Jia Qiaojun, Zhang Jingjuan, Westcott Sharon, Zhang Xiao-Qi, Bellgard Mathew, Lance Reg, Li Chengdao
Institute of Crop and Nuclear Technology Utilization, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
Funct Integr Genomics. 2009 May;9(2):255-62. doi: 10.1007/s10142-009-0120-4. Epub 2009 Mar 12.
The barley sdw1/denso gene not only controls plant height but also yield and quality. The sdw1/denso gene was mapped to the long arm of chromosome 3H. Comparative genomic analysis revealed that the sdw1/denso gene was located in the syntenic region of the rice semidwarf gene sd1 on chromosome 1. The sd1 gene encodes a gibberellic acid (GA)-20 oxidase enzyme. The gene ortholog of rice sd1 was isolated from barley using polymerase chain reaction. The barley and rice genes showed a similar gene structure consisting of three exons and two introns. Both genes share 88.3% genomic sequence similarity and 89% amino acid sequence identity. A single nucleotide polymorphism was identified in intron 2 between barley varieties Baudin and AC Metcalfe with Baudin known to contain the denso semidwarf gene. The single nucleotide polymorphism (SNP) marker was mapped to chromosome 3H in a doubled haploid population of Baudin x AC Metcalfe with 178 DH lines. Quantitative trait locus analysis revealed that plant height cosegregated with the SNP. The sdw1/denso gene in barley is the most likely ortholog of the sd1 in rice. The result will facilitate understanding of the molecular mechanism controlling semidwarf phenotype and provide a diagnostic marker for selection of semidwarf gene in barley.
大麦的sdw1/denso基因不仅控制株高，还影响产量和品质。sdw1/denso基因被定位到3H染色体的长臂上。比较基因组分析表明，sdw1/denso基因位于水稻第1染色体上半矮秆基因sd1的同线区域。sd1基因编码一种赤霉素（GA）-20氧化酶。利用聚合酶链反应从大麦中分离出水稻sd1的同源基因。大麦和水稻基因显示出相似的基因结构，由三个外显子和两个内含子组成。两个基因的基因组序列相似度为88.3%，氨基酸序列一致性为89%。在大麦品种Baudin和AC Metcalfe的内含子2中鉴定出一个单核苷酸多态性，已知Baudin含有denso半矮秆基因。该单核苷酸多态性（SNP）标记在由178个双单倍体系组成的Baudin×AC Metcalfe双单倍体群体中被定位到3H染色体上。数量性状位点分析表明，株高与该SNP共分离。大麦中的sdw/denso基因很可能是水稻中sd1的直系同源基因。这一结果将有助于理解控制半矮秆表型的分子机制，并为大麦半矮秆基因的选择提供诊断标记。
