在异黄酮合成途径中,异黄酮合酶(Isoflavone synthase,IFS)基因起着重要作用,为此,分析了IFS1基因(IFS基因的同源基因之一)在大豆中的表达特点。组织表达分析表明,IFS1基因在根、茎、叶、花、籽粒、豆荚和胚中均有表达,其中在较嫩的组织(萌发7 d的豆苗根、茎、叶)中表达量较高,在较老的组织(生长70 d的豆苗根、茎、叶)中表达量较低,在开花后25,45 d的籽粒和豆荚及花中表达量也较低,而在成熟胚中IFS1基因表达量较高,推测该基因在胚形成早期就已经完成了大豆异黄酮的积聚过程。不同非生物胁迫的诱导表达分析表明,IFS1基因不同程度地受IAA、ABA、PEG、NaCl、低温和创伤胁迫诱导表达,表明该基因参与了大豆的逆境应答。
Previous studies have shown that isoflavone synthase (IFS) encode key enzymes in the isoflavonoids pathway in Soybean．There are two IFS homologues IFS1 and IFS2 in Soybean，The expression level of IFS1 gene in different tissues will be quantified by fluorescence quantitative PCR． The results revealed that the transcripts were widely distributed in all the tested tissues．IFS1 gene showed the higher expression level in the tender organs: root，stem， leaf germinating 7 days than that in the older organs: roots，stems，leaves growing 70 days． Expression level in seeds at 25 days and 45 days post anthesis were also lower，while with higher content in the mature embryo，suggesting that IFS1 gene has finished the Soybean isoflavone accumulation process in the early embryo formation．Further，the analysis of expression induced by abiotic treatments indicated that the genes were differentially regulated under IAA，ABA，PEG，NaCl，cold and wounding treatments． It will provide more knowledges on isoflavone biosynthesis and resistance to abiotic stress in Soybean．
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