ROS-Induced anthocyanin production provides feedback protection by scavenging ROS and maintaining photosynthetic capacity in Arabidopsis

Anthocyanins are water-soluble pigments with antioxidant activities. In plants, multiple factors can trigger the accumulation of anthocyanins, including chemicals and environmental factors. Reactive oxygen species (ROS) are common by-products produced under different biotic and abiotic conditions and cause oxidative stress when accumulated at a high level in plant cells. This in turn leads to the production of anthocyanins. However, the mechanisms of ROS-induced anthocyanin accumulation and the role of anthocyanins in the response of plants to different stresses are largely unknown. We have recently reported the cross-regulation between ROS and anthocyanin production through analyzing ten Arabidopsis mutants covering the main anthocyanin regulatory and biosynthetic genes grown under different ROS-generating stresses. Here, we describe the general phenotypic response of anthocyanin mutants under normal and ROS-generating stress conditions, showing the changing levels of anthocyanin accumulation and their sensitivity to stresses. In addition, we propose a model that describes a particular gene interaction that highlights how the cross-regulation mechanisms between ROS and anthocyanin production are essential for plant resistance to various stresses through removing excessive ROS and maintaining photosynthetic capacity.