壳寡糖抑制十字花科黑腐病菌的活性分析
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中图分类号：S435.654 文献标识码：A文章编号：1673-9868（2026）02-0051-11
Analysis of the Antibacterial Activity of Chitosan Oligosaccharide against Xanthomonas campestris pv. campestris
LI Yan¹， GENG Bingqian1， CHEN Can²， QIN Haodong1， REN Xuesong1， SONG Hongyuan1， LIAO Xiongl 1.College of Horticulture and Landscape Architecture，Southwest University/Chongqing Key Laboratony of Olericulture，Chongqing 400715，China； 2.College of Smart Agriculture，Southwest University，Chongqing 400715，China
Abstract： Xanthomonas cam pestris pv. campestris （Xcc） is the pathogen that causes black rot in the cruciferous family. Chitosan oligosaccharide （COS） has been shown to have broad-spectrum antibacterial activity，but its antibacterial effect on Xcc remains unclear. In this study，a series of in vitro plate test subsystems were used to analyze the inhibitory effect of COS on Xcc ，and the control effect of COS on black rot in cabbage and radish was preliminarily evaluated. The results showed that the growth of Xcc could be significantly inhibited by low concentration of COS 0.06mg/mL ），and the complete antibacterial effect was shown when the concentration was increased to 0.5mg/mL （inhibition rate was 100% ）. COs can effectively inhibit extracellular enzyme activity，extracellular polysaccharide synthesis and motility; The qRT-PCR analysis showed that COS significantly inhibited the expression of multiple effector protein genes （XopD，XopP，XopK ， etc.）. In addition，exogenous application of COS could significantly reduce the severity of black rot in white radish，but the control effect on cabbage was not significant. This study clarified the inhibitory effect of COS on XCC ， and provided theoretical support for the development of COSbased green biopesticides for the control of cruciferous black rot.
Key words： chitosan oligosaccharide； black rot； Xanthomonas cam pestris pv. campestris；antibacterialmechanism;virulence factors
十字花科黑腐病是由野油菜黄单胞菌（Xanthomonas cam pestris pv.campestris，Xcc）引起的一种系统性维管束病害，其典型症状为叶片萎蔫、维管束组织褐变坏死，进而在叶中脉上产生“V"形黄色病斑，严重影响甘蓝（Brassca oleracea var.capitata）、花椰菜（B.oleracea var.botrytis）和西兰花（B.oleraceavar．italica）等具有重要经济价值的蔬菜作物的产量和品质[1-2]。（剩余13157字）
