A Global View of Gene Expression of Aspergillus nidulans on Responding to the Deficiency in Soluble Potassium

Abstract

Many researchers have suggested that microbes can accelerate the weathering of silicate minerals. However, many genes and metabolic pathways related to microorganisms obtaining potassium (K) from silicate remain undiscovered. It is feasible to detect the gene expression within the scope of the whole genome through high-throughput sequencing. Surprisingly, only a few reports have shown fungal weathering of silicate using this technology. This study explored differences in gene expression of Aspergillus nidulans, which was cultured with different K sources, KCl, and K-feldspar. A. nidulans RNA was extracted by the construction of a cDNA library. Identification of K-acquisition-related genes with GO and KEGG pathway analysis revealed that primarily differentially expressed genes were related to the biosynthesis of amino acids. When these genes were grouped in accordance with the physiological functions, the genes involved in the synthesis of protease, ribosome, and mitochondria, trans-membrane transport, and oxidative phosphorylation were significantly different. Moreover, 20 genes selected were further tested using RT-qPCR. One half (10 genes) exhibited differential expression, which was consistent with the results of RNA-seq. Combining the results of RNA-seq and RT-qPCR, we summarised a possible way to obtain mineral K in A. nidulans as well. The differentially expressed genes and their associated metabolic pathways revealed will improve the understanding of the molecular mechanisms of microbial weathering of silicate minerals.