Global transcriptomic profiling of aspen trees under elevated [CO2] to identify potential molecular mechanisms responsible for enhanced radial growth.
Aspen (Populus tremuloides) trees growing under elevated [CO(2)] at a free-air CO(2) enrichment (FACE) site produced significantly more biomass than control trees. We investigated the molecular mechanisms underlying the observed increase in biomass by producing transcriptomic profiles of the vascular cambium zone (VCZ) and leaves, and then performed a comparative study to identify significantly changed genes and pathways after 12 years exposure to elevated [CO(2)]. In leaves, elevated [CO(2)] enhanced expression of genes related to Calvin cycle activity and linked pathways. In the VCZ, the pathways involved in cell growth, cell division, hormone metabolism, and secondary cell wall formation were altered while auxin conjugation, ABA synthesis, and cytokinin glucosylation and degradation were inhibited. Similarly, the genes involved in hemicellulose and pectin biosynthesis were enhanced, but some genes that catalyze important steps in lignin biosynthesis pathway were inhibited. Evidence from systemic analysis supported the functioning of multiple molecular mechanisms that underpin the enhanced radial growth in response to elevated [CO(2)].
School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA. hairong@mtu.edu
Hairong
H
Wei
Jiqing
J
Gou
Yordan
Y
Yordanov
Huaxin
H
Zhang
Ramesh
R
Thakur
Wendy
W
Jones
Andrew
A
Burton
D018533:Biomass; D058506:Cambium / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology; D002245:Carbon Dioxide / Q000494:pharmacology*; D002874:Chromosome Mapping; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D053858:Metabolic Networks and Pathways / Q000187:drug effects; D020411:Oligonucleotide Array Sequence Analysis; D018515:Plant Leaves / Q000378:metabolism; D032107:Populus / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D017434:Protein Structure, Tertiary; D018749:RNA, Plant / Q000235:genetics; D059467:Transcriptome; D014197:Trees
D018749:RNA, Plant; D002245:Carbon Dioxide