title: RP-ACS1, a flooding-induced 1-aminocyclopropane-1-carboxylate synthase gene of Rumex palustris, is involved in rhythmic ethylene production.
abstract: Many semi-aquatic plants respond to flooding by elongating the shoot to reach the water surface. This response is initiated by accumulation of ethylene in the plant due to decreased gas-exchange and continued ethylene production during submergence. Ethylene biosynthesis is often limited by the availability of 1-aminocyclopropane-1-carboxylic acid (ACC), the precursor of ethylene, synthesized by ACC synthase. Here, is reported the cloning of a Rumex palustris cDNA corresponding to an ACC synthase gene (RP-ACS1), whose expression is induced by submergence in the long term but does not precede the observed short-term increase in ACS activity. Under aerated conditions, RP-ACS1 messenger accumulation exhibited circadian rhythmicity with high levels in the dark phase and low levels in the light phase, similar to the oscillations in ethylene production under these conditions. ACC oxidase (RP-ACO1) messenger accumulation also showed a rhythmic pattern, but opposite to that of RP-ACS1, and closely resembled the ethylene oscillation found in R. palustris plants that were waterlogged. Together the results indicate that transcriptional regulation of RP-ACS1 may directly control rhythmic ethylene production under aerated condition and suggest that post-transcriptional regulation is important in initial up-regulation of ACS activity upon submergence.
authors.affiliation: Department of Experimental Botany, Radboud University Nijmegen, Toernooiveld 1, 6525 ED, Nijmegen, The Netherlands.
authors.forename: Ivo
authors.initials: I
authors.lastname: Rieu
authors.forename: Simona M
authors.initials: SM
authors.lastname: Cristescu
authors.forename: Frans J M
authors.initials: FJ
authors.lastname: Harren
authors.forename: Wim
authors.initials: W
authors.lastname: Huibers
authors.forename: Laurentius A C J
authors.initials: LA
authors.lastname: Voesenek
authors.forename: Celestina
authors.initials: C
authors.lastname: Mariani
authors.forename: Wim H
authors.initials: WH
authors.lastname: Vriezen
mesh_terms: D002940:Circadian Rhythm / Q000502:physiology*; D018076:DNA, Complementary / Q000378:metabolism; D005030:Ethylenes / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant; D008190:Lyases / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000096:biosynthesis*; D018515:Plant Leaves / Q000378:metabolism; D031804:Rumex / Q000201:enzymology*; D014867:Water / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D005030:Ethylenes; D010937:Plant Growth Regulators; D014867:Water; C036216:ethylene; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase