How do Mediterranean shrub species cope with shade? Ecophysiological response to different light intensities
| Autor: | J. Valera, María Zunzunegui, Leonor Álvarez-Cansino, Herminia Rodríguez, Mari Paz Esquivias, Mari Cruz Díaz-Barradas |
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| Rok vydání: | 2017 |
| Předmět: |
Chlorophyll
0106 biological sciences 0301 basic medicine Canopy Stomatal conductance Light Perennial plant ved/biology.organism_classification_rank.species Plant Science Xanthophylls Biology Xanthophyll cycle Photochemical efficiency Photosynthesis 01 natural sciences Shrub 03 medical and health sciences chemistry.chemical_compound Botany Ecology Evolution Behavior and Systematics chemistry.chemical_classification Mediterranean Region ved/biology Lutein Cistus Photosystem II Protein Complex food and beverages General Medicine Myrtus Rosmarinus Plant Leaves Light intensity 030104 developmental biology chemistry Agronomy Xanthophyll Pistacia Light availability Photosynthetic rate 010606 plant biology & botany |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 1435-8603 |
| DOI: | 10.1111/plb.12661 |
| Popis: | Under natural conditions, light exposure for Mediterranean shrubs can be highly variable, especially during cloudy days or under a canopy, and can interfere with other environmental factors such as temperature and water availability. With the aim of decoupling the effect of radiation and temperature from water availability, we conducted an experiment where two perennial and three summer semi-deciduous shrub species were subjected to different levels of irradiation. In order to follow plant responses to light exposure, we measured gas exchange, photosystem II photochemical efficiency, photosynthetic pigments and leaf mass area in spring and summer. Results showed that all study species presented a plastic response to different light conditions, and that light-related traits varied in a coordinated manner. Summer semi-deciduous species exhibited a more opportunistic response, with higher photosynthesis rates in full sun, but under shade conditions, the two strategies presented similar assimilation rates. Stomatal conductance did not show such a drastic response as photosynthetsis, being related to changes in WUE. Daily cycles of Fv /Fm revealed a slight photoinhibitory response during summer, mainly in perennial species. In all cases photosynthetic pigments adjusted to the radiation level; leaves had lower chlorophyll content, higher pool of xanthophylls and higher proportion of the de-epoxydaded state of xanthophylls under sun conditions. Lutein content increased in relation to the xanthophyll pool under shade conditions. Our results evidenced that radiation is an important driving factor controlling morphological and physiological status of Mediterranean shrub species, independently of water availability. Summer semi-deciduous species exhibit a set of traits with higher response variability, maximising their photosynthetic assimilation under different sun conditions. |
| Databáze: | OpenAIRE |
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