In this study, the full cDNA sequences of HcADH2 and HcADH3 were cloned from Hedychium coronarium. The amino acid sequences encoded by them contained three most conserved motifs of short-chain alcohol dehydrogenase (ADH), namely NAD⁺ binding domain, TGxxx[AG]xG and active site YxxxK. The highest similarity between two genes and ADH from other plants was 70%. Phylogenetic analysis showed that they belonged to a member of the short-chain dehydrogenases/reductases 110C subfamily, but they were distinctly clustered in different clades. Real-time polymerase chain reaction analyses showed that HcADH2 was specifically expressed in bract, and it was expressed higher in no-scented Hedychium forrestii than other Hedychium species, but was undetectable in Hedychium coccineum. HcADH3 was expressed higher in the lateral petal of the flower than in other vegetative organs, and it was expressed the most in H. coronarium that is the most scented among Hedychium species, and its expression levels peaked at the half opening stage. HcADH2 and HcADH3 had almost no significant expression in leaves, but HcADH2 was expressed in response to external stimuli. The mechanical injury and methyl jasmonate (MeJA) treatment could induce expression of HcADH2 in leaves, whereas HcADH3 could have an induced expression only by MeJA. The recombinant HcADH3 protein, but not HcADH2, expressed in Escherichia coli-catalysed conversion of geraniol into citral. It was speculated that HcADH3 had an induced expression in vegetative organ of H. coronarium and took part in monoterpenoid biosynthesis in H. coronarium flowers, but the role of HcADH2 is relevant only for defensive reactions.

中文翻译：

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冠心日兰中两种短链醇脱氢酶/还原酶的差异表达及功能分析

在这项研究中，从Hedychium coronarium克隆了HcADH2和HcADH3的完整cDNA序列。由它们编码的氨基酸序列包含短链醇脱氢酶（ADH）的三个最保守的基序，即NAD ⁺结合结构域，TGxxx [AG] xG和活性位点YxxxK。两个基因与其他植物的ADH的最高相似度为70％。系统发育分析表明，它们属于短链脱氢酶/还原酶110C亚家族的成员，但它们明显地聚集在不同进化枝中。实时聚合酶链反应分析表明，HcADH2在片中特异表达，在无香的Hedychium forrestii中表达高于其他Hedychium属物种，但在Hedychium coccineum中无法检测到。HcADH3有人在花的侧向瓣比其他营养器官更高，并且它表达了最H.冠的，这是最香味之中姜花种，它的表达水平在半开放阶段见顶。HcADH2和HcADH3在叶中几乎没有明显表达，但是HcADH2在响应外部刺激时表达。机械损伤和茉莉酸甲酯（MeJA）处理可诱导叶片中HcADH2表达，而HcADH3只能由MeJA诱导表达。重组HcADH3蛋白在大肠杆菌催化的香叶醇转化为柠檬醛中表达，但不表达HcADH2。据推测，HcADH3有在营养器官的诱导表达H.冠的，并在单萜生物合成参加H.冠的花，但只用于防御反应HcADH2的作用有关。