Consuming functional foods such as fruit and vegetables are important for reducing the risk of chronic diseases and maintaining good health. At least five to nine daily servings of fruits and vegetables are recommended by the U.S. Department of Agriculture (Zepeda et al., 2014). Fruit and vegetables provide essential vitamins, minerals, fibers (soluble and insoluble forms) as well as bioactive compounds collectively known as phytochemicals. These include polyphenols, carotenoids, and sulfur-containing components. In addition to health benefits, diversity in fruit colors is often associated with unique phytochemical constituents (Camara et al., 1995; Gould et al., 2010; Tzulker et al., 2007). Among several fruit in the Rosaceae family, european plum provide enormous amount of phytonutrients due to their high polyphenolic and fiber content thus constituting a functional health food.
Fruit color is a primary attribute to the appearance and quality of european plum. In general, color is important in attraction of dispersal agents (birds, animals, and primates), protection against ultraviolet damage, an indicator of ripeness, and contributes to polyphenolic content and their associated antioxidant properties (Davies and Schwinn, 2004). As the fruit ripens, color is one of many modifications that occur due to physiological and biochemical changes; including the increase in respiration rate, production of ethylene, flesh softening, and formation of volatiles with associated development of flavor. During the ripening of european plum, there is loss of chlorophyll pigment that leads to development of blue-black, purple, or yellow pigmentation (Abdi et al., 1998). In higher plants these pigments are localized in chromoplasts or vacuoles (Kahlau and Bock, 2008). The compounds responsible for this diverse pigmentation are anthocyanins synthesized through a specific biosynthetic pathway in most plants, including european plum.
Anthocyanin pathway includes an early biosynthetic pathway that leads to the production of colorless dihydroflavonol compounds and late biosynthetic pathway that leads to the production of anthocyanins (color pigmentation) (Holton and Cornish, 1995; Jaakola et al., 2002). The activity of ABGs is believed to be crucial in the formation of anthocyanins with different structure and coloration including conjugates of cyanidin (red), pelargonidin (orange), and delphindin (blue) (Dooner et al., 1991). The expression of the ABGs depends on several factors; including tissue, genotype, developmental stage, and environment (Boss et al., 1996; Takos et al., 2006); and may serve as qualitative and quantitative indicator of pigmentation in ripe fruit. Molecular mechanisms underlying the regulation of anthocyanin biosynthetic pathway have been investigated in some species, such as grape (Vitis vinifera), bilberry (Vaccinium myrtillus), and malay apple (Syzygium malaccense), but not well understood in the case of european plum (Fournand et al., 2006; Jaakola et al., 2002; Kotepong et al., 2011).
In the present study, european plum genotypes with varied fruit colors ranging from green to purple were used as a model system to better understand the role of anthocyanin biosynthetic pathway in the regulation of european plum pigmentation at ripening. The expression of key ABGs was assessed during european plum fruit ripening and the functional analysis of individual ABG was examined using tobacco as a heterologous experimental system. The findings of this research can be used in breeding programs aiming at obtaining european plum with desired colors for the market and consumers.
AbdiN.McGlassonW.B.HolfordP.WilliamsM.MizrahiY.1998Responses of climacteric and suppressed-climacteric plums to treatment with propylene and 1-methylcyclopropenePostharvest Biol. Technol.142939
BossP.K.DaviesC.RobinsonS.P.1996Analysis of the expression of anthocyanin pathway genes in developing Vitis vinifera L. cv shiraz grape berries and the implications for pathway regulationsJ. Plant Physiol.11110591066
CamaraB.HugueneyP.BouvierF.KuntzM.MonegerR.1995Biochemistry and molecular biology of chromoplast developmentIntl. Rev. Cytol.163175247
DurbinM.L.McCaigB.CleggM.T.2000Molecular evolution of the chalcone synthase multigene family in the morning glory genomePlant Mol. Biol.427992
EspanaL.Heredia-GuerreroJ.A.Reina-PintoJ.J.Fernandez-MunozR.HerediaA.DominguezE.2014Transient silencing of chalcone synthase during fruit ripening modifies tomato epidermal cells and cuticle propertiesPlant Physiol.16613711386
FournandD.VicensA.SidhoumL.SouquetJ.MoutounetM.CheynierV.2006Accumulation and extractability of grape skin tannins and anthocyanins at different advanced physiological stagesJ. Agr. Food Chem.5473317338
GouldK.S.DudleD.A.NeufeldH.S.2010Why some stems are red: Cauline anthocyanins shield photosystem II against high light stressJ. Expt. Bot.6127072717
HellensR.P.EdwardsE.A.LeylandN.R.BeanS.MullineauxP.M.2000pGreen: a versatile and flexible binary Ti vector for Agrobacterium-mediated plant transformationPlant Mol. Biol.42819832
HilyJ.ScorzaR.WebbK.RavelonandroM.2005Accumulation of the long class of siRNA is associated with resistance to plum pox virus in a transgenic woody perennial plum treeMol. Plant Microbe Interact.18794799
HondaC.KotodaN.WadaM.KondoS.KobayashiS.SoejimaJ.ZhangZ.TsudaT.MoriguchiT.2002Anthocyanin biosynthetic genes are coordinately expressed during red coloration in apple skinPlant Physiol. Biochem.40955962
HorschR.B.RogersS.G.FraleyR.T.1985Transgenic plants p. 433–437. Cold Spring Harbor Symp. Quantitative Biol. Vol. 50. Cold Spring Harbor Laboratory Press Cold Spring Harbor NY
JaakolaL.MaattaK.PirttilaA.M.TorronenR.KarenlampiS.HohtolaA.2002Expression of genes involved in anthocyanin biosynthesis in relation to anthocyanin, proanthocyanidin, and flavonol levels during bilberry fruit developmentPlant Physiol.130729739
JiaoY.MaR.J.ShenZ.J.YanJ.YuM.L.2014Gene regulation of anthocyanin biosynthesis in two blood-flesh peach (Prunus persica (L.) Batsch) cultivars during fruit developmentJ. Zhejiang Univ. Sci.15809819
KahlauS.BockR.2008Plastid transcriptomics and translatomics of tomato fruit development and chloroplast-to-chromoplast differentiation: Chromoplast gene expression largely serves the production of a single proteinPlant Cell20856874
KimS.H.LeeJ.R.HongS.T.YooY.K.AnG.KimS.R.2003Molecular cloning and analysis of anthocyanin biosynthesis genes preferentially expressed in apple skinPlant Sci.165403413
KotepongP.KetsaS.van DoornW.G.2011A white mutant of malay apple fruit (Syzygium malaccense) lacks transcript expression and activity for the last enzyme of anthocyanin synthesis, and the normal expression of a MYB transcription factorFunct. Plant Biol.387586
LimE.K.BaldaufS.LiY.EliasL.WorrallD.SpencerS.P.JacksonR.G.TaguchiG.RossJ.BowlesD.J.2003Evolution of substrate recognition across a multigene family of glycosyltransferases in ArabidopsisGlycobiology13139145
ListerC.E.LancasterJ.E.WalkerJ.R.1996Phenylalanine ammonia-lyase (PAL) activity and its relationship to anthocyanin and flavonoid levels in New Zealand-grown apple cultivarsJ. Amer. Soc. Hort. Sci.121281285
LiX.J.ZhangJ.Q.WuZ.C.LaiB.HuangX.M.QinY.H.WangH.C.HuG.B.2015Functional characterization of a glucosyltransferase gene, LcUFGT1, involved in the formation of cyanidin glucoside in the pericarp of Litchi chinensisPhysiol. Plant.156139149
MeiselL.FonsecaB.GonzálezS.Baeza-YatesR.CambiazoV.CamposR.GonzálezM.OrellanaA.RetamalesJ.SilvaH.2005A rapid and efficient method for purifying high quality total RNA from peaches (Prunus persica L.) for functional genomics analysesBiol. Res.388388
NakatsukaT.AbeY.KakizakiY.YamamuraS.NishiharaM.2007Production of red-flowered plants by genetic engineering of multiple flavonoid biosynthetic genesPlant Cell Rpt.2619511959
PolashockJ.J.GriesbachR.J.SullivanR.F.VorsaN.2002Cloning of a cDNA encoding the cranberry dihydroflavonol-4-reductase (DFR) and expression in transgenic tobaccoPlant Sci.163241251
SuiX.GaoX.AoM.WangQ.YangD.WangM.FuY.WangL.2011cDNA cloning and characterization of UDP-glucose: Anthocyanidin 3-O-glucosyltransferase in Freesia hybridaPlant Cell Rpt.3012091218
SzankowskiI.FlachowskyH.LiH.HalbwirthH.TreutterD.RegosI.HankeM.StichK.FischerT.C.2009Shift in polyphenol profile and sublethal phenotype caused by silencing of anthocyanidin synthase in apple (Malus sp.)Planta229681692
TakosA.M.RobinsonS.P.WalkerA.R.2006Transcriptional regulation of the flavonoid pathway in the skin of dark-grown ‘Cripps’ red apples in response to sunlightJ. Hort. Sci. Biotechnol.81735744
TzulkerR.GlazerI.Bar-IlanI.HollandD.AviramM.AmirR.2007Antioxidant activity, polyphenol content, and related compounds in different fruit juices and homogenates prepared from 29 different pomegranate accessionsJ. Agr. Food Chem.5595599570
UntergasserA.NijveenH.RaoX.BisselingT.GeurtsR.LeunissenJ.A.2007Primer3Plus, an enhanced web interface to Primer3Nucleic Acids Res.35W71W74
WangZ.MengD.WangA.LiT.JiangS.CongP.LiT.2013The methylation of the PcMYB10 promoter is associated with green-skinned sport in Max Red Bartlett pearPlant Physiol.162885896
WaterhouseA.2002Folin-Ciocalteau micro method for total phenol in wine. Curr. Protocols Food Anal. Chem. 1.1.1–1.1.8
XuW.PengH.YangT.WhitakerB.HuangL.SunJ.ChenP.2014Effect of calcium on strawberry fruit flavonoid pathway gene expression and anthocyanin accumulationPlant Physiol. Biochem.82289298
YangY.YaoG.ZhengD.ZhangS.WangC.ZhangM.WuJ.2015Expression differences of anthocyanin biosynthesis genes reveal regulation patterns for red pear colorationPlant Cell Rpt.34189198
ZhangX.LiuC.J.2015Multifaceted regulations of gateway enzyme phenylalanine ammonia-lyase in the biosynthesis of phenylpropanoidsMol. Plant81727
Primers used for gene expression analysis of anthocyanin biosynthetic genes in european plum genotypes.
Accession numbers of anthocyanin biosynthetic genes from european plum.
Primers used for the isolation of anthocyanin biosynthetic genes from european plum.
Primers used for the genetic transformation of anthocyanin biosynthetic genes (ABG) and to examine the presence of ABG in transgenic tobacco plants.
Total polyphenol content of different colored cultivars of european plum eluted in 100% methanol fraction.
Liquid chromatography–mass spectrometry profile of polyphenols from the european plum purple genotype V982017.
Liquid chromatography–mass spectrometry profile of polyphenols from the european plum greenish-purple genotype V90271.
Liquid chromatography–mass spectrometry profile of polyphenols from the european plum yellow 1 genotype V91058.
Liquid chromatography–mass spectrometry profile of polyphenols from the european plum yellow 2 genotype V91057.
Liquid chromatography–mass spectrometry profile of polyphenols from the european plum green 1 genotype V91048.
Liquid chromatography–mass spectrometry profile of polyphenols from the european plum green 2 genotye V91057.