Differential stress responses of antioxidative systems to drought in pendunculate oak (Quercus robur) and maritime pine (Pinus pinaster) grown under high CO2 concentrations

Abstract

Maritime pine (Pinus pinaster), a drought-avoiding species, contained 2--4-fold lower activities of superoxide dismutase, ascorbate peroxidase, catalase, dehydroascorbate reductase, and glutathione reductase than pendunculate oak (Quercus robur), a drought-tolerant species. The levels of ascorbate, monodehydroascorbate radical reductase activity, and glutathione in pine needles were similar to those in oak leaves. In both species the development of drought stress, characterized by decreasing predawn water potentials, caused gradual reductions in antioxidant protection, increased lipid peroxidation, increased oxidation of ascorbate and glutathione and in pine also significant loss in soluble proteins and carotenoids. These results support the idea that increased drought-tolerance in oak as compared with pine is related to increased biochemical protection at the tissue level. To test the hypothesis that elevated CO(2) ameliorated drought-induced injury, young oak and pine trees acclimated to high CO(2) were subjected to drought stress. Analysis of plots of enzymatic activities and metabolites against predawn water potentials revealed that the drought stress-induced decreases in antioxidant protection and increases in lipid peroxidation were dampened at high CO(2). In pine, protein and pigment degradation were also slowed down. At high CO(2), superoxide dismutase activities increased transiently in drought-stressed trees, but collapsed in pine faster than in oak. These observations suggest that the alleviation of drought-induced injury under elevated CO(2) is related to a higher stability of antioxidative enzymes and an increased responsiveness of SOD to stressful conditions. This ameliorating mechanism existed independently from the effects of elevated CO(2) on plant water relations and is limited within a species-specific metabolic window.

Physiological responses to gradual drought stress in the diploid hybrid Pinus densata and its two parental species

“…These drought-induced responses occur in a wide range of plants, from annuals to long-lived trees (Hacke and Sauter 1996;Munne-Bosch and Alegre 2003;Turtola et al 2003;Ramachandra Reddy et al 2004;Lei et al 2006;Selote and Khanna-Chopra 2006). Most published research suggests that drought stress affects the growth and physiological performance of tree species (Irvine et al 1998;Schwanz et al 1996;Schwanz and Polle 2001;Turtola et al 2003;Munné-Bosch and Penuelas 2004;Lei et al 2006;Valdes et al 2006). Pines are the most economically important forest trees and provide ecosystems for a large number of plant and animal species across the northern hemisphere.…”

Response of juvenile progeny of seven forest tree species and their populations to simulated climate change-related stressors, heat, elevated humidity and drought

“…For example, for P. sylvestris both treatments had positive effect (compared to control) on production of all the analysed pigments, while for P. abies the effect was always negative or neutral. Decline in carotenoid concentration following drought stress and high CO2 concentrations was observed by Schwanz & Polle (2001) in Q. robur and Pinus pinaster Ait. Higher H2O2 levels (compared to control) recorded following drought stress in A. glutinosa, F. excelsior, P. sylvestris and P. abies suggest that these four tree species at young age are sensitive to water deficit.…”

Metabolomics - Useful Tool for Study of Plant Responses to Abiotic Stresses

“…Differences in the acute and the longer-term responses of the plants to any of the stresses during the first 30 h of treatment were observed as well. Mitigation of the oxidative stress induced by increased salinity through the application of elevated CO 2 was determined also with two barley cultivars [145], and the protective role of elevated CO 2 was confirmed also in salt-stressed alfalfa [146], pine and oak [147].…”