Ascorbic acid metabolism during sweet cherry (Prunus avium) fruit development

Area of Science:

• Plant Physiology
• Biochemistry
• Fruit Development

Background:

• Ascorbic acid (AsA), also known as Vitamin C, is a crucial antioxidant in plants.
• Understanding AsA metabolism is vital for improving fruit quality and nutritional value.

Purpose of the Study:

• To investigate the metabolic pathways and gene expression related to ascorbic acid in sweet cherry fruit ('Hongdeng').
• To correlate AsA concentration patterns with the expression of genes and enzyme activities during fruit development and maturation.

Main Methods:

• Quantification of AsA concentration throughout sweet cherry fruit development.
• Cloning of cDNAs for genes involved in AsA biosynthesis and recycling pathways.
• Analysis of mRNA expression levels and enzyme activities of key genes in AsA metabolism.

Main Results:

• AsA concentration was highest at petal-fall and decreased during ripening, with a slight rise at maturity.
• Despite concentration changes, total AsA accumulation increased with fruit fresh weight.
• Expression patterns of genes like GGP2, GalLDH, APX3, AO2, GR1, and DHAR1 correlated with AsA concentration dynamics.

Conclusions:

• Genes involved in ascorbic acid biosynthesis, degradation, and recycling act in concert to regulate AsA accumulation in sweet cherry fruit.
• The interplay between gene expression and enzyme activity is critical for managing AsA levels during fruit development.