Early metabolic and transcriptional variations in fruit of natural white-fruited Fragaria vesca genotypes.
Strawberry fruits (Fragaria vesca) are valued for their sweet fruity flavor, juicy texture, and characteristic red color caused by anthocyanin pigments. To gain a deeper insight into the regulation of anthocyanin biosynthesis, we performed comparative metabolite profiling and transcriptome analyses of one red-fruited and two natural white-fruited strawberry varieties in two tissues and three ripening stages. Developing fruit of the three genotypes showed a distinctive pattern of polyphenol accumulation already in green receptacle and achenes. Global analysis of the transcriptomes revealed that the ripening process in the white-fruited varieties is already affected at an early developmental stage. Key polyphenol genes showed considerably lower transcript levels in the receptacle and achenes of both white genotypes, compared to the red genotype. The expression of the anthocyanidin glucosyltransferase gene and a glutathione S-transferase, putatively involved in the vacuolar transport of the anthocyanins, seemed to be critical for anthocyanin formation. A bHLH transcription factor is among the differentially expressed genes as well. Furthermore, genes associated with flavor formation and fruit softening appear to be coordinately regulated and seem to interact with the polyphenol biosynthesis pathway. This study provides new information about polyphenol biosynthesis regulators in strawberry, and reveals genes unknown to affect anthocyanin formation.
Biotechnology of Natural Products, Technische Universität München, Liesel-Beckmann-Str. 1, 85354 Freising, Germany.
Katja
K
Härtl
Institute for Biology I, RWTH Aachen University, Worringer Weg 3, 52074 Aachen, Germany.
Alisandra
A
Denton
Biotechnology of Natural Products, Technische Universität München, Liesel-Beckmann-Str. 1, 85354 Freising, Germany.
Katrin
K
Franz-Oberdorf
Biotechnology of Natural Products, Technische Universität München, Liesel-Beckmann-Str. 1, 85354 Freising, Germany.
Thomas
T
Hoffmann
Physiology Weihenstephan, TU München, Weihenstephaner Berg 3, 85354 Freising, Germany.
Melanie
M
Spornraft
Institute for Biology I, RWTH Aachen University, Worringer Weg 3, 52074 Aachen, Germany.
Björn
B
Usadel
Biotechnology of Natural Products, Technische Universität München, Liesel-Beckmann-Str. 1, 85354 Freising, Germany.
Wilfried
W
Schwab
D002853:Chromatography, Liquid; D004734:Energy Metabolism; D005419:Flavonoids / Q000096:biosynthesis; D031985:Fragaria / Q000235:genetics* / Q000378:metabolism*; D005638:Fruit / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D005838:Genotype; D013058:Mass Spectrometry; D010641:Phenotype; D014158:Transcription, Genetic; D059467:Transcriptome
D005419:Flavonoids