Gene Cloning And Bioinformatics Analysis Of Phenylalanine Ammonia-lyase In Ginkgo Biloba

Ginkgo (Ginkgo biloba L.), a living fossil, is native to China and cultivated in urban areas throughout the world. In recent years, Ginkgo leaf extracts have been used to treat cerebrovascular and cardiovascular diseases. Ginkgo and its related industry are consisted an important part of the herbal medicine industry in Europe.To develop the ginkgo industry, the first thing is to improve the quality of ginkgo leaf. One of the most hopeful and effective approach is to utilize the gene engineering technology, especially "gene-adding" and "gene-knock out", which can modify the key enzyme in the plant secondary metabolites to enhance or reduce the production of specific secondary metabolites. To do this, the first step is to clone the genes those encoding the key enzyme.Flavonoids are important efficiency components in ginkgo leaf. In the biosynthetic pathway of flavonoids, the phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), which links primary and secondary metabolism by catalyzing the conversion of L-phenylalanine to cinnamic acid, is the first key enzyme in the pathway of plant secondary metabolism. Using degenerate PCR primers that target evolutionary conserved sequences in PAL gene, we have cloned part sequences of the PAL gene in ginkgo. The length of the sequence is 1140bp and was enrolled in the GenBank of NCBI. The accession number is AY231176.Also, the PAL gene sequence of ginkgo was analyzed by bioinformatics. The results show that the ginkgo PAL gene consists of one exon and without intron. The loci in the ginkgo PAL are accords with the characters of other PAL. The phylogenetic tree constructed by PAL sequence is similar with the tree of morphological classification.