T6SS and T4SS Redundantly Secrete Effectors to Govern the Virulence and Bacterial Competition in Pectobacterium PccS1.
Phytopathology
; 114(8): 1926-1939, 2024 Aug.
Article
em En
| MEDLINE
| ID: mdl-38749069
ABSTRACT
Previous studies revealed that the type VI secretion system (T6SS) has an essential role in bacterial competition and virulence in many gram-negative bacteria. However, the role of T6SS in virulence in Pectobacterium atrosepticum remains controversial. We examined a closely related strain, PccS1, and discovered that its T6SS comprises a single-copy cluster of 17 core genes with a higher identity to homologs from P. atrosepticum. Through extensive phenotypic and functional analyses of over 220 derivatives of PccS1, we found that three of the five VgrGs could be classified into group I VgrGs. These VgrGs interacted with corresponding DUF4123 domain proteins, which were secreted outside of the membrane and were dependent on either the T6SS or type IV secretion system (T4SS). This interaction directly governed virulence and competition. Meanwhile, supernatant proteomic analyses with strains defective in the T6SS and/or T4SS confirmed that effectors, such as FhaB, were secreted redundantly to control the virulence and suppress host callose deposition in the course of infection. Notably, this redundant secretion mechanism between the T6SS and T4SS is believed to be the first of its kind in bacteria.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças das Plantas
/
Proteínas de Bactérias
/
Pectobacterium
/
Sistemas de Secreção Tipo VI
Idioma:
En
Revista:
Phytopathology
Assunto da revista:
BOTANICA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
China