Deciphering the synergistic effect of Jasmonic acid and Spermine in mitigating root-knot nematode stress in tomato plants through enhancing growth and activity of antioxidant enzymes

Abstract

Root-Knot nematodes (RKNs) are one of the major plant pathogens that can substantially reduce plant growth and development. Management of RKNs is one of the major concerns as chemical pesticides pose a potential risk to humans and other life forms and also have toxic effects to environment. There is a need to find out some alternative eco-friendly strategies for management of these parasites. Jasmonic acid (JA) and Spermine (Spm) are those plant growth regulators (PGRs) that have positive effects on plant growth and alleviates toxic effects caused by various stresses including RKNs. Keeping this in mind,present study accessed the potential of these (PGRs), JA and Spm on morphological and biochemical attributes in 45 days old Solanum lycopersicum plants under nematode stress. It was observed that nematode infection resulted in reduced plant growth and photosynthetic pigments. Application of JA and Spm improved growth parameters and photosynthetic pigments. Moreover, tomato plants after JA and Spm supplementation lowered the activities of H2O2, DPPH and MDA thus decreasing nuclear and membrane damage caused by nematode stress. Additionally, enzymatic CAT (Catalase), SOD (Superoxide dismutase), GuPOX (Guaiacol peroxidase), APOX (Ascorbate peroxidase), PPO (Polyphenol oxidase), GST (Glutathione-S-transferase) and non-enzymatic (ascorbic acid, glutathione, and tocopherol) antioxidant levels increased markedly under nematode stress, but application of JA and Spm further improved these attributes. Taken together, the current study demonstrated that JA and Spm are suitable agents for managing nematode stress resistance in tomato plants.