ENOD40 affects elongation growth in tobacco Bright Yellow-2 cells by alteration of ethylene biosynthesis kinetics.
Plant developmental processes are controlled by co-ordinated action of phytohormones and plant genes encoding components of developmental response pathways. ENOD40 was identified as a candidate for such a plant factor with a regulatory role during nodulation. Although its mode of action is poorly understood, several lines of evidence suggest interaction with phytohormone response pathways. This hypothesis was investigated by analysing cytokinin-, auxin-, and ethylene-induced responses on cell growth and cell division in transgenic 35S:NtENOD40 Bright Yellow-2 (BY-2) tobacco cell suspensions. It was found that cell division frequency is controlled by the balance between cytokinin and auxin in wild-type cells and that this regulation is not affected in 35S:NtENOD40 lines. Elongation growth, on the other hand, is reduced upon overexpression of NtENOD40. Analysis of ethylene homeostasis shows that ethylene accumulation is accelerated in 35S:NtENOD40 lines. ENOD40 action can be counteracted by an ethylene perception blocker, indicating that ethylene is a negative regulator of elongation growth in 35S:NtENOD40 cells, and that the NtENOD40-induced response is mediated by alteration of ethylene biosynthesis kinetics.
Ruttink
Tom
T
Laboratory of Molecular Biology, Department of Plant Sciences, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.
Boot
Kees
K
Kijne
Jan
J
Bisseling
Ton
T
Franssen
Henk
H
D000594:Amino Acid Oxidoreductases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D049108:Cell Enlargement / Q000187:drug effects; D002478:Cells, Cultured; D003583:Cytokinins / Q000494:pharmacology; D005030:Ethylenes / Q000096:biosynthesis* / Q000494:pharmacology; D006706:Homeostasis; D007210:Indoleacetic Acids / Q000494:pharmacology; D007700:Kinetics; D008190:Lyases / Q000378:metabolism; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic
D003583:Cytokinins; D005030:Ethylenes; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase