title: Changes in cytokinins are sufficient to alter developmental patterns of defense metabolites in Nicotiana attenuata.
abstract: Plant defense metabolites are well known to be regulated developmentally. The optimal defense (OD) theory posits that a tssue's fitness values and probability of attack should determine defense metabolite allocations. Young leaves are expected to provide a larger fitness value to the plant, and therefore their defense allocations should be higher when compared with older leaves. The mechanisms that coordinate development with defense remain unknown and frequently confound tests of the OD theory predictions. Here we demonstrate that cytokinins (CKs) modulate ontogeny-dependent defenses in Nicotiana attenuata. We found that leaf CK levels highly correlate with inducible defense expressions with high levels in young and low levels in older leaves. We genetically manipulated the developmental patterns of two different CK classes by using senescence- and chemically inducible expression of CK biosynthesis genes. Genetically modifying the levels of different CKs in leaves was sufficient to alter ontogenic patterns of defense metabolites. We conclude that the developmental regulation of growth hormones that include CKs plays central roles in connecting development with defense and therefore in establishing optimal patterns of defense allocation in plants.
authors.affiliation: Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans Knöll Str. 8, Jena, 07745, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Brütting
authors.affiliation: Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans Knöll Str. 8, Jena, 07745, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schäfer
authors.affiliation: Laboratory of Hormonal Regulations in Plants, Institute of Experimental Botany AS CR, Rozvojová 263, Prague 6 - Lysolaje, 165 02, Czech Republic.
authors.forename: Radomíra
authors.initials: R
authors.lastname: Vanková
authors.affiliation: Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans Knöll Str. 8, Jena, 07745, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Gase
authors.affiliation: Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans Knöll Str. 8, Jena, 07745, Germany.
authors.forename: Ian T
authors.initials: IT
authors.lastname: Baldwin
authors.affiliation: Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans Knöll Str. 8, Jena, 07745, Germany.|German Centre for integrative Biodiversity Research (iDiv), Deutscher Platz 5, Leipzig, 04107, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Meldau
mesh_terms: D000085:Acetates / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology; D003583:Cytokinins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D060434:Herbivory / Q000502:physiology; D006790:Host-Parasite Interactions / Q000187:drug effects; D018402:Manduca / Q000502:physiology; D054883:Oxylipins / Q000378:metabolism / Q000494:pharmacology; D010935:Plant Diseases / Q000235:genetics / Q000469:parasitology; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D013997:Time Factors; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism* / Q000469:parasitology
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D003583:Cytokinins; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; C072239:methyl jasmonate
keywords: 
  Manduca sexta
  ; 
  Nicotiana attenuata
  ; cytokinins; herbivores; immunosenescence; inducible defense; optimal defense; phytohormones; plant development