13 research outputs found
Differences in Ionic, Enzymatic, and Photosynthetic Features Characterize Distinct Salt Tolerance in Eucalyptus Species
No full textBalti H, Abassi M, Dietz K-J, Kumar V. Differences in Ionic, Enzymatic, and Photosynthetic Features Characterize Distinct Salt Tolerance in Eucalyptus Species. Plants. 2021;10(7): 1401.In the face of rising salinity along coastal regions and in irrigated areas, molecular breeding of tolerant crops and reforestation of exposed areas using tolerant woody species is a two-way strategy. Thus, identification of tolerant plants and of existing tolerance mechanisms are of immense value. In the present study, three Eucalyptus ecotypes with potentially differential salt sensitivity were compared. Soil-grown Eucalyptus plants were exposed to 80 and 170 mM NaCl for 30 days. Besides analysing salt effects on ionic/osmotic balance, and hydrolytic enzymes, plants were compared for dynamics of light-induced redox changes in photosynthetic electron transport chain (pETC) components, namely plastocyanin (PC), photosystem I (PSI) and ferredoxin (Fd), parallel to traditional chlorophyll a fluorescence-based PSII-related parameters. Deconvoluted signals for PC and Fd from PSI allowed identification of PC and PSI as the prime salinity-sensitive components of pETC in tested Eucalyptus species. Eucalyptus loxophleba portrayed efficient K+-Na+ balance (60–90% increased K+) along with a more dynamic range of redox changes for pETC components in old leaves. Young leaves in Eucalyptus loxophleba showed robust endomembrane homeostasis, as underlined by an increased response of hydrolytic enzymes at lower salt concentration (~1.7–2.6-fold increase). Findings are discussed in context of salinity dose dependence among different Eucalyptus species
Metabolite Screening From Pinus pinea Needles Reveals (+)-Isocupressic Acid as a Key Phytotoxin for Weed Management
No full textInhibitory effect of aqueous extracts of Centaurea solstitialis subsp schouwii on seed germination and growth of Sulla coronaria
No full textBiodiversity has been confronted with anthropogenic and several natural threats such as biological invasions. The success of these invasions involves phytotoxic products released by invasive plants that can exhibit allelopathic effects on target species. Thus, aqueous extracts from different parts of the mediterranean yellow star-thistle (Centaurea solstitialis subsp schouwii), were tested for their allelopathic effect on seed germination and seedling growth of Sulla coronaria. Bioassays were conducted in vitro in order to test the effects of the aqueous extracts of shoot, basal and root parts of C. solstitialis subsp schouwii at two different concentrations (50 g L-1 and 10 g L-1). The concentrations of total polyphenols, flavonoids and tannins of the extracts were also evaluated. Our results showed inhibitory effects on germination and seedling growth of S. coronaria seedlings particularly with the basal part extract reaching 84%. This study confirms the linear relationships between allelopathic effects of C. solstitialis subsp schouwii and the polyphenols and flavonoids contents. However, further experiments are needed under field conditions in order to confirm the results obtained under laboratory conditions.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Rponses adaptatives un asschement daphique chez trois provenances de Chne lige (Quercus suber L.)
No full textLes effets du changement climatique induisent dans la rgion mditerranenne la recrudescence d’vnements extrmes comme la scheresse accentuant la dgradation des cosystmes forestiers de Quercus suber L. Des jeunes plants de trois provenances tunisiennes de Quercus suber (EF, BM et OZ) ont t valus pour leur tolrance au manque d’eau en les soumettant durant 90 jours trois rgimes hydriques (S0 : irrigation 100 % de la capacit au champ (CC), S1 : 50 % CC et S2 : 25% CC). De nombreuses variables ont t mesures (croissance des tiges, surface foliaire, densit et dimension des trichomes et des stomates, changes gazeux et concentration en chlorophylles). Le dficit hydrique a occasionn une rduction des variables cophysiologiques et une augmentation de la densit des stomates et des trichomes. Une variabilit intraspcifique a t enregistre. Les plants EF et BM ont montr un indice de plasticit phnotypique suprieur celui des plants OZ. La meilleure flexibilit vis--vis du stress hydrique s’est traduite chez les plants EF par une augmentation de l’EUEi convertie en une croissance plus soutenue des tiges. Dans un contexte global de rchauffement climatique et de fragilit des forts mditerranennes, la russite des nouveaux boisements de Quercus suber exige le choix de provenances les plus adaptes la faible disponibilit en eau l’instar de la provenance EF.
The effects of climate change induce the increase of extreme events such as drought in the Mediterranean region, accentuating the degradation of forest ecosystems of Quercus suber L. Seedlings of Quercus suber (EF, BM and OZ) from three Tunisian provenances were evaluated for their tolerance to water shortage by subjecting them for 90 to three water regimes (S0: irrigation at 100% of the field capacity (FC), S1: 50% FC and S2: 25% FC) for 90 days. Several variables were measured (stem growth, leaf area, trichome and stomatal density and size, gas exchange and chlorophyll concentration). The moisture deficit caused a decrease in ecophysiological variables and an increase in stomata and trichomes density. Intraspecific variability was recorded. EF and BM plants showed a higher phenotypic plasticity index than OZ plants. The better flexibility towards hydric stress was reflected in the EF plants by an increase of the WUEint converted into a more sustained stem growth. In the overall context of global warming and of Mediterranean forests fragility, the success of new afforestation of Quercus suber requires the selection of the best adapted provenances to low water availability, such as the EF provenanceThe presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Capparis spinosa var. inermis Turra: Presentation, Uses and Socio-economic Benefits
No full textThe caper (Capparis spinosa var. Inermis Turra) is a bushy sub-shrub, 30 to 50 cm high. It is a small "sarmentose" shrub with unarmed twigs belonging to the Capparaceae family. It is a species of Saharo-Arabian and Mediterranean origins, which is characterized by food, ecological, socio-economic and ornamental importance. It is also known for its medicinal and therapeutic virtues, which are very interesting given the pharmacological activities of the phytochemicals present in the different parts of the caper tree (roots, leaves, buds, fruits, bark and seeds). Its mode of propagation is by seed or by semi-woody, woody, semi-herbaceous and herbaceous cuttings
Combined Effects of Barley yellow dwarf virus (BYDV) Infection and Salinity Stress on Barley Growth and Yield Parameters
No full textFollowing the current climate changes, Tunisia climate is characterized by less and more irregular
rainfall together with milder and shorter winter, resulting in increased soil salinity and higher incidence
of Barley yellow dwarf virus (BYDV). The selection of productive cultivars adapted to both abiotic and
biotic constraints is crucial for crop breeders, and especially for cereal breeding. In this study, the
behavior of two genotypes (G1 and G2) obtained from a cross breeding (QB813-
2/3/Lignee527/NK1272//JLB70-63) and the most commonly grown cultivar Rihane were compared for
their responses to the combined effects of various salinity levels (0 to 150 mM NaCl) and BYDV virus
infection. Rihane was the most sensitive cultivar under biotic and abiotic stress combination whereas
growth and yield parameters were significantly improved in G1 and G2 genotypes under BYDV+50
mM NaCl treatment. In addition, these two genotypes were less affected by the virus infection and high
salinity (100 and 150 mM NaCl) combination than Rihane. Interestingly, stress tolerance index was
higher in G2, followed by G1 and Rihane, suggesting that this parameter could be a useful trait to
discriminate genotypes for their performance under multiple stress conditions
Évaluation morpho-physiologique de trois clones de <i>Salix</i> des zones semi-arides soumis à un excès de zinc en conditions hydroponiques
No full textContamination Assessment of Durum Wheat and Barley Irrigated with Treated Wastewater through Physiological and Biochemical Effects and Statistical Analyses
No full textThe present work focused on the impact of crop irrigation by treated wastewater (TWW) on soil fertility, in germination, and growth of two species of cereals (T. turgidum and H. vulgare). This investigation was conducted at the germination stage (controlled condition) and in pots containing a soil irrigated with wastewater in comparison with controlled soil. Germination rate, vigor index, seedling growth, total fresh mass, chlorophyll content, proline, ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and catalase (CAT) activities were measured. Similar effects were shown on both species which emphasize the important role of antioxidant enzymes in the defense against oxidative stress induced by prolonged reuse of TWW. The disturbing effect of the reuse TWW on soil fertility, germination, and development of young plants (T. turgidum and H. vulgare) was linked to the presence of micropollutants in TWW. Data were analyzed by R language using a nonparametric statistical hypothesis test. These have caused the disorganization of many physiological mechanism targets, especially growth disorders observed under different abiotic stress conditions. In conclusion, high salt and heavy metal concentrations contained in the TWW are the major constraints related to the reuse of TWW. Hence, repetitive irrigation with this water can induce, at long term, soil contamination which can limit plant production and crop contamination
Potential Use of Two Forest Species (Salix alba and Casuarina glauca) in the Rhizofiltration of Heavy-Metal-Contaminated Industrial Wastewater
No full textThe discharge of raw industrial wastewater (IWW) into ecosystems is a major environmental problem that adversely affects water quality, soil physicochemical properties, the food chain and, therefore, human health. Injection of treated IWW into irrigation and “fertigation” systems is an ecological, sustainable and economical approach for its appropriate disposal. Seedlings of two forest species (Salix alba, Casuarina glauca) were grown hydroponically and subjected to 25% diluted IWW and control (tap water) treatments for 35 days. Morphological and physiological traits were evaluated, including leaf symptoms, stem and root dry masses, leaf water potential, relative water content, chlorophyll content, photosystem II efficiency, hydrogen peroxide, thiobarbituric acid reactive substances, bioaccumulation and translocation factor estimates and removal efficiency for various heavy metals. Application of 25% IWW stress affected many aspects of plant morphology: chlorosis and necrosis in leaves, epinasty, leaf curling, early leaf senescence and root browning. In both species, the 25% IWW treatment reduced leaf, stem and root dry masses relative to controls. S. alba exhibited greater removal capacity for heavy metal ions and could be effective as a remediator of toxic-metal-polluted industrial effluent water
Clonal Variation in Growth, Physiology and Ultrastructure of Populus alba L. Seedlings Under NaCl Stress
No full textAfforestation and reforestation (A/R) of non-agricultural and marginal saline lands by promoting fast-growing and salinity-tolerant woody species are crucial strategies to overcome land degradation and vegetation cover scarcity. To obtain basic information before using Populus alba clones in such degraded areas, morpho-physiological and cellular responses to salt stress were investigated. The experiment was conducted in a nursery where cuttings of three P. alba clones (MA-104, MA-195 and OG) were grown for 90 days in 100 mM NaCl versus a non-saline control. A global approach highlighting clonal differences in terms of dry mass production and plant physiological performance was achieved by comparing plant water status, gas exchange, ionic selectivity, osmotic adjustment and chloroplast ultrastructure under the two treatments. Dry mass production and eco-physiological processes were reduced in response to salt stress, with substantial clonal variation. Clone MA-104 exhibited salinity-tolerant behaviour in contrast to clone MA-195 and OG’s medium or sensitive behaviour towards the stress. Tolerance mechanisms may be attributed to enhanced stomatal control and osmotic adjustment, thereby enabling the maintenance of turgor in plants subjected to salt stress. The chloroplast ultrastructure also showed modifications that are often involved in adaptation to salinity stress
