Bidirectional Interaction between Phyllospheric Microbiotas and Plant Volatile Emissions

Farré-Armengol, G., Filella, I., Llusia, J., Peñuelas, J. (2016) Bidirectional Interaction between Phyllospheric Microbiotas and Plant Volatile Emissions. Trends in Plant Science. 21: 854-860.
Enllaç
Doi: 10.1016/j.tplants.2016.06.005

Resum:

Shifts in plant foliar and floral metabolomes in response to the suppression of the associated microbiota

Gargallo-Garriga A., Sardans J., Pérez-Trujillo M., Guenther A., Llusià J., Rico L., Terradas J., Farré-Armengol G., Filella I., Parella T., Peñuelas J. (2016) Shifts in plant foliar and floral metabolomes in response to the suppression of the associated microbiota. BMC Plant Biology. 16: 0-0.
Enllaç
Doi: 10.1186/s12870-016-0767-7

Resum:

Background: The phyllospheric microbiota is assumed to play a key role in the metabolism of host plants. Its role in determining the epiphytic and internal plant metabolome, however, remains to be investigated. We analyzed the Liquid Chromatography-Mass Spectrometry (LC-MS) profiles of the epiphytic and internal metabolomes of the leaves and flowers of Sambucus nigra with and without external antibiotic treatment application. Results: The epiphytic metabolism showed a degree of complexity similar to that of the plant organs. The suppression of microbial communities by topical applications of antibiotics had a greater impact on the epiphytic metabolome than on the internal metabolomes of the plant organs, although even the latter changed significantly both in leaves and flowers. The application of antibiotics decreased the concentration of lactate in both epiphytic and organ metabolomes, and the concentrations of citraconic acid, acetyl-CoA, isoleucine, and several secondary compounds such as terpenes and phenols in the epiphytic extracts. The metabolite pyrogallol appeared in the floral epiphytic community only after the treatment. The concentrations of the amino acid precursors of the ketoglutarate-synthesis pathway tended to decrease in the leaves and to increase in the foliar epiphytic extracts. Conclusions: These results suggest that anaerobic and/or facultative anaerobic bacteria were present in high numbers in the phyllosphere and in the apoplasts of S. nigra. The results also show that microbial communities play a significant role in the metabolomes of plant organs and could have more complex and frequent mutualistic, saprophytic, and/or parasitic relationships with internal plant metabolism than currently assumed. © 2016 Gargallo-Garriga et al.

Llegeix més

Assessment of the impacts of climate change on Mediterranean terrestrial ecosystems based on data from field experiments and long-term monitored field gradients in Catalonia

Peñuelas, J., Sardans, J., Filella, I., Estiarte, M., Llusià, J., Ogaya, R., Carnicer, J., Bartrons, M., Rivas-Ubach, A., Grau, O., Peguero, G., Margalef, O., Pla-Rabés, S., Stefanescu, C., Asensio, D., Preece, C., Liu, L., Verger, A., Rico, L., Barbeta, A., Achotegui-Castells, A., Gargallo-Garriga, A., Sperlich, D., Farré-Armengol, G., Fernández-Martínez, M., Liu, D., Zhang, C., Urbina, I., Camino, M., Vives, M., Nadal-Sala, D., Sabaté, S., Gracia, C., Terradas, J. (2016) Assessment of the impacts of climate change on Mediterranean terrestrial ecosystems based on data from field experiments and long-term monitored field gradients in Catalonia. Environmental and Experimental Botany. : 0-0.
Enllaç
Doi: 10.1016/j.envexpbot.2017.05.012

Resum:

Vegetation baseline phenology from kilometric global LAI satellite products

Verger A., Filella I., Baret F., Peñuelas J. (2016) Vegetation baseline phenology from kilometric global LAI satellite products. Remote Sensing of Environment. 178: 1-14.
Enllaç
Doi: 10.1016/j.rse.2016.02.057

Resum:

Land surface phenology derived from remotely sensed satellite data can substantially improve our macroecological knowledge and the representation of phenology in earth system models. We characterized the baseline phenology of the vegetation at the global scale from the GEOCLIM climatology of leaf area index (LAI) estimated from 1-km SPOT-VEGETATION time series for 1999-2010. The phenological metrics were calibrated over an ensemble of ground observations of the timing of leaf unfolding and autumnal colouring of leaves. The start and end of season were best identified using respectively 30% and 40% threshold of LAI amplitude values. The accuracy of the derived phenological metrics, evaluated using available ground observations for birch forests over Europe (and lilac shrubs over North America), improved as compared to those derived from MODIS-EVI and produced an overall root mean square error of 7 days (19 days) for the timing of the start of season, 15 for the end of season, and 16 for the length of season. The spatial patterns of the derived LAI phenology agreed well with those from MODIS-EVI and -NDVI, although the timing of the start, end, and length of season differed by about one month at the global scale, with higher uncertainties in areas of limited seasonality of the satellite signal and systematic biases due to the differences in the methodologies and datasets. The baseline LAI phenology was spatially consistent with the global distributions of climatic drivers and biome land cover. © 2016 Elsevier Inc.

Llegeix més

Land surface phenology from SPOT VEGETATION time series [Caracterización de la fenología de la vegetación a escala global mediante series temporales SPOT VEGETATION]

Verger, A., Filella, I., Baret, F., Peñuelas, J. (2016) Land surface phenology from SPOT VEGETATION time series [Caracterización de la fenología de la vegetación a escala global mediante series temporales SPOT VEGETATION]. Revista de Teledeteccion. 2016: 1-11.
Enllaç
Doi: 10.4995/raet.2016.5718

Resum:

Remotely-sensed detection of effects of extreme droughts on gross primary production

Vicca S., Balzarolo M., Filella I., Granier A., Herbst M., Knohl A., Longdoz B., Mund M., Nagy Z., Pintér K., Rambal S., Verbesselt J., Verger A., Zeileis A., Zhang C., Peñuelas J. (2016) Remotely-sensed detection of effects of extreme droughts on gross primary production. Scientific Reports. 6: 0-0.
Enllaç
Doi: 10.1038/srep28269

Resum:

Severe droughts strongly impact photosynthesis (GPP), and satellite imagery has yet to demonstrate its ability to detect drought effects. Especially changes in vegetation functioning when vegetation state remains unaltered (no browning or defoliation) pose a challenge to satellite-derived indicators. We evaluated the performance of different satellite indicators to detect strong drought effects on GPP in a beech forest in France (Hesse), where vegetation state remained largely unaffected while GPP decreased substantially. We compared the results with three additional sites: a Mediterranean holm oak forest (Puéchabon), a temperate beech forest (Hainich), and a semi-arid grassland (Bugacpuszta). In Hesse, a three-year reduction in GPP following drought was detected only by the Enhanced Vegetation Index (EVI). The Photochemical Reflectance Index (PRI) also detected this drought effect, but only after normalization for absorbed light. In Puéchabon normalized PRI outperformed the other indicators, while the short-term drought effect in Hainich was not detected by any tested indicator. In contrast, most indicators, but not PRI, captured the drought effects in Bugacpuszta. Hence, PRI improved detection of drought effects on GPP in forests and we propose that PRI normalized for absorbed light is considered in future algorithms to estimate GPP from space.

Llegeix més

Affecting factors and recent improvements of the photochemical reflectance index (pri) for remotely sensing foliar, canopy and ecosystemic radiation-use efficiencies

Zhang, C., Filella, I., Garbulsky, M.F., Peñuelas, J. (2016) Affecting factors and recent improvements of the photochemical reflectance index (pri) for remotely sensing foliar, canopy and ecosystemic radiation-use efficiencies. Remote Sensing. 8: 0-0.
Enllaç
Doi: 10.3390/rs8090677

Resum:

Optimum temperature for floral terpene emissions tracks the mean temperature of the flowering season

Farre-Armengol G., Filella I., Llusia J., Niinemets U., Penuelas J. (2015) Optimum temperature for floral terpene emissions tracks the mean temperature of the flowering season. Functional Plant Biology. 42: 851-857.
Enllaç
Doi: 10.1071/FP14279

Resum:

Emissions of volatiles from leaves exhibit temperature dependence on maximums, but the optimum temperatures for the release of floral volatiles and the mechanism(s) of optimising these emissions have not been determined. We hypothesised that flowers have an optimum temperature for the emission of volatiles and, because the period of flowering varies highly among species, that this optimum is adapted to the temperatures prevailing during flowering. To test these hypotheses, we characterised the temperature responses of floral terpene emissions of diverse widespread Mediterranean plant species flowering in different seasons by using dynamic headspace sampling and analysis with GC-MS. The floral emissions of terpenes across species exhibited maximums at the temperatures corresponding to the season of flowering, with the lowest optimal temperatures observed in winter-flowering and the highest in summer-flowering species. These trends were valid for emissions of both total terpenes and the various terpene compounds. The results show that the optimum temperature of floral volatile emissions scales with temperature at flowering, and suggest that this scaling is the outcome of physiological adaptations of the biosynthetic or emission mechanisms of flowers. © CSIRO 2015.

Llegeix més

Relationships among floral VOC emissions, floral rewards and visits of pollinators in five plant species of a Mediterranean shrubland

Farre-Armengol G., Filella I., Llusia J., Penuelas J. (2015) Relationships among floral VOC emissions, floral rewards and visits of pollinators in five plant species of a Mediterranean shrubland. Plant Ecology and Evolution. 148: 90-99.
Enllaç
Doi: 10.5091/plecevo.2015.963

Resum:

Background and aims–In plant-pollinator communities seasonal changes in the abundance of pollinators lead to seasonal changes in competition among flowering plants for their services. Here we address the following question: Do flowers of a given species produce more olfactory signals (emissions of volatile compounds) and rewards (nectar and pollen) during the phase(s) of the flowering period within which they have to maximally compete with the signals and rewards of other co-flowering species in the community, compared to the amount of signals and rewards produced during the period(s) with less floral competition? Methods–We analysed the floral emission rates of biogenic volatile organic compounds by gas chromatography and proton transfer reaction mass spectrometry, the visitation rates of pollinators, and the availability of nectar and pollen during the flowering periods of five species to test whether floral rewards and signals would decrease with an increase in pollinator visitation rates during late spring and early summer, i.e. coinciding with decreasing competitive pressure for the services of pollinators. Key results–The results indicate that phenological patterns in the production of rewards are only present at the species level in those species with long flowering periods or with matching periods of changes in pollinator populations. The capacity of emitting isoprenoids and oxidised volatile organic compounds, however, did not present significant patterns during the flowering period in any of the five species studied. Conclusions–The results support the hypothesis of a decreasing competitive pressure for the attraction of pollinators that may drive a decrease in floral investment in rewards but not an accompanying decrease of the capacity of emitting volatile olfactory signals in a species with long flowering period. However, the negative correlation between nectar production and visitation rates may be reinforced by the opposite responses of these variables to climatic conditions. This fact makes difficult to discern possible evolutionary forces tending to decrease rewards from plastic responses to changing environmental conditions in that part of the flowering period in which pollinator visitation rates are higher. © 2015 Botanic Garden Meise and Royal Botanical Society of Belgium.

Llegeix més

Pollination mode determines floral scent

Farre-Armengol G., Filella I., Llusia J., Penuelas J. (2015) Pollination mode determines floral scent. Biochemical Systematics and Ecology. 61: 44-53.
Enllaç
Doi: 10.1016/j.bse.2015.05.007

Resum:

The main objective of this study is to determine if the pollination vector influences the potential floral emissions of flowering plants. We hypothesized that flowers pollinated by insects would emit significantly higher amounts of volatile organic compounds (VOCs) and would present a higher diversity of these compounds than flowers pollinated by wind. The floral emissions of fifteen entomophilous species and eleven anemophilous species were captured by dynamic headspace sampling under field conditions and analyzed by gas chromatography-mass spectrometry. We searched for differences in the emission profiles between anemophilous and entomophilous flowers by considering the effects of phylogeny in our analysis. The floral emissions from the two groups were significantly different. Entomophilous species presented highly diverse emissions in both magnitude of emission rates and richness of compounds depending on the species, but overall, the flowers from entomophilous species had much higher VOC emission rates and VOC richness, both for terpenes and benzenoid compounds, than those from anemophilous species (two orders of magnitude higher emissions). The data thus confirm that the presence of intensely scented flowers with complex scents is strongly related to biotic pollination. © 2015 Elsevier Ltd.

Llegeix més

Pàgines