Artículo
The stress-responsive alternative sigma factor SigB plays a positive role in the antifungal proficiency of Bacillus subtilis
Bartolini, Marco
; Cogliati, Sebastian Claudio
; Vileta, Dario German; Bauman, Carlos; Ramirez, Walter Joel
; Grau, Roberto Ricardo
Fecha de publicación:
05/2019
Editorial:
American Society for Microbiology
Revista:
Applied and Environmental Microbiology
ISSN:
0099-2240
e-ISSN:
1098-5336
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Different Bacillus species with PGPR (plant growth-promoting rhizobacterium) activity produce potent biofungicides and stimulate plant defense responses against phytopathogenic fungi. However, very little is known about how these PGPRs recognize phytopathogens and exhibit the antifungal response. Here, we report the antagonistic interaction between Bacillus subtilis and the phytopathogenic fungus Fusarium verticillioides. We demonstrate that this bacterial-fungal interaction triggers the induction of the SigB transcription factor, the master regulator of B. subtilis stress adaptation. Dual-growth experiments performed with live or dead mycelia or culture supernatants of F. verticillioides showed that SigB was activated and required for the biocontrol of fungal growth. Mutations in the different regulatory pathways of SigB activation in the isogenic background revealed that only the energy-related RsbP-dependent arm of SigB activation was responsible for specific fungal detection and triggering the antagonistic response. The activation of SigB increased the expression of the operon responsible for the production of the antimicrobial cyclic lipopeptide surfactin (the srfA operon). SigB-deficient B. subtilis cultures produced decreased amounts of surfactin, and B. subtilis cultures defective in surfactin production (ΔsrfA) were unable to control the growth of F. verticillioides. In vivo experiments of seed germination efficiency and early plant growth inhibition in the presence of F. verticillioides confirmed the physiological importance of SigB activity for plant bioprotection.
Palabras clave:
BACILLUS SUBTILIS
,
BICONTROL
,
FUNGI
,
SIGMA B
,
STRESS
,
SURFACTIN
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Colecciones
Articulos(CCT - ROSARIO)
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - ROSARIO
Articulos de CTRO.CIENTIFICO TECNOL.CONICET - ROSARIO
Citación
Bartolini, Marco; Cogliati, Sebastian Claudio; Vileta, Dario German; Bauman, Carlos; Ramirez, Walter Joel; et al.; The stress-responsive alternative sigma factor SigB plays a positive role in the antifungal proficiency of Bacillus subtilis; American Society for Microbiology; Applied and Environmental Microbiology; 85; 9; 5-2019; 1-15
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