Metabolomic and transcriptomic analyses of Prunus davidiana reveal the key resistance compound to green peach aphid, betulin

Abstract

Prunus davidiana, a close wild relative of the cultivated peach, has been identified as having a strong resistance to Myzus persicae Sülzer (green peach aphid, GPA), one of the major pests of peach. However, the resistance mechanism of P. davidiana remains unclear. In this study, combined analysis of metabolome and transcriptome was conducted using aphid-resistant (R-32) and aphid-susceptible (S-27) lines, from a segregating population, to investigate the defense mechanism of P. davidiana. These results showed that R-32 continuously accumulated higher levels of betulin than S-27 during aphid infestation. Besides, betulin displayed a strong toxic effect on GPA. Transcriptome analysis revealed that the expression of genes involved in the betulin biosynthesis pathway responded highly to GPA infestation, especially CYP716A1. Our results demonstrate that betulin play an important role in the mechanism of resistance of P. davidiana to GPA.