Role of Arabidopsis BBX proteins in light signaling

Light regulates numerous aspects of plant growth and development like seed germination, seedling de-etiolation, pigment accumulation, cotyledon opening and flowering. Specific photoreceptors in plants sense different wavelengths of light and initiate signaling cascade leading to light-regulated responses. Between these photoreceptors and final response there are a web of transcription factors involved directly or indirectly in the signal transduction. B-Box (BBX) family of transcription factors is one of the largest family of light-regulated proteins acting as signal transducers in the light signaling pathway. B-box proteins are known for their role in light-mediated regulation of seed germination, hypocotyl elongation, flowering, circadian movements and stress tolerance. This review is an up to date compilation of the roles of BBX proteins in Arabidopsis in regulating physiological processes through red/far-red, blue and UV-B light signaling pathways in Arabidopsis. It also summarizes the roles of BBX proteins in modulating developmental pathways and stress-related signaling events in Arabidopsis and some crop species.