title: Erythronium dens-canis L. (Liliaceae): an unusual case of change of leaf mottling.
abstract: Erythronium dens-canis is an early-flowering understory lily of southern Europe with two leaves and a single flower, although a number of plants have only one leaf and do not flower. The leaves are mottled with silvery flecks and brown patches, that gradually vanish turning to a lively green color. The nature and function of this striking variegation pattern were investigated in differently colored leaf parts following the springtime color change. Tissue organization was examined by light and electron microscopy; photosynthetic pigments were analyzed by spectrophotometry and HPLC; chlorophyll fluorescence parameters were evaluated by MINI-PAM. The results showed that brown patches originated in vacuolar anthocyanins in the subepidermal cell layer while air spaces between the upper epidermis and underlying chlorenchyma resulted in silvery flecks. The two leaf areas did not differ in photosynthetic pigments, chloroplast organization and photosynthetic parameters (F(v)/F(m), NPQ, rETR). Greening of brown patches due to anthocyanin resorption was faster in non-flowering plants than in flowering ones, occurring only when young fruits were developing. Anthocyanin disappearance did not change the structural-functional features of photosynthetic tissues. As a whole the results suggest that the anthocyanin pigmentation of E. dens-canis leaves does not affect the photosynthetic light use and has no photoprotective function. It is proposed that the complex leaf color pattern may act as a camouflage to escape herbivores, while the reflective silvery spots may have a role in attracting pollinators of this early-flowering species.
authors.affiliation: Department of Biology, University of Padova, Via U. Bassi 58/B, I-35131 Padova, Italy. Electronic address: nicoletta.larocca@unipd.it.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: La Rocca
authors.affiliation: Department of Pharmacy and Biotechnologies, University of Bologna, Via Irnerio 42, I-40126 Bologna, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pupillo
authors.affiliation: Department of Biological, Geological and Environmental Sciences, University of Bologna, Via Irnerio 42, I-40126 Bologna, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Puppi
authors.affiliation: Department of Biology, University of Padova, Via U. Bassi 58/B, I-35131 Padova, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Rascio
mesh_terms: D016000:Cluster Analysis; D005453:Fluorescence; D019668:Liliaceae / Q000378:metabolism*; D010788:Photosynthesis; D010858:Pigmentation; D018515:Plant Leaves / Q000378:metabolism*
keywords: A; Anthocyanins; Camouflage; Car; Chl; Erythronium dens-canis; F(m); F(v); FW; Fo; Histology; L; Leaf mottling; MINI-PAM; N; NPQ; PAR; Photosynthetic pigments; Pollinator attraction; V; Z; antheraxanthin; chlorophyll; fresh weight; lutein; maximum fluorescence; mini-pulse amplitude modulated; minimum fluorescence; neoxanthin; non-photochemical quenching; photochemically active radiation; rETR; relative electron transport rate; total carotenoids; variable fluorescence; violaxanthin; zeaxanthin; β-car; β-carotene