观赏向日葵花青素苷合成途径同源基因的克隆与表达

Cloning and Expression of Genes Involved in Anthocyanins Synthesis in Ornamental Sunflower

根据已发布的基因保守区域设计引物，从观赏向日葵（Helianthus annuus L.）舌状花中克隆到花青素苷生物合成途径中PAL、CHS、CHI、F3′H、DFR和ANS等6个结构基因的保守序列，序列分析表明这6个结构基因与其它植物来源的花青素苷生物合成相关基因均具有较高的同源性，分别为95％-97％、83％-99％、64％-80％、80％-82％、64％-85％和87％-89％。系统进化分析表明6个结构基因的系统进化基本上符合植物分类学分类。半定量RT-PCR分析表明，除CHS基因在管状花中未表达外，6个基因在舌状花、管状花、花蕾、叶片和茎皮中均有表达；大部分基因在花开放初期和盛期的表达较高，而花完全开放后，所有基因的表达量降低；观赏向日葵花青素苷合成相关基因的表达量在紫红色花瓣中高于红褐色花瓣，深色花瓣高于混杂色花瓣。

Six structural genes （PAL, CHS, CHI, F3′H , DFR , ANS ） involved in anthocyanins synthesis were cloned from the ray florets of ornamental sunflower （Helianthus annuus L.） by homology sequence cloning. Sequence analysis showed that these genes shared high similarity with genes from other plants, ranging from 95%-97% , 83%-99%, 64%-80% , 80% -82% , 64%-85% and 87%-89% , respectively. The results of phylogenetic analysis were in agreement with that described in plant taxonomy. Semi-quantitative RT-PCR indicated that the transcripts of all six genes were detected in ray florets, tubular florets, buds, leaves, and barks except that the transcript of CHS was not detected in tubular florets. Expression levels of most structural genes were higher in first florescence and full bloom periods and then decreased. The transcripts of these genes were higher in purple petals than in chocolate petals, and higher in petal with deep color than with multi-color.