Methionine-Induced Regulation of Secondary Metabolites and Antioxidants in Maize (Zea mays L.) Subjected to Salinity Stress

In nature, plants are frequently exposed to various stresses simultaneously. The effects of salinity stress on plant metabolism are well known, but little has been researched on how amino acid application alleviates abiotic stress. In the present experiment, four maize (Zea mays L.) genotypes (FH-1275, FH-936, FH-1231, and FH-1227) were studied using three methionine levels (0, 5, and 10 mg L-1) under 80 mM NaCl salt stress and 20 mM control levels. Sandy canal soil was used in plastic pots for experimentation. The pots were set in a completely randomized design (CRD) factorial experiment. Results showed that methionine at 5 and 10 mg L-1 levels significantly ameliorated the influence of salinity in all genotypes by improving photosynthetic efficiency, antioxidant activities, and osmolyte and secondary metabolite production. Performance of the salt-tolerant genotypes (FH-1275 and FH-936) was much better than that of salt-sensitive genotypes (FH-1231 and FH-1227), irrespective of salinity treatments. This study confirms the notion that FH-1275 and FH-936 genotypes of maize and methionine at a concentration of 10 mg L-1 could be recommended to farmers to improve maize productivity in salinity-affected areas. The heat map showed high levels of superoxide dismutase and nitrate reductase activities, while low and medium activities were observed for catalase and peroxidase in all treatments. However, the ecological consequences of methionine dose for organisms from distinct trophic levels remains to be investigated.

Automated summary

This study investigated the effects of amino acid application on maize under salt stress. The results showed that proper methionine levels can alleviate the negative effects of salinity, improving photosynthetic efficiency and antioxidant activities in plants.