Relevance of the transcription factor PdSte12 in Penicillium digitatum conidiation and virulence during citrus fruit infection

Vilanova, Laura; Teixidó i Espasa, Neus; Torres Sanchis, Rosario; Usall i Rodié, Josep; Viñas Almenar, Inmaculada; Sánchez-Torres, Paloma

doi:https://doi.org/10.1016/j.ijfoodmicro.2016.07.027

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Issue date

2016

Author

Vilanova, Laura

Teixidó i Espasa, Neus

Torres Sanchis, Rosario

Usall i Rodié, Josep

Viñas Almenar, Inmaculada

Sánchez-Torres, Paloma

Suggested citation

Vilanova, Laura; Teixidó i Espasa, Neus; Torres Sanchis, Rosario; Usall i Rodié, Josep; Viñas Almenar, Inmaculada; Sánchez-Torres, Paloma; . (2016) . Relevance of the transcription factor PdSte12 in Penicillium digitatum conidiation and virulence during citrus fruit infection. International Journal of Food Microbiology, 2016, vol. 235, p. 93-102. https://doi.org/10.1016/j.ijfoodmicro.2016.07.027.

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.

URI

http://hdl.handle.net/10459.1/59624

DOI

https://doi.org/10.1016/j.ijfoodmicro.2016.07.027

Is part of

International Journal of Food Microbiology, 2016, vol. 235, p. 93-102