Transcriptome characterization and expression profile of defense-related genes in pear induced by Meyerozyma guilliermondii

Meyerozyma guilliermondii significantly inhibited natural decay of stored pears without adverse effects on storage qualities and induced resistance of pears. It was noticed that M. guilliermondii had a significant effect on the induction of several defense-related genes compared to the control, such as genes coding for phenylalanine ammonia lyase (PAL), peroxidase(POD)and β-1, 3 glucannase (GLU). Furthermore, the expression level of GLU in pears treated with M. guilliermondii increased 105-fold compared to the control at 0 d. These findings indicated that M. guilliermondii enhanced the defense-related mechanism of pears. The transcriptome of pears treated with M. guilliermondii and the control were explored after 3 days, the result showed that 144 genes (Log2 fold change ≥ 2, FDR ＜ 0.05) were significantly up-regulated by the induction of M. guilliermondii, some of which include genes of defense-related enzymes such as G-protein coupled receptor 1-like, cationic peroxidase 1-like and beta-glucosidase 12-like were induced corresponding to PAL, POD and GLU respectively. Defense-related transcription factors such as WRKY9, WRKY31 and some other pathogenesis-related genes like Major allergen Pyr c 1, major allergen Pru ar 1-like and major allergen Pru av 1-like were also induced. These results provided a new insight into the biocontrol mechanism of the antagonist yeast in pears.