title: Developmental stage specificity of transcriptional, biochemical and CO2 efflux responses of leaf dark respiration to growth of Arabidopsis thaliana at elevated [CO2].
abstract: Plant respiration responses to elevated growth [CO(2)] are key uncertainties in predicting future crop and ecosystem function. In particular, the effects of elevated growth [CO(2)] on respiration over leaf development are poorly understood. This study tested the prediction that, due to greater whole plant photoassimilate availability and growth, elevated [CO(2)] induces transcriptional reprogramming and a stimulation of nighttime respiration in leaf primordia, expanding leaves and mature leaves of Arabidopsis thaliana. In primordia, elevated [CO(2)] altered transcript abundance, but not for genes encoding respiratory proteins. In expanding leaves, elevated [CO(2)] induced greater glucose content and transcript abundance for some respiratory genes, but did not alter respiratory CO(2) efflux. In mature leaves, elevated [CO(2)] led to greater glucose, sucrose and starch content, plus greater transcript abundance for many components of the respiratory pathway, and greater respiratory CO(2) efflux. Therefore, growth at elevated [CO(2)] stimulated dark respiration only after leaves transitioned from carbon sinks into carbon sources. This coincided with greater photoassimilate production by mature leaves under elevated [CO(2)] and peak respiratory transcriptional responses. It remains to be determined if biochemical and transcriptional responses to elevated [CO(2)] in primordial and expanding leaves are essential prerequisites for subsequent alterations of respiratory metabolism in mature leaves.
authors.affiliation: Department of Plant Biology and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA.
authors.forename: R J Cody
authors.initials: RJ
authors.lastname: Markelz
authors.forename: Lauren N
authors.initials: LN
authors.lastname: Vosseller
authors.forename: Andrew D B
authors.initials: AD
authors.lastname: Leakey
mesh_terms: D000704:Analysis of Variance; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D002245:Carbon Dioxide / Q000494:pharmacology*; D019069:Cell Respiration / Q000187:drug effects; D003624:Darkness; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D006019:Glycolysis / Q000187:drug effects; D020411:Oligonucleotide Array Sequence Analysis; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D012333:RNA, Messenger; D002245:Carbon Dioxide; D002244:Carbon; D005947:Glucose
keywords: climate change; gene expression; genomics; leaf respiration; metabolism