a, Hypocotyl length measurements of WT
(n = 30/30), pif457
(n = 30/32, P =
0.271/P < 0.001) and pif457
expressing PIF7:PIF7:4xMYC (n = 36/36,
P = 0.823/P < 0.001) in white
light or in responses to low R:FR. Stars denote statistically significant
differences between WT and the other genotypes for the respective light
condition (two-way ANOVA, Tukey’s multiple comparisons test, n.s.
P > 0.05, * P ≤ 0.05, **
P ≤ 0.01, *** P ≤
0.001). b, Hypocotyl length measurements of WT
(n = 26, P < 0.001),
phyB (n = 33), phyB
pif457 (n = 23, P <
0.001) and phyB pif457 expressing
PIF7:PIF7:4xMYC (n = 34,
P = 0,027) grown in WL. Stars denote statistically
significant differences between phyB and the other
genotypes (one-way ANOVA, Tukey’s multiple comparisons test, n.s.
P > 0.05, * P ≤ 0.05, **
P ≤ 0.01, *** P ≤
0.001). c, Immunoblot with anti-MyC of immunoprecipitated
PIF7:4xMyC that had been treated with boiled (inactive) or native (active)
λ-phosphatase (λ-PPase). PIF7:4xMyC was immunoprecipitated
from 6 days old seedlings, grown in WL and harvested at ZT4. Mark next to
cropped blot represent 50 kDa. d, Immunoblot analysis of
pif457 PIF7:PIF7:4xMYC in LD. 6-day-old seedlings
continued to grow in WL or where exposed to low R:FR at ZT0. Marks next to
cropped blots represent 50 kDa (PIF7:4xMyC) or 37 kDa (ACTIN), respectively.
e, Colocalization of PIF7:4xMyC and phyB containing nuclear
speckles per nucleus. The number of phyB nuclear bodies (n
= 105), PIF7 nuclear bodies (n = 98), and co-localized
PHyB/PIF7 nuclear bodies were scored and used to calculate the percentage of
co-localization of PHyB and PIF7. f, Aggregated profile shows the low R:FR
dependent difference between PIF7 binding at ZT4. PIF7 binding was
determined in WL and low R:FR-exposed pif457
PIF7:PIF7:4xMYC seedlings by ChIP-seq. PIF7 occupancy is shown
from 1 kb upstream to 1 kb downstream of the 500 strongest PIF7 binding
events. In a, b and e, boxes extend
from the 25th to 75th percentiles. Middle lines represent medians. Whiskers
extend to the smallest and largest values, respectively.