title: Relevance of the transcription factor PdSte12 in Penicillium digitatum conidiation and virulence during citrus fruit infection.
abstract: Green mould, resulting from Penicillium digitatum, is the most important postharvest disease of citrus. In a previous study, the PdSte12 transcription factor gene was identified, and disruption mutants were obtained. In the present study, the ΔPdSte12 mutants generated through gene replacement showed significantly reduced virulence during citrus fruit infection. Virulence was affected not only in mature fruit but also in immature fruit, and disease severity was markedly reduced when the oranges were stored at 20 or 4°C. In addition, the ΔPdSte12 mutants were defective in asexual reproduction, producing few conidia. The conidiophores of these mutants had longer metulae with fewer branches at the tip of the hyphae. Gene expression analysis revealed that PdSte12 might act as a negative regulator of several transporter-encoding genes and a positive regulator of two sterol demethylases, all of which are involved in fungicide resistance and fungal virulence. Moreover, PdSte12 exhibited the negative regulation of another transcription factor PdMut3, putatively involved in fungal pathogenesis but with no effect on the MAPK SLT2 P. digitatum orthologue belonging to different transcription pathways relevant to cell integrity. These results indicate the PdSte12 transcription factor is functionally conserved in P. digitatum for infection and asexual reproduction, similar to other Ste12 fungal plant pathogens.
authors.affiliation: IRTA, Parc Científic i Tecnològic Agroalimentari de Lleida, Parc de Gardeny, Edifici Fruitcentre, 25003 Lleida, Catalonia, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Vilanova
authors.affiliation: IRTA, Parc Científic i Tecnològic Agroalimentari de Lleida, Parc de Gardeny, Edifici Fruitcentre, 25003 Lleida, Catalonia, Spain.
authors.forename: Neus
authors.initials: N
authors.lastname: Teixidó
authors.affiliation: IRTA, Parc Científic i Tecnològic Agroalimentari de Lleida, Parc de Gardeny, Edifici Fruitcentre, 25003 Lleida, Catalonia, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Torres
authors.affiliation: IRTA, Parc Científic i Tecnològic Agroalimentari de Lleida, Parc de Gardeny, Edifici Fruitcentre, 25003 Lleida, Catalonia, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Usall
authors.affiliation: Food Technology Department, Lleida University, XaRTA-Postharvest, Agrotecnio Center, Rovira Roure 191. 25198 Lleida, Catalonia, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Viñas
authors.affiliation: Laboratorio de Micología, Centro de Protección Vegetal y Biotecnología, Instituto Valenciano de Investigaciones Agrarias (IVIA), Apartado Oficial. 46113- Moncada, Valencia, Spain. Electronic address: pasantor@upv.es.
authors.forename: Paloma
authors.initials: P
authors.lastname: Sánchez-Torres
mesh_terms: D032084:Citrus sinensis / Q000382:microbiology*; D005638:Fruit / Q000382:microbiology*; D005656:Fungal Proteins / Q000235:genetics; D005659:Fungicides, Industrial; D009154:Mutation / Q000235:genetics; D010407:Penicillium / Q000235:genetics* / Q000472:pathogenicity*; D010935:Plant Diseases / Q000382:microbiology*; D012100:Reproduction, Asexual / Q000235:genetics; D013172:Spores, Fungal / Q000254:growth & development* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics*; D014774:Virulence / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D005659:Fungicides, Industrial; D014157:Transcription Factors
keywords: Citrus; Conidiation; Fruit-pathogen interaction; Penicillium digitatum; Transcription factor; Virulence