Dedication: this manuscript is dedicated to David F. Karnosky, who died in 2008, but provided the initial inspiration following our serendipitous observations in the USA and Italy that leaves stayed green for longer in high CO2.
The transcriptome of Populus in elevated CO2 reveals increased anthocyanin biosynthesis during delayed autumnal senescence
Article first published online: 23 FEB 2010
© The Authors (2010). Journal compilation © New Phytologist Trust (2010)
Volume 186, Issue 2, pages 415–428, April 2010
How to Cite
Tallis, M. J., Lin, Y., Rogers, A., Zhang, J., Street, N. R., Miglietta, F., Karnosky, D. F., De Angelis, P., Calfapietra, C. and Taylor, G. (2010), The transcriptome of Populus in elevated CO2 reveals increased anthocyanin biosynthesis during delayed autumnal senescence. New Phytologist, 186: 415–428. doi: 10.1111/j.1469-8137.2010.03184.x
- Issue published online: 25 MAR 2010
- Article first published online: 23 FEB 2010
- Received: 22 September 2009, Accepted: 8 December 2009
- anthocyanin biosynthesis;
- autumnal senescence;
- cDNA microarray;
- elevated CO2;
- •The delay in autumnal senescence that has occurred in recent decades has been linked to rising temperatures. Here, we suggest that increasing atmospheric CO2 may partly account for delayed autumnal senescence and for the first time, through transcriptome analysis, identify gene expression changes associated with this delay.
- •Using a plantation of Populus × euramericana grown in elevated [CO2] (e[CO2]) with free-air CO2 enrichment (FACE) technology, we investigated the molecular and biochemical basis of this response. A Populus cDNA microarray was used to identify genes representing multiple biochemical pathways influenced by e[CO2] during senescence. Gene expression changes were confirmed through real-time quantitative PCR, and leaf biochemical assays.
- •Pathways for secondary metabolism and glycolysis were significantly up-regulated by e[CO2] during senescence, in particular, those related to anthocyanin biosynthesis. Expressed sequence tags (ESTs) representing the two most significantly up-regulated transcripts in e[CO2], LDOX (leucoanthocyanidin dioxgenase) and DFR (dihydroflavonol reductase), gave (e[CO2]/ambient CO2 (a[CO2])) expression ratios of 39.6 and 19.3, respectively.
- •We showed that in e[CO2] there was increased autumnal leaf sugar accumulation and up-regulation of genes determining anthocyanin biosynthesis which, we propose, prolongs leaf longevity during natural autumnal senescence.