BCH1 expression pattern contributes to the fruit carotenoid diversity between peach and apricot

Area of Science:

• Plant genetics
• Fruit biochemistry
• Agricultural science

Background:

• Peach and apricot fruits differ significantly in carotenoid profiles, impacting their color.
• Apricots are rich in beta-carotene (orange), while peaches accumulate xanthophylls (yellow).
• The beta-carotene hydroxylase 1 (BCH1) gene is present in both species.

Purpose of the Study:

• To investigate the molecular basis for differential carotenoid accumulation in peach and apricot.
• To determine the role of the BCH1 gene in regulating beta-carotene content.
• To understand the genetic mechanisms underlying fruit color diversity in Prunus species.

Main Methods:

• High-performance liquid chromatography with a photodiode array detector (HPLC-PAD) for carotenoid analysis.
• Transcriptional analysis of the BCH1 gene in peach and apricot fruits.
• Enzymatic activity assays using a carotenoid-engineered bacterial system.
• Comparative analysis of BCH1 promoter sequences.
• GUS reporter gene assays to assess promoter activity.

Main Results:

• Apricot fruits have higher beta-carotene content than peaches.
• BCH1 gene expression is significantly higher in peach than in apricot fruits.
• BCH1 enzymatic activity is similar between peach and apricot.
• Differences in BCH1 gene transcription levels correlate with distinct promoter activities.
• The BCH1 promoter function is a key factor in regulating beta-carotene accumulation.

Conclusions:

• The differential promoter function of the BCH1 gene is responsible for the variation in beta-carotene content between peach and apricot.
• BCH1 gene serves as a potential predictor for beta-carotene levels during fruit ripening in these species.
• This study enhances understanding of carotenoid diversity in Prunus fruit development.