Transcriptome- and metabolome-based screening of glycolic acid-related genes in Docynia delavayi fruits

Based on the transcriptomic and metabolomic data of six developmental stages of Docynia delavayi fruits, this study analysed the types and characteristics of soluble sugars and organic acids during fruit development, screened candidate genes related to sugar-acid metabolism, and clarified the key genes and their regulatory networks by combining the joint analyses of differential metabolites and genes.It was found that the major soluble sugars in the fruit of D. delavayi palmatum were fructose, glucose, mannose and galactose, and the major organic acids were citric acid, isocitric acid and malic acid.Forty-nine sugar metabolites and 93 organic acid metabolites were screened.Seven key enzyme genes for sugar synthesis and eight key enzyme genes for acid metabolism were screened.C2H2, MYB and NAC family members were found to significantly regulate sugar-acid metabolism.This study systematically analysed the molecular mechanism of sugar and acid metabolism and its regulatory network, which provided important theoretical support for fruit quality improvement and breeding.