The end of innocence: flowering networks explode in complexity

Substantial recent advances in genome-scale transcription factor target mapping have provided a fresh view of the gene networks governing developmental transitions. In particular, our understanding of the fine-scale spatial and temporal dynamics underlying the floral transition at the shoot apex has seen great advances in the past two years. Single transcription factors are regularly observed to act in complex manners, directly promoting the expression of particular targets while directly repressing the expression of others, based at least partly on defined heterodimerization patterns. For single regulators this behavior reaches into distinct physiological processes, providing compelling evidence that particular transcription factors act to directly integrate diverse processes to orchestrate complex developmental transitions.

► ChIP-Seq/chip studies increase the complexity of the network controlling flowering.
► We show spatial and temporal events at the SAM in the floral transition.
► Certain transcription factors can act both as an activator and as a repressor.
► Flowering transcription factors can regulate multiple developmental processes.
► Cell type and developmental stage-specific studies are the next research phase.