Insight into the mechanism of end-of-day far-red light (EODFR)-induced shade avoidance responses in Arabidopsis thaliana

Takeshi Mizuno, Haruka Oka, Fumi Yoshimura, Kai Ishida, Takafumi Yamashino
2015 Figshare  
Shade avoidance responses are changes in plant architecture to reduce the part of a body that is in the shade in natural habitats. The most common warning signal that induces shade avoidance responses is reduction of red/far-red light ratio perceived by phytochromes. A pair of basic helix–loop–helix transcription factors, named PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) and PIF5, is crucially involved in the shade avoidance-induced hypocotyl elongation in Arabidopsis thaliana. It has been recently
more » ... t has been recently reported that PIF7 also plays a role in this event. Here, we examined the involvement of these PIFs in end-of-day far-red light (EODFR) responses under light and dark cycle conditions. It was shown that PIF7 played a predominant role in the EODFR-dependent hypocotyl elongation. We propose the mechanism by which PIF7 together with PIF4 and PIF5 coordinately transcribes a set of downstream genes to promote elongation of hypocotyls in response to the EODFR treatment. PIF7-dependent EODFR responses are observed immediately after the FR light treatment, while PIF4/PIF5 dependent responses are observed at the end of night. PIF7 and PIF4/5 regulate downstream target genes independently in an additive manner.
doi:10.6084/m9.figshare.1488662 fatcat:fbnb4oavkzclxk44hmjhugbcom