Trichoderma spp. are one of the most versatile and well-recognised biocontrol fungi known to defend plants against soilborne pathogens through direct antagonism, plant growth promotion, and antibiotic production (Malik et al. 2024). Trichoderma spp. can profoundly influence the rhizosphere microbiome by inducing root exudation patterns. For instance, Trichoderma harzianum has been shown to induce alteration in plant root exudates, including the degradation of a series of organic acids to alleviate plant disease. T. harzianum also alters root exudates leading to a shift in fungal communities that can help to suppress Fusarium wilt (Zhang et al. 2025). Until recently, solid evidence was lacking about how Trichoderma-induced root exudates alter the rhizosphere microbiome and control plant diseases. Masson pine (Pinus massoniana) seedlings often suffer from damping-off disease caused by Fusarium oxysporum. Damping-off is one of the most devastating nursery diseases known. Recently, Masson pine inoculation with Trichoderma koningiopsis was shown to suppress damping-off disease by enhancing beneficial microbes, including Penicillium spp., Bacillus spp., within the Masson pine rhizosphere (Wang et al. 2026). This study provided new mechanistic insights into how Trichoderma alters root exudates that link Masson pine and its microbiome, while helping to recruit beneficial allies and suppress F. oxysporum and ultimately damping-off disease. The current study provides an excellent, cost-effective, and sustainable strategy for the biocontrol of Fusarium wilt disease in Masoon pine species (Figure 1). Plants actively interact with effective soil microbes through a complex network of root exudates containing amino acids, organic acids, sugars, and secondary metabolites (Afridi et al. 2024). These exudates are key regulators of rhizosphere microbial community structure. Under pathogen attack, plants induce the secretion of antimicrobial compounds from the roots that directly inhibit the pathogen by impeding spore germination and mycelial growth. In addition, plants under stress recruit advantageous microbes by secreting growth-promoting substances or chemoattractants into the soil. For example, Arabidopsis secretes l-malic acid that helps to attract beneficial Bacillus bacteria to the rhizosphere in response to pathogen attack (Rudrappa et al. 2008). Moreover, Trichoderma combined with Bacillus amendment improves plant growth (Ma et al. 2025). The recruited plant growth-promoting rhizobacteria or other effective microbes inhibit plant pathogens and enhance plant fitness, indicating that plants establish a protective rhizosphere microbiome. T. koningiopsis leverage this strategy in Masson pine (Wang et al. 2026), where pine seedlings treated with T. koningiopsis induce significant alterations in their root exudates, including the secretion of pelargonic acid, lauric acid, and capric acid, suggesting that these organic acids (OAs) mediate microbiome transformation. Importantly, these OAs significantly inhibited Fusarium growth at mM concentrations, while they simultaneously induced the growth of other effective biocontrol microbes in the pine rhizosphere, including Trichoderma, Penicillium, and Bacillus strains. Notably, the combination of these three OAs showed synergistic effects that strongly reduced the viability of F. oxysporum spores and mycelia and stimulated the growth of a wide range of beneficial microbes compared with any single OA. This study is consistent with the earlier report that suggested that plant-derived OAs impaired soilborne pathogens. Earlier studies revealed that supplementation of cucumber plants with T. harzianum altered soil fungal communities linked with disease reduction (Zhang et al. 2025), and Penicillium bacteria associated with watermelon roots enhanced the secretion of antifungal compounds, which led to a decline in Fusarium infection (De Cal et al. 2009). The Masson pine and Trichoderma interactions reveal novel insights into damping-off disease management, where Trichoderma triggers the alteration of exudation, which shape rhizosphere microbiome composition with Trichoderma being antagonistic to F. oxysporum (Figure 1). A remarkable finding is observed in Masson pine, where the exudate-derived microbiome induces systemic physiological responses in the host plant. Masson pine seedlings supplemented with exudate cocktail (e.g., pelargonic acid, lauric acid, and capric acid) were able to reduce F. oxysporum infection, leading to lower disease frequency and severity compared with non-treated plants (Figure 1) (Wang et al. 2026). In this process, damping-off frequency declined by about 73% in pine. In fact, Trichoderma-responsive beneficial exudates protected the host pine through enhanced innate-immunity and improved stress tolerance. Importantly, gene expression profiles indicated that defence-related genes were significantly increased in their relative transcript abundance in pine seedlings in response to Trichoderma-induced exudates with or without pathogen treatment (Wang et al. 2026). Pathogenesis-related protein1gene (PR1) expression, a marker for systemic resistance in plants, showed significantly increased relative transcript abundance, indicating robust immunity responses in pine seedlings exposed to damping-off disease. In addition, the transcriptional analysis revealed that mitogen-activated protein kinase (MAPK), which is linked with systemic plant defence signalling (Shi et al. 2025), was also increased in abundance, suggesting that systematic resistance responses are invoked in pine seedlings following Fusarium attack. Phytohormonal interference is an indicator of plant systemic resistance. Jasmonic acid (JA), abscisic acid (ABA), and gibberellic acid significantly increased in pine seedlings supplemented with beneficial exudates during pathogen attack (Wang et al. 2026). JA and ethylene (ET) are well-recognised signalling molecules involved in Trichoderma-induced systemic resistance, typically associated with defence responses against several Fusarium and other plant pathogens. Another key aspect of systemic resistance is the management of oxidative stress. Colonisation of T. koningiopsis induces the alteration of the microbiome, leading to high catalase and peroxidase activities in pine seeding (Wang et al. 2026). Consequently, T. koningiopsis-treated pine plants exhibited elevated H2O2 levels, which likely reduced Fusarium-infection-induced cellular damage compared with control plants. These findings suggest that a beneficial rhizosphere can activate the redox-buffering capacity, allowing the pine seedlings to mitigate oxidative burst and cellular damage due to pathogen attack. In the same study, the high expression of the CAT1 gene indicated that reactive oxygen species (ROS, e.g., H2O2) were likely detoxified thereby reducing cellular damage in response to pathogen attack. ROS management is a key factor of disease resistance with moderate ROS levels helping to trigger defence metabolites and strengthen plant cell walls (Haghpanah et al. 2025), whereas uncontrolled ROS levels can lead to pathogen invasion and cellular damage. However, pathogen-induced oxidative stress mitigation can vary based upon the type of plant-microbe interaction. For instance, the recruitment of certain beneficial microbes in cucumber increased ROS levels to damage pathogens, whereas in Masson pine, an active quenching-ROS strategy in response to Fusarium helped to prevent seedling damage (Wang et al. 2026). These distinctions suggest that beneficial microbes can alter physiological and metabolic responses to induce systemic resistance, but that these effects might differ in woody and herbaceous plants. T. koningiopsis shows encouraging outcomes on growth and photosynthetic attributes in pine. T. koningiopsis enhanced chlorophyll content and improved photosynthesis rate, stomatal conductance, and transpiration while protecting against damping-off disease. However, the above findings emphasise that T. koningiopsis enabled the Masson pine seedlings to exhibit both improved systemic resistance and healthy growth, thereby avoiding growth-defence trade-offs. These dual benefits are highly desirable for sustainable forestry and agriculture. The biocontrol fungi T. koningiopsis showed direct antagonism to F. oxysporum to control damping-off disease through regulating of root-soil nexus and fortifying Masson pine seedlings on multiple fronts. Trichoderma-mediated disease control could serve as a cost-effective and ecofriendly alternative to chemical fungicides. The study conducted by Wang et al. (2026) was conducted in a greenhouse setting with sterilised soils and a defined Trichoderma application. To expand the use of Trichoderma-mediated disease control in real forest soils, additional studies are needed to understand how other microbes, soil types, temperature, and moisture conditions might influence or compete with the efficacy of Trichoderma treatments. In the future, investigations into the mechanistic basis of how microbiome diversity or environmental variables modulate the efficacy of T. koningiopsis-induced exudation and disease suppression patterns are necessary. The study by Wang et al. (2026), revealed the involvement of JA/ET and ABA signalling and MAPK activation processes, but the exact ways by which the host plant senses Trichoderma and reprogramme their root metabolism remain unknown. Such advances will likely reveal novel targets of Trichoderma-mediated sustainable disease control and improve the practical use of this biocontrol strategy in agriculture and forestry. We thank to Institute of Biological Sciences, University of Rajshahi, Rajshahi, Bangladesh for providing additional research support. The authors sincerely thank Dr. John C. Cushman for his careful review and assistance with English language editing. The authors have nothing to report. The authors declare no conflicts of interest. No new data were generated or analysed in this study. Data sharing does not apply to this article. Data sharing is not applicable to this article as no new data were created or analysed in this study.
Rahman et al. (2026) studied this question.