Scanning and transmission electron microscopy and X-ray analysisof leaf salt glands of Limoniastrum guyonianum Boiss. under NaCl salinity.

Leaf salt glands of Limoniastrum guyonianum were examined by scanning and transmission electron microscopes and energy dispersive X-ray analysis (EDAX) system, after growing for three months on sandy soil with or without 300 mM NaCl. Results showed that salt glands were irregularly scattered on both leaf sides and sunk under the epidermal level. Salt excretion occurred in both conditions and is mainly composed of calcium and magnesium in control plants, and essentially sodium and chloride in plants subjected to salt treatment.

Exogenous salicylic acid protects phospholipids against cadmium stress in flax (Linum usitatissimum L.).

Salicylic acid (SA) promotes plant defense responses against toxic metal stresses. The present study addressed the hypothesis that 8-h SA pretreatment, would alter membrane lipids in a way that would protect against Cd toxicity. Flax seeds were pre-soaked for 8h in SA (0, 250 and 1000µM) and then subjected, at seedling stage, to cadmium (Cd) stress.

Positive effects of salicylic acid pretreatment on the composition of flax plastidial membrane lipids under cadmium stress.

Interest in use of flax (Linum usitatissimum L.) as cadmium (Cd)-accumulating plant for phytoextraction of contaminated soils opened up a new and promising avenue toward improving tolerance of its varieties and cultivars to Cd stress. The aim of this study is to get insights into the mechanisms of Cd detoxification in cell membranes, by exploring the effects of salicylic acid (SA)-induced priming on fatty acids and lipid composition of flax plantlets, grown for 10 days with 50 and 100 μM Cd.

Salicylic acid improves root antioxidant defense system and total antioxidant capacities of flax subjected to cadmium.

Cadmium (Cd) disrupts the normal growth and development of plants, depending on their tolerance to this toxic element. The present study was focused on the impacts of exogenous salicylic acid (SA) on the response and regulation of the antioxidant defense system and membrane lipids to 16-day-old flax plantlets under Cd stress. Exposure of flax to high Cd concentrations led to strong inhibition of root growth and enhanced lipid peroxides, membrane permeability, protein oxidation, and hydrogen peroxide (H2O2) production to varying degrees.

Cadmium tolerance and accumulation characteristics of mature flax, cv. Hermes: contribution of the basal stem compared to the root.

The potential of mature flax plants (cv. Hermes) to tolerate and accumulate cadmium (Cd) was studied to determine which part of the plant would be the key organ for phytoremediation purposes. After 4 month-growth on sand substrate containing 0.

Toward characterizing seed vigor in alfalfa through proteomic analysis of germination and priming.

Alfalfa, the most widely grown leguminous crop in the world, is generally exposed to severe salinity stress in Tunisia, notably affecting its germination performance. Toward a better understanding of alfalfa seed vigor, we have used proteomics to characterize protein changes occurring during germination and osmopriming, a pretreatment that accelerates germination and improves seedling uniformity particularly under stress conditions. The data revealed that germination was accompanied by dynamic changes of 79 proteins, which are mainly involved in protein metabolism, cell structure, metabolism, and defense.

Up-regulation of leucine aminopeptidase-A in cadmium-treated tomato roots.

The effects of cadmium (Cd) on aminopeptidase (AP) activities and Leucine-AP (LAP) expression were investigated in the roots of tomato (Solanum lycopersicum L., var Ibiza) plants. Three-week-old plants were grown for 10 days in the presence of 0.

Characteristics of cadmium tolerance in 'Hermes' flax seedlings: contribution of cell walls.

Most flax (Linum usitatissimum) varieties are described as tolerant to high concentrations of Cd. The aim of the present paper was to better characterize this tolerance, by studying the responses of flax plantlets, cv Hermes, to 18d growth on 0.5mM Cd.

Effects of long-term cadmium exposure on growth and metabolomic profile of tomato plants.

The response of tomato plants to long-term cadmium exposure was evaluated after a 90-days long culture in hydroponic conditions (0, 20, and 100 μM CdCl(2)). Cadmium preferentially accumulated in roots, and to a lower extent in upper parts of plants. Absolute quantification of 28 metabolites was obtained through (1)H NMR, HPLC-PDA, and colorimetric methods.

Osmoregulation and nutritional relationships between Orobanche foetida and faba bean.

The present study aims at comparing the phloem composition of the tolerant XBJ90.03-16-1-1-1 and the susceptible Bachaar genotypes and the impact of the faba bean genotype on the levels of the major solutes and invertase activities in the parasite . In comparison to Bachaar, the XBJ90.

Nitrogen and carbon relationships between the parasitic weed Orobanche foetida and susceptible and tolerant faba bean lines.

The parasitic weed Orobanche foetida (Poiret) is an emergent agronomical problem on faba bean in Tunisia. The Tunisian breeding programs for faba bean resistance to O. foetida have produced several tolerant lines including the line XBJ90.

Ultrastructure of Aeluropus littoralis leaf salt glands under NaCl stress.

The effects of salt uptake on the morphology and ultrastructure of leaf salt glands were investigated in Aeluropus littoralis plants grown for two months in the presence of 400 mM NaCl. The salt gland is composed of two linked cells, as observed in some other studied Poaceae species. The cap cell, which protrudes from the leaf surface, is smaller than the basal cell, which is embedded in the leaf mesophyll tissues and bears the former.

Modifications in endopeptidase and 20S proteasome expression and activities in cadmium treated tomato (Solanum lycopersicum L.) plants.

The effects of cadmium (Cd) on cellular proteolytic responses were investigated in the roots and leaves of tomato (Solanum lycopersicum L., var Ibiza) plants. Three-week-old plants were grown for 3 and 10 days in the presence of 0.

Salt impact on photosynthesis and leaf ultrastructure of Aeluropus littoralis.

The effects of salinity (400 mM NaCl) on growth, biomass partitioning, photosynthesis, and leaf ultrastructure were studied in hydroponically grown plants of Aeluropus littoralis (Willd) Parl. NaCl produced a significant inhibition of the main growth parameters and a reduction in leaf gas exchange (e.g.

[Physiological and structural modifications induced by cadmium-calcium interaction in tomato (Lycopersicon esculentum)].

Tomato seedlings (Lycopersicon esculentum), initially cultivated in a basic nutrient solution during 12 days, were treated with increasing CdCl(2) concentrations for 10 days. The results showed that cadmium inhibited the weight growth depending on the metal concentration and the plant organ. In the presence of 20 microM CdCl(2), the addition of calcium, 0.

Contribution of NaCl excretion to salt resistance of Aeluropus littoralis (Willd) Parl.

Aeluropus littoralis is a perennial halophyte, native to coastal zones. Although it is usually exposed to high saline, this plant grows normally without toxicity symptoms. In order to assess leaf salt excretion, different growth parameters, Na(+), K(+), Ca(2+), Mg(2+) and Cl(-) concentrations, as well as excreted ions were examined in plants grown for 2 months in the presence of various salinity levels (0-800 mM NaCl).

Assessment of enzyme induction and aerenchyma formation as mechanisms for flooding tolerance in Trifolium subterraneum 'Park'.

The objective of this study was to evaluate the role of enzyme induction and aerenchyma formation in prolonged tolerance to soil flooding in a variety of underground clover (Trifolium subterraneum 'Park') previously selected for resistance. Seedlings were grown in hydroponic tanks, initially with aeration for 3 weeks and subsequently in the absence of aeration for up to 3 weeks. After 1 h in the absence of aeration, the oxygen concentration in the hydroponic medium had decreased to 1.