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ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #311478
Title: Genome, transcriptome, and functional analyses of Penicillium expansum provide new insights into secondary metabolism and pathogenicity

Author
item BALLESTER, ANA-ROSA - Instituto De Agroquimica Y Technologia De Alimentos
item MARCET-HOUBEN, MARINA - Center For Genomic Regulation (CRG)
item LEVIN, ELENA - Agricultural Research Organization Of Israel
item SELA, NOA - Agricultural Research Organization Of Israel
item SELMA-LAZARO, CRISTINA - Instituto De Agroquimica Y Technologia De Alimentos
item CARMONA, LOURDES - Instituto De Agroquimica Y Technologia De Alimentos
item Wisniewski, Michael
item DROBY, SAMIR - Agricultural Research Organization Of Israel
item GONZALEZ-CANDELAS, LUIS - Instituto De Agroquimica Y Technologia De Alimentos
item GABALDON, TONI - Center For Genomic Regulation (CRG)

Submitted to: Molecular Plant-Microbe Interactions
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/13/2014
Publication Date: 1/5/2015
Publication URL: http://handle.nal.usda.gov/10113/60400
Citation: Ballester, A., Marcet-Houben, M., Levin, E., Sela, N., Selma-Lazaro, C., Carmona, L., Wisniewski, M.E., Droby, S., Gonzalez-Candelas, L., Gabaldon, T. 2015. Genome, transcriptome, and functional analyses of Penicillium expansum provide new insights into secondary metabolism and pathogenicity. Molecular Plant-Microbe Interactions. 28(3):232-248.

Interpretive Summary: Blue mold of apples, caused by Penicillium expansum, is a major postharvest pathogen of pome fruit in all production areas in the USA and abroad. In addition to the economic losses that occur due to rotting of fruit by this pathogen while in storage and marketing, this pathogen also poses a human health risk to its production of the mycotoxin, patulin. Presently, regulatory agencies regulate the level of patulin allowed to be present in apple-related food products. Understanding the relationship between patulin production and the level of pathogenicity of different strains of blue mold is essential for developing new methods of control. The present study sequenced the genome of three species of blue mold and identified the cluster of genes responsible for patulin production and other secondary metabolites. Additionally, the study identified other genes that potentially play an important role in the ability of blue mold to infect pome fruit (apples and pears). Importantly, the study also conclusively demonstrated for the first time that patulin genes are not needed for blue mold to establish an infection. This research will serve as a foundation for developing a better understanding of resistance and susceptibility of pome fruit to blue mold and the development of new genomic-based strategies for control and breeding for resistance.

Technical Abstract: The relationship between secondary metabolism and infection in pathogenic fungi has remained largely elusive. Penicillium comprises a group of plant pathogens with varying host specificities and with the ability to produce a wide array of secondary metabolites. The genomes of three Penicillium expansum strains, the main postharvest pathogen of pome fruit, and one Pencillium italicum strain, a postharvest pathogen of citrus fruit, were sequenced and compared to 24 other fungal species. A genomic analysis of gene clusters responsible for the production of secondary metabolites was performed. Putative virulence factors in P. expansum were identified by means of a transcriptomic analysis of apple fruits during the course of infection. Despite a major genome contraction, P. expansum is the Penicillium species with the largest potential for the production of secondary metabolites. Results using knockout mutants clearly demonstrated that neither patulin nor citrinin are required by P. expansum to successfully infect apples.