Fig. 2: Innovation of glasshouse-like bracts.

a Chlorophyll (green) and carotenoid (orange) contents in three types of leaves (bract, transitional leaf and rosette) of R. nobile. Three independent biological replicates were used to estimate means (n = 3 biologically independent samples) and standard deviations (SD) in each case. For each photosynthetic pigment, t tests were applied to test the significance of differences in contents between bracts and leaves (rosette and transitional). Double asterisks indicate p < 0.01. b Heatmap of expression of genes involved in chloroplast and mesophyll development in leaves. Gene expression profiles (in fragments per kilobase of exon per million mapped fragments) in the three types of leaves at three time points in the growth season (here June, July and August) are shown from left to right. Colors from gray to green indicate gene expression levels from low to high. Gene names are shown beside each heatmap. CAB, CHLOROPHYLL A/B BINDING PROTEIN; DCL, DEFECTIVE CHLOROPLASTS AND LEAVES; VAR1, VARIEGATED 1; VAR2, VARIEGATED 2; VAR3, VARIEGATED 3. c Cross-sections of rosette leaf (leaf) and bracteal leaf (right) of R. nobile that stained with 0.1% toluidine blue. Bar = 100 μm. d Expression patterns of genes associated with flavonoid biosynthesis and accumulation in indicated tissues, obtained using same tissue panel as in (b), with low to high expression/content indicated by colors from green to orange. PAL phenylalanine ammonia-lyase, C4H cinnamate-4-hydroxylase, 4CL 4-coumarate CoA ligase 4, CHS chalcone synthase, CHI chalcone isomerase, F3H flavanone 3-hydroxylase, FLS flavonol synthase, F3′5′H flavonoid 3′,5′-hydroxylase; F3′H flavonoid 3′-hydroxylase, MYB myeloblastosis transcription factor, bHLH basic helix–loop–helix transcription factor.