Endophytic fungi (EF) can enhance both plant growth and defense barriers against pests and pathogens, contributing to the reduction of chemical pesticides and fertilizers use in agriculture. Beauveria bassiana is an entomopathogenic fungus showing endophytism in several crops, often associated with a good capacity to limit the development of pests and disease agents. However, the diversity of the protective efficacy and plant response to different strains can be remarkable and needs to be carefully assessed for the successful and predictable use of these beneficial microorganisms. This study aims to select B. bassiana strains able to colonize tomato plants as endophytes as well as to control two important disease agents, Botrytis cinerea and Alternaria alternata, and the pest aphid, Macrosiphum euphorbiae. Nine wild-type isolates and one commercial strain were screened for endophytism, then further characterized for plant-growth promotion plus inhibition of disease development and pest infestation. Four isolates proved to have a good control activity against the biotic stressors tested, but only Bb716 was also able to promote plant growth. This work provides a simple workflow for the selection of beneficial EF, paving the way towards more effective use of B. bassiana in Integrate Pest Management (IPM) of tomato.

Endophytic fungi (EF) are increasingly gaining attention due to the numerous benefits many species can offer to the plant host, while reducing the application of chemicals in agriculture, thus providing advantages to human health and the environment. The growing demand for safer agrifood products and the challenge of increasing food production with a lower use of pesticides and fertilizers stimulates investigations on the use and understanding of EF. Other than direct consequences on the plant damaging agents, these microorganisms can also deliver bioactive metabolites with antimicrobial, insecticidal, or plant biostimulant activities. In tomato, EF are artificially introduced as biological control agents or naturally acquired from the surrounding environment. To date, the applications of EF to tomato has been generally limited to a restricted group of beneficial fungi. In this work, considerations are made to the effects and methods of introduction and detection of EF on tomato plants, consolidating in a review the main findings that regard pest and pathogen control, and improvement of plant performance. Moreover, a survey was undertaken of the naturally occurring constitutive endophytes present in this horticultural crop, with the aim to evaluate the potential role in the selection of new beneficial EF useful for tomato crop improvement.

The cultivation of different species of Eucalyptus has recently expanded in Liguria (Italy) due to the growing demand of the North European floricultural market. Eucalyptus tree branches are cut and selected for their quality, resulting in large amounts of waste biomass to be disposed of. The aim of our study was to evaluate the phytotoxic and antimicrobial activities of essential oils (EOs) from pruning wastes of E. cinerea (EC) and E. nicholii (EN), for potential applications in agriculture. Phytochemical analyses showed eucalyptol (1,8-cineole) as the major component in both EOs, but the EO yield of EN was higher than that of EC, in agreement with a significantly higher oil gland density on EN leaves. EOs from both species showed phytotoxicity on both weeds tested, but no significant inhibition on horticultural crop seed germination, except for Raphanus sativus. The EO from EC showed the strongest antibacterial activity, while the EO from EN showed the strongest antifungal activity. Concluding, EOs from Eucalyptus pruning may be used as possible alternatives to synthetic herbicides and pesticides, acting as antimicrobial and antifungal agents, thus representing a safe strategy for crop management programs.

An extensive literature search was performed to review current knowledge about endophytic fungi isolated from plants included in the European Food Safety Authority (EFSA) dossier. The selected genera of plants were Acacia, Albizia, Bauhinia, Berberis, Caesalpinia, Cassia, Cornus, Hamamelis, Jasminus, Ligustrum, Lonicera, Nerium, and Robinia. A total of 120 fungal genera have been found in plant tissues originating from several countries. Bauhinia and Cornus showed the highest diversity of endophytes, whereas Hamamelis, Jasminus, Lonicera, and Robinia exhibited the lowest. The most frequently detected fungi were Aspergillus, Colletotrichum, Fusarium, Penicillium, Phyllosticta, and Alternaria. Plants and plant products represent an inoculum source of several mutualistic or pathogenic fungi, including quarantine pathogens. Thus, the movement of living organisms across continents during international trade represents a serious threat to ecosystems and biosecurity measures should be taken at a global level.

Fusarium oxysporum f. sp. lycopersici (Fol) is a destructive soil-borne pathogen responsible for major global losses in tomato production, within a context of increasingly constrained fungicide use in intensive farming systems. Sustainable alternatives to chemical fungicides are urgently needed, and microbial secondary metabolites represent a promising source of antifungal compounds. This study explores the antifungal potential of secondary metabolites produced by a natural isolate of Beauveria bassiana (Bb758) previously reported to exhibit strong biocontrol activity against Fol. LC-HRMS metabolomic profiling revealed a chemically diverse metabolite profile dominated by amino acid-derived compounds, peptides and alkaloids. Purification of the crude extract by column chromatography and reverse-phase HPLC yielded beauvericin and several 2,5-diketopiperazines as the main bioactive constituents. These compounds were identified by NMR and LC-HRMS analyses. The antifungal activity of beauvericin (BEA), cyclo(l-Phe-l-Pro) (CFP) and fractions was evaluated against spore germination and germ tube development of Fol. BEA exhibited dose-dependent but limited activity, showing significant inhibition only at high concentrations (100 μg mL⁻¹). In contrast, CFP showed significantly higher antifungal activity than BEA, inhibiting both germination and germ tube formation at concentrations as low as 10 μg mL⁻¹. These results identify CFP as a promising antifungal compound targeting the early infection stages of Fol and highlight fungal-derived diketopiperazines as candidate molecules for sustainable disease management strategies.