This study aimed to detect in situ the formation of reactive oxygen species (ROS), specially hydrogen peroxide (H2O2) and superoxide (O2.- ), in bean plants treated with aqueous extracts of mycelium (AEM) and basidiocarp (AEB) from Pycnoporus sanguineus at a concentration of 5% (w/v) and inoculated after three days with Colletotrichum lindemuthianum. Evaluations occurred at 48, 96 and 192 hours after inoculation (hai). Distilled water, azoxystrobin (40 mg a.i. L-1 ) and acibenzolar-S-methyl (75 mg a.i. L-1 ) were used as control treatments. H2O2 formation within 48 hai was detected only for the treatment with basidiocarp extract. As to O2.- , formation was detected mainly for the treatment with mycelium extract within 48 hai. At 192 hai, all treatments showed reaction for H2O2 and O2.- in epidermal and mesophyllic cells probably due to the infectious process. These results indicate the potential of P. sanguineus extracts to induce ROS formation in bean plants in early infection, which may contribute to reduce anthracnose severity.
resistance induction; hydrogen peroxide; superoxide
