Alterations in photosynthetic processes due to the effect of oxidative stress induced by cold and UV-B radiation

Plants of tropical and subtropical origin are damaged by temperatures below 15°C; these conditions produce cold stress in plants. The degradation of the ozone layer leads to a greater penetration of ultraviolet-B (UV-B) radiation to the planet's surface, especially in tropical and subtropical latitudes, which interferes with plant development. Cold and UV-B radiation can inhibit photosynthesis by altering gene expression and damaging photosynthetic components, either directly or through the production of reactive oxygen species (ROS). The photosynthetic components that are most affected are photosystems I (PSI) and II (PSII), light-harvesting complex II (LHCII) and the membranes. Through evolutionary processes, plants have developed different defense mechanisms against these types of stress, such as the synthesis of carotenoids and flavonoids, to protect themselves against the incidence of UV-B radiation and the ROS caused by these stressors. Therefore, this review is focused on analyzing the evidence that describes the effects of cold and UV-B radiation on the main components of the photosynthetic apparatus directly and through the production of ROS induced by photoinhibition as well as the mechanisms that plants use to eradicate the excessive production of ROS.