Abstract
We have previously reported that the large subunit of Rubisco (LSU) is degraded by ROS in cucumber leaves under chilling-light conditions. In present study, we investigated what are causal factors of LSU degradation by ROS. When leaves of eight species having different chilling-sensitivity were chilled under illumination, LSU was degraded only in cucumber and bean. In cucumber and bean, LSU degradation followed PsaB degradation. Furthermore, the rapid increase of thermal dissipation, the decrease of activities of antioxidant enzymes (AOE) and the increase of inactivated Rubisco without binding of anything (E-form Rubisco) were observed in cucumber and bean. On the other hand, the slow increase of thermal dissipation, the maintenance of AOE activities and the decrease of E-form Rubisco were observed in wheat and arabidopsis. These results suggest that the combination of inactivation of AOE, PsaB degradation and the increase of E-form Rubisco can cause LSU degradation under chilling-light conditions.