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. 2017 Jan 1;68(3):457-467.
doi: 10.1093/jxb/erw426.

The acyl-activating enzyme PhAAE13 is an alternative enzymatic source of precursors for anthocyanin biosynthesis in petunia flowers

Guoju Chen  1   2 , Heping Liu  1 , Qian Wei  2 , Huina Zhao  1 , Juanxu Liu  2 , Yixun Yu  2
Affiliations

The acyl-activating enzyme PhAAE13 is an alternative enzymatic source of precursors for anthocyanin biosynthesis in petunia flowers

Guoju Chen et al. J Exp Bot. .

Abstract

Anthocyanins, a class of flavonoids, are responsible for the orange to blue coloration of flowers and act as visual attractors to aid pollination and seed dispersal. Malonyl-CoA is the precursor for the formation of flavonoids and anthocyanins. Previous studies have suggested that malonyl-CoA is formed almost exclusively by acetyl-CoA carboxylase, which catalyzes the ATP-dependent formation of malonyl-CoA from acetyl-CoA and bicarbonate. In the present study, the full-length cDNA of Petunia hybrida acyl-activating enzyme 13 (PhAAE13), a member of clade VII of the AAE superfamily that encodes malonyl-CoA synthetase, was isolated. The expression of PhAAE13 was highest in corollas and was down-regulated by ethylene. Virus-induced gene silencing of petunia PhAAE13 significantly reduced anthocyanin accumulation, fatty acid content, and cuticular wax components content, and increased malonic acid content in flowers. The silencing of PhAAE3 and PhAAE14, the other two genes in clade VII of the AAE superfamily, did not change the anthocyanin content in petunia flowers. This study provides strong evidence indicating that PhAAE13, among clade VII of the AAE superfamily, is specifically involved in anthocyanin biosynthesis in petunia flowers.

Keywords: AAE13; anthocyanin synthesis; malonic acid; malonyl-CoA; petunia.

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Figures

Fig. 1.
Fig. 1.
A simplified view of the anthocyanin biosynthesis pathway (Koes et al., 2005; Rausher et al., 1999). 3GT, UDP-glucose:flavonoid 3-O-glycosyl transferase; 4CL, 4-coumarate:CoA ligase; AAE13, acyl-activating enzyme 13 (malonyl-CoA synthetase); ACC, acetyl-CoA carboxylase; ANS, anthocyanin synthase; C4H, cinnamate-4-hydroxylase; CHS, chalcone synthase; CHI, chalcone flavanone isomerase; DFR, dihydroflavonol 4-reductase; F3H, flavanone 3β-hydroxylase; FAE, fatty acid elongase; PAL, phenylalanine ammonia-lyase.
Fig. 2.
Fig. 2.
Alignment of PhAAE13 with A. thaliana AtAAE13 (BAB02683, AAM61199), S. lycopersicum SlAAE13 (XP_010314289), V. vinifera VvAAE13 (XP_002279139), and O. sativa OsAAE13 (EEC71525). White text on a black background indicates identical residues across all five sequences; dark gray shading indicates identical residues in four out of five sequences; light gray shading indicates similar residues in three out of five sequences and/or conserved substitutions. The arrow represents the start site of the sequence of another protein (ctAAE13) that is localized to the cytosol in Arabidopsis. The sequence underlined with a solid line is the conserved 12-amino acid AMP binding motif and that underline with a dotted line is the ACS (acyl-CoA synthetase) conserved domain. The alignments were generated using DNAMAN software.
Fig. 3.
Fig. 3.
Phylogenetic tree of clade VII of AAEs. Petunia PhAAE13 was aligned with A. thaliana AtAAE13 (AAM61199), AtAAE3 (NP_190468), AtAAE14 (NP_174340), S. lycopersicum SlAAE13 (XP_010314289), V. vinifera VvAAE13 (CBI36114), and O. sativa OsAAE13 (EEC71525) using DNAMAN.
Fig. 4.
Fig. 4.
Expression of PhAAE13 determined using qPCR. (A, B) Expression of (A) PhAAE13 and (B) PhF3H in different organs. (C, D) Expression of (C) PhAAE13 and (D) PhF3H in corollas in response to exogenous ethylene, (E, F) Expression of (E) PhAAE13 and (F) PhF3H in corollas in response to UV-B. (G) Expression of PhAAE13 and (H) anthocyanin accumulation in corollas during flower development. Relative expression levels are shown as fold-change values. Data are presented as means±SD (n=3). Three repetitions are included in the data presented. Data were generated from different flowers from different plants grown in parallel. (I) Images showing the six developmental stages of petunia buds. (This figure is available in colour at JXB online.)
Fig. 5.
Fig. 5.
PhAAE13 silencing reduced anthocyanin accumulation in petunia flowers. (A–G) Appearance of the corollas of (A) control (TRV-infected) and (B) PhCHS-, (C) PhAAE13-, (D) PhACC1-, (E) PhACC2-, (F) PhAAE3-, and (G) PhAAE14-silenced plants. (H) Appearance of the anthers (upper) and styles (lower) of (i) control and (ii) PhCHS-, (iii) PhAAE13-, (iv) PhACC1-, (v) PhACC2-, (vi) PhAAE3-, and (vii) PhAAE14-silenced plants. (I–K) Effects of PhAAE13, PhACC1, PhACC2, PhAAE3, and PhAAE14 silencing on the anthocyanin content of (I) corollas, (J) leaves, and (K) stems 1 month after infection, with TRV-based PhCHS silencing as a positive control. Data were generated from different flowers from at least three different plants grown in parallel. Data are presented as the means±SD of three independent measurements. Statistical analysis was performed using one-way ANOVA followed by Duncan’s multiple range test with three replicates. Values of P≤0.05 were considered significant.
Fig. 6.
Fig. 6.
Effects of (A) TRV-PhAAE13, (B) TRV-PhAAE3, and (C) TRV-PhAAE14 treatment on the expression of PhAAE13, PhAAE3, and PhAAE14 in flowers at anthesis as determined by qPCR. Relative expression levels are shown as fold-change values. Data are presented as means±SD (n=3).
Fig. 7.
Fig. 7.
Effects of (A) TRV2-PhAAE13 treatment on the expression of PhACC1 and PhACC2, (B) TRV-PhACC1 treatment on the expression of PhAAE13 and PhACC2, and (C) TRV-PhACC2 treatment on the expression of PhAAE13 and PhACC1 in flowers at anthesis as determined using qPCR. Data are presented as means±SD (n=3).
Fig. 8.
Fig. 8.
Effects of TRV2-PhAAE13 on concentrations of malonic acid in flowers at anthesis. Data are presented as means±SD (n=3). Statistical analysis was performed using one-way ANOVA followed by Duncan’s multiple range test with three replicates. Values of P≤0.05 were considered significant.
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References

    1. Abbruzzese A, Park MH, Folk JE. 1986. Deoxyhypusine hydroxylase from rat testis. Partial purification and characterization. Journal of Biological Chemistry 261, 3085–3089. - PubMed
    1. Albert NW, Lewis DH, Zhang H, Irving LJ, Jameson PE, Davies KM. 2009. Light-induced vegetative anthocyanin pigmentation in Petunia. Journal of Experimental Botany 60, 2191–2202. - PMC - PubMed
    1. Belkebir A, Benhassaine-Kesri G. 2013. Sethoxydim treatment inhibits lipid metabolism and enhances the accumulation of anthocyanins in rape (Brassica napus L.) leaves. Pesticide Biochemistry and Physiology 107, 120–126. - PubMed
    1. Black PN, DiRusso CC. 2007. Yeast acyl-CoA synthetases at the crossroads of fatty acid metabolism and regulation. Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1771, 286–298. - PubMed
    1. Black PN, Zhang Q, Weimar JD, DiRusso CC. 1997. Mutational analysis of a fatty acyl-coenzyme A synthetase signature motif identifies seven amino acid residues that modulate fatty acid substrate specificity. Journal of Biological Chemistry 272, 4896–4903. - PubMed

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