Meyer P, Heidmann I, Forkmann G, Saedler H
Max-Planck-Institut für Züchtungsforschung, Köln, FRG.
Nature. 1987;330(6149):677-8. doi: 10.1038/330677a0.
Petunia hybrida is one of the classical subjects of investigation in plants in which the pathway of anthocyanin biosynthesis has been analysed genetically and biochemically. In petunia cyanidin- and delphinidin-derivatives, but no pelargonidin-derivatives are produced as pigments. This is due to the substrate specificity of the dihydroflavonol 4-reductase of petunia, which cannot reduce dihydrokaempferol. The petunia mutant RL01, which accumulates dihydrokaempferol, shows no flower pigmentation. RL01 served as a recipient for the transfer of the A1 gene of Zea mays encoding dihydroquercetin 4-reductase, which can reduce dihydrokaempferol and thereby provided the intermediate for pelargonidin biosynthesis. Transformation of RL01 with a vector p35A1, containing the A1-complementary DNA behind the 35S promotor leads to red flowers of the pelargonidin-type. Thus a new flower pigmentation pathway has been established in these plants.
矮牵牛是植物研究中的经典对象之一，其花青素生物合成途径已从遗传学和生物化学角度进行了分析。在矮牵牛中，作为色素产生的是花青素和飞燕草色素衍生物，而没有天竺葵色素衍生物。这是由于矮牵牛二氢黄酮醇4-还原酶的底物特异性，它不能还原二氢山奈酚。积累二氢山奈酚的矮牵牛突变体RL01没有花色。RL01作为受体，用于转移玉米编码二氢槲皮素4-还原酶的A1基因，该酶可以还原二氢山奈酚，从而为天竺葵色素的生物合成提供中间体。用载体p35A1转化RL01，该载体在35S启动子后含有A1互补DNA，可产生天竺葵色素型的红色花朵。因此，在这些植物中建立了一条新的花色形成途径。
