Ascorbic acid metabolism during bilberry (Vaccinium myrtillus L.) fruit development.

Area of Science:

• Plant Physiology
• Biochemistry
• Fruit Development

Background:

• Bilberry (Vaccinium myrtillus L.) is rich in antioxidants like anthocyanins and ascorbic acid (AsA).
• Understanding ascorbic acid metabolism is crucial for bilberry's nutritional value and antioxidant properties.

Purpose of the Study:

• To investigate ascorbic acid accumulation and related gene expression during bilberry fruit development and ripening.
• To analyze the activity of enzymes involved in ascorbic acid biosynthesis, oxidation, and recycling.

Main Methods:

• Quantification of ascorbic acid content throughout fruit maturation.
• Analysis of gene expression for key enzymes in ascorbic acid pathways.
• Assay of enzyme activities related to ascorbic acid metabolism.

Main Results:

• Ascorbic acid levels remained stable during bilberry fruit ripening.
• Gene expression in the main AsA biosynthetic route correlated with AsA levels, especially early in ripening.
• Enzymes involved in AsA oxidation and recycling exhibited significant developmental changes.
• Fully ripe bilberry skin showed higher AsA content and gene expression than pulp.

Conclusions:

• Bilberry fruit regulates ascorbic acid levels through coordinated gene expression and enzyme activity during ripening.
• The ascorbate-glutathione cycle plays a dynamic role in bilberry fruit maturation.
• Differential accumulation of AsA and gene expression in skin versus pulp suggests localized importance in ripe berries.