Nitric oxide treatment alleviates drought stress in wheat seedlings

To investigate the mechanism by which laser irradiation enhances the chilling tolerance of wheat seedlings, seeds were exposed to different treatments, and biochemical parameters were measured. Compared with the control group, chilling stress (CS) led to an increase in the concentrations of malondialdehyde (MDA) and H2O2, and decreases in the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), catalase (CAT), peroxidase (POD), and nitric oxide synthase (NOS), and the concentrations of nitric oxide (NO) and protein. Treatment with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO), sodium tungstate (ST), and NG-nitro-L-arginine methyl ester (L-NAME) followed by CS resulted in further increases in the concentrations of MDA and H2O2 and further decreases in the other parameters. However, treatment with PTIO, ST, and L-NAME followed by laser irradiation had the opposite effects on these parameters. When the seeds were treated with PTIO, ST, and L-NAME followed by laser and CS, the concentrations of MDA and H2O2 were significantly lower and the other parameters were higher than in the PTIO, ST, and L-NAME plus CS groups. These results suggest that CO2 laser irradiation enhances the chilling tolerance of wheat seedlings by stimulating endogenous NO synthesis.

Download Full-text

Enhancement of drought tolerance in Triticum aestivum L. seedlings using Azospirillum brasilense NO40 and Stenotrophomonas maltophilia B11

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00546-6 ◽

2021 ◽

Vol 45 (1) ◽

Author(s):

Wedad A. Kasim ◽

Mohamed E. H. Osman ◽

Mohamed N. Omar ◽

Samar Salama

Keyword(s):

Triticum Aestivum ◽

Drought Stress ◽

Drought Tolerance ◽

Azospirillum Brasilense ◽

Stenotrophomonas Maltophilia ◽

Protein Pattern ◽

Triticum Aestivum L ◽

Protein Patterns ◽

Wheat Seedlings ◽

Enhanced Production

Abstract Background The effectiveness of two PGPB; Azospirillum brasilense NO40 and Stenotrophomonas maltophilia B11 was investigated in enhancing the drought tolerance of wheat (Triticum aestivum L.) seedlings cultivar Gemiza9. The inoculated or uninoculated grains were sown in unsterilized sandy soil and watered normally untill the 8th day. Drought stress was initiated by completely withholding water for 7 days (until wilting). Samples were collected after 15 days from sowing to evaluate some growth criteria, damage and defense indicators and to analyze the roots’ protein pattern. Results The results showed that inoculating wheat seedlings with these strains significantly diminished the inhibitory effects of drought stress on the relative water content of roots, shoots and leaves; area of leaves; contents of pigments (chlorophyll a and b) and ascorbic acid; and on the protein patterns of roots. Moreover, the bacterial inoculation notably reduced the drought-induced damage indicated by lower leakage of electrolytes and less accumulation of Malondialdehyde and hydrogen peroxide, surprisingly with less enhanced production of proline and activities of catalase and peroxidase than their uninoculated counterparts. Under normal conditions, inoculating wheat plants with these PGPB resulted in significantly promoted growth and elevated contents of pigments and altered protein patterns of roots. Conclusion Overall, we can say that both Azospirillum brasilense NO40 and Stenotrophomonas maltophilia B11 were able to deactivate the growth inhibition in wheat seedlings to some extent, while maintaining a certain level of efficient protection against damage under drought stress.

Download Full-text

Effects of Nitric Oxide Application on Antioxidant Enzyme Activities of Pepper Plants under Drought Stress

ISPEC Journal of Agricultural Sciences ◽

10.46291/ispecjasvol5iss4pp846-853 ◽

2021 ◽

Vol 5 (4) ◽

pp. 846-853

Author(s):

Fikret YAŞAR ◽

Özlem ÜZAL

Keyword(s):

Nitric Oxide ◽

Drought Stress ◽

Plant Growth ◽

Nutrient Solution ◽

Enzyme Activities ◽

Growth Parameters ◽

Antioxidative Enzyme ◽

High Dose ◽

Antioxidant Enzyme Activities ◽

Hoagland Nutrient Solution

The purpose of the study was to determine the relationship between the messenger molecule Nitric oxide (NO) and antioxidative enzyme (SOD: Superoxide Dismutase; CAT: Catalase; APX: Ascorbate Peroxidase) activities in some metabolic changes that occur under the effect of drought stress in plants, to determine the possible roles of Nitric Oxide and to obtain complementary information. The experiment conducted in a controlled environment, and plant were cultured in containers containing Hoagland nutrient solution. For drought stress application, 10% Polyethylene Glycol (PEG 6000) was added to the nutrient solution, which is equivalent to -0.40 MPa osmotic potential. Before the drought stress is applied, pepper seedlings of Demre cv were pre-treated with different doses of Sodium Nitroprusside (SNP) and Carboxy-PTIO (potassium salt) (cPTIO) (SNP 0.01, SNP 1, SNP 100 and SNP 0.01 + cPTIO, SNP + cPTIO, SNP 100+ cPTIO). On the 10th day of the drought application, the growth parameters of the plants; the plant fresh weights and their Antioxidative Enzyme Activities (SOD, CAT, APX) were determined. In terms of plant growth parameters, both plant growth and antioxidant anzyme activities of plants pretreated with 0.01 and 1 doses of SNP were lower than the high dose of SNP and the PEG application without pretreatment. The reason for the low enzyme activities in these applications can be attributed to factors such as the excess accumulation of organic acids such as proline in the cells of the plants and the decrease in H2O2 and O-2 levels in the presence of SNP.

Download Full-text