Boosting of Free Radical Scavenging Capacity and Physiological Markers of Tomato Plants by Vermicompost Application During Nematode Stress

Meloidogyne incognita is a potentially harmful member of the root-knot nematode family that is capable of impairing plant growth and lowering crop production. They harm their host plants by restricting nutrition, changing cell physiology, dampening the defense system, causing mechanical damage and structural changes, and finally leading to plant death. The aim of this study is to investigate how vermicompost treatment influences the ability of tomato plants to combat free radicals and the changes in their structural components under nematode stress. Tomato seedlings were subjected to vermicompost extract treatment and allowed to germinate in earthen pots. Following germination, they were transplanted into individual pots and exposed to freshly hatched juveniles of Meloidogyne incognita. After a 45-day period, the plants were harvested, and various physiological aspects (such as free radical scavenging capacity and electrolyte leakage) and structural components (including carbohydrate content, elemental composition, and functional groups) were analyzed. Additionally, a fluorescence microscope was employed to measure the buildup of glutathione and hydrogen peroxide in the roots. The study reveals that nematodes adversely affect both radical scavenging capacity and structural components. Nevertheless, treatments involving vermicompost substantially enhance free radical scavenging capacity and mitigate the structural abnormalities induced by nematodes. All of these findings imply that vermicompost can reduce nematode damage and serve as an alternative to chemical nematicides. This is the first study in literature to focus on tomato plant structural and physiological markers, including Fourier transform infrared spectroscopy (FTIR), carbon hydrogen nitrogen (CHN), and free radical scavenging capacity during nematode stress after supplementing with vermicompost for 45 days in field conditions.