Study : Transcriptomic and metabolomic sequencing provide novel insights into fruit development and flesh coloration in Prunus mira Koehne, a special wild peach species
Transcriptomic and metabolomic sequencing provide novel insights into fruit development and flesh coloration in Prunus mira Koehne, a special wild peach species
To unravel the regulatory network involved in Prunus mira fruit flesh coloration, which is an important fruit quality trait in peach, we performed integrated analysis of transcriptome and metabolome of 3 fruit types with various flesh pigmentations (milk-white, yellow and blood) at 3 developmental stages viz. pit-hardening, inflation and ripening. Transcriptome analysis showed that an intense transcriptional adjustment is required for the transition from the pit-hardening to the fruit inflation stage. In contrast, few genes were differentially expressed (DEGs) from the fruit inflation to the fruit ripening stages and importantly, the 3 fruits displayed diverse transcriptional activities, indicating that difference in fruit flesh pigmentations mainly occurred during the ripening stage. We further investigated the DEGs between pairs of fruit types during the ripening stage and identified 563 DEGs representing the ‘core transcriptome’ associated with major differentiations between the 3 fruit types, including flesh pigmentation. Meanwhile, we analyzed the metabolome, particularly, at the ripening stage and uncovered 40 differential metabolites (‘core metabolome’) between the 3 fruit types including 5 anthocyanins which may be the key molecules associated with flesh coloration. Finally, we constructed the regulatory network depicting the interactions between anthocyanins and important transcripts involved in fruit flesh coloration. This study provided valuable information which will undoubtedly assist in breeding towards fruit quality improvement in peach.