Uncovering a novel function of the CCR4-NOT complex in phytochrome A-mediated light signalling in plants

Phytochromes are photoreceptors regulating growth and development in plants. Using the model plant Arabidopsis, we identified a novel signalling pathway downstream of far-red light-sensing phytochrome, phyA, that depends on highly conserved CCR4-NOT complex. is integral to RNA metabolism yeast animals, but its function plants largely unknown. NOT9B, an Arabidopsis homologue human CNOT9, component complex, acts as negative regulator phyA-specific light when bound NOT1, scaffold protein Light-activated phyA interacts with displaces NOT9B from suggesting potential mechanism for through CCR4-NOT. ARGONAUTE 1 proteins involved splicing associate show required specific phyA-dependent alternative events. Furthermore, association nuclear localised raises possibility phyA-modulated gene expression.