title: UV-B radiation impacts shoot tissue pigment composition in Allium fistulosum L. cultigens.
abstract: Plants from the Allium genus are valued worldwide for culinary flavor and medicinal attributes. In this study, 16 cultigens of bunching onion (Allium fistulosum L.) were grown in a glasshouse under filtered UV radiation (control) or supplemental UV-B radiation [7.0  μ mol·m(-2) · s(-2) (2.68 W · m(-2))] to determine impacts on growth, physiological parameters, and nutritional quality. Supplemental UV-B radiation influenced shoot tissue carotenoid concentrations in some, but not all, of the bunching onions. Xanthophyll carotenoid pigments lutein and β -carotene and chlorophylls a and b in shoot tissues differed between UV-B radiation treatments and among cultigens. Cultigen "Pesoenyj" responded to supplemental UV-B radiation with increases in the ratio of zeaxanthin + antheraxanthin to zeaxanthin + antheraxanthin + violaxanthin, which may indicate a flux in the xanthophyll carotenoids towards deepoxydation, commonly found under high irradiance stress. Increases in carotenoid concentrations would be expected to increase crop nutritional values.
authors.affiliation: Plant Sciences Department, The University of Tennessee, 2431 Joe Johnson Drive, Knoxville, TN 37996, USA.
authors.forename: Kristin R
authors.initials: KR
authors.lastname: Abney
authors.forename: Dean A
authors.initials: DA
authors.lastname: Kopsell
authors.forename: Carl E
authors.initials: CE
authors.lastname: Sams
authors.forename: Svetlana
authors.initials: S
authors.lastname: Zivanovic
authors.forename: David E
authors.initials: DE
authors.lastname: Kopsell
mesh_terms: D000490:Allium / Q000502:physiology* / Q000528:radiation effects; D002338:Carotenoids / Q000378:metabolism*; D002734:Chlorophyll / Q000378:metabolism*; D010858:Pigmentation / Q000502:physiology / Q000528:radiation effects*; D018520:Plant Shoots / Q000502:physiology* / Q000528:radiation effects; D011829:Radiation Dosage; D014466:Ultraviolet Rays
chemical_list: D002734:Chlorophyll; D002338:Carotenoids