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

Abstract

Black rot, caused by Xanthomonas campestris pv. campestris (Xcc), is the most devastating disease of brassica, but the mechanisms of basal or induced resistance in cabbage remain largely unknown. Here, we performed three experiments to investigate biochemical features associated with cabbage resistance to black rot. In the first experiment, biochemical changes were assessed in plants that were inoculated with a highly (UFPR 5) or a moderately (Xcc 10) aggressive Xcc isolate. In the second experiment, we examined the biochemical responses in two cultivars (Chato de Quintal [CQ] and Louco de Verão [LV], susceptible and moderately resistant to Xcc, respectively). Finally, we examined whether acibenzolar‐S‐methyl (ASM) could induce cabbage resistance to Xcc. Plants inoculated with the Xcc 10 isolate displayed higher activities of superoxide dismutase (SOD), peroxidase (POX) and ascorbate peroxidase (APX), whereas activities of chitinase (CHI), β‐1,3‐glucanase (GLU) and polyphenol oxidase (PPO) as well as the concentrations of hydrogen peroxide (H2O2) and malondialdehyde (MDA) were lower compared to plants inoculated with the UFPR 5 isolate. The resistance of the cultivar LV to Xcc was linked to increases in the activities of CHI, GLU, and PPO and decreases in the activities of SOD, POX and APX as well as in the concentrations of H2O2 and MDA relative to the cultivar CQ. In general, ASM‐sprayed plants displayed higher activities for the enzymes studied, which was associated with decreased disease symptoms and oxidative stress. Taken together, our results demonstrated that high activities of both defence and antioxidant enzymes played a major role in both basal and induced resistance of cabbage to black rot.

Phosphites of manganese and zinc potentiate the resistance of common bean against infection by Xanthomonas axonopodis pv. phaseoli

“…Different enzymes are involved in plant defence against bacterial pathogens such as GLU, PAL and PPO (Amaral et al., 2019; Lee & Hwang, 1996). The GLU hydrolyses cell wall polysaccharides releasing elicitors of defence responses in plants (Hong & Hwang, 2005).…”

“…vesicatoria (Lee & Hwang, 1996) and GLU, PAL and PPO activities in cabbage leaves infected by X. campestris pv. campestris (Amaral et al., 2019). The GLU, PAL and PPO activities were associated with the basal level of resistance of cabbage to bacterial black rot as well as with phosphite‐induced resistance of common bean to anthracnose (Costa et al., 2017) and white mould (Fagundes‐Nacarath, Debona, Oliveira, et al, 2018).…”

“…Accumulation of ROS is a common feature of bacteria‐infected plants (Amaral et al., 2019; Silveira et al., 2015), and antioxidant enzymes play a pivotal role in constraining ROS damage in the cell membrane and limiting pathogen colonization (Kumar, Ebel, & Roberts, 2011). Accordingly, the activities of antioxidant enzymes were generally higher in Xapf ‐infected plants than in their non‐infected counterparts.…”

Novel Cucumis enzymes associated with host-specific disease resistance to Phytophthora melonis Katsura

“…In cucumber the activities of peroxidase increased following the inoculation with Fusarium oxysporum [20]. [21] reported that high activities of antioxidant enzymes played a major role in both basal and induced resistance of cabbage to black rot. Moreover, regarding the oxidative burst, CAT and SOD are useful biochemical indicators of disease resistance [22].…”

Novel Cucumis Enzymes Associated with Host-Specific Disease Resistance to Phytophthora melonis

“…In cucumber increasing in the activities of peroxidase were reported following the inoculation with Fusarium oxysporum (Zhao et al, 2012). Amaral et al (2019) reported that high activities of antioxidant enzymes played a major role in both basal and induced resistance of cabbage to black rot. Moreover, regarding the oxidative burst, CAT and SOD are useful biochemical indicators of disease resistance (Su et al, 2019).…”