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The effect of calcium on the antioxidant systems in the halophyte Cakile maritima under salt stress

100%

Amor N. B., Megdiche W., Jimenez A., Sevilla F., Abdelly C.

Acta Physiologiae Plantarum

2010

tom 32

nr 3

The purpose of the current investigation was to study the effect of Ca²⁺ (0, 3.5 and 20 mM concentrations) on the antioxidant systems in the halophyte Cakile maritima under NaCl stress (0, 100, 200 and 400 mM NaCl). Plants treated with both moderate calcium (3.5 mM) and salt levels (100 mM) showed the maximum growth, and the addition of 20 mM calcium to the nutrient media did not significantly reduce the growth under the moderate salt treatment. The absence of calcium associated with high salt concentration induced a strong reduction of biomass production. The tolerance of C. maritima at moderate salinity and calcium was related with the lowest values of the parameters indicative of oxidative stress (malondialdehyde, electrolyte leakage and hydrogen peroxide concentration). This was accompanied with a higher peroxidase, superoxide dismutase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase activities. In contrast, in the absence of calcium, those enzymes showed the lowest activities under all salt treatments. As a whole, it can be noticed that salt tolerance was improved by moderate calcium concentration; however, the absence of calcium has a drastic effect on C. maritima.

Salt tolerance of the annual halophyte Cakile maritima as affected by the provenance and the development stage

86%

Megdiche W., Amor N. B., Debez A., Hessini K., Ksouri R., Zuily-Fodil Y., Abdelly C.

Acta Physiologiae Plantarum

2007

tom 29

nr 4

Though halophytes are naturally adapted to salinity, their salt-tolerance limits are greatly influenced by their provenance and developmental stage. In the present study, physio-biochemical responses of two Tunisian ecotypes of the oilseed coastal halophyte Cakile maritima (Brassicaceae) to salinity (0–400 mM NaCl) were monitored during germination and vegetative growth stages. Tabarka and Jerba seeds were collected from humid or arid climatic areas, respectively. Plant response to salinity appeared to depend on the ecotype and salinity levels. Increasing salinity inhibited germination process. Jerba seeds were found to be more salt tolerant than the Tabarka ones. At the autotrophic stage of growth and under salt-free conditions, Jerba was less productive than Tabarka (in terms of dry matter accumulation), but plant biomass production and leaf expansion (area and number) of the former ecotype were progressively improved by 100 mM NaCl, as compared to the control. In contrast, at the same salt concentration, these parameters decreased under increasing salinity in Tabarka (salt sensitive). Leaf chlorophyll content was reduced at severe salinity, but this effect was more conspicuous in the sensitive Tabarka plants. Na⁺ contents in the Jerba and Tabarka leaves collected from the 400 mM NaCl-treated plants were 17- and 12-fold higher than in the respective controls. This effect was accompanied by a significant reduction in the leaf K⁺, Mg²⁺ and Ca²⁺ contents, especially in the salt-treated Tabarka. A significant accumulation of proline and soluble carbohydrates in leaves was found during the period of intensive leaf growth. These organic compounds likely play a role in leaf osmotic adjustment and in protection of membrane stability at severe salinity.

Ograniczanie wyników

2 Acta Physiologiae Plantarum

2 Abdelly C.

2 Amor N. B.

2 Megdiche W.

1 Debez A.

1 Hessini K.

1 Jimenez A.

1 Ksouri R.

1 Sevilla F.

1 Zuily-Fodil Y.

1 2010

1 2007

Wyniki wyszukiwania

The effect of calcium on the antioxidant systems in the halophyte Cakile maritima under salt stress

Salt tolerance of the annual halophyte Cakile maritima as affected by the provenance and the development stage