SECRETOMIC ANALYSIS OF A NATIVE TRICHODERMA HARZIANUM STRAIN UNDER OPTIMAL GROWTH CONDITIONS OR NUTRIENT STARVATION

GALLO, MICAELA BELÉN ; BADER, ARACELI NATALIA; ALVAREZ, VERA ALEJANDRA; CONSOLO, VERÓNICA FABIANA

Rosario, Santa Fé

Congreso; V Encuentro y II Workshop de la Red Argentina de Tecnología Enzimática; 2023

REDBIO, Red de Laboratorios de biotecnología para América Latina y el Caribe

Trichoderma genera (Ascomycetes, Hyprocreales) are soilborne and rhizospheric filamentous fungi and some species are used in agriculture fortheir properties as bioinoculants and biocontrol agents. Some species are capable of synthesizing a variety of important secondary metabolites,phytohormones as plant growth regulators, antibiotics, and hydrolytic enzymes as proteases, chitinases, and glucanases (1). Particularly, Trichodermaharzianum specie is the main mycoparasite used against plant pathogens. Although, many secretome studies have been performed on T. harzianumin relation to growth promotion, stress tolerance and interaction with plant roots (2), studies on the composition of the secretome in response todifferent culture conditions have not been reported.The objective of this work was to analyze the proteomic profile of a strain of T. harzianum selected for its properties (potent antagonist, producerof secondary metabolites and effective in promoting plant growth) under conditions of nutrient sufficiency vs nutrient starvation.After analysis 147 proteins weredetermined in the culture medium (CM)and 1355 proteins in the aqueous solution(AS).The functional classification ofproteins showed that exclusive proteinswere excreted by the fungus in the CMand involved in synthesis and primarymetabolic processes. Under AS, weidentified proteins in response tochemicals and stress, involved in sexualreproduction, regulation to stimuli andcell communication, negative regulationof metabolic, cellular and biologicalprocesses. Importantly, under molecularfunction classification of the identifiedproteins in AS, oxidoreductase, hydrolaseand peroxidase proteins were identifiedand associated with intracellular andmembrane components. Hydrolyticenzymes as cellulase, glucosidase andquitinase were shared both in CM as inAS.The proteins identified in the culture medium were involved in typical processes accordingly to primary metabolism in which an increase in fungal biomassoccurs. Regarding the proteins present in the aqueous solution, numerous proteins with diverse functions were identified, involved both in synthesis processesand primary metabolic processes, as well as in response to stress, sexual reproduction, and related to oxidation-reduction processes. These results are consistentwith a stage of oxidative stress in the fungus caused by nutrient deficiency.This study disclosed the variation of T. harzianum secretome in response to different conditions, allowing us to know the plasticity of the fungus.