A metabolomics analysis reveals the potential mechanism of chilling tolerance of red side of mango fruit during low temperature storage

Abstract

Previous studies demonstrated that there is difference of cold tolerance between red side and green side of mango fruit exocarp, but the related mechanism is not clear yet. Here, an ultrahigh-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) based metabolomic approach was performed to explain possible mechanism of cold tolerance difference between two sides of fruit exocarp. Results showed that red side was more cold tolerant than green side, as indicated by higher Fv/Fm but lower membrane permeability and lipid peroxidation along with less chilling injury (CI) severity in red side compared to green side. Furthermore, a total of 925 metabolites were characterized in mango exocarp. Multivariate metabolomics analysis identified differentially accumulated metabolites in different exocarp sides. Specific metabolites, including hesperetin-5-O-glucoside, quercetin-4′-O-glucoside, quercetin-7-O-glucoside, cyanidin-3-O-glucoside, pelargonidin-3-O-glucoside, L-arginine, L-glutamic acid, L-tryptophan, protocatechuic acid-4-O-glucoside, 9,16-dihydroxypalmitic and putrescine, were observed more in red exocarp side, which might be involved in positive regulation of chilling tolerance of mango fruit. Our results are beneficial to identify important metabolite markers associated with cold tolerance in red pigments-enriched mango.