Characterization of the aodA, dnmA, mnSOD and pimA genes in Aspergillus nidulans

Abstract

Mitochondria play key roles in cellular energy generation and lifespan of most eukaryotes. To understand the functions of four nuclear-encoded genes predicted to be related to the maintenance of mitochondrial morphology and function in Aspergillus nidulans, systematic characterization was carried out. The deletion and overexpression mutants of aodA, dnmA, mnSOD and pimA encoding alternative oxidase, dynamin related protein, manganese superoxide dismutase and Lon protease, respectively, were generated and examined for their growth, stress tolerances, respiration, autolysis, cell death, sterigmatocystin production, hyphal morphology and size, and mitochondrial superoxide production as well as development. Overall, genetic manipulation of these genes had less effect on cellular physiology and ageing in A. nidulans than that of their homologs in another fungus Podospora anserina with a well-characterized senescence. The observed interspecial phenotypic differences can be explained by the dissimilar intrinsic stabilities of the mitochondrial genomes in A. nidulans and P. anserina. Furthermore, the marginally altered phenotypes observed in A. nidulans mutants indicate the presence of effective compensatory mechanisms for the complex networks of mitochondrial defense and quality control. Importantly, these findings can be useful for developing novel platforms for heterologous protein production, or on new biocontrol and bioremediation technologies based on Aspergillus species.

Aflatoxin Biosynthesis and Genetic Regulation: A Review

“…In A. parasiticus: Inhibition of AF production induced by Lentinula edodes increases SOD enzymatic activity within its mechanism of action [179]. In A. nidulans: Deletion of mnSOD increased both glutathione reductase and catalase activities while its overexpression reduced the activity of catalase but increased SOD activity [180].…”

Alternative Oxidase: A Potential Target for Controlling Aflatoxin Contamination and Propagation of Aspergillus flavus

“…However, when the cultures were illuminated, sterigmatocystin productions were greatly reduced and exhibited no significant difference among the wild-type and the mutants. However, Leiter et al (2016) reported that both the deletion and overexpression of AOX in A. nidulans negatively affected sterigmatocystin production. Nevertheless, these observations clearly indicate the importance of AOX in the regulation of sterigmatocystin and aflatoxin production.…”

“…AOX activity is associated with reactive oxygen species (ROS) control, metabolic homeostasis, cellular energy demand, the redox state, and the stress response (Li et al, 2011;Vanlerberghe, 2013). Furthermore, AOX affects mycotoxin production, such as sterigmatocystin, which is the penultimate intermediate in aflatoxin B 1 biosynthesis (Leiter et al, 2016;Molnár et al, 2018a). As AOX is absent in mammals, it has been investigated as a potential drug target for pathogenic fungi (Tudella et al, 2004;Ebiloma et al, 2019).…”

Study on the glutathione metabolism of the filamentous fungus Aspergillus nidulans

“…In this study, we primarily aimed at screening for new GSHmetabolism-related phenotypes especially concerning conidiospore germination and also for GSH-dependent stress defenses. Any new information on the physiological and developmental functions of GSH and GSH metabolic enzymes in fungi may help us to gain a deeper insight in the pathogeneses of human pathogenic fungi [15], to set up new antifungal drug development strategies [25,26] and also to develop new GSH overproducer [27][28][29] as well as more stress tolerant and more stable [1,2,17,30] industrial fungal strains.…”