*Review* **Endophytic Fungi of Tomato and Their Potential Applications for Crop Improvement**

**Martina Sinno 1,\*,**†**, Marta Ranesi 1,\*,**†**, Laura Gioia 1, Giada d'Errico <sup>1</sup> and Sheridan Lois Woo 2,3,4**


Received: 31 October 2020; Accepted: 25 November 2020; Published: 27 November 2020

**Abstract:** 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.

**Keywords:** endophytes; biocontrol; biostimulants; induced systemic resistance; ISR; plant pathogens; fungal entomopathogens
