Damaging and Defense Processes Induced in Plant Cells by UVB Radiation

Abstract

UVB radiation (290–320 nm) activates various signaling mechanisms triggering the processes of programmed cell death in plants or their protection against the damaging action of this type of radiation. In the case of high dosages of UVB radiation, the mechanisms of cell death are associated with DNA damage and oxidative stress. In the first case, activation of DNA damage checkpoints and cell cycle arrest may occur; in the second case, cytochrome c is released from mitochondria with the subsequent activation of metacaspases. According to the existing data, both mechanisms induce DNA fragmentation and other changes typical for apoptotic cells, while low-intensity UVB radiation, which is perceived by a UVR8 photoreceptor, initiates protective processes promoting plant acclimatization to sunlight.