Endophytes are being considered for use in biological control, and the enzymes they secrete might facilitate their initial colonization of internal plant tissues and direct interactions with microbial pathogens. Microbial proteases are also biotechnologically important products employed in bioremediation processes, cosmetics, and the pharmaceutical, photographic and food industries. In the present study, we evaluated antagonism and competitive interactions between 98 fungal endophytes and Alternaria alternata, Colletotrichum sp., Phyllosticta citricarpa and Moniliophthora perniciosa. We also examined the proteolytic activities of endophytes grown in liquid medium and conducted cup plate assays. The results showed that certain strains in the assemblage of P. hispidum endophytes are important sources of antifungal properties, primarily Lasiodiplodia theobromae JF766989, which reduced phytopathogen growth by approximately 54 to 65%. We detected 28 endophytes producing enzymatic halos of up to 16.40 mm in diameter. The results obtained in the present study highlight the proteolytic activity of the endophytes Phoma herbarum JF766995 and Schizophyllum commune JF766994, which presented the highest enzymatic halo diameters under at least one culture condition tested. The increased activities of certain isolates in the presence of rice or soy flour as a substrate (with halos up to 17.67 mm in diameter) suggests that these endophytes have the potential to produce enzymes using agricultural wastes.

The protective and growth-promoting activities of Colletrotrichum and Diaporthe endophytes on tomato plants (Lycopersicon esculentum Mill.) are underexplored. We screened 40 endophytic fungi associated with Mexican shrimp plant (Justicia brandegeana) using an in vitro dual culture assay for Fusarium oxysporum, one of the most important phytopathogens of tomato plants. The three best antagonists, Colletotrichum siamense (JB224.g1), C. siamense (JB252.g1), and Diaporthe masirevicii (JB270), were identified based on multilocus sequence analysis. They were assessed in vitro for their inhibition of F. oxysporum and phosphate solubilisation capacity, and for the production of indole acetic acid. Greenhouse experiments verified the growth-promoting effects of these endophytes and the suppression of F. oxysporum symptoms in tomato plants. Under greenhouse conditions, the JB252.g1 and JB270 isolates showed positive results for seedling emergence speed. The radicular system depth of plants inoculated with JB270 was greater than that in uninoculated plants (27.21 vs 21.95 cm). The soil plant analysis development chlorophyll metre (SPAD) index showed statistically significant results, especially for the endophyte JB224.g1 (36.99) compared to the control plants (30.90) and plants infected solely with F. oxysporum (33.64).