phytochrome A-mediated shade avoidance responses

Arabidopsis is a shade avioding plant. Under simulated shade light with reduced red-to-far red (R:FR) ratio around 0.7, hypocotyls of Arabidopsis seedlings elongate, which is one of the typical shade avoidance responses.We discovered that when the R:FR ratio further decreases to around 0.1 (strong shade), the shade-induced elongation of hypocotyl is abolished and phytochrome A (phyA) mediates this response.In this study, we aim to examine the difference between shade and strong shade treatment and uncover the role of phyA in regulating the shade avoidance responses. In this study, there are a total of 16 samples. We used 5-day old arabidopsis seedlings, tested three light conditions: continuous light (wc), shade (s,R:FR=0.7) and strong shade (s_s, R:FR=0.1) and two genotypes Col-0 wild type (C) and phyA-211 (A, a null phyA mutant). For each conditions, three biological replicates were included, except for those of the continuous light treatment.