Jung Chun Suk, Griffiths Helen M, De Jong Darlene M, Cheng Shuping, Bodis Mary, De Jong Walter S
Department of Plant Breeding, Cornell University, Ithaca, NY 14853-1901, USA.
Theor Appl Genet. 2005 Jan;110(2):269-75. doi: 10.1007/s00122-004-1829-z. Epub 2004 Nov 24.
The potato P locus is required for the production of blue/purple anthocyanin pigments in any tissue of the potato plant such as tubers, flowers, or stems. We have previously reported, based on RFLP mapping in tomato, that the gene coding for the anthocyanin biosynthetic enzyme flavonoid 3',5'-hydroxylase (f3'5'h) maps to the same region of the tomato genome as P maps in potato. To further evaluate this association a Petunia f3'5'h gene was used to screen a potato cDNA library prepared from purple-colored flowers and stems. Six positively hybridizing cDNA clones were sequenced and all appeared to be derived from a single gene that shares 85% sequence identity at the amino acid level with Petunia f3'5'h. The potato gene cosegregated with purple tuber color in a diploid F1 sub-population of 37 purple and 25 red individuals and was found to be expressed in tuber skin only in the presence of the anthocyanin regulatory locus I. A potato f3'5'h cDNA clone was placed under the control of a doubled CaMV 35S promoter and introduced into the red-skinned cultivar 'Desiree'. Tuber and stem tissues that are colored red in Desiree were purple in nine of 17 independently transformed lines.
马铃薯的P基因座是马铃薯植株任何组织（如块茎、花朵或茎）中产生蓝色/紫色花青素色素所必需的。我们之前基于番茄的RFLP图谱报道，编码花青素生物合成酶类黄酮3',5'-羟化酶（f3'5'h）的基因定位于番茄基因组的同一区域，该区域与马铃薯中的P基因座相对应。为了进一步评估这种关联，使用矮牵牛f3'5'h基因筛选了一个由紫色花朵和茎制备的马铃薯cDNA文库。对六个阳性杂交cDNA克隆进行了测序，结果显示它们似乎都来自同一个基因，该基因在氨基酸水平上与矮牵牛f3'5'h具有85%的序列同一性。在一个由37个紫色个体和25个红色个体组成的二倍体F1亚群中，该马铃薯基因与紫色块茎颜色共分离，并且发现仅在花青素调控基因座I存在的情况下，该基因才在块茎表皮中表达。将一个马铃薯f3'5'h cDNA克隆置于双CaMV 35S启动子的控制下，并导入红皮品种‘德西蕾’。在17个独立转化的株系中，有9个株系中原本红色皮肤的‘德西蕾’的块茎和茎组织变成了紫色。
