背景:根癌农杆菌引起的冠胆病是一种影响葡萄树的破坏性疾病。已经发现内生细菌通过使用几种机制来控制植物病害。这项研究研究了三种内生细菌控制冠胆的潜力,这些内生细菌先前是从健康的栽培和野生葡萄中分离出的,包括假单胞菌Ba35,绿鱼假单胞菌Ba47和液化沙雷氏菌Ou55。
结果:在不同程度上,三种内生细菌抑制根癌根癌根癌Gh1的种群,并大大减少了冠胆的症状。此外,内生细菌的无细胞培养上清液(CFCS)极大地抑制了根癌农杆菌Gh1的生物膜产生和运动行为。根据我们的发现,CFCS可以减少根癌农杆菌Gh1细胞与葡萄cv的粘附。Rashe根组织及其向根提取物的趋化性运动性。与未处理的对照相比,统计分析表明,CFCS显著降低了游泳,抽搐,和根癌A.Gh1的成群运动。结果表明,内生细菌有效地刺激了植物防御酶的产生,包括超氧化物歧化酶(SOD),多酚氧化酶(PPO),过氧化物酶(POD),苯丙氨酸解氨酶(PAL),接种根癌农杆菌Gh1的葡萄中不同时间间隔的总可溶性酚。Ba47菌株显着增加了与植物抗性相关的防御基因的表达水平。葡萄叶片中PR1、PR2、VvACO1和GAD1基因的上调表明SA和JA途径的激活,在增强对病原体入侵的抵抗力方面发挥作用。结果表明,用Ba47处理葡萄可增强抗氧化防御活性和防御相关基因的表达,减少了根癌引起的氧化损伤,降低了冠胆病的发病率。
结论:这是关于根癌,葡萄藤冠胆剂,在生长和毒力特征方面受内生细菌产生的CFCS的影响。创造更安全的植物病害管理技术,微生物相互作用过程中CFCS介导的生物防治过程的知识至关重要。
BACKGROUND: Crown gall disease caused by Agrobacterium tumefaciens is a very destructive affliction that affects grapevines. Endophytic bacteria have been discovered to control plant diseases via the use of several mechanisms. This research examined the potential for controlling crown gall by three endophytic bacteria that were previously isolated from healthy cultivated and wild grapevines including Pseudomonas kilonensis Ba35, Pseudomonas chlororaphis Ba47, and Serratia liquefaciens Ou55.
RESULTS: At various degrees, three endophytic bacteria suppressed the populations of A. tumefaciens Gh1 and greatly decreased the symptoms of crown gall. Furthermore, biofilm production and motility behaviors of A. tumefaciens Gh1were greatly inhibited by the Cell-free Culture Supernatant (CFCS) of endophytic bacteria. According to our findings, CFCS may reduce the adhesion of A. tumefaciens Gh1 cells to grapevine cv. Rashe root tissues as well as their chemotaxis motility toward the extract of the roots. When compared to the untreated control, statistical analysis showed that CFCS significantly reduced the swimming, twitching, and swarming motility of A. tumefaciens Gh1. The findings demonstrated that the endophytic bacteria effectively stimulated the production of plant defensive enzymes including superoxide dismutase (SOD), polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), and total soluble phenols at different time intervals in grapevine inoculated with A. tumefaciens Gh1. The Ba47 strain markedly increased the expression levels of defense genes associated with plant resistance. The up-regulation of PR1, PR2, VvACO1, and GAD1 genes in grapevine leaves indicates the activation of SA and JA pathways, which play a role in enhancing resistance to pathogen invasion. The results showed that treating grapevine with Ba47 increased antioxidant defense activities and defense-related gene expression, which reduced oxidative damage caused by A. tumefaciens and decreased the incidence of crown gall disease.
CONCLUSIONS: This is the first study on how A. tumefaciens, the grapevine crown gall agent, is affected by CFCS generated by endophytic bacteria in terms of growth and virulence features. To create safer plant disease management techniques, knowledge of the biocontrol processes mediated by CFCS during microbial interactions is crucial.