Semidwarf (sd-1), "green revolution" rice, contains a defective gibberellin 20-oxidase gene
Semidwarf (sd-1), "green revolution" rice, contains a defective gibberellin 20-oxidase gene
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DOI：
10.1073/pnas.132266399
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发表时间：
2002-06-25
影响因子：
11.1
通讯作者：
Chandler, PM
中科院分区：
文献类型：
--
作者：
Spielmeyer, W;Ellis, MH;Chandler, PM
半矮秆稻 (Oryza sativa L.) 的引入导致 20 世纪 60 年代整个亚洲的产量创历史新高。主要的半矮化等位基因 sd-1 仍广泛用于现代水稻品种中。 sd-1 的表型与由于赤霉素 (GA) 植物生长激素缺乏而导致的侏儒症一致。我们认为半矮化（sd-1）表型是由于 20-氧化酶 GA 生物合成酶缺陷导致伸长茎中活性 GA 缺乏的结果。将水稻基因组的序列数据与之前的作图研究相结合，将推定的 GA 20 氧化酶基因 (Os2Gox2) 定位在 1 号染色体上 sd-1 的预测图谱位置。两个独立的 sd-1 等位基因在 Os20ox2 内包含改变：预计 Os20ox2 编码区内 280 bp 的缺失将编码籼型半矮秆中的无功能蛋白。 (Doongara)，而双加氧酶中高度保守的氨基酸残基 (Leu-266) 的取代可以解释粳稻半矮秆 (Calrose76) 中 Os20ox2 功能的丧失。 GC-MS对伸长茎中GA的定量表明，与高株相比，半矮秆中GA 20氧化酶活性的初始底物GA(53)积累，而主要产物(GA(20))和生物活性GA的含量较低。我们认为 Os20ox2 基因对应于 sd-1 位点。
The introduction of semidwarf rice (Oryza sativa L.) led to record yield increases throughout Asia in the 1960s. The major semidwarfing allele, sd-1, is still extensively used in modern rice cultivars. The phenotype of sd-1 is consistent with dwarfism that results from a deficiency in gibberellin (GA) plant growth hormones. We propose that the semidwarf (sd-1) phenotype is the result of a deficiency of active GAs in the elongating stem arising from a defective 20-oxidase GA biosynthetic enzyme. Sequence data from the rice genome was combined with previous mapping studies to locate a putative GA 20-oxidase gene (Os2Gox2) at the predicted map location of sd-1 on chromosome 1. Two independent sd-1 alleles contained alterations within Os20ox2: a deletion of 280 bp within the coding region of Os20ox2 was predicted to encode a nonfunctional protein in an indica type semidwarf (Doongara), whereas a substitution in an amino acid residue (Leu-266) that is highly conserved among dioxygenases could explain loss of function of Os20ox2 in a japonica semidwarf (Calrose76). The quantification of GAs in elongating stems by GC-MS showed that the initial substrate of GA 20-oxidase activity GA(53) accumulated, whereas the content of the major product (GA(20)) and of bioactive GA, was lower in semidwarf compared with tall lines. We propose that the Os20ox2 gene corresponds to the sd-1 locus.