Light mediated regulation of cell division, endoreduplication and cell expansion

• Light suppresses inhibitors of cell division.
• The effect of light on endoreduplication and cell expansion is organ dependent.
• Interaction of photoreceptors and phytochrome interacting factors plays a key role.

Cell division, endoreduplication and cell expansion are key processes for plant growth and development. Light is the main source of energy for plants and as such has a strong effect on plant growth and development. Insight into the role of light in cellular processes is important for our understanding of plant responses to light. Recent advances in artificial plant lighting, cell imaging techniques and molecular biology have provided opportunities to study light responses of plants at the cell and gene level. Regulatory networks for cellular processes have also been unravelled and many transcription factors identified. In this review, we highlight key transcription factors and photoreceptors involved in the regulation of cell division, endoreduplication and cell expansion by light. We suggest that light responses result from either degradation of transcription factors or inhibitory competition between transcription factors for promoter regions of target genes. We also suggest that light stimulates cell division irrespective of the organ under consideration, while endoreduplication and cell expansion responses to light vary from organ to organ.