Screening and Regulation Mechanism of Key Transcription Factors of Penicillium expansum Infecting Postharvest Pears by ATAC-Seq Analysis

Transcription factors play a key role in Penicillium expansum infection process. Although the crucial characteristics of some transcription factors of pathogenic fungi have been found, many transcription factors involved in P. expansum infections have not been explored and studied. This study aimed to screen the transcription factors of P. expansum involved in postharvest pear infections by ATAC-seq analysis and to analyze the differentially expressed peak-related genes by GO enrichment and KEGG pathway analysis. Our results found the up-regulation of differentially expressed peak-related genes involved in the MAPK signaling pathway, pentose phosphate pathway, starch and sucrose metabolism, and pentose and glucuronate interconversions. Our study especially confirmed the differential regulation of transcription factors MCM1, Ste12 and gene WSC in the MAPK signaling pathway and PG1, RPE1 in the pentose and glucuronate interconversions pathway. These transcription factors and related genes might play an essential role in pear fruit infection by P. expansum. RT-qPCR validation of twelve expressed peak-related genes in P. expansum showed that the expression levels of these twelve genes were compatible with the ATAC-Seq. Our findings might shed some light on the regulatory molecular networks consisting of transcription factors that engaged in P. expansum invasion and infection of pear fruits.