草莓果实基因表达与花色苷代谢的关系

Relation of gene expression to anthocyanins metabolism in strawberry fruits

为进一步探究草莓果实花色苷合成过程中各个酶的作用,明确草莓果实花色苷的代谢机制,以‘阿尔比’草莓(Fragaria×ananassa‘Albion’)为试材,利用RT-PCR从草莓果实中克隆到DFR、ANS和LAR基因的编码序列,对预测的氨基酸序列进行分析,结果表明:各基因与NCBI(美国国立生物技术信息中心)上已有的草莓品种‘Queen Elisa’及‘Korona’(Fragaria×ananassa)所对应基因的同源性高达99%～100%。半定量RT-PCR分析表明,DFR基因依次在幼果期、白熟期和红熟期出现了3个表达峰值,其中红熟期最大;ANS基因的表达量在白熟期后迅速增加,红熟期达最大值;LAR基因的最大表达量出现在幼果期,后呈降低趋势。草莓果实发育过程中,DFR基因在幼果期和红熟期的表达峰值分别与黄烷-3-醇类和花色苷的合成峰值相一致,ANS及LAR分别与花色苷和黄烷-3-醇类的合成密切相关。

The aim of this research is to probe further into the anthocyanins metabolism and functions of enzymes involved in the synthesis of anthocyanins in strawberry fruits. The coding sequences of three genes encoding DFR,ANS and LAR were cloned from ＇ Albion＇ （Fragaria x ananassa） strawberry fruits by RT-PCR. The predicted protein sequences shared 99 % ~ 100% homology to those of ＇Queen El isa ＇ and ＇ Korona＇ （Fragaria x ananassa） strawberry published in NCBI. Semiquantitative RT-PCR showed that DFR had three transcript level peaks at fruitlet stage, white stage and red stage, respectively, with the highest at red stage. The transcript level of ANS increased rapidly from white stage, reaching the highest at red stage. The transcript level of LAR showed a decreased trend with the highest at fruitlet stage. During the development of strawberry fruits, the transcript level of DFR peaks at fruitlet and red stages correlated with the concentration of flavan-3-nols and anthocyanins. The LAR and ANS were closely correlative with the synthesis of anthocyanins and flavan-3-ols, respectively.