Peach, the third most important of the deciduous fruit trees worldwide, is well received by consumers. In peach (Prunus persica f. atropurpurea), color is a key quality trait and is often regulated by anthocyanin. Anthocyanin concentration varies considerably in leaves, flower, and fruits, depending on the genotype and environmental conditions.

Scientists from Wuhan Botanical Garden and Institute of Tropical Bioscience and Biotechnology isolated putative anthocyanin biosynthetic genes and photorespiration genes in peach with high sequence similarity to Arabidopsis homologs. They studied the expression profiles of both anthocyanin biosynthetic genes and photorespiratory genes under darkness or heat stress. The results were discussed in terms of changes of expression of anthocyanin biosynthetic genes and photorespiratory genes in the Arabidopsis chi/f3′h double mutant and cop1 mutant.

Real-time PCR analysis revealed a strong correlation between the expression levels of anthocyanin biosynthetic genes and anthocyanin content in leaves at different developmental stages. The expression profiles of both anthocyanin biosynthetic genes and photorespiratory genes showed significant changes in leaves held in the dark or exposed to heat stress, compared with controls. The expression of anthocyanin biosynthetic genes dramatically decreased in peach red leaves following dark or heat treatments, resulting in a significant decrease of anthocyanin accumulation. However, the photorespiration-related genes GDCH and GOX exhibited increased expression in peach leaves after dark or heat treatment. Moreover, the expression levels of GDCH and GOX in the Arabidopsis chi/f3′h mutant that does not accumulate anthocyanins were higher than in the wild type.

Overall, these results support the hypothesis that photorespiration-related genes might be involved in the regulation of anthocyanin biosynthesis. This finding provides a new insight into our understanding of the mechanism underlying the control of anthocyanin biosynthesis in plants.

Results were published in Tree Genetics & Genomes entitled “Coordinated regulation of anthocyanin biosynthesis through photorespiration and temperature in peach (Prunus persica f. atropurpurea)”.

 Anthocyanin content and expression profiles of anthocyanin pathway genes in leaves of RR at different developmental stages (Image by Professor HAN’s group)