Molecular response of plant cells to UV-B stress

UV-B radiation (UV-B: 280-320 nm) can cause a wide range of responses in plant cells. These responses depend on the perception of the UV-B radiation, signal transduction mechanisms, and modification of gene expression. Studies over the last ten years have revealed a complex molecular response of plant cells to UV-B radiation. A number of signal transduction pathways are established and specific changes in gene activity take place. In addition, other environmental parameters strongly influence the UV-B-induced response. Although molecular studies have advanced our knowledge, our understanding of UV-B-induced cellular changes remains limited compared with other areas of plant photobiology/molecular biology. This review will focus on UV-B-induced signal transduction, gene expression and defence mechanisms. Comparisons will be made with other light-regulated systems to provide an insight into UV-B responses. This review will also attempt to identify present limitations to our understanding of molecular responses of plant cells to UV-B radiation.