Transcriptomics analysis provides insights into metabolisms of sugars and carotenoids of nectarine fruit subjected to different temperature storage

Abstract

Improper temperature storage of nectarine fruit after harvest could easily lead to rapid fruit softening, decrease of fruit sugar content, loss of flavor substances, and browning of tissues. Transcriptomics and bioinformatic analyses were applied to explore the effect of different storage temperature in regulating the metabolic pathways in nectarine fruit. In this study, we observed that differentially expressed genes (DEGs) were accumulated at high levels to starch and sucrose metabolism and the biosynthesis process of terpenoid skeleton. A detailed analysis of sugar and carotenoid metabolism indicated that the changes of sugars and carotenoids were accurately associated with the gene expressions of invertase, sucrose phosphate synthase, carotenoid cleavage dioxygenase, geranylgeranyl diphosphate synthase and phytoene desaturase. Further analysis found that nectarine fruit stored at low temperature exhibited lower content of sucrose and carotenoids compared with room temperature storage. Low temperature storage mainly inhibited the synthesis of sucrose and carotenoids by down-regulating expressions of invertase and carotenoid cleavage dioxygenase. Moreover, Coexpression network analysis revealed that 3 PpWRKYs, 2 PpMYBs and 1 PpNAC could be identified as putative transcription factors in the regulation of carotenoid metabolism in nectarine fruit. In summary, this research explained the general molecular mechanism of the changes of sugars and carotenoids in nectarine fruit in response to different temperature storage.