Lei W, Yao R X, Kang X H, Tang S H, Qiao A M, Sun M
Key Laboratory of Eco-Environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Science, Southwest University, Chongqing, China.
Genet Mol Res. 2011 Nov 22;10(4):3385-402. doi: 10.4238/2011.November.22.7.
Anthocyanidin is a group of flavonoid compounds used as a vegetable pigment and plays an important role in flower coloration and environmental adaptations of the Chinese ornamental plant Scutellaria viscidula. We determined the cDNA sequences of phenylalanine ammonia-lyase (SvPAL), flavanone 3-hydroxylase (SvF3H) and dihydroflavonol 4-reductase (SvDFR) genes in S. viscidula. Comparative analysis showed that the protein products of these three genes did not have a transit peptide at their N-terminal portion, which indicated that these enzymes were directly involved in the substrate conversion in the cytoplasmic matrix. Bioinformatic analysis further revealed that Svpal, Svf3h and Svdfr were the members of flavonoid biosynthetic genes with highly conserved motifs. Based on phylogenetic tree analysis, it appears that PAL, F3H or DFR from different plants might have originated from the same ancestor. This study can help to map and regulate the important stages involved in anthocyanidin biosynthesis by genetic engineering to diversify flower color and improve the ornamental value of S. viscidula.
花青素是一类用作植物色素的黄酮类化合物，在中国观赏植物粘毛黄芩的花色形成和环境适应性中发挥着重要作用。我们测定了粘毛黄芩中苯丙氨酸解氨酶（SvPAL）、黄烷酮3-羟化酶（SvF3H）和二氢黄酮醇4-还原酶（SvDFR）基因的cDNA序列。比较分析表明，这三个基因的蛋白质产物在其N端部分没有转运肽，这表明这些酶直接参与细胞质基质中的底物转化。生物信息学分析进一步揭示，SvpAL、SvF3H和SvDFR是具有高度保守基序的类黄酮生物合成基因成员。基于系统发育树分析，不同植物的PAL、F3H或DFR似乎起源于同一祖先。本研究有助于通过基因工程绘制和调控花青素生物合成的重要阶段，以使花色多样化并提高粘毛黄芩的观赏价值。
