Deciphering the ecophysiological traits involved during water stress acclimation and recovery of the threatened wild carnation, Dianthus inoxianus.
Dianthus inoxianus is an endangered species endemic from a small littoral area in the SW Spain, with an unusual flowering season under the adverse conditions of dry Mediterranean summer. A greenhouse experiment was designed to assess the physiological traits involved in drought acclimation and recovery of 3-month-old plants. The evolution of plant water status, leaf gas exchange, chlorophyll fluorescence, photosynthetic pigments concentrations and a quantitative analysis of photosynthesis limitations were followed during water stress and re-watering. Our results indicated that the plant water status, Ψwand RWC, only decreased at the end of the drought period (18th day), together with the net photosynthetic rate, AN. Photosynthetic impair was mainly caused by diffusional limitations (SL and MCL) of CO2, as indicated the joint and marked decrease of gs, gmand Ciduring drought period, while Vc,maxdid not vary. After rewatering, leaf water status recovered faster than photosynthetic one, reaching control values on day 1 after recovery, while AN, gmand Citook 7 days. Additionally, gsshowed the slowest recovery taking 15 days, but gsdecrease was enough to keep Ψwand RWC at constant values throughout the experiment. Results suggest a high tolerance and recovery of D. inoxianus from severe drought periods. This drought tolerance was also reflected in the stability of its photochemical apparatus and pigments concentrations, as indicated the constant values of Fv/Fm, ФPSIIand pigments concentrations through experimental period. However, prolonged drought events due to global climate change could negatively affect the physiological mechanisms of this species.
Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Apdo. 1095, 41080 Sevilla, Spain. Electronic address: javlopez@us.es.
Javier
J
López-Jurado
Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Apdo. 1095, 41080 Sevilla, Spain.
Francisco
F
Balao
Departamento de Biología Vegetal y Ecología, Facultad de Biología, Universidad de Sevilla, Apdo. 1095, 41080 Sevilla, Spain.
Enrique
E
Mateos-Naranjo
D000064:Acclimatization / Q000502:physiology; D057231:Climate Change; D003681:Dehydration / Q000378:metabolism; D029749:Dianthus / Q000502:physiology*; D055864:Droughts; D017753:Ecosystem; D056727:Endangered Species; D019083:Mediterranean Region; D010788:Photosynthesis; D012621:Seasons; D013030:Spain; D014867:Water / Q000378:metabolism
D014867:Water
Climate change; Dianthus inoxianus; Drought-stress recovery; Photosynthesis; Threatened species; Water stress