title: Health-promoting compounds of broccoli (Brassica oleracea L. var. italica) plants as affected by nitrogen fertilisation in projected future climatic change environments.
abstract: BACKGROUND
  The complex interactions between CO2 increase and salinity were investigated in relation to decreased N supply, in order to determine the nutritional quality of broccoli (Brassica oleracea L. var. italica) plants under these conditions. Three different decreased N fertilisation regimes (NO3(-)/NH4(+) ratios of 100:0, 50:50 and 0:100 respectively) were combined with ambient (380 ppm) and elevated (800 ppm) [CO2 ] under non-saline (0 mmol L(-1) NaCl) and saline (80 mmol L(-1) NaCl) conditions. Nutrients (minerals, soluble protein and total amino acids) and natural antioxidants (glucosinolates, phenolic acids, flavonoids and vitamin C) were determined.
  
  
  RESULTS
  In NH4(+) -fed broccoli plants, a marked growth reduction was shown and a redistribution of amino acids to cope with NH4(+) toxicity resulted in higher levels of indolic glucosinolate and total phenolic compounds. However, the positive effect of the higher [CO2] - ameliorating adverse effects of salinity--was only observed when N was supplied as NO3(-). Under reduced N fertilisation, the total glucosinolates were increased by a decreased NO3(-)/NH4 (+) ratio and elevated [CO2] but were unaffected by salinity.
  
  
  CONCLUSIONS
  Under future climatic challenges, such as increased salinity and elevated [CO2], a clear genotypic dependence of S metabolism was observed in broccoli plants. In addition, an influence of the form in which N was supplied on plant nutritional quality was observed; a combined NO3(-)/NH4(+) (50:50) supply allowed broccoli plants not only to deal with NH4(+) toxicity but also to modify their glucosinolate content and profile. Thus, for different modes of N fertilisation, the interaction with climatic factors must be considered in the search for an optimal balance between yield and nutritional quality.
authors.affiliation: Laboratoire Aridoculture et Cultures Oasiennes, Institut des Régions Arides, Route de Djerba Km 22.5, 4119, Médenine, Tunisia.
authors.forename: Chokri
authors.initials: C
authors.lastname: Zaghdoud
authors.affiliation: Department of Plant Nutrition, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Ap. de Correos 164, E-30100, Murcia, Spain.
authors.forename: Micaela
authors.initials: M
authors.lastname: Carvajal
authors.affiliation: Department of Food Science and Technology, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Ap. de Correos 164, E-30100, Murcia, Spain.
authors.forename: Diego A
authors.initials: DA
authors.lastname: Moreno
authors.affiliation: Laboratoire Aridoculture et Cultures Oasiennes, Institut des Régions Arides, Route de Djerba Km 22.5, 4119, Médenine, Tunisia.
authors.forename: Ali
authors.initials: A
authors.lastname: Ferchichi
authors.affiliation: Department of Plant Nutrition, Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC), Campus Universitario de Espinardo, Ap. de Correos 164, E-30100, Murcia, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Del Carmen Martínez-Ballesta
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000975:Antioxidants; D001205:Ascorbic Acid / Q000737:chemistry; D018533:Biomass; D001937:Brassica / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism*; D057231:Climate Change; D005308:Fertilizers / Q000032:analysis*; D005961:Glucosinolates / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry / Q000494:pharmacology*; D010636:Phenols / Q000737:chemistry; D010940:Plant Proteins / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000975:Antioxidants; D005308:Fertilizers; D005961:Glucosinolates; D010636:Phenols; D010940:Plant Proteins; D009584:Nitrogen; D001205:Ascorbic Acid
keywords: Brassica oleracea; amino acids; climate change; glucosinolates; phenolic compounds; vitamin C