Morpho-physiological changes and metabolomic profiles of cucumber seedlings following seed treatment with Trichoderma strains

M. Cardarelli, G. Colla, A.V. Ceccarelli, C. Pane, P. Bonini
Trichoderma is a plant growth-promoting fungus recognized for the ability to foster root development, defense mechanisms against pathogens, biosynthesis of antioxidant enzymes and secondary metabolites to enhance tolerance to abiotic stresses of plants. Even if usually applied to the soil, seed treatment with spores of Trichoderma is recommended for promoting the formation of the plant-microorganism mutualistic linkage from the earliest stages of development and facilitates the establishment of the microorganism in the rhizosphere. The aim of the present study was to investigate the effects of different Trichoderma strains (TL41 belonging to T. longibrachiatum and AT10, TA56, TAT11, TA117 belonging to T. atroviride) applied to the seeds through film coating on root structure, seedling growth, and biochemical parameters that may detect the onset of stress phenomena (antioxidant enzymes, phenols). Cucumber seeds (Cucumis sativus L. ‘Marketmore’ hybrid, La Semiorto Sementi srl, Italy), were coated with Trichoderma strains at the dose of 1×104 spores seed‑1 and sown on a sterile substrate (sand:peat; 1:1). TA117 and AT10 strains were the most effective in increasing dry weight and root development of seedlings with respect to the control (uncoated seeds). Moreover, TA117 also improved seed vigor index compared to control and other treatments. Biochemical parameters also allowed to discriminate the most valuable strains, as both AT10 and TA117 showed phenol, MDA and APX levels comparable to the control; these parameters, being indicative of probable oxidative stress, increased with TA56 and TAT11 treatments. A positive effect of AT10 was found to reduce the activity of GPX, enzyme involved in protecting cells from damage induced by free radicals, indicating an enhanced ability of the strain to contain stress. Moreover, Trichoderma treatments changed the metabolomic profile at epigean level suggesting different biochemical responses in the seedlings following the colonization of their roots by beneficial microorganisms. In conclusion, the results revealed the efficacy of seed treatment with Trichoderma on seedling development but also evidenced specific strain-plant interactions with significant biostimulant action.
Cardarelli, M., Colla, G., Ceccarelli, A.V., Pane, C. and Bonini, P. (2025). Morpho-physiological changes and metabolomic profiles of cucumber seedlings following seed treatment with Trichoderma strains. Acta Hortic. 1416, 1-8
DOI: 10.17660/ActaHortic.2025.1416.1
https://doi.org/10.17660/ActaHortic.2025.1416.1
film coating, seedling quality, oxidative stress, root development, phenols, antioxidant enzymes
English

Acta Horticulturae