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Summary The majority of plant colours are produced by anthocyanin and carotenoid pigments, but colouration obtained by nanostructured materials (i.e. structural colours) is increasingly reported in plants. Here, we identify a multilayer photonic structure in the fruits ofLantana strigocamaraand compare it with a similar structure inViburnum tinusfruits.We used a combination of transmission electron microscopy (EM), serial EM tomography, scanning force microscopy and optical simulations to characterise the photonic structure inL. strigocamara. We also examine the development of the structure during maturation.We found that the structural colour derives from a disordered, multilayered reflector consisting of lipid droplets ofc.105 nm that form a plate‐like structure in 3D. This structure begins to form early in development and reflects blue wavelengths of light with increasing intensity over time as the structure develops. The materials used are likely to be lipid polymers.Lantana strigocamarais the second origin of a lipid‐based photonic structure, convergently evolved with the structure inViburnum tinus. Chemical differences between the lipids inL. strigocamaraand those ofV. tinussuggest a distinct evolutionary trajectory with implications for the signalling function of structural colours in fruits.
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Multiple origins of lipid‐based structural colors contribute to a gradient of fruit colors in Viburnum (Adoxaceae)
Summary Structural color is poorly known in plants relative to animals. In fruits, only a handful of cases have been described, including inViburnum tinuswhere the blue color results from a disordered multilayered reflector made of lipid droplets. Here, we examine the broader evolutionary context of fruit structural color across the genusViburnum.We obtained fresh and herbarium fruit material from 30Viburnumspecies spanning the phylogeny and used transmission electron microscopy, optical simulations, and ancestral state reconstruction to identify the presence/absence of photonic structures in each species, understand the mechanism producing structural color in newly identified species, relate the development of cell wall structure to reflectance inViburnum dentatum, and describe the evolution of cell wall architecture acrossViburnum.We identify at least two (possibly three) origins of blue fruit color inViburnumin species which produce large photonic structures made of lipid droplets embedded in the cell wall and which reflect blue light.Examining the full spectrum of mechanisms producing color in pl, including structural color as well as pigments, will yield further insights into the diversity, ecology, and evolution of fruit color.
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- Award ID(s):
- 1907293
- PAR ID:
- 10485235
- Publisher / Repository:
- New Phytologist
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 237
- Issue:
- 2
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- 643 to 655
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1111/nph.18538
