玉米株型相关基因ZmDwarf2的克隆及表达分析

以玉米紧凑型自交系豫82、平展型自交系沈137为材料,利用同源克隆法成功克隆了与水稻Dwarf基因同源的玉米Dwarf2基因,该基因水稻上通过参与BR生物合成途径调控其株型形态建成。序列分析发现,玉米Dwarf2基因cDNA序列全长1 501bp,开放阅读框1 398bp,编码465个氨基酸。与水稻Dwarf基因的同源度达84%。实时荧光定量PCR分析表明,豫82、沈137中Dwarf2基因表达趋势基本一致,3～4叶期表达量低,8～12叶期处于表达高峰,13叶期后表达量逐渐下降。沈137中表达量较豫82高;就不同器官来说,沈137在叶片、叶枕、叶鞘、茎尖等器官中表达量较豫82高,其中,叶枕处ZmDwarf2表达量相对较高,而叶鞘上ZmDwarf2表达量相对较低。可以推测,基因ZmDwarf2可能参与玉米中BR生物合成途径,进而调控其相关株型形态建成。

Clone and Quantitative Analysis by Real-Time RT-PCR of Plant Architecture Traits Gene ZmDwarf2 in Maize

This study with inbred lines Yu 82 (a compact plant type) and Shen137 (a spreading plant type), cloning maize Dwarf2 gene with homology gene of the rice Dwarf by homology cloning method. The rice Dwarf participate in brassinolide (BR) biosynthesis. Sequence analysis indicated that the maize Dwarf2 gene was composed of 1501bp sequences including an open reading frame (ORF) of 1398bp region which encoded 465 amino acids. And it shared an amino acid sequence homology of 84%. Real-time quantitative PCR(RT-PCR) analysis revealed that the expression trends of ZmDwarf2 was the same as in the 3-4 leaf stage in expression initial, 8-12 leaf stage in express peak, after 13 leaf stage at a low volume expression basically with Yu 82 and Shen 137, and Shen 137 was highly expressed than Yu 82. As for the different tissue, Shen 137 was highly expressed amount than Yu 82 in the leaf, leaf cushion, leaf sheath and Meristem-tip, and ZmDwarf2 was highly expressed in theleaf cushion while its expression was very low in the leaf sheath. It is speculated that the ZmDwarf2 may be involved in BR biosynthetic pathway, and regulating the plant morphological built with maize.