Department of Crop and Soil Sciences, Pennsylvania State University, University Park, PA 16802, USA.
Genetics. 2011 May;188(1):69-79. doi: 10.1534/genetics.110.126136. Epub 2011 Mar 8.
In maize, mutations in the pr1 locus lead to the accumulation of pelargonidin (red) rather than cyanidin (purple) pigments in aleurone cells where the anthocyanin biosynthetic pathway is active. We characterized pr1 mutation and isolated a putative F3'H encoding gene (Zmf3'h1) and showed by segregation analysis that the red kernel phenotype is linked to this gene. Genetic mapping using SNP markers confirms its position on chromosome 5L. Furthermore, genetic complementation experiments using a CaMV 35S::ZmF3'H1 promoter-gene construct established that the encoded protein product was sufficient to perform a 3'-hydroxylation reaction. The Zmf3'h1-specific transcripts were detected in floral and vegetative tissues of Pr1 plants and were absent in pr1. Four pr1 alleles were characterized: two carry a 24 TA dinucleotide repeat insertion in the 5'-upstream promoter region, a third has a 17-bp deletion near the TATA box, and a fourth contains a Ds insertion in exon1. Genetic and transcription assays demonstrated that the pr1 gene is under the regulatory control of anthocyanin transcription factors red1 and colorless1. The cloning and characterization of pr1 completes the molecular identification of all genes encoding structural enzymes of the anthocyanin pathway of maize.
在玉米中,pr1 基因座的突变导致在胚乳细胞中积累矢车菊素(红色)而不是飞燕草素(紫色),而花青素生物合成途径在这些细胞中是活跃的。我们对 pr1 突变进行了表征,并分离出一个假定的 F3'H 编码基因(Zmf3'h1),并通过分离分析表明红色种皮表型与该基因相关。使用 SNP 标记的遗传作图证实了它在 5L 染色体上的位置。此外,使用 CaMV 35S::ZmF3'H1 启动子-基因构建体进行的遗传互补实验证实,编码的蛋白产物足以进行 3'-羟化反应。在 Pr1 植物的花和营养组织中检测到 Zmf3'h1 特异性转录本,而在 pr1 中则不存在。表征了四个 pr1 等位基因:两个在 5'上游启动子区域携带 24 TA 二核苷酸重复插入,第三个在 TATA 盒附近有 17 个碱基对缺失,第四个在外显子 1 中含有 Ds 插入。遗传和转录分析表明,pr1 基因受花青素转录因子 red1 和 colorless1 的调控。pr1 的克隆和表征完成了玉米花青素途径所有结构酶编码基因的分子鉴定。