| The role of reactive oxygen species (ROS) in the macroalgal wound response was investigated with emphasis on their occurrence, source, and ecological role. In a survey of Antarctic macroalgae, an oxidative response to wounding was common and ROS in seawater decreased the feeding rate of sympatric amphipod grazers. The macroalgal oxidative response was also sensitive to light. In contrast to the current understanding of the macroalgal oxidative burst, initial wound-induced ROS from the temperate kelp Saccharina latissima were light-dependent and arose from disrupted photosynthetic electron transport rather than from a defense-related enzyme such as an NADPH-oxidase. Furthermore, the light-dependence of wound-induced ROS had consequences for macroalgal-herbivore interactions. The consumption of macroalgae by amphipods was shown to depend on a light-dependent, wound-induced metabolite such as ROS. Consequently, light--via wound-induced ROS--may play a more complex role in the feeding ecology of small primary consumers than previously recognized. |
