Correlation Study About CYT B Gene Intron3and The G143A Mutation In Monilinia Fructicola

Peach brown rot is one of the major diseases of peach around the world. It causes not only fruit rot or drop in the orchard, but also continues to infect during storage, which seriously affect the quality and yield of peaches. The causal agents of brown rot (Monilinia spp.) belong to the genus of Monilinia in the family of Sclerotiniaceae.Currently, the application of fungicides is the primary means for the management of peach brown rot. The quinone outside inhibitors (QoIs) are main fungicides against peach brown rot. The G143A mutation in cytochrome b(Cyt b) gene leads to high resistance to QoIs in many pathogens except for Monilinia spp. Studies have shown that a self-splicing group Ⅰ intron was located just downstream of the G143codon. This research mainly explores the relationship between the G143A mutation and the self-splicing mechanism of group Ⅰ intron.Firstly, the Cyt b gene of Monilinia fructicola was recombinated in vitro by double-joint PCR and site-directed mutagenesis based on overlap extension PCR. Then the recombinant Cyt b gene was transferred to yeast cells and nuclear genome of M. fructicola through Pichia transformation system and Agrobacterium-mediated genetic transformation system. The results showed that the group Ⅰ intron of Cyt b gene cannot be spliced regardless of whether the G143A mutation exists in yeast cells or not, and the transcription of recombinated Cyt b gene was abnormal in nuclear genome of M. fructicola. The results in this article have positive significance in improving the QoIs resistance risk assessment in M. fructicola.