title: Interaction of light quality and fertility on biomass, shoot pigmentation and xanthophyll cycle flux in Chinese kale.
abstract: BACKGROUND
  Nutritionally important carotenoids in 21-day-old brassica microgreens increase following short and long-term exposure to narrow-band wavelengths from light-emitting diodes (LED). The present study aimed to measure the impact of: (1) fluorescent/incandescent light and different percentages of blue/red LED light and (2) different levels of nutrient fertility on biomass and pigment concentrations in 30-day-old 'Green Lance' Chinese kale (Brassica oleracea var. alboglabra). Kale plants were exposed to four light treatments and two fertility levels and were harvested 30 days after seeding and analyzed for nutritionally important shoot pigments.
  
  
  RESULTS
  Kale under the fluorescent/incandescent light treatment had a significantly higher shoot fresh and dry mass. The shoot tissue concentrations of most pigment were significantly higher under blue/red LED light treatments. The higher fertility level resulted in higher concentrations for most pigments. Interestingly, the pool of xanthophyll cycle pigments and de-epoxidized xanthophylls was higher under all LED treatments.
  
  
  CONCLUSIONS
  The results obtained in the present study support previous data demonstrating the stimulation of nutritionally important shoot tissue pigment concentrations following exposure to sole source blue/red LEDs compared to traditional lighting. Xanthophyll cycle flux was impacted by LEDs and this may support the role of zeaxanthin in blue light perception in leafy specialty crops. © 2016 Society of Chemical Industry.
authors.affiliation: Plant Sciences Department, The University of Tennessee, Knoxville, TN, 37996, USA.
authors.forename: Dean A
authors.initials: DA
authors.lastname: Kopsell
authors.affiliation: Plant Sciences Department, The University of Tennessee, Knoxville, TN, 37996, USA.
authors.forename: Carl E
authors.initials: CE
authors.lastname: Sams
authors.affiliation: Orbital Technologies Corporation, Madison, WI, 53717, USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Morrow
mesh_terms: D000072759:Biofortification / Q000379:methods; D001937:Brassica / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D000069599:Crop Production / Q000379:methods; D005308:Fertilizers / Q000009:adverse effects; D005453:Fluorescence; D006801:Humans; D018527:Hydroponics / Q000379:methods; D049450:Incandescence; D007700:Kinetics; D008027:Light / Q000009:adverse effects; D008029:Lighting / Q000379:methods; D009753:Nutritive Value; D010860:Pigments, Biological / Q000032:analysis / Q000096:biosynthesis*; D018515:Plant Leaves / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D018520:Plant Shoots / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D015854:Up-Regulation / Q000528:radiation effects; D024341:Xanthophylls / Q000032:analysis / Q000096:biosynthesis*; D065146:Zeaxanthins / Q000032:analysis / Q000096:biosynthesis
chemical_list: D005308:Fertilizers; D010860:Pigments, Biological; D024341:Xanthophylls; D065146:Zeaxanthins
keywords: LED; blue light; carotenoid; light-emitting diode; lutein; zeaxanthin