Physiological Functions of the Cello-Oligosaccharides Binding CebE in the Pathogenic Streptomyces sp. AMCC400023

Potato common scab, an economically important disease worldwide, is caused by pathogenic strains mainly through the effects of thaxtomin. The cello-oligosaccharides binding protein CebE is proposed as a gateway to the pathogenic development of . In this study, two functional CebE encoding genes, and , were identified in pathogenic sp. AMCC400023. With a higher binding affinity towards signal molecules, the deletion of severely impaired thaxtomin-producing capacity and reduced the strain's pathogenicity. Transcriptional analysis confirmed that CebE is also responsible for the import and provision of carbon sources for cell growth. With lower binding affinity, the pathogenicity island (PAI)-localized CebE may assume a new function of mediating the biological process of sporulation, given the significantly impaired formation of Δ spores. The mechanisms of action of CebE proteins unraveled in sp. AMCC400023 will help pave the way for more effective prevention of the potato common scab disease.