3.3.6. Antioxidant Isozymes

The antioxidant isozymes (POD and PPO) could be detected using native PAGE. The results (Figures 6 and 7) revealed the expression of 4 PPO and 9 POD isozymes in the leaves of pepper plants. For PPO isozymes, infected pepper plants treated with *A. platensis* through the soil application showed the strongest PPO expression as it produced 5 bands, including 4 high-intensity bands at Rf (0.487, 0.658, 0.748, and 0.895) and one medium intensity band at Rf (0.950), followed by *A. platensis* through the foliar spraying and *A. oryzae* through the soil application as they showed the same number and density of 4 bands. Referring to POD isozymes, it was observed that treatment of *D. muscorum* (foliar) application showed the strongest POD expression as it produced 11 bands, including four high-intensity bands at Rf (0.274, 0.444, 0.586, and 0.812), five moderated intensity bands at Rf (0.160, 0.244, 0.654, 0.707, and 0.880), and two weak intensity bands at Rf (0.142 and 0.944). In addition,

applying cyanobacteria through foliar spraying showed the same number and density of 10 bands for all used cyanobacteria.

**Figure 5.** Effect of cyanobacteria on the activity of oxidative enzymes in the infected pepper plants (T1-healthy control, T2-infected control, T3-infected plants treated with *D. muscorum* soil, T4-infected plants treated with *A. oryzae* soil, T5-infected plants treated with *A. platensis* soil, T6-infected plants treated with *D. muscorum* foliar spray, T7-infected plants treated with *A. oryzae* foliar spray and T8-infected plants treated with *A. platensis* foliar application.) (Data represent mean ± SD, n = 3), (a–g Letters revered to significant in statically analysis).

**Figure 6.** The effect of *F. oxysporum* and the application of cyanobacteria on (**A**) Polyphenol oxidase isozyme. (**B**) Ideogram analysis of PPO isozyme of the infected pepper plants. 1 = Healthy control; 2 = Infected control; 3 = Infected plant + *D. muscorum* (soil); 4 = Infected plant + *A. oryzae* (soil); 5 = Infected plant + *A. platensis* (soil); 6 = Infected plant + *D. muscorum* (foliar); 7 = Infected plant + *A. oryzae* (foliar); 8 = Infected plant + *A. platensis* (foliar).

**Figure 7.** The effect of *F. oxysporum* and the application of cyanobacteria on (**A**) Peroxidase isozyme. (**B**) Ideogram analysis of POD isozyme of the infected pepper plants. 1 = Healthy control; 2 = Infected control; 3 = Infected plant + *D. muscorum* (soil); 4 = Infected plant + *A. oryzae* (soil); 5 = Infected plant + *A. platensis* (soil); 6 = Infected plant + *D. muscorum* (foliar); 7 = Infected plant + *A. oryzae* (foliar); 8 = Infected plant + *A. platensis* (foliar).
