Phenoloxidase and peroxidase activities in Sphagnum-dominated peatland in a warming climate

Peatlands still suffer from the scarcity of available data about the characterization and the response to climate forcing of the main oxidative enzymes that occur over the seasons. In the present study, phenoloxidase and peroxidase activities were examined in Sphagnum lawns along a narrow fen-bog gradient under experimental elevated temperatures. We showed that peroxidase activities from Sphagnum mosses were 1000-fold higher than those of phenoloxidases irrespective of seasons and sampling areas. Peroxidase activities increased (+30%) with the rise of air temperatures (an average of 1 °C), while warming did not alter phenoloxidase activities. These results suggest that the monitoring of peroxidase activities in peatlands may represent a suitable and forward indicator of the impact of climate warming on carbon cycle in peatlands.

► We investigated phenoloxidases and peroxidases activities in a Sphagnum peatland.
► 2,7-DAF is a relevant substrate to quantify both enzymatic activities in peatland.
► Peroxidases are the dominant oxidative system in Sphagnum peatland.
► Increasing air temperature of 1 °C induces a rise of peroxidase activities.
► Peroxidases represent an early indicator of warming impact in peatlands.