title: Multiple microscopic approaches demonstrate linkage between chromoplast architecture and carotenoid composition in diverse Capsicum annuum fruit.
abstract: Increased accumulation of specific carotenoids in plastids through plant breeding or genetic engineering requires an understanding of the limitations that storage sites for these compounds may impose on that accumulation. Here, using Capsicum annuum L. fruit, we demonstrate directly the unique sub-organellar accumulation sites of specific carotenoids using live cell hyperspectral confocal Raman microscopy. Further, we show that chromoplasts from specific cultivars vary in shape and size, and these structural variations are associated with carotenoid compositional differences. Live-cell imaging utilizing laser scanning confocal (LSCM) and confocal Raman microscopy, as well as fixed tissue imaging by scanning and transmission electron microscopy (SEM and TEM), all demonstrated morphological differences with high concordance for the measurements across the multiple imaging modalities. These results reveal additional opportunities for genetic controls on fruit color and carotenoid-based phenotypes.
authors.affiliation: Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, 88003, USA.
authors.forename: James
authors.initials: J
authors.lastname: Kilcrease
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Collins
authors.forename: Richard D
authors.initials: RD
authors.lastname: Richins
authors.forename: Jerilyn A
authors.initials: JA
authors.lastname: Timlin
authors.forename: Mary A
authors.initials: MA
authors.lastname: O'Connell
mesh_terms: D002212:Capsicum / Q000378:metabolism / Q000648:ultrastructure*; D002338:Carotenoids / Q000032:analysis / Q000378:metabolism*; D005638:Fruit / Q000378:metabolism / Q000648:ultrastructure*; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D015999:Multivariate Analysis; D010641:Phenotype; D018087:Plastids / Q000378:metabolism / Q000648:ultrastructure*; D013045:Species Specificity
chemical_list: D002338:Carotenoids
keywords: Capsicum annuum; carotenoids; chromoplast; electron microscopy; hyperspectral confocal Raman microscopy; pericarp; technical advance