title: Induction of phenolic metabolites and physiological changes in chamomile plants in relation to nitrogen nutrition.
abstract: Alternative tools, such as the manipulation of mineral nutrition, may affect secondary metabolite production and thus the nutritional value of food/medicinal plants. We studied the impact of nitrogen (N) nutrition (nitrate/NO3(-) or ammonium/NH4(+) nitrogen) and subsequent nitrogen deficit on phenolic metabolites and physiology in Matricaria chamomilla plants. NH4(+)-fed plants revealed a strong induction of selected phenolic metabolites but, at the same time, growth, Fv/Fm, tissue water content and soluble protein depletion occurred in comparison with NO3(-)-fed ones. On the other hand, NO3(-)-deficient plants also revealed an increase in phenolic metabolites but growth depression was not observed after the given exposure period. Free amino acids were more accumulated in NH4(+)-fed shoots (strong increase in arginine and proline mainly), while the pattern of roots' accumulation was independent of N form. Among phenolic acids, NH4(+) strongly elevated mainly the accumulation of chlorogenic acid. Within flavonoids, flavonols decreased while flavones strongly increased in response to N deficiency. Coumarin-related metabolites revealed a similar increase in herniarin glucosidic precursor in response to N deficiency, while herniarin was more accumulated in NO3(-)- and umbelliferone in NH4(+)-cultured plants. These data indicate a negative impact of NH4(+) as the only source of N on physiology, but also a higher stimulation of some valuable phenols. Nitrogen-induced changes in comparison with other food/crop plants are discussed.
authors.affiliation: Institute of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic. jozkovacik@yahoo.com
authors.forename: Jozef
authors.initials: J
authors.lastname: Kováčik
authors.forename: Bořivoj
authors.initials: B
authors.lastname: Klejdus
mesh_terms: D000596:Amino Acids / Q000032:analysis / Q000378:metabolism; D020843:Chamomile / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism*; D062385:Hydroxybenzoates / Q000032:analysis / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D018517:Plant Roots / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism
chemical_list: D000596:Amino Acids; D062385:Hydroxybenzoates; C017616:phenolic acid; D009584:Nitrogen
keywords: Antioxidants; Flavonoids; Mineral nutrition; Nitrogen deficiency; Phenolic metabolism