Ozone bioindication in Barcelona and sorrounding area of Catalonia.

Ribas A, Peñuelas J (2002) Ozone bioindication in Barcelona and sorrounding area of Catalonia. In Klumpp A, Fomin A, Klumpp G, Ansel W (eds) Bioindication and Air Quality in European Cities. Research, Application, Communication. Verlag Günter Heimbach, Stuttgart, pp. 221-225.

Intraspecific variability of phenolic concentrations and their responses to elevated CO2 in two mediterranean perennial grasses

Castells E., Roumet C., Peñuelas J., Roy J. (2002) Intraspecific variability of phenolic concentrations and their responses to elevated CO2 in two mediterranean perennial grasses. Environmental and Experimental Botany. 47: 205-216.
Enllaç
Doi: 10.1016/S0098-8472(01)00123-X

Resum:

Intraspecific variability of total phenolic compound concentrations and their responses to elevated CO2 were studied in two wild Mediterranean perennial grasses, Dactylis glomerata and Bromus erectus. Ten and nine genotypes of each species were grown in climate-controlled naturally-lit glasshouses under plant intergenotypic and interspecific competition for water, light and nutrients. Carbon source-sink balance hypotheses of resource allocation were also tested. Elevated CO2 induced changes in dry shoot biomass (DM), leaf total non-structural carbohydrate concentrations [TNC] and leaf nitrogen concentrations [N] found in a previous study (New Phytol. 143 (1999) 73) were related to changes in phenolic compound concentrations. Phenolic compound concentrations increased to 15.2% DM in D. glomerata and 86.9% DM in B. erectus under elevated CO2. These changes were more pronounced when expressed on a structural dry mass basis (DMst). Increases in DMst and [TNCst] and decreases in [Nst] were also found according to current resource allocation hypotheses. However, there were no proportional changes between phenolic responses to elevated CO2 and DMst, [TNCst] and [Nst] responses. Phenolic concentrations were highly determined by genetics in both species, but all studied genotypes responded in a similar way to elevated CO2. Considering the present experimental conditions with plants growing in intraspecific and interspecific competition, the absence of CO2 × genotype interaction would lead to little changes of fitness in terms of antiherbivore chemical defence, and, therefore, to low evolutionary consequences in CBSC under the increasing atmospheric CO2 concentrations of the next decades. © 2002 Elsevier Science B.V. All rights reserved.

Llegeix més

Ethylene- and ozone-induced regulation of a grapevine resveratrol synthase gene: Different responsive promoter regions

Grimmig B., Gonzalez-Perez M.N., Welzl G., Penuelas J., Schubert R., Hain R., Heidenreich B., Betz C., Langebartels C., Ernst D., Sandermann Jr. H. (2002) Ethylene- and ozone-induced regulation of a grapevine resveratrol synthase gene: Different responsive promoter regions. Plant Physiology and Biochemistry. 40: 865-870.
Enllaç
Doi: 10.1016/S0981-9428(02)01448-1

Resum:

Stilbene synthases (STSs) are enzymes that play a critical role in the biosynthesis of stilbenes, phytoalexins that are induced by various biotic and abiotic stressors like pathogen attack, UV radiation or ozone exposure. To investigate the molecular basis for ozone- and ethylene-induced plant stress responses, we analysed the full size promoter of the grapevine resveratrol synthase gene (Vst1). Transgenic tobacco plants harbouring a Vst1 promoter::β-glucuronidase (GUS) reporter construct showed an increased GUS activity upon ozone (0.3 μl 1-1, 8 h) or ethylene (10 μl 1-1, 8 h) treatment. Using the fluorimetric GUS assay, deletion analysis of the 5′-flanking sequence identified a minimal ethylene-responsive region between -280 and -40 bp upstream of the translation start codon. This region differs from the ozone-responsive Vstl promoter region, suggesting that ethylene is not directly involved in signalling ozone-induced stilbene biosynthesis. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.

Llegeix més

Alteracions produïdes pel canvi climàtic en els cicles de les plantes i dels animals.

Filella I, Peñuelas J (2002) Alteracions produïdes pel canvi climàtic en els cicles de les plantes i dels animals. Sostenible (edició electrònica). Revista de la Xarxa de Ciutats i Pobles cap a la Sostenibilitat (http://bd.sostenible.es/sostenible/pubNoticia). Maig-Juny.

Canvi de clima, canvi de vida.

Filella I, Peñuelas J (2002) Canvi de clima, canvi de vida. Mètode 34:16-22.

Síntomas biológicos del cambio climático.

Peñuelas J (2002) Síntomas biológicos del cambio climático. Mundo Científico 236:48-51.

Símptomes biològics del canvi climàtic.

Peñuelas J (2002) Símptomes biològics del canvi climàtic. Medi Ambient 31:1-8.

Plant Ecophysiological studies in the frame of global changes: upscaling from molecule to environment, or walking across space and time.

Peñuelas J, Filella I, Estiarte M, Ogaya R, Ribas A, Llorens L, Mangirón M, Munné S, Bruna P, Sardans J, Prieto P, Asensio D (2002) Plant Ecophysiological studies in the frame of global changes: upscaling from molecule to environment, or walking across space and time. 13 th Congress of the Federation of European Societies of Plant Physiology, Crete. Greece 2002.

La emisión de compuestos volátiles por las plantas mediterraneas

Peñuelas J, Llusià J (2002) La emisión de compuestos volátiles por las plantas mediterraneas Ecosistemas (edició electrònica). Revista de la Asociación Española de Ecología Terrestre. Any XI, Núm. 1. (http://www.aeet.org/ecosistemas/).

Developmental instability and gas exchange responses of a heathland shrub to experimental drought and warming

Llorens L., Peñuelas J., Emmett B. (2002) Developmental instability and gas exchange responses of a heathland shrub to experimental drought and warming. International Journal of Plant Sciences. 163: 959-967.
Enllaç
Doi: 10.1086/342713

Resum:

The effects of predicted climatic changes on the physiological stress of bilberry (Vaccinium myrtillus L.) were investigated in a field experiment in a heathland of northern Wales (U.K.). In the experiment, drought was increased during the growing season by excluding precipitation, and night warming was created by reducing heat loss. To assess physiological stress, leaf size and leaf fluctuating asymmetry (FA) as integrative measures of stress during leaf development and leaf gas exchange as a classical instantaneous method to detect physiological stress, were measured. Since leaf FA increased with increasing size, comparisons of asymmetries were made for relative rather than absolute asymmetry. Relative leaf FA was calculated as the absolute difference between leaf size (area or width) of left and right halves, corrected for trait size. Drought treatment increased the relative leaf area FA in 2000 and not in 1999, in agreement with a stronger treatment in 2000. Conversely, the warming treatment decreased the relative leaf area FA in 1999 and not in 2000, coinciding with the lower minimum temperatures in the growing season of 1999. Differences in water availability and temperature between years were related with changes in the relative leaf area FA, which were consistent with the treatment effects. In contrast, leaf gas exchange rates and leaf size showed no significant response to the environmental manipulations, although there was a slight decrease of photosynthetic values and leaf size in drought treatments in both years. Leaf FA therefore appeared to be a more sensitive indicator of physiological stress than leaf size or gas exchange measurements. Our results indicate that a future increase in the severity of drought during the growing season will increase physiological stress of V. myrtillus, whereas warming will decrease physiological stress during leaf development because of the alleviation of temperature constraints.

Llegeix més

Pàgines