The transcriptome of Populus in elevated CO₂

Abstract

Summary• The consequences of increasing atmospheric carbon dioxide for long-term adaptation of forest ecosystems remain uncertain, with virtually no studies undertaken at the genetic level. A global analysis using cDNA microarrays was conducted following 6 yr exposure of Populus × euramericana (clone I-214) to elevated [CO 2 ] in a FACE (free-air CO 2 enrichment) experiment.• Gene expression was sensitive to elevated [CO 2 ] but the response depended on the developmental age of the leaves, and < 50 transcripts differed significantly between different CO 2 environments. For young leaves most differentially expressed genes were upregulated in elevated [CO 2 ], while in semimature leaves most were downregulated in elevated [CO 2 ].• For transcripts related only to the small subunit of Rubisco, upregulation in LPI 3 and downregulation in LPI 6 leaves in elevated CO 2 was confirmed by ANOVA . Similar patterns of gene expression for young leaves were also confirmed independently across year 3 and year 6 microarray data, and using real-time RT-PCR.• This study provides the first clues to the long-term genetic expression changes that may occur during long-term plant response to elevated CO 2 .

Downregulation of Cinnamoyl-Coenzyme A Reductase in Poplar: Multiple-Level Phenotyping Reveals Effects on Cell Wall Polymer Metabolism and Structure

“…The POP2 Populus glass-spotted cDNA microarrays were used for this study (http://www.populus.db.umu.se) and hybridized in an automated slide processor (Lucidea ASP Hybridization Station; Ge-Healthcare) as described by Taylor et al (2005) according to an all pairwise-comparison design (see Supplemental Figure 2 online). A dye-swap replication was done for each hybridization.…”

“…cDNA was synthesized as described (Taylor et al, 2005) with slight modifications: 30 mg of total RNA and 1 mL oligo(dT) anchor (5 mg/mL; TTTTTTTTTTTTTTTTTTTTVN) in a volume of 10 mL was incubated at 708C for 5 min and subsequently chilled on ice. First-strand synthesis was done in reverse transcriptase buffer (Invitrogen), 0.6 mL aa-dUTP/dNTP mix (500 mM of dATP, dCTP, dGTP, 100 mM dTTP, and 400 mM aa-dUTP; Sigma-Aldrich), 1 mM DTT, 30 units of RNase inhibitor (Invitrogen), and 200 units of Superscript II RNase H À reverse transcriptase (Invitrogen) in a total volume of 30 mL.…”

The Effects of Elevated CO2 Concentration on Soybean Gene Expression. An Analysis of Growing and Mature Leaves

“…Transcript analysis of growing poplar (Populus spp.) leaves exposed to elevated [CO 2 ] showed that genes involved in cell wall loosening and synthesis were up-regulated (Taylor et al, 2005;Druart et al, 2006). Therefore, at least in poplar, elevated [CO 2 ] appears to stimulate or prolong expansion in leaves (Ferris et al, 2001;Taylor et al, 2003;Druart et al, 2006).…”

An Integrated Functional Genomics Consortium to Increase Carbon Sequestration in Poplars: Optimizing Aboveground Carbon Gain

“…Microarray analysis was conducted, and real time PCR was run to verify microarray analyses. Early results from this work allowed us to compared CO 2 -responsive and CO 2 -nonresponsive clones (Taylor et al 2005, Rae et al 2007). …”

“…The combined treatment of +CO 2 +O 3 resulted in the differential expression of genes that were not up-regulated with individual gas treatments. Taylor et al (2005) used cDNA microarrays for Populus euramericana (clone I-214) that had received 6 years of elevated CO 2 to study long-term changes in genetic expression in response to elevated CO 2 . They found gene expression was sensitive to elevated CO 2 , but the response depended on the developmental age of the leaves.…”