Transcriptional control of anthocyanin biosynthetic genes in the Caryophyllales

Abstract

Anthocyanins and betacyanins, two types of red pigment, have never been found to occur together in plants. Although anthocyanins are widely distributed in higher plants, betacyanins have replaced anthocyanins in the Caryophyllales. The accumulation of flavonols in the Caryophyllales suggests that the step(s) of anthocyanin biosynthesis from dihydroflavonols to anthocyanins could be blocked in the Caryophyllales. Dihydroflavonol 4-reductase (DFR) and anthocyanidin synthase (ANS) cDNAs were isolated from plants of the Caryophyllales. An enzyme activity assay showed that the Caryophyllales possess functional DFR and ANS. The expression profile revealed that DFR and ANS are not expressed in most tissues and organs except the seeds in Spinacia oleracea. Here, the promoter regions of DFR and ANS were isolated from S. oleracea. Analysis of DFR and ANS promoter sequences revealed several putative transcriptional factor-binding motifs. A yeast one-hybrid assay showed that Petunia hybrida AN2 (PhAN2) and JAF13 (PhJAF13), which were the regulators of anthocyanin synthesis in P. hybrida, could bind to the S. oleracea DFR and ANS promoters. However, the transient assay in Phytolacca americana cell cultures and leaves of S. oleracea showed that the promoters were not activated by ectopic expression of PhAN2 and PhJAF13, while the DFR and ANS promoters of Arabidopsis thaliana, an anthocyanin-producing species, were activated. One possible explanation for the lack of anthocyanins in the Caryophyllales is the difference in the promoter regions of DFR and ANS compared with those of anthocyanin-producing species.

Biosynthesis of plant pigments: anthocyanins, betalains and carotenoids

“…Transposon tagging, which has been successfully used to identify relevant genes in the flavonoid biosynthetic pathways in maize, petunia and morning glories, may be the most efficient way to identify the genes involved in betalain biosynthesis. Characterization of the genes encoding the flavonoid/anthocyanidin biosynthetic enzymes in betacyanin-producing plants has begun (Shimada et al, 2004(Shimada et al, , 2005(Shimada et al, , 2007. This may help clarify the taxonomic mystery of Caryophyllales.…”

Expression divergence of cellulose synthase (CesA) genes after a recent whole genome duplication event in Populus

“…Transient expression assay pUC18-based vectors containing CaMV35S::firefly luciferase (LUC) and CaMV35S::Renilla reniformis luciferase (RLUC) (Shimada et al 2007) were provided by Prof. Masaaki Sakuta (Department of Biology, Ochanomizu University). To construct reporter plasmids, Pt 9 tCesA promoters amplified by PCR were introduced into the HindIII/SalI site of plasmid CaMV35S::LUC using an InFusion cloning kit (Takara Bio, Shiga, Japan), replacing CaMV35S.…”

Potential of <i>VlmybA1-2</i> as a Candidate Marker for Visual Identification of Transgenic Plants: Induced Anthocyanin Production in <i>Arabidopsis</i> and Tobacco

“…VlmybA genes (Kobayashi et al 2002) and previously cloned regulatory genes such as C1 (Cone et al 1986;Paz-Ares et al 1987), AN2 (Quattrocchio et al 1998), DELILA (Goodrich et al 1992), Lc (Ludwig et al 1990), AN11 (Quattrocchio et al 1993) and TTG1 (Shirley et al 1995) would provide a means to test this hypothesis in transgenic betalain-producing plants. Lack of distinguishable pigmentation from control in the VlmybA1-2 spinach plant and regenerated shoots on kanamycin medium, may be due to the inability of VlmybA1-2 to induce structural genes of anthocyanin biosynthesis pathway in non anthocyanin producing spinach (Shimada et al 2007).…”