Widely Targeted Metabolomics Analysis of the Effects of Myzus persicae Feeding on Prunus persica Secondary Metabolites

The objective of this study is to clarify the underlying biochemical mechanisms related to the resistance and susceptibility of peach towards Myzus persicae, and to identify the key secondary metabolites of peach responding to the M. persicae infection.

New shoots of resistant (‘96-5-1’ (9651), ZaoYouTao (ZYT)) and susceptible (Zhong You 13 (CN13), Zhong Nong Jin Hui (ZNJH)) peach trees were inoculated with M. persicae for 3 days and used for secondary metabolite extraction and UPLC-MS/MS analysis. Differentially altered metabolites (DAMs) were screened with |log₂ fold change|≥1, P-value≤0.01 as threshold. The VIP value of the OPLS-DA model was used to perform differences between resistant and susceptible peach.

To illustrate the biochemical mechanisms of M. persicae resistance in peach, aphid-resistant/aphid-susceptible peach varieties infested with M. persicae for 3 days. A total of 528 metabolites were identified in the treated samples through widely targeted metabolomics analysis. Using principal component analysis (PCA), hierarchical cluster analysis (HCA) and Venn diagram analysis, it was found that 7 DAMs were identified from the susceptible variety CN13, and 2 of them were significantly decreased, 5 of them were significantly increased. 7 DAMs were identified from the susceptible variety ZNJH, and 3 of them were significantly decreased, 4 of them were significantly increased. 33 DAMs were identified from the resistant variety ‘96-5-1’, and 1 of them was significantly decreased, 32 of them were significantly increased. 55 DAMs were identified from the resistant variety ZYT, and 12 of them were significantly decreased, 43 of them were significantly increased. The majority of the DAMs were identified from the two resistant varieties, and the overall magnitude of change was greater in the resistant varieties than that in the susceptible varieties. Finally, 15 secondary metabolites (6 amino acids and their derivatives, 5 phenolic acids, 3 nucleotides and their derivatives, and 1 organic acid) were considered to be involved in M. persicae resistance of ‘Shou xing tao’.

The significantly up-regulated secondary metabolites obtained in M. persicae-resistant peach varieties were mainly involved in the response to M. persicae feeding. The regulation of these secondary metabolites (amino acids and their derivatives, phenolic acids, nucleotides and their derivatives, organic acid) is the important mechanism of defense reaction to M. persicae.