Fig. 8: Hypocotyl elongation phenotypes correlate well with induction of autophagy in response to changing light environments.

a Western blot analysis of GFP-ATG8a and free GFP in WT seedlings treated for 8 h with LB or LP without ConA. b Quantification of free-GFP bands in (a). Each data point indicates a biologically independent sample (average of two technical replicates for each data point), horizontal bar represents the median, and whiskers extend to show the data range. c Hypocotyl elongation of WT seedlings treated with LB, LP, or LB with increased PAR (High PAR, HP) compared to WL. d GFP-ATG8a and free-GFP levels are detected in WT seedlings treated with 8 h of LB, LRFR, or LRFR + LB without ConA. e Hypocotyl elongation of seedlings with the indicated genotypes treated with the indicated light conditions. The sample size (n) that is given on top indicates biologically independent seedlings examined over one experiment. The experiments were repeated four (a, d) and three (e) times with similar results. H3 (a, d) and TUB (d) were used as a loading control. c, e The horizontal bar represents the median; boxes extend from the 25th to the 75th percentile, whiskers extend to show the data range. b, c, e Different letters indicate significant difference (P < 0.05, two-way ANOVA with Tukey’s HSD test, the exact P values are available in the Source Data). f Model for hypocotyl elongation in full sunlight, neighbor proximity, and vegetative shade conditions. In full sunlight (left panel) and neighbor proximity (middle panel), plants receive high-intensity blue light (high blue, shown by the color white) and autophagy remains at basal levels. Vegetative shade (right panel) decreases the blue light intensity (low blue, shown by the dark-gray color) and promotes autophagy-mediated recycling. The reduced R/FR ratio in neighbor proximity and vegetative shade inactivates phyB thereby promoting PIF activity.