Resistance of native oak to recurrent drought conditions simulating predicted climatic changes in the Mediterranean region |
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Authors: | Amélie Saunier Elena Ormeño Michel Havaux Henri Wortham Brigitte Ksas Brice Temime‐Roussel James D Blande Caroline Lecareux Jean‐Philippe Mévy Anne Bousquet‐Mélou Thierry Gauquelin Catherine Fernandez |
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Institution: | 1. Aix‐Marseille University, Avignon University, CNRS, IRD, IMBE, Marseille, France;2. Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland;3. CEA Cadarache, CNRS UMR 7265 BVME, Aix‐Marseille University, Laboratoire d'Ecophysiologie Moléculaire des Plantes, Saint‐Paul‐lès‐Durance, France;4. Aix‐Marseille University, CNRS, LCE, Laboratoire de Chimie de l'Environnement, Marseille, France |
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Abstract: | The capacity of a Quercus pubescens forest to resist recurrent drought was assessed on an in situ experimental platform through the measurement of a large set of traits (ecophysiological and metabolic) studied under natural drought (ND) and amplified drought (AD) induced by partial rain exclusion. This study was performed during the third and fourth years of AD, which correspond to conditions of moderate AD in 2014 and harsher AD in 2015, respectively. Although water potential (Ψ) and net photosynthesis (Pn) were noticeably reduced under AD in 2015 compared to ND, trees showed similar growth and no oxidative stress. The absence of oxidative damage could be due to a strong accumulation of α‐tocopherol, suggesting that this compound is a major component of the Q. pubescens antioxidant system. Other antioxidants were rather stable under AD in 2014, but slight changes started to be observed in 2015 (carotenoids and isoprene) due to harsher conditions. Our results indicate that Q. pubescens could be able to cope with AD, for at least 4 years, likely due to its antioxidant system. However, growth decrease was observed during the fifth year (2016) of AD, suggesting that this resistance could be threatened over longer periods of recurrent drought. |
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Keywords: | antioxidants drought gas exchanges growth isoprene emissions |
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