Study On Interspecific Browning Of Potatoes Based On Transcriptomic And Metabolomic

The fresh-cut fruit and vegetables have recently been popular such as fresh-cut potatoes,but the browning had limited the industrialization of many fruits and vegetables during processing.However,the browning degree of different cultivars of fresh-cut potatoes existed significant differences,and the available information of browning mechanism between different cultivars potatoes were limited.Hence,this study focused on four cultivar potatoes(Kexin 4(KX4),Kexin 13(KX13),Yunshu 401(YS401)and Yunshu505(YS505))which had different browning sensitivity.Combined the metabolomics and transcriptomics methods to analyze the critical points of browning and signaling pathways,and the expression of browning-related genes was also analyzed to reveal the mechanism of browning deeply.In this study,browning was closely related to cultivars and the storage time.The browning index(BI)value of KX13 cultivar were lower than others in this study.And YS505 potatoes were the most prone to browning and it had the most serious browning degree.Moreover,the activities of browning-related enzymes of YS505 cultivar were the highest like PPO,POD,PAL,C4 H,4CL than others.According to the metabolomics and transcriptomics results,both KX13 and YS505 cultivars had significant differences in metabolites and genes.The browning differences between different potato cultivars were closely related to the critical metabolites produced in the phenolic metabolic pathway.Phenolic metabolism was important differential metabolic pathway in all metabolic pathways.The relative content of metabolites related to phenolic metabolism pathway in YS505 was higher than KX13 such as L-phenylalanine,P-coumaric acid,cinnamic acid and chlorogenic acid.Amino acid metabolism played an important role in browning.Some critical amino acid metabolites like phenylalanine,aspartic acid and glutamic acid were found.The relative content of aspartic acid and glutamic acid in KX13 cultivar were higher than YS505 cultivar.Transcriptomics found the expression of some lipid metabolism-related genes in YS505 was significantly higher than KX13,and it was relatively consistent with physiological indicators like MDA in fresh-cut potatoes.Besides,signal molecular pathways like ROS signal,jasmonic acid signal,glutamate signal and plant hormone signal may be critical in regulating browning.Metabolites related to signal transduction such as jasmonic acid,glutamic acid and gibberellin were detected and enriched in anti-browning cultivar of KX13.The critical gene expression experiments showed that the up-regulation of PPO-5738、PPO-0718、PPO-8914、PPO-8916、PPO-9576、POD-9501、PAL-5026、C4H-5644 and C4H-6761 genes may be involved in the browning of fresh-cut potatoes.Besides,the 1073 and 9296 gene may play a critical role in regulating browning by amino acid metabolism.In conclusion,the browning mechanism may be the collective effect of metabolic pathways,dynamic signal transduction and gene expression.The browning factors included phenolic metabolism,amino acid metabolism,lipid metabolism,and respiratory metabolism.This study provided the references for more accurate and effective control of the browning of fresh-cut products,improved the research in the field of fresh-cut,and promoted the development of the fresh-cut industry.