In Aspergillus spp., the laeA (loss of aflR expression) gene acts as global regulator of secondary metabolism. We found that the T. reesei orthologue LAE1 regulates cellulase and hemicellulase gene expression (Seiboth, Karimi et al. unpublished data). In order to identify all targets of LAE1 in T. reesei, we analysed the transcriptome of lae1 deletion (Dlae1) and LAE1 overexpressing (OE) strains during growth on lactose. 1186 (13 % of theÂ Â total 9143) genes of T. reesei were affected more than 28208;fold in the Dlae1 strain, and 701 in the OE strain, and almost all of the latter (696) were also significantly expressed in the former strain. Amino acid permeases, ankyrins, and G8208;protein coupled receptors were most strongly downregulated in Dlae1 and upregulated in OE. Expression of known (PKS, NRPS) or predicted (monooxygenases, dioxgenases, multicopper oxidases) enzymes involved in secondary metabolite production was also affected, with roughly equal numbers of genes being up8208;Â and downregulated. Approximately 15 % of the genes presumably regulated by LAE1 occurred in 40 discrete clusters in the T. reesei genome. ChIP8208;seq analyses suggest that LAE1 does not directly alter the balance of an active (H3K4me2) and silencing (H3K9me3) histone modification under our conditions. Conidiation was strongly reduced in the delta8208;lae1 strain, both in light and in darkness, and about one third of conidiation genes were affected in the Dlae1 strain, indicating a major effect of LAE1 on T. reesei sporulation. Our data expand the current knowledge of LAE1 function and point to a major involvement in conidiation in T. reesei.
Full conference title:
11 th European Conference on Fungal Genetics
- ECFG 11th (2012)