Effects on Gene Transcription Profile and Fatty Acid Composition by Genetic Modification of Mevalonate Diphosphate Decarboxylase MVD/Erg19 in Aspergillus Oryzae

Abstract

Mevalonate diphosphate decarboxylase MVD/Erg19 is required for ergosterol biosynthesis, growth, sporulation, and stress tolerance in Aspergillus oryzae. In this study, RNA-seq was used to analyze the gene transcription profile in AoErg19 overexpression (OE) and RNAi strains. There were 256 and 74 differentially expressed genes (DEGs) in AoErg19 OE and RNAi strains, respectively, compared with the control strain (CK). The most common DEGs were transport- and metabolism-related genes. Only 22 DEGs were obtained that were regulated in both OE and RNAi strains. The transcriptomic comparison between CK and AoErg19 overexpression strain (CK vs. OE), and between CK and AoErg19 RNAi strain (CK vs. RNAi) revealed that the greatest difference existed in the number of genes belonging to the cytochrome P450 family; 12 were found in CK vs. OE, whereas 1 was found in CK vs. RNAi. The expression patterns of lipid biosynthesis and metabolism related genes were altered in OE and RNAi strains, either by gene induction or suppression. Moreover, the total fatty acid content in the RNAi strain was 12.1% greater than the control strain, but no difference in total acid content was found between the overexpression strain and the control strain. Therefore, this study highlights the gene expression regulation within mevalonate (MVA), ergosterol biosynthesis, and fatty acid biosynthesis pathways.

Strategies for the Enhancement of Secondary Metabolite Production via Biosynthesis Gene Cluster Regulation in Aspergillus oryzae

“…Mevalonate diphosphate decarboxylase, also known as Erg19, is a crucial enzyme in the mevalonate pathway [102,103]. The AoErg19-overexpressed and RNAi A. oryzae strains exhibit reduced ergosterol content and increased sensitivity to abiotic stress [104]. Moreover, the transcription levels of AoErg19 are decreased with an increasing salt concentration, ethanol concentration, and temperature [105,106].…”

Identification of Six Thiolases and their Effects on Fatty Acid and Ergosterol Biosynthesis in Aspergillus oryzae

“…Ergosterol and total lipid extraction was performed according to previously described methods (27,(29)(30)(31). The 72 h-old A. oryzae mycelium was harvested and vacuum freeze-dried to a constant weight.…”

Biosynthesis and regulation of terpenoids from basidiomycetes: exploration of new research

“…The MVA pathway begins with acetyl-CoA, which is catalysed by several enzymes (AACT, HMGS, HMGS-CoA, HMGR) to generate mevalonate (MVA), of which HMGR is the recognized rate-limiting enzyme (Costa et al 2019 ). Subsequently, isopentenyl pyrophosphate (IPP) is formed by the catalysis of MK, MPK, MVD and other enzymes (Hu et al 2019a , b ). IPP is a precursor intermediate metabolite of terpenoid biosynthesis.…”

“…To develop a universal host for basidiomycete genes, gene expression was detected using the genomic DNA sequence of an ascomycete host ( Aspergillus oryzae ), and the fungal natural product biosynthesis gene was expressed directly from the genomic DNA of the system. As a result, 29 biologically active pleuromutilin sesquiterpene synthase genes and diterpenoid biosynthesis genes were successfully expressed using the system (Hu et al 2019a , b ). Because an increasing number of derivatives of diterpenoid antibiotics are produced biologically, understanding the biosynthetic pathway of pleuromutilin is a basic requirement for the large-scale production of natural products.…”