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Using structural colour to track length scale of cell‐wall layers in developing Pollia japonica fruits
Author(s) -
Middleton Rox,
Moyroud Edwige,
Rudall Paula J.,
Prychid Christina J.,
Conejero Maria,
Glover Beverley J.,
Vignolini Silvia
Publication year - 2021
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.17346
Subject(s) - cell wall , morphogenesis , cellulose , materials science , optics , polysaccharide , reflectivity , biophysics , live cell imaging , japonica , microscopy , biology , botany , cell , physics , biochemistry , gene , genetics
Summary Helicoidally arranged layers of cellulose microfibrils in plant cell walls can produce strong and vivid coloration in a wide range of species. Despite its significance, the morphogenesis of cell walls, whether reflective or not, is not fully understood. Here we show that by optically monitoring the reflectance of Pollia japonica fruits during development we can directly map structural changes of the cell wall on a scale of tens of nanometres. Visible‐light reflectance spectra from individual living cells were measured throughout the fruit maturation process and compared with numerical models. Our analysis reveals that periodic spacing of the helicoidal architecture remains unchanged throughout fruit development, suggesting that interactions in the cell‐wall polysaccharides lead to a fixed twisting angle of cellulose helicoids in the cell wall. By contrast with conventional electron microscopy, which requires analysis of different fixed specimens at different stages of development, the noninvasive optical technique we present allowed us to directly monitor live structural changes in biological photonic systems as they develop. This method therefore is applicable to investigations of photonic tissues in other organisms.