Characterization of chloroplast iridescence in <i>Selaginella erythropus</i>.

Abstract

Iridescence in shade-dwelling plants has previously been described in only a few plant groups, and even fewer where the structural colour is produced by intracellular structures. In contrast with other <i>Selaginella</i> species, this work reports the first example in the genus of structural colour originating from modified chloroplasts. Characterization of these structures determines that they form one-dimensional photonic multilayers. The <i>Selaginella</i> bizonoplasts present an analogous structure to recently reported <i>Begonia</i> iridoplasts; however, unlike <i>Begonia</i> species that produce iridoplasts, this <i>Selaginella</i> species was not previously described as iridescent. This therefore raises the possibility of widespread but unobserved and uncharacterized photonic structures in plants.