Amelioration of Oxidative Stress and Growth Enhancement by Application of Vermicompost via Modulating Phyto-constituents in Tomato Plants During Nematode Stress

Tomato (Solanum lycopersicum) plants are facing different kinds of biotic stress, and root-knot nematodes (Meloidogyne incognita) are among the dreadful pathogens which not only affect the growth of plants but also have a negative impact on the total yield. Nematode population management is a major issue since the chemicals used as nematicides have a harmful influence on the environment and mankind's health. Among several eco-friendly strategies, the usage of vermicompost has been shown to be effective in the management of nematodes. The main aim of the present study was to design an eco-friendly approach for the management of nematodes. In the present study, the effect of vermicompost was evaluated for such a purpose. Variable quantities of vermicompost (0%, 20%, 40%, 60%, 80%, and 100%) (w/w) and soil were placed in clay pots after completely mixing and grinding to investigate its pesticidal abilities against M. incognita in tomato plants. After 45 days of nematode infestation, several morphological aspects were assessed, including lengths of root and shoot along with their fresh weight, number of galls, and leaves. Protein content, antioxidative enzymes (catalase, superoxide dismutase, polyphenol oxidase, ascorbate peroxidase, glutathione-s-transferase, guaiacol peroxidase), non-enzymatic antioxidants (ascorbic acid, glutathione, tocopherol content), stress markers (malondialdehyde, hydrogen peroxide content), photosynthetic pigments (chlorophyll a, b, total chlorophyll, carotenoid content), osmolyte (proline) content, and secondary metabolites (phenol, flavonoid, anthocyanin content) were all assessed in addition to growth variables. The findings of the preceding experiments showed a considerable rise in all morphological, biochemical, and photosynthetic parameters with the exception of stress markers, which were found to be reduced after the application of vermicompost in a concentration-dependent manner when compared to nematode-infected and untreated plants. The present study revealed that vermicompost has a high potential as a biopesticide against M. incognita because it reduces oxidative stress and promotes tomato plant growth and development by modifying the level of bioactive phyto-constituents. This is the first study in which tomato plant growth and phyto-constituents levels were evaluated by supplementing with vermicompost after 45 days of nematode exposure.