Enhanced production and usage of silver nanoparticles (AgNPs) raise concerns about
their potential impacts in aquatic ecosystems. Effects of AgNPs and Ag+ were assessed
based on the variations in the overall proteome and the activities of selected antioxidant
enzymes in two fungal strains of Articulospora tetracladia, one isolated from a non-polluted
stream (At72) and the other from a metal-polluted stream (At61). For that, fungi were
exposed to concentrations of AgNPs and Ag+ affecting 20% of growth (EC20). A total
of 432 proteins were identified, of which 172 belonged to At72 and 260 to At61; 71 were
expressed in both strains. At72 had 58% and 52% of the proteins induced by AgNPs and
Ag+, respectively. For At61, the percentages were higher ( ˜77%). The higher percentages
of proteins suppressed by either Ag forms suggest higher stress in At72 than in At61, which
is consistent with the background of this fungal strain. Major groups of proteins were
related to carbohydrate metabolism, amino-acid and protein biosynthesis. Both Ag forms
also induced stress-responsive proteins, including catalase and superoxide dismutase which
remained consistent with the profile of their enzymatic activities. These results supported the
ability of these fungi in initiating an efficient antioxidant response to cope with Ag-induced
toxicity. Overall, the functional proteomic approach can be useful to get a mechanistic insight
on the stress induced by AgNPs or Ag+ in aquatic fungi that play a key role in plant litter
decomposition in stream
