title: Expression patterns of C- and N-metabolism related genes in wheat are changed during senescence under elevated CO2 in dry-land agriculture.
abstract: Projected climatic impacts on crop yield and quality, and increased demands for production, require targeted research to optimise nutrition of crop plants. For wheat, post-anthesis carbon and nitrogen remobilisation from vegetative plant parts and translocation to grains directly affects grain carbon (C), nitrogen (N) and protein levels. We analysed the influence of increased atmospheric CO2 on the expression of genes involved in senescence, leaf carbohydrate and nitrogen metabolism and assimilate transport in wheat under field conditions (Australian Grains Free Air CO2 Enrichment; AGFACE) over a time course from anthesis to maturity, the key period for grain filling. Wheat grown under CO2 enrichment had lower N concentrations and a tendency towards greater C/N ratios. A general acceleration of the senescence process by elevated CO2 was not confirmed. The expression patterns of genes involved in carbohydrate metabolism, nitrate reduction and metabolite transport differed between CO2 treatments, and this CO2 effect was different between pre-senescence and during senescence. The results suggest up-regulation of N remobilisation and down-regulation of C remobilisation during senescence under elevated CO2, which is consistent with greater grain N-sink strength of developing grains.
authors.affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden AL5 4TX, UK. Electronic address: peter.buchner@rothamsted.ac.uk.
authors.forename: Peter
authors.initials: P
authors.lastname: Buchner
authors.affiliation: School of Ecosystem and Forest Sciences, The University of Melbourne, 4 Water Street, Creswick, VIC 3363, Australia. Electronic address: michael.tausz@unimelb.edu.au.
authors.forename: Michael
authors.initials: M
authors.lastname: Tausz
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville Campus, Melbourne, VIC 3010, Australia. Electronic address: rebeccaf@unimelb.edu.au.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Ford
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville Campus, Melbourne, VIC 3010, Australia. Electronic address: aleo@unimelb.edu.au.
authors.forename: Audrey
authors.initials: A
authors.lastname: Leo
authors.affiliation: Department of Economic Development, Jobs, Transport and Resources, 110 Natimuk Road, Horsham, VIC 3400, Australia. Electronic address: glenn.fitzgerald@ecodev.vic.gov.au.
authors.forename: Glenn J
authors.initials: GJ
authors.lastname: Fitzgerald
authors.affiliation: Plant Biology and Crop Science Department, Rothamsted Research, Harpenden AL5 4TX, UK. Electronic address: malcolm.hawkesford@rothamsted.ac.uk.
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Hawkesford
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville Campus, Melbourne, VIC 3010, Australia. Electronic address: sposch@unimelb.edu.au.
authors.forename: Sabine
authors.initials: S
authors.lastname: Tausz-Posch
mesh_terms: D000383:Agriculture; D002244:Carbon / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D014908:Triticum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014739:Victoria
chemical_list: D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen
keywords: Elevated CO(2); Gene expression; Nitrogen and carbohydrate metabolism; Remobilisation; Senescence; Wheat