AtfA-Independent Adaptation to the Toxic Heavy Metal Cadmium in Aspergillus nidulans

Microorganisms

卷:9

Jae-Hyuk Yu¹  Heungyun Moon¹  István Pócsi²  Barnabás Gila²  Fanni Fekete²  Tamás Emri²  Károly Antal³ 

[1] Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA;

[2] Department of Molecular Biotechnology and Microbiology, Faculty of Sciences and Technology, University of Debrecen, 4032 Debrecen, Hungary;

[3] Department of Zoology, Eszterházy Károly University, 3300 Eger, Hungary;

关键词: Aspergillus nidulans;    AtfA;    cadmium;    oxidative stress;    transcriptomics;   

DOI  :  10.3390/microorganisms9071433

来源: DOAJ

【 摘 要 】

Cadmium is an exceptionally toxic industrial and environmental pollutant classified as a human carcinogen. In order to provide insight into how we can keep our environment safe from cadmium contamination and prevent the accumulation of it in the food chain, we aim to elucidate how Aspergillus nidulans, one of the most abundant fungi in soil, survives and handles cadmium stress. As AtfA is the main transcription factor governing stress responses in A. nidulans, we examined genome-wide expression responses of wild-type and the atfA null mutant exposed to CdCl₂. Both strains showed up-regulation of the crpA Cu²⁺/Cd²⁺ pump gene and AN7729 predicted to encode a putative bis(glutathionato)-cadmium transporter, and transcriptional changes associated with elevated intracellular Cys availability leading to the efficient adaptation to Cd²⁺. Although the deletion of atfA did not alter the cadmium tolerance of the fungus, the cadmium stress response of the mutant differed from that of a reference strain. Promoter and transcriptional analyses of the “Phospho-relay response regulator” genes suggest that the AtfA-dependent regulation of these genes can be relevant in this phenomenon. We concluded that the regulatory network of A. nidulans has a high flexibility allowing the fungus to adapt efficiently to stress both in the presence and absence of this important transcription factor.

【 授权许可】

Unknown