Isolation of a set of ripening-related genes from strawberry: their identification and possible relationship to fruit quality traits

The production of anthocyanins in fruit tissues is highly controlled at the developmental level. We have studied the expression of flavonoid biosynthesis genes during the development of bilberry (Vaccinium myrtillus) fruit in relation to the accumulation of anthocyanins, proanthocyanidins, and flavonols in wild berries and in color mutants of bilberry. The cDNA fragments of five genes from the flavonoid pathway, phenylalanine ammonia-lyase, chalcone synthase, flavanone 3-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase, were isolated from bilberry using the polymerase chain reaction technique, sequenced, and labeled with a digoxigenin-dUTP label. These homologous probes were used for determining the expression of the flavonoid pathway genes in bilberries. The contents of anthocyanins, proanthocyanidins, and flavonols in ripening bilberries were analyzed with high-performance liquid chromatography-diode array detector and were identified using a mass spectrometry interface. Our results demonstrate a correlation between anthocyanin accumulation and expression of the flavonoid pathway genes during the ripening of berries. At the early stages of berry development, procyanidins and quercetin were the major flavonoids, but the levels decreased dramatically during the progress of ripening. During the later stages of ripening, the content of anthocyanins increased strongly and they were the major flavonoids in the ripe berry. The expression of flavonoid pathway genes in the color mutants of bilberry was reduced. A connection between flavonol and anthocyanin synthesis in bilberry was detected in this study and also in previous data collected from flavonol and anthocyanin analyses from other fruits. In accordance with this, models for the connection between flavonol and anthocyanin syntheses in fruit tissues are presented.Fruit development from flower to ripe fruit is a complex process that involves modification of cellular compartments, loss of cell wall structure causing softening, and accumulation of carbohydrates (Brady, 1987). The production of secondary metabolites during the ripening process is an essential phenomenon for the contribution of seed dispersal of the plant in the form of accumulation of pigments and flavor compounds. The significance of secondary products in defense against diseases in developing fruits should also be remembered (Harborne, 1997;Mercier, 1997).Flavonoids are a large group of phenolic secondary metabolites that are widespread among plants and are involved in many plant functions. Anthocyanins, a flavonoid subclass, are the main pigments in flowers and fruits, acting as insect and animal attractants (Bohm, 1998;Harborne and Williams, 2000). Anthocyanins are synthesized via the phenylpropanoid pathway (Fig. 1). Anthocyanin biosynthesis has been extensively studied in several plant species, and, therefore, detailed information of the course of reactions is available. Two classes of genes are required for anthocyanin biosynthesis, the structural genes encoding the enzymes...

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“…3) is similar to what has been found in strawberry (Fragaria spp. ;Manning, 1998) and in grape berry (Boss et al, 1996;Kobayashi et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

Expression of Genes Involved in Anthocyanin Biosynthesis in Relation to Anthocyanin, Proanthocyanidin, and Flavonol Levels during Bilberry Fruit Development

Määttä²,

et al. 2002

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“…According to this proposal, the auxins that are produced by achenes and released to the fruit receptacle would repress the expression of a vast majority of the ripening-related genes (Medina-Escobar et al, 1997;Manning, 1998;Moyano et al, 1998;Blanco-Portales et al, 2002, 2004Raab et al, 2006;Medina-Puche et al, 2014). To determine whether FaEOBII gene expression was under auxin control, we determined the changes in FaEOBII gene expression in unripe fruit receptacles after removing the achenes from the fruit surface.…”

Section: The Expression Of Faeobii Is Hormonally Regulated Throughoutmentioning

confidence: 99%

An R2R3-MYB Transcription Factor Regulates Eugenol Production in Ripe Strawberry Fruit Receptacles

et al. 2015

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Eugenol is a volatile phenylpropanoid that contributes to flower and ripe fruit scent. In ripe strawberry (Fragaria 3 ananassa) fruit receptacles, eugenol is biosynthesized by eugenol synthase (FaEGS2). However, the transcriptional regulation of this process is still unknown. We have identified and functionally characterized an R2R3 MYB transcription factor (EMISSION OF BENZENOID II [FaEOBII]) that seems to be the orthologous gene of PhEOBII from Petunia hybrida, which contributes to the regulation of eugenol biosynthesis in petals. The expression of FaEOBII was ripening related and fruit receptacle specific, although high expression values were also found in petals. This expression pattern of FaEOBII correlated with eugenol content in both fruit receptacle and petals. The expression of FaEOBII was repressed by auxins and activated by abscisic acid, in parallel to the ripening process. In ripe strawberry receptacles, where the expression of FaEOBII was silenced, the expression of CINNAMYL ALCOHOL DEHYDROGENASE1 and FaEGS2, two structural genes involved in eugenol production, was down-regulated. A subsequent decrease in eugenol content in ripe receptacles was also observed, confirming the involvement of FaEOBII in eugenol metabolism. Additionally, the expression of FaEOBII was under the control of FaMYB10, another R2R3 MYB transcription factor that regulates the early and late biosynthetic genes from the flavonoid/phenylpropanoid pathway. In parallel, the amount of eugenol in FaMYB10-silenced receptacles was also diminished. Taken together, these data indicate that FaEOBII plays a regulating role in the volatile phenylpropanoid pathway gene expression that gives rise to eugenol production in ripe strawberry receptacles.The octoploid cultivated strawberry (Fragaria 3 ananassa) is one of the most economically important, nonclimacteric, soft fruits, in which volatile compounds influence fruit flavor and aroma. Both characteristics contribute to the fruit organoleptic traits and are crucial factors to determine fruit quality.At present, extensive surveys on the components that contribute to strawberry flavor have been performed. In these studies, more than 360 volatiles have been identified (Latrasse, 1991;Nijssen, 1996;Zabetakis and Holden, 1997), but only 15 to 20 of them in wild varieties of strawberry are believed to be essential for sensory quality, together with nonvolatile sugars and organic acids (Schieberle and Hofmann, 1997). In contrast, in cultivated varieties of strawberry, only about six odor-active compounds have been identified as contributors to fruit flavor (Raab et al., 2006;Ulrich et al., 2007). Strawberry aroma is the result of the combined perception of fruity (ethyl butanoate, ethyl hexanoate, and methyl 2-methylbutanoat), green (Z-3-hexenal), sweaty (butanoic acid and 2-methylbutanoic acid), peach-like (g-decalactone), and caramel-like [4-hydroxy-2,5-dimethyl-3(2H)-furanone and 2,5-dimethyl-4-methoxy-3(2H)-furanone] flavor notes (Pyysalo et al., 1979;Larsen and Poll, 1992). Several wild strawb...

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“…Because some strawberry fruit-specific genes have been shown to be expressed under the control of auxins (Medina-Escobar et al, 1997;Manning, 1998;Moyano et al, 1998;Trainotti et al, 1999;Blanco-Portales et al, 2002), we performed gene expression analysis on deachened green fruit (G2 stage) to determine whether the expression of FaQR was also under this hormonal control. QRT-PCR analyses were performed with mRNA isolated from deachened fruits and from deachened fruits treated with the auxin naphthalene acetic acid (NAA).…”

Section: Faqr Expression Correlates Inversely With Auxin Levelsmentioning

confidence: 99%

“…Along these lines, several recent studies of the molecular aspects of strawberry fruit ripening have been performed, determining the expression patterns of genes encoding already known enzymes involved in cell wall hydrolysis and softening, including pectate lyases (Benítez-Burraco et al, 2003), polygalacturonases (Redondo-Nevado et al, 2001;, pectin methyl esterases , cellulases (Harpster et al, 1998;Manning, 1998;Trainotti et al, 1999), b-galactosidases (Trainotti et al, 2001), and expansins (Civello et al, 1999;Harrison et al, 2001). In addition, genes corresponding to flavonoid biosynthesis enzymes that catalyze steps in the production of anthocyanins in strawberry have been isolated (Manning, 1998;Moyano et al, 1998;, and the genes encoding enzymes of the lignification pathway have been cloned and their expression patterns characterized throughout fruit development and ripening Blanco-Portales et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, genes corresponding to flavonoid biosynthesis enzymes that catalyze steps in the production of anthocyanins in strawberry have been isolated (Manning, 1998;Moyano et al, 1998;, and the genes encoding enzymes of the lignification pathway have been cloned and their expression patterns characterized throughout fruit development and ripening Blanco-Portales et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

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FaQR, Required for the Biosynthesis of the Strawberry Flavor Compound 4-Hydroxy-2,5-Dimethyl-3(2H)-Furanone, Encodes an Enone Oxidoreductase

Raab

López‐Ráez

Klein³

et al. 2006

Plant Cell

161

159

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The flavor of strawberry (Fragaria 3 ananassa) fruit is dominated by an uncommon group of aroma compounds with a 2,5-dimethyl-3(H)-furanone structure. We report the characterization of an enzyme involved in the biosynthesis of 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF; Furaneol), the key flavor compound in strawberries. Protein extracts were partially purified, and the observed distribution of enzymatic activity correlated with the presence of a single polypeptide of ;37 kD. Sequence analysis of two peptide fragments showed total identity with the protein sequence of a strongly ripeninginduced, auxin-dependent putative quinone oxidoreductase, Fragaria 3 ananassa quinone oxidoreductase (FaQR). The open reading frame of the FaQR cDNA consists of 969 bp encoding a 322-amino acid protein with a calculated molecular mass of 34.3 kD. Laser capture microdissection followed by RNA extraction and amplification demonstrated the presence of FaQR mRNA in parenchyma tissue of the strawberry fruit. The FaQR protein was functionally expressed in Escherichia coli, and the monomer catalyzed the formation of HDMF. After chemical synthesis and liquid chromatography-tandem mass spectrometry analysis, 4-hydroxy-5-methyl-2-methylene-3(2H)-furanone was confirmed as a substrate of FaQR and the natural precursor of HDMF. This study demonstrates the function of the FaQR enzyme in the biosynthesis of HDMF as enone oxidoreductase and provides a foundation for the improvement of strawberry flavor and the biotechnological production of HDMF.

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Isolation of a set of ripening-related genes from strawberry: their identification and possible relationship to fruit quality traits

Cited by 165 publications

References 61 publications

Expression of Genes Involved in Anthocyanin Biosynthesis in Relation to Anthocyanin, Proanthocyanidin, and Flavonol Levels during Bilberry Fruit Development

Expression of Genes Involved in Anthocyanin Biosynthesis in Relation to Anthocyanin, Proanthocyanidin, and Flavonol Levels during Bilberry Fruit Development

An R2R3-MYB Transcription Factor Regulates Eugenol Production in Ripe Strawberry Fruit Receptacles

FaQR, Required for the Biosynthesis of the Strawberry Flavor Compound 4-Hydroxy-2,5-Dimethyl-3(2H)-Furanone, Encodes an Enone Oxidoreductase

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