不同花色菊花品种花色素结构基因的表达特性

Expression Profiles of Anthocyanin Biosynthetic Genes in Chrysanthemum Cultivars with Different Flower Colors

对红色、黄色、粉紫色和白色菊花品种不同开放度的花序舌状花中CHS、CHI、DFR、F3H、F3′H和3GT基因的表达量进行了相对定量分析。结果表显示:6个基因的表达因不同花色、不同发育阶段而异。‘钟山红鹰’(红色)中各基因的表达量均较高,且均在Ⅱ(松蕾期)或Ⅲ(半开期)期达到峰值,其中DFR、3GT基因的表达量远高于其他花色品种。‘金陵娇黄’(黄色)中CHS、CHI基因表达量较高,且Ⅰ(紧蕾期)、Ⅱ期表达量高于Ⅲ、Ⅳ(盛开期)期;3GT、DFR基因表达量分别高或低于‘金陵笑靥’(粉紫色)品种中相应基因的表达量,但均比红色品种低;F3H在4个品种中表达量最低,F3′H表达量接近或略低于红色或粉紫色品种,且各阶段表达水平较稳定。‘金陵笑靥’中DFR表达量仅次于‘钟山红鹰’,3GT和CHS表达量低于红色与黄色品种。‘钟山雪桂’(白色)中各基因仅有微量表达,除F3H外各基因的表达量明显低于其他花色品种。研究表明,花色素结构基因DFR、3GT是菊花花色素合成的关键基因,DFR很可能是限速关键基因,一定表达水平的CHS、CHI也是菊花花色素合成所必须的,F3H基因与花色素合成不存在直接相关。

In order to clarify the roles of anthocyanin biosynthetic genes in the anthocyanin biosynthesis and pigmentation of chrysanthemum flower,CHS,CHI,DFR,F3H,F3＇H and 3GT in the ray florets from florescences at different development stages were quantified in the red,yellow,pale purple and white-flowered chrysanthemum cultivars.The results showed that expression profiles of the genes are cultivar-dependent and varied at different development stages.In red ＇Zhongshanhongying＇,all six genes＇ transcripts are of high levels,and peaked at stage Ⅱ （loosen bud） or Ⅲ （half-opened flower）,of which the transcript levels of DFR and 3GT were extremely higher than those in the remaining cultivars.In yellow-flowered chrysanthemum ＇Jinlingjiaohuang＇,transcripts of CHS and CHI were relatively high,the levels at stage Ⅰ and Ⅱ were higher than those at stage Ⅲ and Ⅳ.The transcripts level of 3GT and DFR was higher or lower than that in pale purple cultivar,respectively,but both were lower than that in red ＇Zhongshanhongying＇.F3H transcript level in ＇Jinlingjiaohuang＇ was the lowest among four cultivars studied,while accumulation of F3＇H transcripts was near or slightly lower to that of red and pale purple cultivars,and remained stable throughout four stages.In pale purple ＇Jinlingxiaoye＇,transcripts level of DFR is close to that of ＇Zhongshanhongying＇,transcript levels of 3GT and CHS were lesser compared with those of red and yellow cultivars.In white ＇Zhongshanxuegui＇,all genes except F3H showed trace of expression and were lower than those in other three colored cultivars.It inferred that DFR and 3GT genes play key roles in the anthocyanin biosynthesis,and DFR is likely the bottle-neck gene in anthocyanin biosynthesis.A certain levels of CHS and CHI transcripts are necessary,the relationship of F3H expression and anthocyanin biosynthesis remained unclear.