Genome sequence and transcriptome profiles of pathogenic fungus Paecilomyces penicillatus reveal its interactions with edible fungus Morchella importuna

Paecilomyces penicillatus is one of the pathogens of morels, which greatly affects the yield and quality of Morchella spp.. In the present study, we de novo assembled the genome sequence of the fungus P. penicillatus SAAS_ppe1. We analyzed the transcriptional profile of P. penicillatus SAAS_ppe1 infection of Morchella importuna at different stages (3 days and 6 days after infection) and the response of M. importuna using the transcriptome. The assembled genome sequence of P. penicillatus SAAS_ppe1 was 39.78 Mb in length (11 scaffolds; scaffold N50, 6.50 Mb), in which 99.7% of the expected genes were detected. A total of 7.48% and 19.83% clean transcriptional reads from the infected sites were mapped to the P. penicillatus genome at the early and late stages of infection, respectively. There were 3,943 genes differently expressed in P. penicillatus at different stages of infection, of which 24 genes had increased expression with the infection and infection stage, including diphthamide biosynthesis, aldehyde reductase, and NAD (P)H-hydrate epimerase (P < 0.05). Several genes had variable expression trends at different stages of infection, indicating P. penicillatus had diverse regulation patterns to infect M. importuna. GO function, involving cellular components, and KEGG pathways, involving glycerolipid metabolism, and plant-pathogen interaction were significantly enriched during infection by P. penicillatus. The expression of ten genes in M. importuna increased during the infection and infection stage, and these may regulate the response of M. importuna to P. penicillatus infection. This is the first comprehensive study on P. penicillatus infection mechanism and M. importuna response mechanism, which will lay a foundation for understanding the fungus-fungus interactions, gene functions, and variety breeding of pathogenic and edible fungi.