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Root rot disease of <i>Cuminum cyminum</i> caused by <i>Fusarium solani</i> is one of the most destructive diseases threatening cumin production. The present study investigates the biocontrol potential of some endophytes against <i>F. solani</i> and their effect on the induction of defense-related enzymes in a greenhouse. The results herein presented illustrate the strong biocontrol potential of three (out of twelve) endophytes. During the in vitro assay, three isolates demonstrated strong mycelial growth inhibition of <i>F. solani</i>: isolates 3, 4, and 9, with 87%, 65%, and 80% reductions, respectively, with respect to the control (100%). These isolates were identified as <i>Trichoderma harzianum</i>, <i>T. longibrachiatum</i>, and <i>Chaetomium globosum</i>, which produce siderophore and indole-3-acetic acid (IAA). Cumin seed priming with the culture filtrates of <i>T. harzianum</i>, <i>C. globosum</i>, and <i>T. longibrachiatum</i> positively affected the seed germination, as a higher germination (%) of culture filtrate-treated seeds was observed followed by infected and healthy control/untreated seeds. In the greenhouse, the application of <i>T. harzianum</i>, <i>T. longibrachiatum</i>, and <i>C. globosum</i> caused a reduction in disease severity (67.7%, 58.1%, and 59.3%, respectively) on cumin plants, with a lower disease severity (20%, 26%, and 25%, respectively) recorded in treated plants compared to the infected control (62%). Furthermore, a significant increase in defense-related enzymes in culture filtrate-treated cumin plants was recorded. Higher peroxidase (PO), polyphenoloxidase (PPO), and phenylalanine ammonia-lyase (PAL) activity, and a higher content of phenolic compounds, were found in culture filtrate-treated plants. These results indicate that the culture filtrates of these bioagents not only increased seed germination, but also protected the plants from <i>F. solani</i> infection by acting as important elements of the cellular antioxidant system in plants upon infection, conferring the biocontrol potential of <i>C. globosum</i> and <i>Trichoderma</i> species toward mitigating the root rot disease of cumin plants in a greenhouse.