Microscopic detection of H₂O₂ accumulation using DAB staining during disease development in pathosystems I-III.

<p>H₂O₂ accumulation was visualized by DAB staining in control and infected potato sprouts and soybean hypocotyls and leaves. White arrows indicate dark brown precipitate developed at necrotic and surrounding areas. Control potato sprout (<b>A</b>), soybean hypocotyl (<b>C</b>), and soybean leaf (<b>E</b>) with no evidence of endogenous H₂O₂ at 120 HPT, 36h HPT, and 18h HPT, respectively. <i>R</i>. <i>solani</i> mycelia and <i>S</i>. <i>tuberosum</i> sprout (<b>B</b>), <i>G</i>. <i>max</i> hypocotyl (<b>D</b>), and <i>G</i>. <i>max</i> leaf (<b>F</b>) in pathosystems I-III with H₂O₂ accumulation. Bar = 500 μm.