title: LaeA regulation of secondary metabolism modulates virulence in Penicillium expansum and is mediated by sucrose.
abstract: Penicillium expansum, the causal agent of blue mould rot, is a critical health concern because of the production of the mycotoxin patulin in colonized apple fruit tissue. Although patulin is produced by many Penicillium species, the factor(s) activating its biosynthesis are not clear. Sucrose, a key sugar component of apple fruit, was found to modulate patulin accumulation in a dose-responsive pattern. An increase in sucrose culture amendment from 15 to 175 mm decreased both patulin accumulation and expression of the global regulator laeA by 175- and five-fold, respectively, whilst increasing expression of the carbon catabolite repressor creA. LaeA was found to regulate several secondary metabolite genes, including the patulin gene cluster and concomitant patulin synthesis in vitro. Virulence studies of ΔlaeA mutants of two geographically distant P. expansum isolates (Pe-21 from Israel and Pe-T01 from China) showed differential reduction in disease severity in freshly harvested fruit, ranging from no reduction for Ch-Pe-T01 strains to 15%-25% reduction for both strains in mature fruit, with the ΔlaeA strains of Is-Pe-21 always showing a greater loss in virulence. The results suggest the importance of abiotic factors in LaeA regulation of patulin and other secondary metabolites that contribute to pathogenicity.
authors.affiliation: Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel.
authors.forename: Dilip
authors.initials: D
authors.lastname: Kumar
authors.affiliation: Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel.|Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
authors.forename: Shiri
authors.initials: S
authors.lastname: Barad
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Plant Pathology, University of Wisconsin - Madison, Madison, WI, 53706-1598, USA.
authors.forename: Xingyu
authors.initials: X
authors.lastname: Luo
authors.affiliation: Department of Medical Microbiology and Immunology, University of Wisconsin - Madison, Madison, WI, 53706-1598, USA.
authors.forename: Joanna
authors.initials: J
authors.lastname: Tannous
authors.affiliation: Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel.
authors.forename: Amit
authors.initials: A
authors.lastname: Dubey
authors.affiliation: Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel.|Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, 76100, Israel.
authors.forename: Nofar
authors.initials: N
authors.lastname: Glam Matana
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Shiping
authors.initials: S
authors.lastname: Tian
authors.affiliation: Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
authors.forename: Boqiang
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Plant Pathology, University of Wisconsin - Madison, Madison, WI, 53706-1598, USA.|Department of Medical Microbiology and Immunology, University of Wisconsin - Madison, Madison, WI, 53706-1598, USA.|Department of Bacteriology, University of Wisconsin - Madison, Madison, WI, 53706-1598, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Keller
authors.affiliation: Department of Postharvest Science of Fresh Produce, Agricultural Research Organization, The Volcani Center, Bet Dagan, 50250, Israel.
authors.forename: Dov
authors.initials: D
authors.lastname: Prusky
mesh_terms: D015169:Colony Count, Microbial; D005656:Fungal Proteins / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D027845:Malus / Q000382:microbiology; D005810:Multigene Family; D009154:Mutation / Q000235:genetics; D010365:Patulin / Q000096:biosynthesis; D010407:Penicillium / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D064210:Secondary Metabolism; D013395:Sucrose / Q000494:pharmacology*; D014774:Virulence / Q000187:drug effects
chemical_list: D005656:Fungal Proteins; D013395:Sucrose; D010365:Patulin
keywords: Penicillium; mycotoxin; pathogenicity; patulin; sucrose