Combinatorial function of velvet and AreA in transcriptional regulation of nitrate utilization and secondary metabolism.
Velvet is a conserved protein complex that functions as a regulator of fungal development and secondary metabolism. In the soil-inhabiting pathogen Fusarium oxysporum, velvet governs mycotoxin production and virulence on plant and mammalian hosts. Here we report a previously unrecognized role of the velvet complex in regulation of nitrate metabolism. F. oxysporum mutants lacking VeA or LaeA, two key components of the complex, were impaired in growth on the non-preferred nitrogen sources nitrate and nitrite. Both velvet and the general nitrogen response GATA factor AreA were required for transcriptional activation of nitrate (nit1) and nitrite (nii1) reductase genes under de-repressing conditions, as well as for the nitrate-triggered increase in chromatin accessibility at the nit1 locus. AreA also contributed to chromatin accessibility and expression of two velvet-regulated gene clusters, encoding biosynthesis of the mycotoxin beauvericin and of the siderophore ferricrocin. Thus, velvet and AreA coordinately orchestrate primary and secondary metabolism as well as virulence functions in F. oxysporum.
Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 14071 Córdoba, Spain; Campus de Excelencia Internacional Agroalimentario ceiA3, 14071 Córdoba, Spain.
Manuel S
MS
López-Berges
Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 14071 Córdoba, Spain; Campus de Excelencia Internacional Agroalimentario ceiA3, 14071 Córdoba, Spain.
Katja
K
Schäfer
Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 14071 Córdoba, Spain; Campus de Excelencia Internacional Agroalimentario ceiA3, 14071 Córdoba, Spain.
Concepción
C
Hera
Departamento de Genética, Facultad de Ciencias, Universidad de Córdoba, 14071 Córdoba, Spain; Campus de Excelencia Internacional Agroalimentario ceiA3, 14071 Córdoba, Spain. Electronic address: ge2dipia@uco.es.
Antonio
A
Di Pietro
D002843:Chromatin / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005670:Fusarium / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005810:Multigene Family; D009183:Mycotoxins / Q000235:genetics / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D064210:Secondary Metabolism; D017262:Siderophores / Q000235:genetics / Q000378:metabolism
D002843:Chromatin; D005656:Fungal Proteins; D009183:Mycotoxins; D009566:Nitrates; D017262:Siderophores
Fusarium oxysporum; GATA factor; Nitrate utilization; Secondary metabolism; Siderophore; Virulence