The VELVET A orthologue VEL1 of Trichoderma reesei regulates fungal development and is essential for cellulase gene expression.
Trichoderma reesei is the industrial producer of cellulases and hemicellulases for biorefinery processes. Their expression is obligatorily dependent on the function of the protein methyltransferase LAE1. The Aspergillus nidulans orthologue of LAE1--LaeA--is part of the VELVET protein complex consisting of LaeA, VeA and VelB that regulates secondary metabolism and sexual as well as asexual reproduction. Here we have therefore investigated the function of VEL1, the T. reesei orthologue of A. nidulans VeA. Deletion of the T. reesei vel1 locus causes a complete and light-independent loss of conidiation, and impairs formation of perithecia. Deletion of vel1 also alters hyphal morphology towards hyperbranching and formation of thicker filaments, and with consequently reduced growth rates. Growth on lactose as a sole carbon source, however, is even more strongly reduced and growth on cellulose as a sole carbon source eliminated. Consistent with these findings, deletion of vel1 completely impaired the expression of cellulases, xylanases and the cellulase regulator XYR1 on lactose as a cellulase inducing carbon source, but also in resting mycelia with sophorose as inducer. Our data show that in T. reesei VEL1 controls sexual and asexual development, and this effect is independent of light. VEL1 is also essential for cellulase gene expression, which is consistent with the assumption that their regulation by LAE1 occurs by the VELVET complex.
Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria.
Razieh
R
Karimi Aghcheh
Department of Biochemical Engineering, Faculty of Sciences and Technology, University of Debrecen, H-4032 Debrecen, Hungary.
Zoltán
Z
Németh
Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria.
Lea
L
Atanasova
Department of Biochemical Engineering, Faculty of Sciences and Technology, University of Debrecen, H-4032 Debrecen, Hungary.
Erzsébet
E
Fekete
Department of Human Genetics, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary.
Melinda
M
Paholcsek
Faculty of Agricultural and Food Science and Environmental Management, Institute of Food Science, H-4032 Debrecen, Hungary.
Erzsébet
E
Sándor
Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria.
Benigno
B
Aquino
Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria; Austrian Center of Industrial Biotechnology, c/o Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria.
Irina S
IS
Druzhinina
Department of Biochemical Engineering, Faculty of Sciences and Technology, University of Debrecen, H-4032 Debrecen, Hungary.
Levente
L
Karaffa
Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria; Austrian Center of Industrial Biotechnology, 8010 Graz, Austria.
Christian P
CP
Kubicek
D000595:Amino Acid Sequence; D002244:Carbon / Q000378:metabolism; D002480:Cellulase / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D025301:Hyphae / Q000502:physiology; D007785:Lactose / Q000378:metabolism; D008027:Light; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000235:genetics / Q000378:metabolism; D014242:Trichoderma / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology
D005656:Fungal Proteins; D011134:Polysaccharides; D002244:Carbon; C007916:hemicellulose; D002480:Cellulase; D007785:Lactose