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Effects of enhanced UV radiation and water availability on performance, biomass production and photoprotective mechanisms of Laurus nobilis seedlings

Climate models predict an increase in ultraviolet (UV) radiation and a reduction in precipitation in the Mediterranean region in the coming decades. High levels of UV radiation and water shortage can both cause photo-oxidative stress in plants. The aim of this study was to investigate the effects of enhanced UV radiation and its interaction with low water availability on seedling performance, biomass production, and photoprotective mechanisms of the sclerophyllous evergreen species Laurus nobilis L. (laurel). To achieve this goal, one-year-old seedlings of L. nobilis were grown outdoors under three UV conditions (ambient UV, enhanced UV-A, and enhanced UV-A. +. UV-B) and under two watering regimes (watered to field capacity and reduced water supply). The results show that plants produced more biomass when exposed to above ambient levels of UV-A or UV-A. +. UV-B radiation, especially under low water availability. This was probably related to a UV-induced increase in leaf relative water content and in leaf water use efficiency under water shortage. Even though our results suggest that UV-A supplementation may play an important role in the stimulation of biomass production, plants grown under enhanced UV-A plots showed higher levels of energy dissipation as heat (measured as NPQ) and a higher de-epoxidation state of the violaxanthin cycle. This suggests a greater excess of light energy under UV-A supplementation, in accordance with the observed reduction in the foliar content of light-absorbing pigments in these plants. Strikingly, the addition of UV-B radiation mitigated these effects. In conclusion, UV enhancement might benefit water status and growth of L. nobilis seedlings, especially under low water availability. The results also indicate the activation of different plant response mechanisms to UV-A and UV-B radiation, which would interact to produce the overall plant response

This research was supported by the following projects: CGL2007-64583, CGC2010-17172, Consolider Ingenio Montes (CSD2008-00040) and CGL2011-26977 funded by the Spanish Government and by the SGR 2009-458 project funded by the Catalan Government

© Environmental and Experimental Botany, 2015, vol. 109, p. 264-275

Elsevier

Autor: Bernal Montolio, Meritxell
Verdaguer i Murlà, Dolors
Badosa i Franch, Jordi
Abadía, Anunciación
Llusià, Joan
Peñuelas, Josep
Núñez-Olivera, Encarnación
Llorens Guasch, Laura
Data: 1 gener 2015
Resum: Climate models predict an increase in ultraviolet (UV) radiation and a reduction in precipitation in the Mediterranean region in the coming decades. High levels of UV radiation and water shortage can both cause photo-oxidative stress in plants. The aim of this study was to investigate the effects of enhanced UV radiation and its interaction with low water availability on seedling performance, biomass production, and photoprotective mechanisms of the sclerophyllous evergreen species Laurus nobilis L. (laurel). To achieve this goal, one-year-old seedlings of L. nobilis were grown outdoors under three UV conditions (ambient UV, enhanced UV-A, and enhanced UV-A. +. UV-B) and under two watering regimes (watered to field capacity and reduced water supply). The results show that plants produced more biomass when exposed to above ambient levels of UV-A or UV-A. +. UV-B radiation, especially under low water availability. This was probably related to a UV-induced increase in leaf relative water content and in leaf water use efficiency under water shortage. Even though our results suggest that UV-A supplementation may play an important role in the stimulation of biomass production, plants grown under enhanced UV-A plots showed higher levels of energy dissipation as heat (measured as NPQ) and a higher de-epoxidation state of the violaxanthin cycle. This suggests a greater excess of light energy under UV-A supplementation, in accordance with the observed reduction in the foliar content of light-absorbing pigments in these plants. Strikingly, the addition of UV-B radiation mitigated these effects. In conclusion, UV enhancement might benefit water status and growth of L. nobilis seedlings, especially under low water availability. The results also indicate the activation of different plant response mechanisms to UV-A and UV-B radiation, which would interact to produce the overall plant response
This research was supported by the following projects: CGL2007-64583, CGC2010-17172, Consolider Ingenio Montes (CSD2008-00040) and CGL2011-26977 funded by the Spanish Government and by the SGR 2009-458 project funded by the Catalan Government
Format: application/pdf
ISSN: 0098-8472
Accés al document: http://hdl.handle.net/10256/12349
Llenguatge: eng
Editor: Elsevier
Col·lecció: MEC/PN 2007-2010/CGL2007-64583/BOS
Reproducció digital del document publicat a: http://dx.doi.org/10.1016/j.envexpbot.2014.06.016
Articles publicats (D-CCAA)
És part de: © Environmental and Experimental Botany, 2015, vol. 109, p. 264-275
Drets: Tots els drets reservats
Matèria: Radiació ultraviolada
Ultraviolet radiation
Plantes -- Efecte de la sequera
Plants, Effect of drought on
Plantes -- Efecte de la radiació
Plants -- Effect of radiation on
Títol: Effects of enhanced UV radiation and water availability on performance, biomass production and photoprotective mechanisms of Laurus nobilis seedlings
Tipus: info:eu-repo/semantics/article
Repositori: DUGiDocs

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