| UV-B causes plant damage directly via high-energy photons and indirectly through production of reactive oxygen species (ROS). Because in vitro studies have shown that flavonoids are ROS scavengers, we set out to determine if ROS are an important component in UV damage by assessing the effect a radical quencher would have in protecting plants against UV radiation. We also investigated if flavonoids play an important role as antioxidants in UV protection by studying the effect that differences in flavonoid levels in mutants would have on lipid peroxidation in UV-exposed tissues. We present evidence that damage by ROS is an important part of the overall effects of UV radiation. Furthermore, we show that flavonoids, in addition to their UV-screening function, play a significant role as antioxidant against ROS damage caused by UV, and thus they might be very important family molecules to protect plants against UV. |
