Deletion of <i>pbpC</i> Enhances Bacterial Pathogenicity on Tomato by Affecting Biofilm Formation, Exopolysaccharides Production, and Exoenzyme Activities in <i>Clavibacter michiganensis</i>
Penicillin-binding proteins (PBPs) are considered essential for bacterial peptidoglycan biosynthesis and cell wall assembly. <i>Clavibacter michiganensis</i> is a representative Gram-positive bacterial species that causes bacterial canker in tomato. <i>pbpC</i> plays a signif...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-03-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/6/5324 |
| Summary: | Penicillin-binding proteins (PBPs) are considered essential for bacterial peptidoglycan biosynthesis and cell wall assembly. <i>Clavibacter michiganensis</i> is a representative Gram-positive bacterial species that causes bacterial canker in tomato. <i>pbpC</i> plays a significant role in maintaining cell morphological characteristics and stress responses in <i>C. michiganensis</i>. The current study demonstrated that the deletion of <i>pbpC</i> commonly enhances bacterial pathogenicity in <i>C. michiganensis</i> and revealed the mechanisms through which this occurs. The expression of interrelated virulence genes, including <i>celA, xysA, xysB</i>, and <i>pelA</i>, were significantly upregulated in △<i>pbpC</i> mutants. Compared with those in wild-type strains, exoenzyme activities, the formation of biofilm, and the production of exopolysaccharides (EPS) were significantly increased in △<i>pbpC</i> mutants. It is noteworthy that EPS were responsible for the enhancement in bacterial pathogenicity, with the degree of necrotic tomato stem cankers intensifying with the injection of a gradient of EPS from <i>C. michiganensis</i>. These findings highlight new insights into the role of <i>pbpC</i> affecting bacterial pathogenicity, with an emphasis on EPS, advancing the current understanding of phytopathogenic infection strategies for Gram-positive bacteria. |
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| ISSN: | 1661-6596 1422-0067 |