Biochemical responses of common bean to white mold potentiated by phosphites

Biochemical insights into basal and induced resistance in cabbage to black rot

“…Both necrotic and chlorotic areas were considered in BRS assessments. The leaves were scanned at 300 dpi resolution, and the obtained images were further processed using the software quant (Fagundes‐Nacarath et al, ) to quantify the BRS. Data of BRS were used to obtain the area under the black rot progress curve (AUBRPC) (Shaner & Finney, ).…”

“…The powder was homogenized in 2 ml of 100 mM potassium phosphate (pH 6.8) containing 1 mM phenylmethylsulphonyl fluoride (PMSF), 0.1 mM ethylenediaminetetraacetic acid (EDTA) and polyvinylpyrrolidone (PVP) 1% (w/v). The homogenized material was centrifuged at 12,000 g for 15 min at 4°C, and the supernatant was used to determine the enzymes activities as described by Fagundes‐Nacarath et al (). SOD activity was assessed based on the production of formazan blue that was monitored by determining absorbance at 560 nm.…”

“…For CHI and GLU, the powder was homogenized in 2 ml of 50 mM sodium phosphate (pH 6.5) containing 1 mM PMSF, 0.1 mM EDTA and PVP 1% (w/v). The homogenate was centrifuged at 20,000 g for 25 min at 4°C, and the supernatant was used for enzymes determination (Fagundes‐Nacarath et al, ). Nitrophenyl‐β‐D‐N‐N′‐diacetylchitobiose (2 mg/ml) was used as a substrate for CHI determination at 410 nm after incubation at 37°C for 2 hr.…”

“…The product released by GLU was measured at 540 nm using the substrate laminarin (4 mg/ml) whose reaction was incubated for 30 min at 45°C. Protein was quantified as described previously (Fagundes‐Nacarath et al, ). Briefly, 2 µl of the crude extract was mixed with 198 µl water and 1,000 µl Bradford's reagent and the absorbance was determined at 595 nm.…”

“…Pathogens attack induces the overproduction of reactive oxygen species (ROS) including hydrogen peroxide (H 2 O 2 ), superoxide () and hydroxyl radical (OH − ), which damage cell membrane (lipid peroxidation), pigments, proteins and nucleic acids (Fagundes‐Nacarath, Debona, Oliveira, Hawerroth, & Rodrigues, ). In order to counteract the deleterious effects of ROS, enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and ascorbate peroxidase (APX) are produced by the infected plant; the determination of their activities can help to understand what defence mechanisms are operating in host resistance against the diseases (Roohie & Umesha, ).…”