Biomedical subjects

Giuseppe Scarascia-Mugnozza

Publications and source records attributed to Giuseppe Scarascia-Mugnozza.

3 recordsLinked to original sources

PubMed2005

Canopy profiles of photosynthetic parameters under elevated CO2 and N fertilization in a poplar plantation.

A poplar plantation has been exposed to an elevated CO2 concentration for 5 years using the free air CO2 enrichment (FACE) technique. Even after such a long period of exposure, leaves of Populus x euramericana have not shown clear signs of photosynthetic acclimation. Only at the end of the growing season for shade leaves was a decrease of maximum velocity of carboxylation (Vcmax) observed. Maximum electron transport rate (Jmax) was increased by FACE treatment in July. Assimilation rates at CO2 partial pressure of 400 (A400) and 600 (A600) micromol mol(-1) were not significantly different under FACE treatment. Most notably FACE significantly decreased stomatal conductance (g(s)) both on upper and lower canopy leaves. N fertilization increased N content in the leaves on mass basis (Nm) and specific leaf area (SLA) in both CO2 treatments but did not influence the photosynthetic parameters. These data show that in poplar plantations the long-term effects of elevated CO2 on photosynthesis do not differ considerably from the short-term ones even with N deposition.

Acclimatization↗

PubMed2005

The transcriptome of Populus in elevated CO2.

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 x 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).

Adaptation, Physiological↗

PubMed2003

Stem respiration of Populus species in the third year of free-air CO2 enrichment.

Carbon cycling in ecosystems, and especially in forests, is intensively studied to predict the effects of global climate change, and the role which forests may play in 'changing climate change'. One of the questions is whether the carbon balance of forests will be affected by increasing atmospheric CO2 concentrations. Regarding this question, effects of elevated [CO2] on woody-tissue respiration have frequently been neglected. Stem respiration of three Populus species (P. alba L. (Clone 2AS-11), P. nigra L. (Clone Jean Pourtet), and P. x euramericana (Clone I-214)) was measured in a managed, high-density forest plantation exposed to free-air CO2 enrichment (POPFACE). During the period of measurements, in May of the third year, stem respiration rates were not affected by the FACE treatment. Moreover, FACE did not influence the relationships between respiration rate and both stem temperature and relative growth rate. The results were supported by the reported absence of a FACE-effect on growth and stem wood density.

Journal Article↗