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Salinity inhibits plant growth due to osmotic and ionic effects. However, little is known about the impact of genotype and salinity on biochemical and molecular processes in the leafy vegetable lettuce. We report here evaluations of two lettuce types, Verte (NaCl tolerant) and Romaine (NaCl sensitive), under iso-osmotic 100 mM NaCl and 77 mM Na(2)SO(4) treatments. As compared to Romaine, NaCl-treated Verte displayed better growth, contained lower levels of inorganic cations in leaves, and possessed superior antioxidative capacity due to enhanced carotenoid and phenolics biosynthesis and more active antioxidative enzymes resulting in reduced membrane damage. Both genotypes had relatively similar growth patterns under Na(2)SO(4) treatment, but Romaine showed enhanced root lignification, greater malondialdehyde formation, and suppressed Fe-superoxide dismutase expression in roots as compared with Verte.

The interactive effects of salinity and potassium (K+) availability on biomass production, water status, and ionic composition were investigated in Hordeum maritimum, an annual grass growing natively on saline soils. Plants were grown for 7 weeks on Hewitt nutrient solution supplied with NaCl (0, 100, 150, 200, and 300 mM) combined with low (0.232 mM) or high (5.8 mM) K+ levels. Independent of potassium availability, dry matter of both roots and shoots decreased consistently with increasing NaCl levels in the culture medium, in association with a significant reduction of the shoot water content. This salt‐induced growth reduction did not result from a restriction of K+ nutrition, since H. maritimum expressed similar growth under both low and high K+ supply. NaCl decreased shoot K+ concentrations. This effect was more pronounced in plants grown at high K+ supply than in plants grown at low K+ supply. This result suggests that the absorption systems were strongly selective for K+, and that this selectivity was enhanced by salt.

In this study, a detailed phytochemical analysis of the medicinal herb Inula viscosa leaves was performed. Furthermore, in vitro antioxidant and antifungal properties of its methanolic extract were evaluated and compared with the corresponding phenolic profile obtained by high-performance liquid chromatography and mass spectrometry. Data obtained underscore the high amount of total lipids (6.14%) in leaves. Chromatographic analysis revealed its high content of unsaturated fatty acids (UFAs) with the essential ones α-linolenic and linoleic acids being the main compounds. It also showed good nutritional quality because of its high UFA/saturated fatty acid ratio and the lower values of atherogenic and thrombogenic indices. The volatile oil analyzed by gas chromatography-mass spectrometry showed the abundance of nonterpenic compounds, namely aliphatic alkanes. The total phenol content (TPC) and total flavonoid content (TFC) were higher in I. viscosa leaves (103 mg GAE/g dw and 99 mg CE/g dw for TPC and TFC, respectively). The use of HPLC-PDA-ESI-MS/MS allowed the identification of 17 components with hydroxycinnamic acids, namely mono-and dicaffeoylquinic acids being the most prominent components. The presence of these phenolic compound conferred strong free radical scavenging and antifungal properties to the methanol extract. Therefore, I. viscosa leaves could be considered as an excellent source of food functional ingredients with high nutritional value and health benefits.

The effect of iron deficiency on photosynthetic electron transport in Photosystem II (PS II) was studied in leaves and thylakoid membranes of lettuce (Lactuca sativa, Romaine variety) plants. PS II electron transport was characterized by oxygen evolution and chlorophyll fluorescence parameters. Iron deficiency in the culture medium was shown to affect water oxidation and the advancement of the S-states. A decrease of maximal quantum yield of PS II and an increase of fluorescence intensity at step J and I of OJIP kinetics were also observed. Thermoluminescence measurements revealed that charge recombination between the quinone acceptor of PS II, Q(B), and the S(2) state of the Mn-cluster was strongly perturbed. Also the dark decay of Chl fluorescence after a single turnover white flash was greatly retarded indicating a slower rate of Q(A)(-) reoxidation.

The effects of different sodium salts on some physiological parameters and antioxidant responses were investigated in a medicinal and aromatic plant, Ocimum basilicum L. (cultivar Fine). Plants were subjected to an equimolar concentration of Na2SO4 (25 mM) and NaCl (50 mM) for 15 and 30 days. Growth, oxidative stress parameters [electrolyte leakage, peroxidation, and hydrogen peroxide (H2O2) concentration], antioxidant enzyme\ud activities [ascorbate peroxidase (APX, EC 1.11.1.11), glutathione reductase (GR, EC 1.6.4.2), and peroxidases (POD, EC 1.11.1.7)], as well as antioxidant molecules [ascorbate and glutathione] were determined. The two salts affected leaf growth rates to the same extent, after 15 or 30 days of treatment, indicating a similar effect of Na2SO4\ud and NaCl salinity on growth, even if different (enzymatic and non-enzymatic) antioxidant mechanisms were involved in H2O2 detoxification. However, under both salts, the\ud efficiency of the antioxidant metabolism seemed to be sufficient to avoid the deleterious effects of reactive oxygen species (ROS). Indeed, both ion leakage and peroxidation\ud did not change under either Na2SO4 or NaCl salinity. As a whole, these data suggest that a cooperative process between the antioxidant systems is important for the tolerance of Ocimum basilicum L., cv. Fine to Na2SO4 and NaCl salinity