UHPLC-PAD Protocol for the Simultaneous Identification of Polyphenols and Bitter Acids: Organoleptic and Nutraceutical Fingerprinting of Bergamot-Flavored Craft Beer.

In this study, a UHPLC-PDA method for the simultaneous identification of polyphenols and bitter acids (alpha, beta, and isoalpha) in beer was developed. The resulting chemical profiles were leveraged to distinguish the characteristics of four (IPA, Lager, Blanche, ALE) bergamot-flavored beers, produced on a pilot-scale plant. In a streamlined 29 min analysis, thirty polyphenols and fourteen bitter acids were successfully identified under optimized separation conditions. Validation, encompassing parameters such as LOD (from 0.028 ppm for isorhamnetin to 0.106 for narirutin), LOQ (from 0.077 ppm for naringenin to 0.355 for narirutin), R2 (always more than 0.9992), repeatability (from 0.67% for tangeretin to 6.38% for myricetin), and reproducibility (from 0.99% for sinensetin to 6% for naringin), was conducted for polyphenol quantification using constructed calibration curves with seven levels. Exploring polyphenolic components as potential discriminators among different beer styles, a total of thirty-two polyphenolic compounds were identified and quantified, including characteristic bergamot peel polyphenols like neoeriocitrin (from 7.85 ppm for CBS2 to 11.95 ppm in CBS1); naringin (from 4.56 ppm for CBS4 to 10.96 in CBS1), and neohesperidin (from 5.93 in CBS3 to 15.95 for CBS2). The multivariate analysis provided additional insights into variations among specific beer styles, revealing discrepancies in the presence or relative concentrations of specific compounds linked to brewing ingredients and processes. This research enhances the fingerprinting of the chemistry governing beer quality through a straightforward and cost-effective analytical approach.

Oxidative Stress: The Role of Antioxidant Phytochemicals in the Prevention and Treatment of Diseases.

Oxidative stress, characterized by an imbalance favouring oxidants over antioxidants, is a key contributor to the development of various common diseases. Counteracting these oxidants is considered an effective strategy to mitigate the levels of oxidative stress in organisms. Numerous studies have indicated an inverse correlation between the consumption of vegetables and fruits and the risk of chronic diseases, attributing these health benefits to the presence of antioxidant phytochemicals in these foods. Phytochemicals, present in a wide range of foods and medicinal plants, play a pivotal role in preventing and treating chronic diseases induced by oxidative stress by working as antioxidants. These compounds exhibit potent antioxidant, anti-inflammatory, anti-aging, anticancer, and protective properties against cardiovascular diseases, diabetes mellitus, obesity, and neurodegenerative conditions. This comprehensive review delves into the significance of these compounds in averting and managing chronic diseases, elucidating the key sources of these invaluable elements. Additionally, it provides a summary of recent advancements in understanding the health benefits associated with antioxidant phytochemicals.

A Predictive Model to Correlate Amino Acids and Aromatic Compounds in Calabrian Honeys.

To better understand the biochemistry of the organoleptic properties of honey influencing its commercial value, a predictive model for correlating amino acid profiles to aromatic compounds was built. Because the amino acid composition of different varieties of honey plays a key role as a precursor of specific aroma bouquets, it is necessary to relate the amino acid typesetting to aromatic molecules. A selection of unifloral honeys produced in Calabria, South Italy, were used, and a new methodology based on the use of HILIC-UHPLC-ESI-MS/MS and HS-SPME-GC-MS combined with multivariate processing has been developed. This study, carried out for the first time on honey, shows its excellent potential as a modern analytical tool for a rapid multicomponent analysis of food-quality indicators. Data obtained showed strong positive linear correlations between aldehydes and isoleucine, valine, leucine, and phenylalanine. Furans are correlated with isoleucine, leucine, and phenylalanine; hydrocarbons with serine, glutamic acid, and aspartic acid; and ketones with serine, alanine, glutamine, histidine, asparagine, and lysine. Alcohols were more associated with tyrosine than esters with arginine. Proline, tryptophan, and threonine showed poor correlations with all the classes of aroma compounds.

Plant Responses to Biotic and Abiotic Stresses: Crosstalk between Biochemistry and Ecophysiology.

Biotic and abiotic stresses, such as drought, salinity, extreme temperatures (cold and heat) and oxidative stress, are often interrelated; these conditions singularly or in combination induce cellular damage [...].

Phytochemicals from Red Onion, Grown with Eco-Sustainable Fertilizers, Protect Mammalian Cells from Oxidative Stress, Increasing Their Viability.

Red onion, a species of great economic importance rich in phytochemicals (bioactive compounds) known for its medicinal properties, was fertilized with sulphur-bentonite enriched with orange residue or olive pomace, with the aim of producing onion enriched in health beneficial compounds. There is a worldwide great demand of minimally processed food or food ingredients with functional properties because of a new awareness of how important healthy functional nutrition is in life. Phytochemicals have the capacity to regulate most of the metabolic processes resulting in health benefits. Red onion bioactive compound quantity and quality can vary according to cultivation practices. The main aims of the current research were to determine the chemical characteristics of the crude extracts from red onion bulbs differently fertilized and to evaluate their biological activity in normal and oxidative stress conditions. The lyophilized onion bulbs have been tested in vitro on two cellular models, i.e., the H9c2 rat cardiomyoblast cell line and primary human dermal fibroblasts, in terms of viability and oxygen radical homeostasis. The results evidenced different phytochemical compositions and antioxidant activities of the extracts obtained from red onions differently fertilized. Sulphur-bentonite fertilizers containing orange waste and olive pomace positively affected the red onion quality with respect to the red onion control, evidencing that sulphur-bentonite-organic fertilization was able to stimulate plant a secondary metabolism inducing the production of phytochemicals with healthy functions. A positive effect of the extracts from red onions treated with fertilizers-in particular, with those containing orange waste, such as the reduction of oxidative stress and induction of cell viability of H9c2 and human fibroblasts-was observed, showing a concentration- and time-dependent profile. The results evidenced that the positive effects were related to the phenols and, in particular, to chlorogenic and p-coumaric acids and to the flavonol kaempferol, which were more present in red onion treated with low orange residue than in the other treated ones.

Pomegranate Wastes Are Rich in Bioactive Compounds with Potential Benefit on Human Health.

Pomegranate use is increasing worldwide, as it is considered a tasteful healthy food. It is mainly used as fruit, juice, and jam. The pomegranate peel represents about 40-50% of the total fruit weight and contains numerous and diverse bioactive substances. The aim of this research was to analyze the pomegranate peel chemical composition of Wonderful cultivated in Southern Italy and treated with an innovative physic dry concentration procedure in comparison with the peel composition of freeze-dried Wonderful cultivated in Southern Italy, freeze-dried Wonderful cultivated in South Africa, and freeze-dried pomegranate cultivated in India. The specific aim was to verify how much the growth area, cultivar type, and dry procedure influenced the chemical composition of the peels in terms of valuable bioactive compounds. Spectrophotometric and HPLC identification methods were used to detect antioxidants, antioxidant activities, and phenolic and flavonoid components. Results evidenced that in pomegranate peels of Wonderful cultivated in Calabria and dried with the innovative process, total phenolic substances, total flavonoids, vitamin C, vitamin E, and antioxidant activities were the highest. Great amounts of single phenolic acids and flavonoids were found in Calabrian Wonderful peels dried with the innovative process. Overall, it emerged that a great amount of bioactive and diverse compounds found in Calabrian Wonderful pomegranate peel comes from the niche pedoclimatic conditions, and the physic drying innovative methodology turned out to be an advantageous procedure to concentrate and conserve biocompounds.

AnchoisFert: A New Organic Fertilizer from Fish Processing Waste for Sustainable Agriculture.

The "AnchoisFert", the solid residue comprised of milled anchovy leftovers after fish oil extraction with biobased limonene, is a powerful organic fertilizer. Employed to promote the growth of Tropea's red onion (Allium cepa), the fertilizer turns out to largely be superior to commonly used organic (manure) and chemical (nitrogen phosphorous potassium) fertilizers. Rich in proteins, organic carbon, flavonoids, magnesium, potassium, phosphate and sulfate, and devoid of antibiotics and antibiotic resistance genes, the new organic fertilizer can replace both conventional organic and inorganic fertilizers. This discovery closes the fishing material cycle for the most fished species across the seas opening the route to a new class of organic fertilizers of exceptional performance derived from abundant biowaste via a low-cost and environmentally-friendly circular economy process.

Evaluation of Physiological and Morphological Traits for Improving Spring Wheat Adaptation to Terminal Heat Stress.

Wheat crop experiences high temperature stress during flowering and grain-filling stages, which is termed as "terminal heat stress". Characterizing genotypes for adaptive traits could increase their selection for better performance under terminal heat stress. The present study evaluated the morpho-physiological traits of two spring wheat cultivars (Millet-11, Punjab-11) and two advanced lines (V-07096, V-10110) exposed to terminal heat stress under late sowing. Early maturing Millet-11 was used as heat-tolerant control. Late sowing reduced spike length (13%), number of grains per spike (10%), 1000-grain weight (13%) and biological yield (15-20%) compared to timely sowing. Nonetheless, higher number of productive tillers per plant (19-20%) and grain yield (9%) were recorded under late sowing. Advanced lines and genotype Punjab-11 had delayed maturity and better agronomic performance than early maturing heat-tolerant Millet-11. Advanced lines expressed reduced canopy temperature during grain filling and high leaf chlorophyll a (20%) and b (71-125%) contents during anthesis under late sowing. All wheat genotypes expressed improved stem water-soluble carbohydrates under terminal heat stress that were highest for heat-tolerant Millet-11 genotype during anthesis. Improved grain yield was associated with the highest chlorophyll contents showing stay green characteristics with maintenance of high photosynthetic rates and cooler canopies under late sowing. The results revealed that advanced lines and Punjab-11 with heat adaptive traits could be promising source for further use in the selection of heat-tolerant wheat genotypes.

Agro-Morphological, Yield and Quality Traits and Interrelationship with Yield Stability in Quinoa (Chenopodium quinoa Willd.) Genotypes under Saline Marginal Environment.

Quinoa (Chenopodium quinoa Willd.) is a halophytic crop that shows resistance to multiple abiotic stresses, including salinity. In this study we investigated the salinity tolerance mechanisms of six contrasting quinoa cultivars belonging to the coastal region of Chile using agro-physiological parameters (plant height (PH), number of branches/plant (BN), number of panicles/plant (PN), panicle length (PL), biochemical traits (leaf C%, leaf N%, grain protein contents); harvest index and yield (seed yield and plant dry biomass (PDM) under three salinity levels (0, 10, and 20 d Sm-1 NaCl). The yield stability was evaluated through comparision of seed yield characteristics [(static environmental variance (S2) and dynamic Wricke's ecovalence (W2)]. Results showed that significant variations existed in agro-morphological and yield attributes. With increasing salinity levels, yield contributing parameters (number of panicles and panicle length) decreased. Salt stress reduced the leaf carbon and nitrogen contents. Genotypes Q21, and AMES13761 showed higher seed yield (2.30 t ha-1), more productivity and stability at various salinities as compared to the other genotypes. Salinity reduced seed yield to 44.48% and 60% at lower (10 dS m-1) and higher salinity (20 dS m-1), respectively. Grain protein content was highest in NSL106398 and lowest in Q29 when treated with saline water. Seed yield was positively correlated with PH, TB, HI, and C%. Significant and negative correlations were observed between N%, protein contents and seed yield. PH showed significant positive correlation with APL, HI, C% and C:N ratio. HI displayed positive correlations with C%, N% and protein content., All measured plant traits, except for C:N ratio, responded to salt in a genotype-specific way. Our results indicate that the genotypes (Q21 and AMES13761) proved their suitability under sandy desert soils of Dubai, UAE as they exhibited higher seed yield while NSL106398 showed an higher seed protein content. The present research highlights the need to preserve quinoa biodiversity for a better seedling establishment, survival and stable yield in the sandy desertic UAE environment.

Effect of Organic Fertilizers on Selected Health Beneficial Bioactive Compounds and Aroma Profile of Red Topepo Sweet Pepper.

Phytochemicals and antioxidant properties of red sweet pepper cv Topepo grown in soil amended with different organic fertilizers were compared with that grown in unamended soil. Organic fertilizers are an environmentally friendly alternative to recovery infertile soils that resulted from the intensified agricultural practices in red Topepo production. The aim was to discriminate the effects of organic fertilizers one from each other on the quality of red Topepo to find out the better sustainable fertilization practice for its cultivation. Results showed that compost from vegetable residues (CV) enhanced the synthesis of total phenols, flavonoids, ascorbic acid, vitamin E, carotenoids, anthocyanins, as well as carbohydrates, antioxidant activities, and aroma profiling, compared to horse manure (HD), compost from olive pomace (CO), and control (CTR). The results indicated a specificity between the quality of red Topepo and compost composition, highlighting that vegetable residues increased the synthesis of secondary metabolites, enhancing sustainably, the nutraceutical, sensorial, and economic value of red Topepo. The fertilizer composition resulted largely responsible for the synthesis of bioactive compounds, flavor, and aroma of this fruit.

Crop diversification and saline water irrigation as potential strategies to save freshwater resources and reclamation of marginal soils-a review.

Feeding 9 billion by 2050 is one of major challenges for researchers. Use of diversified crops, nonconventional water resources and rehabilitation of marginal lands are alternate options to produce more food to face climate change projections. Adaptation to climate change through climate smart agriculture practices, agroecology activities, and crop-based management packages can help transform the marginal lands from environmental burdens into productive and economic blocks. This review discusses the recent advancements on specialty group of alternate crops (oil seeds, legumes, cereals, medicinal, lignocellulose, and fruit crops) which can adapt in the marginal environments. Availability of alternate water resources (saline water, treated wastewater) for irrigation cannot be omitted. Crop diversification systems involving drought and salt-tolerant crops are likely to be the key to future agricultural and economic growth in the regions where salt-affected soils exist and/or saline aquifers are pumped for irrigation. These systems may tackle three main tasks: sustainable management of land resources and enhancement of per unit productivity; intensification of agroecological practices to increase soil fertility; and improving productivity of marginal lands for diversified climate smart crops. This review explores various aspects of marginal lands and selection of tolerant crop genotypes, crop diversification, and agroecological practices to maximize benefits.

Sulfur bentonite-organic-based fertilizers as tool for improving bio-compounds with antioxidant activities in red onion.

BACKGROUND: Red onion is popular in cuisines worldwide and is valued for its potential medicinal properties. Red onion is an important source of several phytonutrients such as flavonoids, thiosulfinates and other sulfur compounds, recognized as important elements of the diet. Nowadays, there is the need of producing food enriched in health benefit compounds. In this study, pads of sulfur bentonite (SB) with the addition of orange residue (OR) or olive pomace (OP) were used to improve the quality of red onion. The experiment was conducted for 3 months in the field to evaluate the phytochemicals of differently amended red onion. RESULTS: Treated plants were better in quality than controls. Antioxidant activity, detected as DPPH, ORAC and ABTS, was highest in plants grown in the presence of SB enriched with agricultural wastes, particularly SB-OR. Polyphenols increased in all treated plants. The volatile fraction was clearly dominated by sulfur compounds that are strictly related to the concentration of the aroma precursors S-alkenyl cysteine sulfoxides. The greater amount of thiosulfinates in treated compared with untreated onion evidenced that SB pelletized with agricultural wastes can represent a new formulation of organic fertilizer able to improve the beneficial properties of onion. The results highlighted that the best red onion quality was obtained using SB-OR pads. CONCLUSION: The use of SB bound with agricultural wastes represents a novel strategy to increase bio-compounds with beneficial effects on human health, to enhance the medical and economic values of sulfur-loving crops, with important consequences on the bio and green economy. © 2019 Society of Chemical Industry.

Three different methods for turning olive pomace in resource: Benefits of the end products for agricultural purpose.

In Mediterranean countries the olive oil industry produces, yearly, a huge quantity of pollutant wastes in a short time that are phytotoxic for their high content of phenols and wax that affect soil and groundwater quality. With the use of biological processes, we can transform these wastes into fertilizers for a sustainable agriculture. We used three different methods anaerobic digestion, aerobic digestion, and crude agricultural waste management system to produce organic fertilizers. The obtained compounds were chemically analysed to verify if their characteristics fell into the marketability limits permitted by the current Italian regulation. Their effects on soil were subsequently assessed. Results evidenced that all the by-products obtained were suitable as fertilizers. They were able to increase soil organic matter, microbial biomass, and nutrients with beneficial effects on soil fertility, but at different extent. The best effects were in the order: compost, olive pomace-sulphur-bentonite pelletized and digestate. Considering that the three different methodologies dispose different amounts of olive pomace (90% in aerobic digestion, 12% in anaerobic digestion and 5% in sulphur bentonite pelletized) in different time (4months for compost, 1month for anaerobic digestion and 1day for sulphur-bentonite pelletized) and processing set-up, each method can be differently competitive for environment and/or agriculture. Aerobic digestion has economic advantage over other alternatives and has the greatest fertilizer effect even if the production time is longer than the other two. Digestate, coming from anaerobic digestion, reduces the environmental impact of greenhouse gas emissions it is rich in nutrients and can be obtained in a shorter time than compost. Olive pomace-sulphur-bentonite pelletized represents a crude waste management systems that reduce greenhouse gas emission in the atmosphere producing fertilizers able to generate, mainly in alkaline soils, a soluble zone of nutrients while minimizing leaching losses to the environment.

Carbon (δ13C) and Nitrogen (δ15N) Stable Isotope Composition Provide New Insights into Phenotypic Plasticity in Broad Leaf Weed Rumex acetosa under Allelochemical Stress.

Phenolic compounds, hydroquinone and cinnamic acid derivatives have been identified as major allelochemicals with known phytotoxicity from allelopathic plant Acacia melanoxylon R. Br. Several phenolic compounds such as ferulic acid (FA), p-hydroxybenzoic acid (pHBA) and flavonoid (rutin, quercetin) constituents occur in the phyllodes and flowers of A. melanoxylon and have demonstrated inhibitory effects on germination and physiological characteristics of lettuce and perennial grasses. However, to date, little is known about the mechanisms of action of these secondary metabolites in broad-leaved weeds at ecophysiological level. The objective of this study was to determine the response of Rumex acetosa carbon isotope composition and other physiological parameters to the interaction of plant secondary metabolites (PSM) (FA and pHBA) stress and the usefulness of carbon isotope discrimination (Δ13C) as indicative of the functional performance of intrinsic water use efficiency (iWUE) at level of plant leaf. R. acetosa plant were grown under greenhouse condition and subjected to PSM stress (0, 0.1, 0.5, 1.0, and 1.5 mM) for six days. Here, we show that FA and pHBA are potent inhibitors of Δ13C that varied from 21.0‰ to 22.9‰. Higher pHBA and FA supply enhanced/retard the Nleaf and increased the Cleaf while ratio of intercellular CO2 concentration from leaf to air (Ci/Ca) was significantly decreased as compared to control. Leaf water content and leaf osmotic potential were decreased following treatment with both PSM. The Ci/Ca decreased rapidly with higher concentration of FA and pHBA. However, iWUE increased at all allelochemical concentrations. At the whole plant level, both PSM showed pronounced growth-inhibitory effects on PBM and C and N concentration, root fresh/dry weight, leaf fresh/dry weight, and root, shoot length of C3 broad leaf weed R. acetosa. Carbon isotope discrimination (Δ) was correlated with the dry matter to transpiration ratio (transpiration efficiency) in this C3 species, but its heritability and relationship to R. acetosa growth are less clear. Our FA and pHBA compounds are the potent and selective carbon isotope composition (δ13C) inhibitors known to date. These results confirm the phytotoxicity of FA and pHBA on R. acetosa seedlings, the reduction of relative water content and the induction of carbon isotope discrimination (Δ) with lower plant biomass.

Anaerobic co-digestion of recalcitrant agricultural wastes: Characterizing of biochemical parameters of digestate and its impacts on soil ecosystem.

Anaerobic digestion (AD) of organic wastes is a promising alternative to landfilling for reducing Greenhouse Gas Emission (GHG) and it is encouraged by current regulation in Europe. Biogas-AD produced, represents a useful source of green energy, while its by-product (digestate) is a waste, that needs to be safely disposal. The sustainability of anaerobic digestion plants partly depends on the management of their digestion residues. This study has been focused on the environmental and economic benefits of co-digest recalcitrant agricultural wastes such olive wastes and citrus pulp, in combination with livestock wastes, straw and cheese whey for biogas production. The aim of this work was to investigate the effects of two different bioenergy by-products on soil carbon stock, enzymes involved in nutrient cycling and microbial content. The two digestates were obtained from two plants differently fed: the first plant (Uliva) was powered with 60% of recalcitrant agricultural wastes, and 40% of livestock manure milk serum and maize silage. The second one (Fattoria) was fed with 40% of recalcitrant agricultural wastes and 60% of livestock manure, milk serum and maize silage. Each digestate, separated in liquid and solid fractions, was added to the soil at different concentrations. Our results evidenced that mixing and type of input feedstock affected the composition of digestates. Three months after treatments, our results showed that changes in soil chemical and biochemical characteristics depended on the source of digestate, the type of fraction and the concentration used. The mainly affected soil parameters were: Soil Organic Matter (SOM), Microbial Biomass Carbon (MBC), Fluorescein Diacetate Hydrolysis (FDA), Water Soluble Phenol (WSP) and Catalase (CAT) that can be used to assess the digestate agronomical feasibility. These results show that the agronomic quality of a digestate is strictly dependent on percentage and type of feedstocks that will be used to power the digester.

Introduction to the Special Issue: Halophytes in a changing world.

Climate change will bring about rising sea levels and increasing drought, both of which will contribute to increasing salinization in many regions of the world. There will be consequent effects on our crops, which cannot withstand significant salinization. This Special Issue looks at the roles that can be played by halophytes, extremophiles that do tolerate salinities toxic to most plants. In an ecological context, papers deal with the conservation of a rare species, the effects of rising concentrations of CO2 and flooding on coastal vegetation, and the consequences of tree planting in inland plains for salinization. Physiological studies deal with the different effects of chlorides and sulfates on the growth of halophytes, the ability of some parasitic plants to develop succulence when growing on halophytic hosts and the interesting finding that halophytes growing in their natural habitat do not show signs of oxidative stress. Nevertheless, spraying with ascorbic acid can enhance ascorbic acid-dependent antioxidant enzymes and growth in a species of Limonium. Enzymes preventing oxidative stress are expressed constitutively as is the case with the vacuolar H-ATPase, a key enzyme in ion compartmentation. A comparison of salt-excreting and non-excreting grasses showed the former to have higher shoot to root Na(+) ratios than the latter. A particularly tolerant turf grass is described, as is the significance of its ability to secrete ions. A study of 38 species showed the importance of the interaction of a low osmotic potential and cell wall properties in maintaining growth. From an applied point of view, the importance of identifying genotypes and selecting those best suited for the product required, optimizing the conditions necessary for germination and maximizing yield are described. The consequence of selection for agronomic traits on salt tolerance is evaluated, as is the use of halophytes as green manures. Halophytes are remarkable plants: they are rare in relation to the total number of flowering plants and they tolerate salinities that most species cannot. It is clear from the papers published in this Special Issue that research into halophytes has a distinct place in aiding our understanding of salt tolerance in plants, an understanding that is likely to be of importance as climate change and population growth combine to challenge our ability to feed the human population of the world.

Manipulating the antioxidant capacity of halophytes to increase their cultural and economic value through saline cultivation.

Halophytes, salt-tolerant plants, are a source of valuable secondary metabolites with potential economic value. The steady-state pools of many stress-related metabolites are already enhanced in halophytes when compared with glycophytes, but growth under conditions away from the optimum can induce stress and consequently result in changes to secondary metabolites such as antioxidants. However, direct evidence for increasing the concentration of valuable secondary metabolites as a consequence of altering the salinity of the growing environment still remains equivocal. To address this, we analysed a range of metabolites with antioxidant capacity (including total phenols, flavonoids, ascorbate, reduced/oxidized glutathione and reactive oxygen species scavenging enzymes) in seedlings and plants from different families (Amaranthaceae, Brassicaceae, Plantaginaceae and Rhizophoraceae) and habitats grown under different salt concentrations. We show that it is possible to manipulate the antioxidant capacity of plants and seedlings by altering the saline growing environment, the length of time under saline cultivation and the developmental stage. Among the species studied, the halophytes Tripolium pannonicum, Plantago coronopus, Lepidium latifolium and Salicornia europaea demonstrated the most potential as functional foods or nutraceuticals.

Salt tolerance traits increase the invasive success of Acacia longifolia in Portuguese coastal dunes.

Salt tolerance of two co-occurring legumes in coastal areas of Portugal, a native species--Ulex europaeus, and an invasive species--Acacia longifolia, was evaluated in relation to plant growth, ion content and antioxidant enzyme activities. Plants were submitted to four concentrations of NaCl (0, 50, 100 and 200 mM) for three months, under controlled conditions. The results showed that NaCl affects the growth of both species in different ways. Salt stress significantly reduced the plant height and the dry weight in Acacia longifolia whereas in U. europaeus the effect was not significant. Under salt stress, the root:shoot ratio (W(R):W(S)) and root mass ratio (W(R):W(RS)) increased as a result of increasing salinity in A. longifolia but the same was not observed in U. europaeus. In addition, salt stress caused a significant accumulation of Na+, especially in U. europaeus, and a decrease in K+ content and K+/Na+ ratio. The activities of antioxidant enzymes were higher in A. longifolia compared to U. europaeus. In A. longifolia, catalase (CAT, EC 1.11.1.6) and glutathione reductase (GR, EC 1.6.4.2.) activities increased significantly, while ascorbate peroxidase (APX, EC 1.11.1.11) and peroxidase (POX, EC 1.11.1.7) activities remained unchanged in comparison with the control. In U. europaeus, NaCl concentration significantly reduced APX activity but did not significantly affect CAT, GR and POX activities. Our results suggest that the invasive species copes better with salinity stress in part due to a higher rates of CAT and GR activities and a higher K+/Na+ ratio, which may represent an additional advantage when competing with native species in co-occurring salty habitats.