Early Defense Mechanisms of Brassica oleracea in Response to Attack by Xanthomonas campestris pv. campestris

Abstract

Black rot disease, caused by Xanthomonas campestris pv. campestris (Xcc), results in significant yield losses in Brassica oleracea crops worldwide. To find black rot disease-resistant cabbage lines, we carried out pathogenicity assays using the scissor-clipping method in 94 different B. oleracea lines. By comparing the lesion areas, we selected a relatively resistant line, Black rot Resistance 155 (BR155), and a highly susceptible line, SC31. We compared the two cabbage lines for the Xcc-induced expression pattern of 13 defense-related genes. Among them, the Xcc-induced expression level of PR1 and antioxidant-related genes (SOD, POD, APX, Trx H, and CHI) were more than two times higher in BR155 than SC31. Nitroblue tetrazolium (NBT) and diaminobenzidine tetrahydrochloride (DAB) staining analysis showed that BR155 accumulated less Xcc-induced reactive oxygen species (ROS) than did SC31. In addition, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays showed that BR155 had higher antioxidant activity than SC31. This study, focused on the defense responses of cabbage during the early biotrophic stage of infection, indicated that Xcc-induced ROS might play a role in black rot disease development. We suggest that non-enzymatic antioxidants are important, particularly in the early defense mechanisms of cabbage against Xcc.

A GBS-based genetic linkage map and quantitative trait loci (QTL) associated with resistance to Xanthomonas campestris pv. campestris race 1 identified in Brassica oleracea

“…In a previous study, two inbred cabbage lines ( Brassica oleracea L. var. capitate ), SC31 and BR155, showed susceptibility and high resistance to Xcc R1, respectively ( Lu et al., 2021 ). In the current study, they were utilized as parents to generate a segregating population (F 1 , F 2 , and F 2:3 ).…”

“…In a previous study ( Lu et al., 2021 ), we selected an Xcc -resistant line, Black rot Resistance 155 (BR155), and a susceptible line, SC31, by comparing symptom development. Using these two cabbage lines, we studied the early defense mechanisms of B. oleracea in response to Xcc infection and found that BR155 had a relatively strong antioxidant activity.…”

Assessment of Black Rot in Oilseed Rape Grown under Climate Change Conditions Using Biochemical Methods and Computer Vision

“…This results in the appearance of characteristic V-shaped patterns in leaf margins, initially chlorotic and eventually necrotic, as the infection progresses from biotrophic to necrotrophic stages. Eventually, plants die [ 45 , 46 , 47 ]. In addition, it is thought that Xcc will become an increasingly important disease due to climate change in the more northern latitudes of vegetable production, including the warmer regions of Europe [ 42 ].…”

Study of cabbage antioxidant system response on early infection stage of Xanthomonas campestris pv. campestris

“…By measuring the physiological indexes of broccoli and cabbage, it was found that the activities of antioxidant enzymes such as SOD and POD decreased after Xcc infection [20,35]. In addition, transcriptome and metabolomic studies have found that antioxidant genes and substances also show signi cant responses after Xcc infection [10,[36][37][38][39][40][41][42][43][44]. However, most of these studies have focused on using single physiological indexes assay or omics assay to analyze the mechanism of the cabbage antioxidant system response to BR infection.…”