摘要:
丙二烯氧合酶(AOS)是茉莉酸(JA)生物合成途径中的关键酶，为深入研究AOS基因在唐菖蒲茉莉酸生物合成途径中的作用及唐菖蒲球茎膨大的分子机制，以唐菖蒲品种‘Rose Supreme’的球茎为试材，采用RT--PCR和RACE技术，克隆到了一个GhAOS的cDNA序列，序列内部含有一个1 533 bp的开放阅读框（ORF）,编码510个氨基酸，推导的蛋白质分子质量为56.53 kD。组织特异性RT--PCR表达分析表明：GhAOS基因在唐菖蒲叶、花、根、匍匐茎、新球茎和籽球上都表达，而在叶和匍匐茎中表达量较高；经过不同浓度梯度的水杨酸(SA) 0、0.1、0.5、1.0、2.0 mmol/L处理后，在唐菖蒲球茎中GhAOS基因的表达水平随着浓度的升高而降低。结果表明，GhAOS是一个新的AOS基因，SA抑制了该基因的表达，初步验证了SA与JA在信号途径中相互拮抗的作用。
关键词:
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唐菖蒲
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茉莉酸
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丙二烯氧合酶
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克隆
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表达
Abstract:
As a key enzyme, allene oxide synthase(AOS) plays an important role in the biosynthesis of jasmonic acid(JA). In order to study its function in the process and molecular mechanism of corm expansion for Gladiolus hybridus, a full-length cDNA of GhAOS, containing a 1 533 bp open reading frame(ORF) encoding 510 putative amino acids with a calculated protein molecular weight of 56.53 kD, was cloned from the corms of G. hybridus ‘Rose Supreme’ through RT-PCR and RACE technologies. The tissue-specific expression analysis using RT-PCR showed that the GhAOS was expressed in leaves, stolons, flowers, roots, corms and cormels. Moreover, its RNA level was higher in leaves and stolons. In corms, the expression level of GhAOS decreased with the increasing concentrations of salicylic acid(SA) from 0, 0.1, 0.5, 1.0 to 2.0 mmol/L.In summary, results indicate that GhAOS is a novel AOS gene and repressed by SA in mRNA level, which primarily verifies the antagonistic interaction between SA and JA in signaling pathways.
百度学术
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