的基础上获得了多个突变体，并获得了这两个品系的双突变株系。在15,000个品系中，共选择168株作为开花时间突变体。这些新的突变体将为我们理解如何控制水稻的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.