The Influence of the Verticillium dahliae Kleb Infection on the Anti-Enzyme Inside the Body of the Cotton with Different Root Injured Degree

Abstract This study was to explore the influence of the Verticillium dahliae Kleb inflection on the anti-enzyme inside the body of the cotton with a different root injured degree. When the cotton seedling was long, with four leaves, it was flushed with water carefully, and then the following were obtained: (1) complete root seedling; (2) cut root seedling – by cutting off the lower part, 3–5 cm of the root, with a disinfected knife; (3) injured root seedling – by cutting off most of the side roots, but keeping the main root. Three kinds of cotton seedlings with different roots were immersed separately in different concentrations of the germ liquid ( V. dahliae ) of 20 mL each. Through 0–48 h, the wilt degree of the seedling was recorded, and the related anti-enzyme of the variety was measured. After being immersed in the germ liquid, there was a significant difference in the wilt degree of the three kinds of injured root. When the germ liquid was in the ratio of 1:10, the complete root seedling was the lightest with no wilt; the injured root seedling was the second with a 2-degree wilt; but the cut root seedling was the most serious with a 3-degree wilt. At the same time, the changes in the peroxidase and malondialdehvde activities were determined. Peroxidase (POD) activities in the cut root seedling were 38.2 U mg −1 min −1 , in the injured root seedling were 42.96 U mg −1 min −1 , and in the complete root seedling were the highest at 49.2 U mg −1 min −1 . The malondialdenvde (MDA) content in cut root seedling was 39.483 mmol g −1 , injured root seedling was 27.12 mmol g −1 , and the complete root seedling was only 3.845 mmol g −1 . The activity of the related anti-enzymes, such as POD was high or low, the quantity of the MDA was more or less, which they met the order of the harm of the seedlings. The change of SOD activities in cut root seedling was the most obvious as well. After injuring and inflecting the young roots, the exterior pathological reaction of the seedling and the dynamic state biochemical reaction of the related enzymes inside the plant body were studied. It showed that the plant exterior pathology responded to the test, with the internal biochemical reaction fitting together mutually.