Bioactive Compounds of Ganoderma lucidum Activate the Defense Mechanisms of Soybean Plants and Reduce the Severity of Powdery Mildew

Ganoderma lucidum is a medicinal mushroom widely used in Eastern countries and currently in global scale. Its fruiting body and mycelium are composed by polysaccharides, triterpenes and more than 200 secondary metabolites. These compounds exhibit a range of bioactivities, such as anti-inflammatory, antitumorigenic, antibacterial and antifungal action. Several scientific publications have demonstrated the potential and performance of G. lucidum compounds in the control of diseases in animals and humans. However, there is a lack of information on the effect of their compounds on the phytopathogens control, whether directly or by activating plant defense mechanisms. In the search of new molecules that has induced activity and disease control, this study was aimed to evaluate the bioactive compounds produced by G. lucidum through liquid culture under elicitation to control powdery mildew (Erysiphe diffusa) in soybean plants. The compounds tested were- C01-distilled water, C02-copper oxychloride (1 L ha-1), FC01-filtered mycelial growth of G. lucidum without elicitation, FC02-G. lucidum filtration of lignin elicitation and FC03-G. lucidum filtration from SA elicitation. The upper part of the plant was sprayed at 20 % (v/v) concentration and 10 mL per plant were applied. All data were analyzed using R® software. The Ganoderma filtrates have shown the induction of resistance potential in soybean plants by the activation of phytoalexins, activation of the enzyme phenylalanine ammonia-lyase, increase of phenolic compounds, peroxidases and chitinase activity, such induction has specificity in relation to time activation and association with elicitors. New studies should be considered, seeking to identify and isolate the active principles present in the filtrates, as well as to evaluate the action of these substances in other pathosystems of agricultural interest.