title: Xylem-borne cytokinins: still in search of a role?
abstract: Leaf expansion and xylem cytokinin concentration ([X-CK]) decrease in response to nitrogen (N) deprivation. Debate continues over cause, effect, and correlation. Supporting studies provide, at best, correlative evidence that [X-CK] controls leaf growth in response to N-deprivation, while dissenting studies indicate that leaf growth responses to N can be independent of changes in X-CK supply to leaves. A model is proposed to evaluate the physiological significance to leaf growth of changes in plant and environment N concentrations, and plant CK concentrations.
authors.affiliation: Department of Biological Sciences, Lancaster Environment Centre, University of Lancaster, Lancaster LA1 4YQ, UK. I.Dodd@lancaster.ac.uk
authors.forename: Ian C
authors.initials: IC
authors.lastname: Dodd
authors.forename: Christine A
authors.initials: CA
authors.lastname: Beveridge
mesh_terms: D003583:Cytokinins / Q000502:physiology*; D009584:Nitrogen / Q000502:physiology; D018515:Plant Leaves / Q000254:growth & development*
chemical_list: D003583:Cytokinins; D009584:Nitrogen