Molecular cloning, characterization and expression of phenylalanine ammonia-lyase gene from Ginkgo biloba
Molecular cloning, characterization and expression of phenylalanine ammonia-lyase gene from Ginkgo biloba
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DOI：
10.4314/ajb.v7i6.58514
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发表时间：
2008
影响因子：
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通讯作者：
F. Xu;R. Cai;S. Cheng;H. Du;Yan Wang
中科院分区：
文献类型：
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作者：
F. Xu;R. Cai;S. Cheng;H. Du;Yan Wang
首次从银杏中分离到一个苯丙氨酸解氨酶基因的全长cDNA和基因组DNA（命名为GbPAL，GenBank登录号为EU 071050）。GbPAL基因的cDNA序列与基因组DNA序列完全相同，即该基因是无内含子的。该基因编码区全长2172 bp，编码蛋白由724个氨基酸组成，预测分子量为79.1 kDa，等电点为5.96。GbPAL蛋白与其它植物帕尔斯蛋白具有较高的同源性。基因组DNA的Southern杂交分析表明，GbPAL属于一个多基因小家族。实时荧光定量PCR分析表明，GbPAL在所有供试组织中均组成型表达，尤其在叶和茎中表达量较高。GbPAL也被观察到由各种胁迫诱导，包括UV-B，伤害，寒冷和水杨酸。时间表达谱分析表明，GbPAL的转录水平与类黄酮的积累显著相关，提示GbPAL可能在银杏叶片类黄酮的合成中起调控作用。biloba在转录水平上。
A full-length cDNA and genomic DNA of phenylalanine ammonia-lyase gene, which catalyzes the first step in the flavonoid biosynthetic pathway, were isolated from Ginkgo biloba for the first time (designated as GbPAL, GenBank Accession No. EU071050). The cDNA and genomic DNA sequences of GbPAL were the same, in other words, this gene is intronless. The coding region of the gene was 2172 bp long, and its deduced protein consists of 724 amino acids with a predicted molecular mass of 79.1 kDa and a pI of 5.96. The deduced GbPAL protein showed high identities to other plant PALs. Southern hybridization analysis of the genomic DNA indicated that GbPAL belonged to a small multi-gene family. Tissue expression analysis by real-time PCR revealed that GbPAL constitutively expressed in all the tested tissues, especially highly in leaf and stem. GbPAL was also observed to be induced by a variety of stresses including UV-B, wounding, cold and salicylic acid. Temporal expression profiling analyses showed that the transcription levels of GbPAL were significantly correlated with flavonoid accumulation, suggesting that GbPAL might play a regulatory role in flavonoid biosynthesis in leaves of G. biloba at the transcriptional level.