abstract
Cork oak (Quercus suber L.) is a research priority in the Mediterranean area and because of cork oaks' distribution these stands are experiencing daily stress. Based on projections of intensifying climate change and considering the key role of exploring the recovery abilities, cork oak seedlings were subjected to a cumulative temperature increase from 25 degrees C to 55 degrees C and subsequent recovery. CO2 assimilation rate, chlorophyll fluorescence, anthocyanins, proline and lipid peroxidation were used to evaluate plant performance, while the relative abundance of seven genes encoding for proteins of cork oak with a putative role in thermal/stress regulation (POX1, POX2, HSP10.4, HSP17a.22, CHS, MTL and RBC) was analyzed by qPCR (quantitative Polymerase Chain Reaction). A temperature change to 35 degrees C showed abundance alterations in the tested genes; at 45 degrees C, the molecular changes were associated with an antioxidant response, possibly modulated by anthocyanins. At 55 degrees C, HSP17a.22, MTL and proline accumulation were evident. After recovery, physiological balance was restored, whereas POX1, HSP10.4 and MTL abundances were suggested to be involved in increased thermotolerance. The data presented here are expected to pinpoint some pathways changes occurring during such stress and further recovery in this particular Mediterranean species. (C) 2013 Elsevier GmbH. All rights reserved.
keywords
HIGH-TEMPERATURE STRESS; QUERCUS-SUBER; LIPID-PEROXIDATION; CLIMATE-CHANGE; HIGHER-PLANTS; PHENOTYPIC PLASTICITY; CHALCONE SYNTHASE; DIURNAL CHANGES; SHOCK PROTEINS; WATER-STRESS
subject category
Plant Sciences
authors
Correia, B; Rodriguez, JL; Valledor, L; Almeida, T; Santos, C; Canal, MJ; Pinto, G
Groups
acknowledgements
This work was supported by FEDER through COMPETE (Programa Operacional Fatores de Competitividade) and by the FCT (Foundation for Science and Technology) project PTDC/AGR-CFL/112996/2009. G Pinto is hired under the programme Ciencia 2008 (FCT, Portugal), co-funded by the Human Potential Operational Programme (National Strategic Reference Framework 2007-2013) and European Social Fund (EU). FCT supported the fellowships of B Correia (SFRH/BD/86448/2012) and T Almeida (SFRH/BD/44410/2008). The authors thank Armando Costa for his technical assistance and Dr. Monica Meijon and Dr. Nuria de Diego for their critical reviews.