Drought effects on buds growth and dynamic of Tunisian cork oak populations

Forest species have adapted to their local climate by changing some of their phenological characteristics. Differential phenological responses may modify tree chance of survival by altering the competitive balance between them. The study of key phenological stages (budding, budburst, flowering, falling leaves ...) knew a renewed interest these last years for climate changes consequences researches. Characterizing the phenological variability response, of five Tunisian cork oak populations from contrasting climatic situations, in front to water deficit, has been the subject of this study. Large differences between populations from highest and coldest sites as well as those of lowest and warm sites were detected and adaptative responses specific to some populations were founded

Identification of Salt Stress Biomarkers in Romanian Carpathian Populations of Picea abies (L.) Karst

The Norway spruce (Picea abies), the most important tree species in European forests, is relatively sensitive to salt and does not grow in natural saline environments. Yet many trees are actually exposed to salt stress due to the common practice of de-icing of mountain roads in winter, using large amounts of NaCl. To help develop strategies for an appropriate use of reproductive seed material on reforestation sites, ensuring better chances of seedling survival in salt-affected areas, we have studied the responses of young spruce seedlings to salt treatments. The specific aim of the work was to identify the optimal salt stress biomarkers in Picea abies, using as experimental material seedlings obtained by germination of seeds with origin in seven populations from the Romanian Carpathian Mountains. These responses included general, conserved reactions such as the accumulation of ions and different osmolytes in the seedlings needles, reduction in photosynthetic pigments levels, or activation of antioxidant systems. Although changes in the contents of different compounds involved in these reactions can be associated to the degree of stress affecting the plants, we propose that the (decreasing) levels of total phenolics or total carotenoids and the (increasing) levels of Na+ or K+ ions in Picea abies needles, should be considered as the most reliable and useful biomarkers for salt stress in this species. They all show very high correlation with the intensity of salt stress, independently of the genetic background of the seeds parental population, and relatively easy, quantitative assays are available to determine their concentrations, requiring simple equipment and little amount of plant material.Funding: Sorin Schiop is a PhD student at the University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. This paper was published under the frame of European Social Found, Human Resources Development Operational Programme 2007-2013, project no. POSDRU/159/1.5/S/132765. Mohamad Al Hassan is a recipient of an Erasmus Mundus pre-doctoral scholarship financed by the European Commission (Welcome Consortium).Schiop, ST.; Al Hassan, M.; Sestras, AF.; Boscaiu Neagu, MT.; Sestras, RE.; Vicente Meana, Ó. (2015). Identification of Salt Stress Biomarkers in Romanian Carpathian Populations of Picea abies (L.) Karst. PLoS ONE. 10(8). doi:10.1371/journal.pone.0135419Se013541910

Exploring the teleported information in two two-level atoms interacting with a deformed cavity field

The possibility of teleporting a single-qubit system in an atomic system that interacts with a deformed cavity mode is being discussed. The average fidelity is used to investigate the quality of the teleported information in either ideal or deformed cavity. The quantum Fisher information is used as an estimator for the weight and phase angle parameters of the initial input state. The study shows that maximizing/minimizing the estimation degree and fidelity depends on the initial state settings of the atomic system, dipole–dipole coupling, and the estimated parameters. To maximize the information in the presence of a deformed cavity, one has to set large values of the atomic coupling dipole subsystem and reduce the deformation parameter

Oscillation Criteria for Qusilinear Even-Order Differential Equations

In this study, we extended and improved the oscillation criteria previously established for second-order differential equations to even-order differential equations. Some examples are given to demonstrate the significance of the results accomplished

Effects of heavy metals on antioxidant activities of Atriplex hortensis and Atriplex rosea

In the present study, the effects of heavy metals generating antioxidative defense systems such as superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11) glutathione reductase (GR, EC 1.6.4.2) and catalase (CAT, EC 1.11.1.6) were studied in the leaves of Atriplex plants grown in polluted soil with different heavy metals (Cu, Ni, Pb and Zn). The results showed that the exposure of plants to different levels of metals reduced the dry matter production and height of shoots. The decrease in root growth caused by the toxicity of metals was severe than the decrease in shoot growth. Atriplex showed gradual decrease in height following metal treatments, a four week exposure of A. hortensis var. rubra L. (red) to 25%,50%,75% and 100% contaminated soil gave a respective mean values of 21.4, 12.2, 9.3 and 6.5 cm which were lower in comparison to the plants of the control group. Of the antioxidant enzymes, the results showed that SOD and APX, were diminished by metal toxicity. However, the activity of CAT and GR were increased by the metal stress. Hence, the plants of the three annual arroach species or varieties used, all showed an intermediate level of tolerance according to the imposed treatments. The antioxidative activity seems to be of fundamental importance for adaptive responses of Atriplex plants against the metal toxicity.Abbreviations: SOD, superoxide dismutase; CAT, catalase; APX, ascorbate peroxidase; GR, glutathione reductase; GSH, reduced glutathione; GSSG, oxidized glutathione; ROS, reactive oxygen species; MDHA, monodehydroascorbate; NBT, nitroblue tetrazolium; POD, peroxidase

Drought effects on buds growth and dynamic of Tunisian cork oak populations

Forest species have adapted to their local climate by changing some of their phenological characteristics. Differential phenological responses may modify tree chance of survival by altering the competitive balance between them. The study of key phenological stages (budding, budburst, flowering, falling leaves ...) knew a renewed interest these last years for climate changes consequences researches. Characterizing the phenological variability response, of five Tunisian cork oak populations from contrasting climatic situations, in front to water deficit, has been the subject of this study. Large differences between populations from highest and coldest sites as well as those of lowest and warm sites were detected and adaptative responses specific to some populations were founded

Effects of Heavy Metals on Growth and Bioaccumulation of the Annual Halophytes Atriplex Hortensis and A. Rosea

Abstract: Heavy metals such Zn, Pb, Cu and Cd can cause a non-degradable pollution in numerous sites in France as well as in Tunisia, or elsewhere. This pollution resulting from various human polluting activities, related to industry or mining, is often diffuse in soils. Vegetation can play an important role in decontaminating these soils, their rehabilitation, and making their environment safer. For a better understanding of metal reactivity, a review of general knowledge concerning this kind of polluting metals and plant tolerance mechanisms is presented. A study was also conducted on the accumulation of the following metals: Cd, Cu, Zn, Pb and Ni, in their localisation in plant tissues and their induced toxic effects. The most general visible, but nonspecific symptom of heavy metal stress is growth inhibition, which has been investigated in many plants, including Atriplex. A cultivation of annual Atriplex plants was conducted according to hydroponic experimental design. The experimental approach consisted of hydroponic cultures using simplified medium represented by a nutritive solution. Results showed that plant final biomass, leaf area and metal accumulation, all varied with the metals level of toxicity and the plant species considered. Hence, the plants of the three annual arroach species or varieties used, all showed an intermediate level of tolerance according to the imposed treatments. Metal induces a number of physiological changes, such as growth inhibition, a significant reduction in biomass production was observed in metal treated plants compared with the control plants. The bioaccumulation factor decreased at the highest metal level, the low transfer of metal from solution to above-ground organs at higher solution metal concentrations indicates an exclusion mechanism. Trace element accumulation in shoots and the bioconcentration factors were proportional to the initial concentration of individual metals in the growth medium and the duration of exposure. Annual orach : A. hortensis seem to have a good capability for tolerance and phytostabilisation areas containing heavy metals