Synergistic interaction between juglone‐induced oxidative stress and high‐temperature stress in the nematode C. elegans

In human cell lines, oxidative stress can cause translational blockage of heat shock response proteins, increasing susceptibility to heat stress. We tested whether oxidative stress and heat stress interact to affect survival of C. elegans . Young‐adult C. elegans were exposed to oxidative stress, induced by the ecologically‐relevant compound juglone at six levels (0, 20, 40, 60, 80, 100 mM), fully crossed with four levels of heat stress, (20, 25, 30, 35 °C). After a 2 h stress exposure, the worms were allowed to recover for 16 h (0 mM juglone, 20 °C), survival was then determined by SYTOX ® Green staining and worm morphology. Survival was essentially unaffected by juglone or high‐temperature treatment alone, whereas the combination of juglone and high‐temperature severely affected survival, with almost complete mortality at 35 °C and 100 mM juglone. These results indicate that high‐temperature and oxidative stress can interact synergistically to reduce survival in a whole‐animal model. This ecologically‐relevant, synergistic interaction may have implications for the mechanisms by which climate change influences species distributions and species interactions. Supported by NIH R01AG021042.