scholarly journals Effect Of Priming Of Seeds Of Medicago Sativa ‘Bami’ With Gibberellic Acid On Germination, Seedlings Growth And Antioxidant Enzymes Activity Under Salinity Stress

2014 ◽  
Vol 22 (2) ◽  
pp. 167-174 ◽  
Author(s):  
Omid Younesi ◽  
Ali Moradi

AbstractThe experiment was conducted in order to study effects of seeds priming with gibberellic acid (GA3) at 0, 3, 5 and 8 mM on germination, growth and antioxidant enzymes activity in alfalfa seedlings under salinity stress (200 mM NaCl). All control seeds germinated. The rate of germinated seeds was reduced to 48% in the presence of NaCl, and increased to 76% after seeds priming with 5 mM GA3. Priming with 5 mM GA3 was also correlated with an increase of dry weight of seedlings derived from both stressed and non-stressed seeds as well as with the reduction of electrolyte leakage (EL) and malondialdehyde (MDA) level in salt stressed seedlings. The activity of superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase in primed and non-primed seeds increased in the presence of NaCl and after priming of seeds with 5 mM GA3, whereas only small effect on glutathione reductase activity in both primed and non-primed seeds was observed. The total ascorbate level was higher in both stressed and non-stressed seedlings from primed seeds. These results suggest that GA3 priming might increase the salt tolerance of alfalfa seedlings through enhancing the activities of antioxidant enzymes and reducing the membrane damage as estimated using biomarkers, EL index and MDA content.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fereshteh Yousefi ◽  
Zohreh Jabbarzadeh ◽  
Jafar Amiri ◽  
Mir Hassan Rasouli-Sadaghiani

Abstract The effect of foliar application of polyamines on roses (Rosa hybrida cv. ‘Herbert Stevens’) was investigated in a factorial experiment based on a completely randomized design with three replications in a greenhouse. Two factors were applied including polyamine type (putrescine, spermidine, and spermine) and polyamine concentration (0, 1, 2 and 4 mM). The recorded traits included root fresh and dry weight, root length, number of flowers, flower longevity, chlorophyll content, carotenoids, antioxidant enzymes activity (catalase, ascorbate peroxidase and guaiacol peroxidase) and some macronutrients such as nitrogen, phosphorus and potassium. The results showed that among polyamines, putrescine had the greatest effect on root dry weight; spermidine showed the greatest effect on root length, chlorophyll content, plant phosphorus and spermine affected root fresh weight and flower longevity most strongly. Polyamine concentration of 1 mM had the strongest effect on flower longevity, carotenoids, nitrogen and phosphorus content. The highest potassium rate was observed in treatments with the concentration of 4 mM. Polyamine treatments had no significant effect on the number of flowers per plant and antioxidant enzymes.


2015 ◽  
Vol 48 (3) ◽  
pp. 53-61 ◽  
Author(s):  
A. Dolatabadi ◽  
B. Sani ◽  
P. Moaveni

Abstract In order to investigate the effect of exogenous application of nano-TiO2 on annual medic, a field study was conducted in a factorial design based on randomized complete blocks with four replications. The experimental treatments included six concentrations of nano-TiO2 (Control, 0.01%, 0.02%, 0.03%, 0.04%, 0.06% g/l) and spraying at two growing stages (pod stage and 10% flowering stage). Results showed that the effects of nano-TiO2 and spraying times on dry forage yield were significant (p<0.01). Nano-TiO2 spray appear to influence the malone dialdehyde (MDA) content (p<0.01). With increasing concentrations of nano-TiO2 the values of aforementioned measured variable significantly decreased. The activities of antioxidant enzymes, including catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) were affected by nanoparticle (p<0.01) and spraying times (p<0.01), as well as their interactive effect of two mentioned factors were significant in terms of guaiacol peroxidase (GPX) (p<0.01) activity and dry forage yield. Among different concentrations of nano-TiO2, 0.04% and 0.06% have the best effect on all traits. Totally, treatment with nano-TiO2 were more effective in the pod stage, compared to 10% flowering stage.


2011 ◽  
Vol 50 (No. 1) ◽  
pp. 27-32 ◽  
Author(s):  
T. Takáč

The changes in some physiological parameters of maize seedlings in response to chilling were studied. The emphasis was laid upon their relationship to chilling induced alterations in antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) activity. The exposure of maize seedlings to chilling caused substantial defects in the 4-day-old seedlings and the seedlings with two fully developed leaves, respectively. The membrane semipermeability perturbations and the loss of viability in the young seedlings were observed. Similarly, we found a decrease of chlorophyll content, appearance of necrotic lesions and inhibition of growth in older plants. The measurements of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase activities provide an evidence of reactive oxygen species formation, that is assumed to be a reason of the found damages. Significant differences between two cultivars were found in the studied parameters. The electrolyte leakage and viability test provided effective methods for the characterization of the chilling tolerance-level in maize cultivars.


Author(s):  
Apurba Pal ◽  
Debjani Dutta ◽  
Anjan Kumar Pal ◽  
Sunil Kumar Gunri

Aims: To better understand the physiological and biochemical mechanisms in the light of antioxidative enzymes activity under salinity stress between tolerant and susceptible genotypes of groundnut. Study Design: Completely Randomized Design. Place and Duration of Study: The laboratory experiment was carried out in the departmental laboratory of Plant Physiology, Bidhan Chandra Krishi Viswavidyalaya (BCKV), Mohanpur, Nadia, and West Bengal during the year 2017-18. Methodology: A controlled study was conducted to screen 26 genotypes of groundnut under 200 mM NaCl salinity stress. Fourteen-day old seedlings were subjected to salinity treatment. For this, the modified Hoagland nutrient solution containing 200 mM NaCl (osmotic potential: -0.8 MPa) was applied in each case and the pH was adjusted to 6.3. The treatments were repeated on every third day. Control set without salinity stress was also maintained similarly in each case for comparison of results. Results: The salt tolerance index or STI of the genotypes ranged from 47.57% to 96.40%. Out of all the genotypes KDG-197 (STI= 96.40%) was found to be the most tolerant under a salinity stress of 200 mM NaCl and it was closely followed by R 2001-2 (STI=87.92%), VG 315 (STI=84.05%), TCGS 1157 (STI=77.59%) and TG 51 (STI=73.67%). While the genotypes Girnar 3 (STI= 47.57%), OG 52-1 (STI=49.09%), TVG 0856 (STI= 49.28%) and J 86 (STI= 50.66%) were the most susceptible genotypes based on their relative performance under stress in respect of total dry weight. It has been noted further that, out of the nine genotypes, enhancement of antioxidative enzyme like super oxide dismutase (SOD), guaiacol peroxidase (GPOX) and catalase (CAT) activity was recorded maximally in tolerant genotype KDG 197 (64.18%, 71.74% and 52.82% increase over control respectively) and R 2001-2 (53.68 %, 93.48% and 53.96 % increase over control respectively) but the activity of these enzyme in the four susceptible genotypes declined considerably under salinity treatment. Conclusion: Tolerant genotypes of groundnut in general registered much higher activities of antioxidative enzymes in their leaves as compared to the susceptible genotype under high salinity stress.


2021 ◽  
Author(s):  
Maryam Nekoee Mehmandar ◽  
Farzad Rasouli ◽  
Mousa Torabi Giglou ◽  
Seyed Morteza Zahedi ◽  
Mohammad Ali Aazami

Abstract Water deficit in first growth stages of melon (Cucumis melo L.) in formation of first true leaves after germination can be a factor limiting production. The first step for resolve the problem is genotypes evaluation and identification of drought tolerant melons. An effective method to achieve the goal is use of osmotic solution in tissue culture. Responses of Iranian melon landraces to drought was evaluated using sorbitol at 0.1, 0.2 and 0.4 M or polyethyleneglycol (PEG 6000) at 0.009, 0.012 and 0.015 M concentrations, and MS medium without treatment as the control. Coleoptile length, fresh and dry weight of shoots and roots, photosynthetic pigments, protein, proline, malondialdehyde (MDA) and antioxidant enzymes superoxide dismutase, guaiacol peroxidase and ascorbate peroxidase were measured. The PEG or sorbitol decreased coleoptile length, fresh weight and photosynthetic pigments, and led to enhancement of proline and MDA. Contents of protein and antioxidant enzymes was completely dependent on genotype and type and concentration of osmotic material. The in vitro culture for screening and identification of tolerant and sensitive drought genotypes could be rapid, useful and effective, with sorbitol mimicing drought better than PEG. After in vitro evaluation, the genotype responses to induced water deficit need to be confirmed under field conditions.


Author(s):  
Apurba Pal ◽  
Anjan Kumar Pal

Salinity can affect different physiological activity of plant in various ways. A controlled study was conducted to screen 26 genotypes of groundnut under 200mM NaCl salinity stress. The salt tolerance index or STI of the genotypes ranged from 47.57% to 96.40%. Out of all the genotypes KDG-197 (STI= 96.40%) was found to be the most tolerant under a salinity stress of 200 mM NaCl and it was closely followed by R 2001-2 (STI=87.92%), VG 315 (STI=84.05%), TCGS 1157 (STI=77.59%) and TG 51 (STI=73.67%). While the genotypes Girnar 3 (STI= 47.57%), OG 52-1 (STI=49.09%), TVG 0856 (STI= 49.28%) and J 86 (STI= 50.66%) were the most susceptible genotypes based on their relative performance under stress in respect of total dry weight. It has been noted further that out of the nine genotypes, KDG 197 registered the minimum reduction (4.51% over control, 2.70% over control) in total chlorophyll and sugar accumulation respectively under NaCl stress whereas, Girnar 3 recorded the highest reduction in both parameters (60.00%, 70.32% over control) respectively, under saline condition. The genotype KDG 197 and R 2001-2 accounted for the highest increase in soluble protein and proline content in their leaves (144.02%, 780.16% over control) respectively than Girnar 3. KDG 197 recorded the minimum (3.39%) increase in lipid peroxidation under stress followed by R 2001-2 with an increase of 13.04% over control plants. In contrast, Girnar 3 registered the highest increase of TBARS content and electrolyte leakage (44.44%, 31.47% over control respectively) indicating maximum membrane damage but R 2001-2 recorded the minimum (3.00%) increase in electrolyte leakage percentage than Girnar 3 (31.47% over control) followed by OG 52-1 (26.14% over control) under stress. So, better osmotic adjustment through accumulation of proline, less membrane damage the leaves helped the tolerant genotypes to sustain under salinity stress in a better way than the susceptible genotypes.


2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Mervat Sh. Sadak ◽  
Iman M. Talaat

Abstract Background Chitosan and Ca+ are natural signal molecules that can be used in agriculture as biostimulants and elicitors. They enhance different physiological responses and mitigate the negative effects of salinity. So, this investigation was done to study the effect of soaking wheat grains in chitosan and CaCO3 (20 and 40 mg/L) on alleviating the adverse effect of salinity stress (0.0 and 5000 mg/L) on growth, some biochemical and physiological and yields of wheat plant. Results Shoot length (cm), leaves no/tiller, shoot dry weight (g), root fresh weight (g) and root dry weight (g) were significantly decreased as a result of salt stress. Soaking wheat grains in Chitosan or CaCO3 significantly promoted plant growth under normal and stressed conditions. Irrigation of wheat plants with saline water significantly decreased photosynthetic pigments (Chlo-a, Chlo-b, carotenoids and total pigments) in addition to Chlo-a/Chlo-b ratio, indole acetic acid content in the plant leaves. Meanwhile, saline water significantly increased phenolics, total soluble sugars (TSS) and proline content. H2O2 and lipid peroxidation expressed by malondialdehyde (MDA) content clearly showed significant increases under salinity stress compared with untreated control. Soaking wheat grains in chitosan or CaCO3 before sawing significantly increased the accumulation of H2O2 and MDA in the leaves of wheat plants. Treatment of wheat grains with chitosan or CaCO3 significantly promoted the activity of various antioxidant enzymes (SOD and POX) as compared to the control. CAT activity was significantly decreased as a result of chitosan or CaCO3 treatments. The highest CAT activity was recorded in plants irrigated with 5000 mg/L saline water followed by control plants which recoded 36.40 and 24.82 U/min/g FW, respectively. On the other hand, irrigation of wheat plants with 5000 mg/L saline water significantly decreased spike length (cm), spikelets no/spike, grains wt/plant (g), 1000-grains wt (g), yield and biomass/plant (g) as well as, carbohydrate % and protein % compared with the control. However, treating wheat plants either with Chitosan or calcium carbonate resulted in obvious significant increases in carbohydrates and protein contents, especially in plants treated with 40 mg/L chitosan followed by 40 mg/L calcium carbonate. Soaking wheat grains in chitosan, especially at 40 mg/L, exhibited the strongest scavenging potential (2,2-diphenyl-1-picryl-hydrazyl-hydrate assay (DPPH%) followed by treatment with 40 mg/L CaCO3. Conclusion In conclusion, the used treatment enhanced the protective parameters such as antioxidant enzymes, total phenols and free radical scavengers and consequently helped the plants to decrease lipid peroxidation, increased their tolerance and improved yield and spike quality. Application of 40 mg/L chitosan recorded the highest increment in the scavenging ability of the natural antioxidants of the plant extract toward the stable free radical DPPH.


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