砀山酥梨果实苯丙氨酸解氨酶基因cDNA克隆及序列分析

为了研究梨石细胞形成与木质素合成的关系，以砀山酥梨果实为材料，通过基于同源性的RT—PCR方法，克隆木质素合成途径中的关键酶苯丙氨酸解氨酶（PAL）基因。同时利用基因数据库资料对克隆的PAL序列进行比较分析。结果表明，从砀山酥梨果实中克隆的PAL基因eDNA片段长度为585bp，推断其编码195个氨基酸序列。该序列包含与其它植物PAL相同的活性催化位点，经序列分析和同源性比对，该氨基酸序列与其它植物PAL氨基酸序列的同源性在90％以上。系统进化树分析表明，砀山酥梨PAL氨基酸序列与蔷薇科的甜樱桃PAL氨基酸序列聚类关系最近。

Cloning and Sequencing of a Phenylalanine Ammonia-lyase cDNA from Pyrus bretschneideri cv

Phenylalanine Ammonia-lyase （PAL） is the key enzyme in lignin biosynthetic pathway. The PAL gene was cloned from the fruit of Pyrus bretschneideri cv by RT-PCR in order to study the relationship between stone cells and lignin synthsis. The sequence of the eDNA fragment was 582 base pairs and encoded a 195 amino acid protein. And it was found to have 90 % homology with those of other plants PAL genes via multiple alignments. The catalytic active sites in PAL protein of other plants were also found in the deduced PAL protein. Phylogenetie tree analysis revealed that the PAL amino acid of the Pyrus bretschneideri cv had closer relationship with the PAL amino acid of the Pyrunus avium than from other plants.