The Populus transcriptome in elevated CO2 reveals increased anthocyanin biosynthesis during delayed autumnal senescence
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ABSTRACT: Over recent decades the progression of natural autumnal senescence has been increasingly delayed across wide areas of the Northern Hemisphere and is thought to be caused by rising temperature. Recently this delay has been shown to be partly attributable to rising atmospheric carbon dioxide concentrations [CO2]. Here, for the first time, we present a possible mechanistic explanation for this phenomenon. Using a plantation of Populus x euramericana grown at elevated [CO2] (e[CO2]) using Free-Air CO2 Enrichment (FACE) technology, we investigated the molecular and biochemical basis underlying this response. Using a poplar cDNA microarray where late growing season and senescing leaves from ambient [CO2] (a[CO2]) and e[CO2] were compared, revealed unique increases and decreases in transcript abundance in the e[CO2] treatment. Growth at e[CO2]caused the greatest increase in the abundance of transcripts catalysing steps in the anthocyanin biosynthetic pathway and an increase in leaf anthocyanin content. Leaf sucrose and starch content were also increased during senescence in e[CO2] and associated with a higher abundance of transcripts in the sucrose and starch biosynthetic pathways. We propose that in e[CO2], autumnal photosynthesis and sugar accumulation results in changes in genes expression that include further investment in secondary carbon metabolism leading to anthocyanin production. This enables prolonged leaf longevity during natural autumnal senescence through increased availability of carbon and improved stress tolerance while in contrast this may also have a negative effect on the control of dormancy.
ORGANISM(S): Populus x canadensis Populus tremula x Populus alba Populus trichocarpa x Populus deltoides Populus euphratica
PROVIDER: GSE15874 | GEO | 2010/02/01
SECONDARY ACCESSION(S): PRJNA117027
REPOSITORIES: GEO
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