Globally, nematodes are parasites that destroy many crops, however, their presence also serves as an indicator of the state of soil health. Tomato is a very studied, cultivated vegetable. In the micro-space of the knots we determine its pathogenesis. The macronutrients, micronutrients and beneficial elements present on root-knot nematodes were C>O> N (54.73, 37.57, and 3.55%), phosphorus (0.133%), Na>Ca>Mg>K cations (1.13, 1,032, 0.094, and 0.048%), S (0.247%), micronutrients Fe>Cl (0.163, 0.027%), and beneficial elements Si>Al (0.354, 0.985%). Progenesis of the chromatograms (ES+/ES-), 202 compounds were detected in the first polarity, in which 195 have at least one possible identification candidate, the second were 42 compounds, and 41 match with at least one compound. Putative compounds with the highest scores are reported in this research: kukoamina (57.6), furmecyclox (51.1), feruloylputrescina (55.3), N1-transferuloylagmatine (53.9), dehydrotomatin (49.8, 50.8, 52.3, 52.6), jurubine (54.8,51.6), etnangien (50.2), dehydromelilotoside (41.5), tomatine (55), minutissamide (51.7). Nematodes in state (J2), six nematodes within the knots with an average length of 1.16 mm, were found and their interaction with other microorganisms is possible. With the high concentrations of Na+ in the root, the concentration of the cation Mg2+ and K+ decreases; while the N does not present any change.
