洋葱苯丙氨酸解氨酶基因AcPAL2的克隆与表达分析

利用简并PCR技术和RACE技术克隆得到了一条洋葱的苯丙氨酸解氨酶(PAL)基因全长cDNA序列。该cDNA序列全长2349 bp,编码长685个氨基酸残基的多肽序列,命名为AcPAL2。Blast分析表明该序列与虎眼万年青Galtonia saundersiae、野蕉Musa balbisiana的相似性均较高。Real-time PCR表达及花青素含量分析表明,红皮洋葱该基因表达量最大,而黄皮和白皮洋葱表达量极低;在红皮洋葱中该基因在膨大初期大量表达,并迅速降低至一定程度后趋于相对平稳表达,且与花青素的积累过程相一致。

Molecular Cloning and Expression Analysis of AcPAL2 in Onion

A full-length cDNA of phenylalanine ammonia lyase-homologue（AcPAL2）was isolated from onion using degenerate PCR and the RACE（rapid amplification of cDNA ends）method. The full-length cDNA is 2 349 bp long，which encodes a polypeptide of 685 amino acids. Blast analysis indicate that the polypeptide shares a relatively high similarity with Galtonia saundersiae and Musa balbisiana. Real-time PCR analysis demonstrate that AcPAL2 mRNA express abundantly in red onions，but extremely low in yellow and white onions；AcPAL2 in different bulb swelling stage in red onion has a high expression during the initiation，then express stable after a rapid decrease. And anthocyanin content change also shows the same tendency with AcPAL2 expression.