Use of biotic elicitors in Tagetes erecta to improve the production of photodynamic secondary metabolites with antifungal activity.

RIVERO MÁRQUEZ, LUZ AMIRA; SVETAZ, LAURA; RODRÍGUEZ, MARÍA VICTORIA; STREBOT, MARÍA SOL; ARAUJO, C.; SORTINO, MAXIMILIANO A.

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencias - Reunión Conjunta SAIC SAB AAFE AACYTAL 2023; 2023

Sociedad Argentina de Biología

To generate changes in the production of photodynamic antifungal secondary metabolites in the ornamental and medicinal plant Tagetes erecta, it was grown on a substrate inoculated with different treatments: A) sterile water (control) and in the presence of live microorganisms: B) Gluconacetobacter diazotrophicus (Gd), C) Trichoderma harzianum (Th), and D) Fusarium solani (Fs), either alone or in combination: E) Gd+Th, F) Gd+Fs, G) Fs+Th, and H) Gd+Fs+Th. Exomorphological parameters (stem length, number of leaves, midrib length, and leaf area) were measured, and chlorophyll content (total, a, and b) was quantified using spectrophotometry. Antifungal activity of leaf, stem, and root hexane extracts against Candida albicans ATCC10231 was evaluated by spot and developed bioautography, and the amount and intensity of the bands obtained were compared by thin layer chromatography (using CAMAG® Automatic TLC Sampler 4-ATS 4) at 254 and 366 nm wavelengths (λ). Exomorphological parameters were evaluated using the Kruskal-Wallis test, finding significant differences from control treatments D-H with fewer leaves and B-H in the rate of change in stem length. A higher growth rate in leaf area and midrib length was observed for treatments with Gd alone or combined with a fungus. Treatments E, F, and G resulted in a greater decrease in the percentage of chlorophyll. Through spot bioautography, the antifungal activity of stem extracts was observed for treatments C, D, and H, and in all root treatments, but not in leaf extracts. In developed bioautography, two active bands were detected for all stem treatments; for the root, three bands were detected for D, E, F, G, and H; four bands for A and C; and five bands for treatment B. Differences in intensity and number of bands for both λ were observed. The microorganisms affected the exomorphology and production of secondary metabolites in T. erecta. Extracts from plants treated with Gd showed higher inhibition and number of active bands.