Effects of Plant Regulators on the Seed Germination and Antioxidant Enzyme Activity of Cotton under Compound Salt Stress

by Selleckchem | Feb 14 2024

Salinity stress significantly hampers cotton seed germination and seedling growth. Employing plant growth regulators stands out as an effective strategy to mitigate salt stress. In this study, we assessed the impact of varying concentrations of natural composite salt conditions (0%, 0.6%, and 1.2%) on cotton seed germination, seedling growth, and physiology. Additionally, we explored the effects of compound sodium nitrophenolate (CSN: 2 mg·L-1 and 10 mg·L-1), 24-epibrassinolide (EBR: 0.02 mg·L-1 and 0.1 mg·L-1), and gibberellic acid (GA: 60 mg·L-1 and 300 mg·L-1), against a control (CK: distilled water) group. The results indicate that with an increase in the composite salt concentration, the germination potential (GP) and germination rate (GR) of cotton seeds gradually decrease. Simultaneously, the fresh weight and root vitality of seedlings also correspondingly decrease, while the degree of membrane lipid peroxidation increases. Under high-salt (1.2%) conditions, soaking treatments with CSN and EBR significantly enhance both GP (45-59% and 55-64%) and GR (30-33% and 39-36%) compared to the CK. However, the GA treatment does not increase the GP and GR of cotton. Moreover, under high-salt (1.2%) conditions, CSN and EBR treatments result in the increased activities of superoxide dismutase (56-66% and 71-80%), peroxidase (20-24% and 37-51%), and catalase (26-32% and 35-46%). Consequently, cotton exhibits a relatively good tolerance to natural composite salts. Soaking treatments with CSN and EBR effectively improve cotton germination by enhancing antioxidant enzyme activities, thereby strengthening cotton's tolerance to salt stress. These findings offer new insights for enhancing the salt tolerance of cotton.

Comments:

The study you described highlights the detrimental effects of salinity stress on cotton seed germination and seedling growth, and it explores the potential of certain plant growth regulators (PGRs) in mitigating these effects.

The main findings indicate that as the salt concentration increases, the germination potential and rate of cotton seeds decrease, leading to reduced seedling growth. Additionally, high salt levels increase membrane lipid peroxidation, a marker of cellular damage due to stress.

However, the use of compound sodium nitrophenolate (CSN) and 24-epibrassinolide (EBR) in soaking treatments showed promising results. Under high-salt conditions, these treatments significantly improved both germination potential and rate compared to the control group. Interestingly, soaking with gibberellic acid (GA) did not show the same positive impact on cotton germination under high-salt conditions.

Moreover, the study found that CSN and EBR treatments increased the activities of antioxidant enzymes like superoxide dismutase, peroxidase, and catalase. These enzymes play a crucial role in scavenging reactive oxygen species and reducing oxidative stress caused by high salt levels. Consequently, the enhanced activities of these enzymes contributed to improved salt tolerance in cotton.

Overall, the research suggests that soaking treatments with CSN and EBR could be effective strategies for enhancing cotton's salt tolerance by boosting antioxidant enzyme activities, thereby improving germination and seedling growth under high-salt conditions. These findings could have practical implications for agricultural practices aimed at improving crop resilience to salinity stress.