Tibouchina granulosa (Vell.) Cogn (Melastomataceae) as source of endophytic fungi: isolation, identification, and antiprotozoal activity of metabolites from Phyllosticta capitalensis

Abstract

Endophytes are microorganisms that form symbiotic relationships with their own host. Included in this group are the species Phyllosticta capitalensis, a group of fungi that include saprobes that produce bioactive metabolites. The present study aimed to identify the cultivable endophytic fungal microbiota present in healthy leaves of Tibouchina granulosa (Desr.) Cogn. (Melastomataceae) and investigate secondary metabolites produced by a strain of P. capitalensis and their effects against both Leishmania species and Trypanossoma cruzi. Identification of the strains was accomplished through multilocus sequencing analysis (MLSA), followed by phylogenetic analysis. The frequency of colonization was 73.66% and identified fungi belonged to the genus Diaporthe, Colletotrichum, Phyllosticta, Xylaria, Hypoxylon, Fusarium, Nigrospora, and Cercospora. A total of 18 compounds were identified by high-resolution mass spectrum analysis (UHPLC-HRMS), including fatty acids based on linoleic acid and derivatives, from P. capitalensis. Crude extracts had activity against Leishmania amazonensis, L. infantum, and Trypanosoma cruzi, with inhibitory concentration (IC 50) values of 17.2 μg/mL, 82.0 μg/mL, and 50.13 μg/mL, respectively. This is the first report of the production of these compounds by the endophytic P. capitalensis isolated from T. granulosa.

Endophytic Fungi as a Source of Antiviral Compounds – A Review

“…[17] Thus, the presence of endophytic fungi can provide host plants with several benefits, such as resistance to attack by herbivores, heat and drought, in addition to promoting growth and increasing nutrient recycling. [18 -20] According to Azevedo, [20] endophytic microorganisms can be found in the tissues of all plants studied around the world, including those in tropical forests, [7] coastal forests, [21] deserts, [22] Brazilian savannas, [23] tundra, [24] mangroves, [25] Antarctica, [26] the Arctic region, [27] Pantanal, [28] and prairies. [29] Some works have reported that secondary metabolites of fungi are also produced by the respective host plant, which may be related to a horizontal transfer of genes that may have occurred during the co-evolution between the endophytic fungus and the host plant.…”

“…In previous studies, we reported the potential of endophytes against several types of microorganisms, including protozoa [7] and bacteria, [8] and described the main compounds produced, such as linoleic acid, [7] mellein and β-orcinaldehyde, [44,45] kojic acid, α-cyclopiazonic acid, and 20,25-dihydroxyaflavinine. [46] Thus, the study of the endophyte-host relationship can establish alternative sources of substances of biotechnological interest.…”

“…Endophytic microorganisms produce secondary metabolites, substances that are not directly involved in the organism's growth and reproduction but play essential roles in the relationship with the host plant, contributing to the well‐being of both [6] . Studies have shown that these endophytic organisms can produce bioactive substances similar to those of the host plant; these substances can inhibit growth and even eliminate a wide variety of pathogenic microorganisms such as viruses, bacteria, protozoa, and fungi [7–9] . The interactions between endophytes and their hosts provide excellent potential for the discovery of new compounds that combat diseases affecting humans [10] .…”

“…[6] Studies have shown that these endophytic organisms can produce bioactive substances similar to those of the host plant; these substances can inhibit growth and even eliminate a wide variety of pathogenic microorganisms such as viruses, bacteria, protozoa, and fungi. [7][8][9] The interactions between endophytes and their hosts provide excellent potential for the discovery of new compounds that combat diseases affecting humans. [10] Microorganisms represent one of the life forms that can favor the production of bioactive products using biotechnological instruments, the study of which is often neglected, but highly diverse.…”

Commodity risk assessment of Jasminum polyanthum plants from Israel

“…except for Tibouchina granulosa which was found to be colonised endophytically by a non-identified strain of Colletotrichum sp. in Brazil (Golias et al, 2020). Tools are never transferred between plant species and are always sterilised prior to every treatment as a precaution, preventing the transfer of the endophytically grown pest.…”