Identification and Nematicidal Characterization of Proteases Secreted by Endophytic Bacteria Bacillus cereus BCM2

• DOI: 10.1094/phyto-05-19-0164-r
• Publication Date: 2019-09-16T15:22:40Z
• Authors: Haijing Hu; Yang Gao; Xia Li; Shuanglin Chen; Shuzhen Yan; Xinjun Tian
• Keywords: Identification; Bacillus (shape)

The endophytic bacterium Bacillus cereus BCM2 has shown great potential as a biocontrol organism against Meloidogyne incognita, which causes severe root-knot diseases in crops. In our previous study, the metabolite of showed high nematicidal activity M. incognita second-stage juveniles. However, mechanism employed by bacteria to infect and kill nematodes is still unclear. Here, we investigate both bacterial extracellular proteins with their killing nematodes. first step was detecting activities crude proteins. results show that nematode mortality rate reached 100% within 72 h, damaged cuticle eggshell, before finally destroying targets. This suggests possible proteinaceous pathogeny BCM2. Throughout process, fine-detail changes intestinal structure were observed using scanning electron microscopy transmission microscopy. These images did not damage internal organization but severely its cuticle, led content leakage. From proteins, chitosanase, alkaline serine protease, neutral protease purified identified. incognita–B. microenvironment simulation demonstrates adheres surface helps metabolites produced rapidly recognize incognita. relationship between plants, bacteria, offers insight into biological mechanisms can be utilized for management.