biosynthetic pathway are functionally conserved across diverse plant species and the genes that encode these enzymes share high sequence similarity across species. Six enzymes are commonly involved in anthocyanin biosynthesis ( Griesbach, 2005 ). Chalcone
John R. Stommel and Judith M. Dumm
Satoru Kondo, Kentaro Hiraoka, Shozo Kobayashi, Chikako Honda, and Norihiko Terahara
Cyanidin 3-galactoside was the primary anthocyanin in red `Tsugaru' apples [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.]. The concentration of cyanidin 3-galactoside in the skin decreased from 20 to 62 days after full bloom (DAFB), then increased rapidly after 104 DAFB. Small amounts of cyanidin 3-arabinoside and cyanidin 3-glucoside were detected at 122 and 133 DAFB (harvest). The expression of five anthocyanin biosynthetic genes of chalcone synthase (MdCHS), flavanone 3-hydroxylase (MdF3H), dihydroflavonol 4-reductase (pDFR), anthocyanidin synthase (MdANS), and UDP glucose-flavonoid 3-O-glucosyltransferase (pUFGluT) was examined in the skin of red and nonred apples. In general, the expression of anthocyanin biosynthetic genes in red apples was strong in juvenile and ripening stages. The expression of MdCHS, MdF3H, pDFR, and MdANS was observed before ripening stage when anthocyanin was not detected. In contrast, the expression of pUFGluT was detected in the development stage only when anthocyanin was detected. However, the expression of all five genes was observed at 20 DAFB in fruit bagged after fertilization, and anthocyanin was not detected. The expression of MdCHS, MdF3H, pDFR, and MdANS, excluding pUFGluT, was detected at 98 DAFB in fruit bagged after 30 DAFB, and anthocyanin was not detected. These results suggest that pUFGluT may be closely related to the anthocyanin expression in apple skin at the ripening stage.
189 COLLOQUIUM 4 (Abstr. 10061010) Strategies for Developing Horticulturally Useful Genes
Paola S. Cotroneo, Maria P. Russo, Manuela Ciuni, Giuseppe Reforgiato Recupero, and Angela R. Lo Piero
Genes encoding chalcone synthase (CHS), anthocyanidin synthase (ANS), and UDP-glucose-flavonoid 3-O-glucosyltransferase (UFGT), some of the enzymes of anthocyanin biosynthetic pathway, were assayed in two different experiments using quantitative real-time reverse transcriptase (RT)-PCR, in order to test their transcription levels in the flesh of blood and common orange [Citrus sinensis (L.) Osbeck] fruit, and to investigate their role in anthocyanin accumulation in the same tissue. The first experiment compared a blood orange and a common orange cultivar during seven different fruit maturation stages. This was followed by the test of 11 different genotypes at the end of the winter season. Data collected from the first experiment, over the blood orange cultivar, were statistically analyzed using the Pearson correlation coefficient. Results show that CHS, ANS, and UFGT mRNA transcripts are up- and co-regulated in the blood orange cultivar, whereas they are down-regulated in the common orange cultivar. There is evidence of correspondence between the target genes expression level and the content of the pigment assessed. The second test confirms this correlation and shows that enzyme synthesis levels and pigment accumulation, in plants grown under the same environmental conditions, are dependent on the differences occurring among the genotypes tested. These results suggest that the absence of pigment in the common orange cultivars may be caused by the lack of induction on the structural genes expression. This is the first report on the characterization of the relationships between biosynthetic genes expression and fruit flesh anthocyanin content in blood oranges.
Rasika G. Mudalige-Jayawickrama, Michele M. Champagne, A. David Hieber, and Adelheid R. Kuehnle
kind support and providing facilities for radioactive work. Two new gene sequences were submitted to GenBank. Accession numbers are AY741318 and AY741319 for dihydroflavonol 4-reductase gene and chalcone synthase gene, respectively.
John R. Stommel, Gordon J. Lightbourn, Brenda S. Winkel, and Robert J. Griesbach
, and the B locus ( Dooner et al., 1991 ). R-like MYC proteins were shown to physically interact with C1 MYB proteins to coactivate anthocyanin synthesis by directly binding to the promoters of the biosynthetic genes. The third component of the
Ji Tian, Zhen-yun Han, Li-ru Zhang, Ting-Ting Song, Jie Zhang, Jin-Yan Li, and Yuncong Yao
transcription factors (TFs) from the R2R3-MYB, bHLH, and WD40 classes ( Hichri et al., 2011 ). The MYB/bHLH/WDR (MBW) complex is thought to recognize and bind to response elements in promoter regions of the late biosynthetic genes (LBGs) of the anthocyanin
Yanjie Wang, Yeqing Chen, Man Yuan, Zeyun Xue, Qijiang Jin, and Yingchun Xu
between expression patterns of flavonoid biosynthetic genes and pigment accumulation in diverse flower color cultivars of N . nucifera throughout flower development, and molecular mechanisms involved in pigmentation process, especially anthocyanin
Dineshkumar Selvaraj, Sherif Sherif, Mohd Sabri Pak Dek, Gopinadhan Paliyath, Islam El-Sharkawy, and Jayasankar Subramanian
-glucosyl transferase (Pd-UFGT) were evaluated based on corolla color intensity. ( B ) Schematic representation of anthocyanin biosynthetic pathway. All the enzymes involved in the pathway are in bold. The candidate genes examined in this study are boxed. The