利用RT-PCR、RACE和LA PCR相结合的方法,从大豆中克隆了GmAOS基因及其启动子序列(登录号为EU366252),GmAOS基因共1 789 bp碱基,等电点8.97,分子量58.3 kD,在3种不同抗性大豆材料中均有2个拷贝.生物信息学分析表明,GmAOS酶的N末端有典型叶绿体定位信号肽,基因序列上有多个丝氨酸、苏氨酸、酪氨酸的磷酸化位点.该研究克隆到ATG上游472个碱基的GmAOS基因启动子部分序列,其含有赤霉素的响应元件(TAACAA),可诱导性抗性基因响应元件(W box),细菌和盐诱导的响应元件(GAAAAA),茉莉酸诱导的响应元件(Gbox).GmAOS能强烈响应茉莉酸的诱导,且在黄皮小青豆(高抗斜纹夜蛾)中表达量高于徐疃大豆,两种材料抗虫性的差异可能是由GmAOS基因受诱导后的表达量差异引起的,即GmAOS基因与作物抗虫性相关,可作为培育高诱导抗性材料的候选基因.%Allene oxide synthase (AOS) is a major intermediate enzyme in octadecanoid pathway to JA biosynthesis affecting the synthesis and levels of all JA-related compounds in plants, and therefore plays a significant role in plant defense.In this study, a full length cDNA of GmAOS and its promoter were cloned from the soybean (Glycine max) by RT-PCR, RACE, and LA PCR methods.GmAOS cDNA coding 519 amino acids (58.3 kD) with an isoelectric point of 8.97 and two genes copies in the soybean genome coding for GmAOS.Bioinformatics analysis indicated that the N-terminal region of GmAOS displayed features of a typical chloroplast targeting peptide including an enrichment of serine, threonine and tyrosine phosphorylation sites.The length of the promoter was 472 bp, containing several stress-induced elements: GA inducing elements (TAACAA), W-box element which was in response to elicitor-responsive transcription of defense genes, element responsive to salt and pathogen (GAAAAA) and G-box (CACGTG) induced by JA.Jasmonic acid showed a strong inducement of the GmAOS transcript level, expression patterns of GmAOS were explored in two soybean accessions with distinct resistance to cotton worm: XTDD was highly susceptible and HPXQD highly resistant, showing that GmAOS had higher transcript level in HPXQD(HR) than in XTDD(HS).GmAOS transcript level were correlated with soybean material resistance grades.These results suggest GmAOS is likely to be a useful tool for improving self-resistance abality of high plants.
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