Seaweeds are potentially excellent sources of highly bioactive materials that could represent useful leads in the alleviation of salinity stress. The effects of presoaking wheat grains in water extract of
Salinity is one of the major abiotic stresses which limit the yield of major crops [
Seed germination is an important and critical development phase in the life cycle of plants [
Seaweeds are macroscopic algae, growing in intertidal and subtidal regions of the sea, and serve as an excellent source of food, fodder, fertilizer, and industrial raw material [
Seaweeds provide an excellent source of bioactive compounds such as essential fatty acids, vitamins, amino acids, minerals, and growth promoting substances [
Although a lot of study on seaweeds has been reported on their taxonomy, distribution, photochemistry, and antibacterial activities, a little work has been done on the influence of their extract on the growth of wheat plant under salt stress conditions. Therefore this study was planned to determine the effect of
Grains of wheat (
Green alga
Collected marine macroalgal species
A homogenous lot of grains of wheat plant were selected for uniformity of size, shape, and viability. Before germinating, the grains were surface sterilized by soaking for 3 minutes in 2.5% sodium hypochlorite solution, after which they were washed several times with distilled water. The sterilized grains were presoaked in distilled water (control) and different concentrations of algal extract (1, 5, and 10%) for 12 hours. Thereafter the grains were allowed to drain for one hour. The grains were transferred to sterile petri dishes containing two sheets of Whitman number 1 filter paper moistened with 15 mL of different concentrations of NaCl solutions (0, 50, 100, 150, 200, and 250 mM). Each petri dish contained 20 grains and each treatment was replicated 3 times. The grains were allowed to germinate at 25°C in the darkness and 2 mL of NaCl solutions was added to each petri dish on the third day of the germination. At the end of the experimental period (7 days), the germination percentage, seedlings—fresh and dry matter, some metabolites, and some enzymes activities were recorded in addition to protein patterns.
The extraction of seedling proteins was carried out according to Polar [
Polyacrylamide gel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS) was used for determining the molecular weight of the extracted proteins [
Samples of plant tissues (0.5 g) were homogenized in ice cold 0.1 M phosphate buffer (pH = 7.5) containing 0.5 mM EDTA. Each homogenate was centrifuged at 4°C for 15 min at 15000 g. The supernatant was used for enzyme activity assay [
Glutathione was extracted by grinding 0.5 g of plant tissues in 1% picric acid (w/v) under cold condition. After centrifugation at 10,000 g for 10 min, the supernatant was collected immediately for assay [
The total ascorbic acid content was estimated using Folin phenol reagent [
Soluble sugars were extracted from algal material according to the method adopted by Upmeyer and Koller [
The experimental design was a random complete block, with three replications. The data were analyzed by the STATGRAPHICS (Statistical Graphics Corporation, Princeton, USA) statistical package by the
The data in Figure
Effect of NaCl on germination percentage of
The changes of growth criteria (fresh-dry matter) of
Effect of NaCl on fresh-dry matter of
The results in Figure
Effect of NaCl on enzyme activity of
The glutathione and ascorbic acid contents of
Effect of NaCl on glutathione and ascorbate of
SDS-PAGE protein profile of
Electrophoretic protein pattern of salinity stressed
M. Wt (KDa) |
|
Salinity levels | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0 mM | 50 mM | 100 mM | 150 mM | 200 mM | 250 mM | ||||||||
% |
Band |
% |
Band |
% |
Band |
% |
Band |
% |
Band |
% |
Band | ||
230.1 | 0.396 | 100 | 15.39a | ||||||||||
142.39 | 0.412 | 100 | 15.81 | ||||||||||
79.71 | 0.556 | 100 | 14.2 | ||||||||||
49.01 | 0.593 | 100 | 24.06a | ||||||||||
44.72 | 0.636 | 100 | 18.74 | ||||||||||
42.26 | 0.659 | 100 | 18.68 | ||||||||||
34.89 | 0.705 | 100 | 17.13a | ||||||||||
22.85 | 0.74 | 100 | 45.51 | ||||||||||
22.50 | 0.761 | 100 | 38.5 | ||||||||||
20.55 | 0.785 | 100 | 30.18a | ||||||||||
20.12 | 0.795 | 100 | 36.07 | ||||||||||
12.71 | 0.915 | 100 | 46.8 | ||||||||||
11.92 | 0.923 | 100 | 40.29 | ||||||||||
11.35 | 0.939 | 100 | 50.12 | ||||||||||
11.33 | 0.945 | 100 | 42.75 | ||||||||||
11.21 | 0.958 | 100 | 45.76 | ||||||||||
10.63 | 0.988 | 100 | 100 |
Electrophoretic protein pattern of salinity stressed
M. Wt (KDa) |
|
Salinity levels | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0 mM | 50 mM | 100 mM | 150 mM | 200 mM | 250 mM | ||||||||
% Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | ||
215.04 | 0.364 | 0 | 14.2b | ||||||||||
132.44 | 0.431 | 0 | 9.13b | ||||||||||
125.82 | 0.451 | 0 | 16.6b | ||||||||||
98.09 | 0.494 | 0 | 18.2b | ||||||||||
79.72 | 0.556 | 122.39 | 18.91 | ||||||||||
52.73 | 0.585 | 0 | 25.1b | ||||||||||
44.72 | 0.636 | 85.95 | 14.32 | ||||||||||
42.26 | 0.659 | 166.68 | 23.72 | ||||||||||
22.85 | 0.74 | 80.69 | 39.95 | ||||||||||
22.65 | 0.755 | 0 | 23.8b | ||||||||||
22.50 | 0.761 | 143.32 | 49.04 | ||||||||||
20.12 | 0.795 | 74.76 | 35.7 | ||||||||||
12.71 | 0.915 | 103.77 | 64.3 | ||||||||||
11.92 | 0.923 | 93.86 | 41.14 | ||||||||||
11.35 | 0.939 | 90.99 | 34.72 | ||||||||||
11.33 | 0.945 | 96.47 | 36.65 | ||||||||||
11.21 | 0.958 | 130.75 | 34.55 | ||||||||||
10.63 | 0.988 | 160.11 | 100 |
Electrophoretic protein pattern of salinity stressed
M. Wt (KDa) |
|
Salinity levels | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0 mM | 50 mM | 100 mM | 150 mM | 200 mM | 250 mM | ||||||||
% Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | ||
125.82 | 0.451 | 0 | 13.9b | ||||||||||
117.84 | 0.465 | 0 | 10.2b | ||||||||||
65.76 | 0.578 | 0 | 9.0 b | ||||||||||
52.73 | 0.585 | 0 | 24.1b | ||||||||||
44.72 | 0.636 | 117.9 | 25.95 | ||||||||||
35.83 | 0.695 | 0 | 29.2b | ||||||||||
22.85 | 0.74 | 63.69 | 43.87 | ||||||||||
22.65 | 0.755 | 0 | 26.2b | ||||||||||
22.50 | 0.761 | 72.47 | 32.76 | ||||||||||
20.12 | 0.795 | 190.95 | 38.5 | ||||||||||
12.71 | 0.915 | 161.76 | 42.32 | ||||||||||
11.92 | 0.923 | 92.05 | 56.13 | ||||||||||
11.35 | 0.939 | 91.83 | 70.84 | ||||||||||
11.33 | 0.945 | 82.25 | 41.29 | ||||||||||
11.21 | 0.958 | 119.82 | 35.64 | ||||||||||
10.63 | 0.988 | 154.3 | 100 |
Electrophoretic protein pattern of salinity stressed
M. Wt |
|
Salinity levels | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
0 mM | 50 mM | 100 mM | 150 mM | 200 mM | 250 mM | ||||||||
% Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | % Content | Band % | ||
215.04 | 0.364 | 0 | 13.4b | ||||||||||
142.40 | 0.412 | 65.25 | 7.47 | ||||||||||
125.82 | 0.451 | 0 | 17b | ||||||||||
117.84 | 0.465 | 0 | 20.9b | ||||||||||
104.36 | 0.475 | 0 | 14.8b | ||||||||||
94.99 | 0.521 | 0 | 14.3b | ||||||||||
52.73 | 0.585 | 0 | 23.9b | ||||||||||
46.88 | 0.613 | 0 | 25.2b | ||||||||||
42.26 | 0.659 | 193.54 | 26.17 | ||||||||||
22.85 | 0.74 | 87.46 | 46.14 | ||||||||||
22.65 | 0.755 | 0 | 28.1b | ||||||||||
20.12 | 0.795 | 75.51 | 22.93 | ||||||||||
17.82 | 0.842 | 0 | 28.5b | ||||||||||
12.71 | 0.915 | 142.63 | 56.19 | ||||||||||
11.92 | 0.923 | 115.33 | 53.86 | ||||||||||
11.35 | 0.939 | 105.23 | 38.17 | ||||||||||
11.33 | 0.945 | 74.25 | 32.06 | ||||||||||
11.21 | 0.958 | 121.14 | 31 | ||||||||||
10.63 | 0.988 | 287.11 | 100 |
SDS-PAGE protein profile of salinity stressed
The electrophoretic protein pattern of salinity stressed seedling (Table
The protein profile of seedling presoaked in 1% algal extract and then treated with different levels of salinity is represented in Table
The protein profile of seedling presoaked in 5% algal extract and then treated with different concentrations of NaCl is shown in Table
The electrophoretic protein pattern of seedlings presoaked in 10% algal extract and treated with different levels of NaCl is represented in Table
The major biochemical components of
Some biochemical analyses of marine alga
Protein (mg/g) | 2.5 ± 0.032 | Glutathione (mg/g) | 0.071 ± 0.001 |
Carbohydrate (mg/g) | Ascorbic acid (mg/g) | 0.146 ± 0.006 | |
Soluble | 0.58 ± 0.005 | Betaine (mg/g) | 0.146 ± 0.003 |
Insoluble | 0.23 ± 0.005 | Choline (mg/g) | 0.194 ± 0.003 |
Phenolic compound (mg/g) | Amino acids (mg/g) | ||
Glychone | 0.35 ± 0.008 | Free amino acids | 1.39 ± 0.003 |
Aglychone | 0.23 ± 0.007 | Proline | 0.78 ± 0.005 |
Values are expressed as mean ± standard error of three replicates.
Salinity stress is thought to result in production of reactive oxygen species (ROS) in plants causing oxidative stress [
The data has clearly demonstrated that NaCl significantly inhibited the germination percentage at all salinity levels. The adverse effect of NaCl has been attributed to changes in osmotic potential resulting from reduced water [
A correlation between antioxidants capacity and NaCl tolerance has been demonstrated in several plant species. The present investigation was therefore undertaken to study the effect of NaCl on ascorbate and glutathione contents. The results showed that presoaking of grains in algal extract significantly increased the seedlings glutathione and ascorbic acid under saline conditions when compared with water presoaked grains. These results are in accordance with the results obtained by Akladious and Abbas [
Antioxidative enzymes are the first response mechanism against salinity stress. As such, their activity profiles are important in the evaluation of tolerance mechanisms. The results showed significantly decrease in the activities of APX, SOD, and CAT in salinity stressed seedlings. Presoaking of grains in different concentrations of
Under stress conditions, total protein synthesis usually decreases in plant cells [
One possible explanation for bands which have disappeared in protein pattern of salinity stressed seedlings and newly formed in protein pattern of algal presoaked seedlings is that the gene(s) responsible for certain proteins had not been completely suppressed, but inhibited as the result of stress [
To our knowledge, this is the first study for the application of
The authors declare that there is no conflict of interests regarding the publication of this paper.