水稻品種不同,，開花的早晚時期也有所不同。日本一個研究小組在2月24日出版的美國《國家科學(xué)院院刊》（PNAS）上報告說,，水稻花期早晚是由負責(zé)調(diào)節(jié)成花素的基因決定的,。
世界各地栽培的水稻都有適應(yīng)當(dāng)?shù)貧夂虻拈_花時期。日本奈良尖端科學(xué)技術(shù)研究生院大學(xué)的研究人員在2007年就發(fā)現(xiàn)了誘導(dǎo)花芽形成的植物激素——成花素,。在最新研究中,，他們又分析了世界各地64個品種的水稻，結(jié)果發(fā)現(xiàn),，基因“Hd1”負責(zé)調(diào)節(jié)水稻中成花素的量,，合成成花素量最多的水稻品種開花時期要比成花素量最少的品種早100天以上。
研究人員認為,，從人類開始栽培水稻以來,，“Hd1”基因為適應(yīng)不同的環(huán)境發(fā)生了不同的變化,，導(dǎo)致不同的水稻品種合成成花素的量不同。今后若能人為控制水稻的開花時期,，水稻的產(chǎn)量就有可能提高,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS，doi: 10.1073/pnas.0812092106,，Yasuyuki Takahashi,，Ko Shimamoto
Variations in Hd1 proteins, Hd3a promoters, and Ehd1 expression levels contribute to diversity of flowering time in cultivated rice
Yasuyuki Takahashia, Kosuke M. Teshimab, Shuji Yokoia,1, Hideki Innanb and Ko Shimamotoa,2
aLaboratory of Plant Molecular Genetics, Nara Institute of Science and Technology, Ikoma, Nara 630-0101, Japan; and
bThe Graduate University for Advanced Studies, Hayama, Kanagawa 240-0193, Japan
Abstract
Rice is a facultative short-day plant, and molecular genetic studies have identified the major genes involved in short-day flowering. However, the molecular mechanisms promoting the diversity of flowering time in cultivated rice are not known. We used a core collection of 64 rice cultivars that represent the genetic diversity of 332 accessions from around the world and studied the expression levels and polymorphisms of 6 genes in the short-day flowering pathway. The RNA levels of Heading date 3a (Hd3a), encoding a floral activator, are highly correlated with flowering time, and there is a high degree of polymorphism in the Heading date 1 (Hd1) protein, which is a major regulator of Hd3a expression. Functional and nonfunctional alleles of Hd1 are associated with early and late flowering, respectively, suggesting that Hd1 is a major determinant of variation in flowering time of cultivated rice. We also found that the type of Hd3a promoter and the level of Ehd1 expression contribute to the diversity in flowering time and Hd3a expression level. We evaluated the contributions of these 3 factors by a statistical analysis using a simple linear model, and the results supported our experimental observations.
