Sequenced application of ascorbate-proline-glutathione improves salt tolerance in maize seedlings

Area of Science:

• Plant Science
• Agricultural Science
• Biochemistry

Background:

• Salt stress is a major abiotic factor limiting crop productivity worldwide.
• Maize (Zea mays) is susceptible to salinity, impacting growth and yield.
• Antioxidants play a crucial role in mitigating oxidative stress induced by salt.

Purpose of the Study:

• To evaluate the efficacy of exogenously applied antioxidants, individually and sequentially, in enhancing salt tolerance in maize.
• To investigate the impact of these treatments on endogenous antioxidant systems and phytohormone levels.
• To identify optimal antioxidant application strategies for improving maize salinity tolerance.

Main Methods:

• Maize seedlings were subjected to 100mM NaCl stress.
• Antioxidants including ascorbic acid (AsA), glutathione (GSH), and proline were applied individually and in sequences (AsA-Pro-GSH, GSH-Pro-AsA).
• Measurements included growth parameters, relative water content, membrane stability index, enzymatic/non-enzymatic antioxidant activities, and phytohormone concentrations.

Main Results:

• Sequential application of AsA, GSH, and proline improved salt tolerance more effectively than individual applications.
• The AsA-Pro-GSH sequence demonstrated superior results compared to the GSH-Pro-AsA sequence.
• Improved seedling health correlated with enhanced antioxidant activity, osmoprotectant levels, and tissue integrity.

Conclusions:

• Sequenced application of AsA, Proline, and GSH is a promising strategy for enhancing maize salt tolerance.
• The AsA-Pro-GSH integrated soaking treatment is recommended for maize cultivation under salt stress conditions.
• This approach effectively boosts endogenous defense mechanisms against salinity.