Reactive oxygen species in aerobic methane formation from vegetation.

The first report of aerobic methane emissions from vegetation by an unknown mechanism suggested that this potential new source may make a significant contribution to global methane emissions. We recently investigated possible mechanisms and reported experiments in which UV-irradiation caused methane emissions from pectin, a major plant cell wall polysaccharide. Our findings also suggest that UV-generated reactive oxygen species (ROS) release methane from pectin. This has implications for all other, UV-independent processes which may generate ROS in or close to the plant cell wall and suggests a need to evaluate additional systems for ROS-generated methane emissions in leaves.