Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2021
Publication Date: 8/2/2021
Citation: Wei, W., Burbank, L.P. 2021. Csp1, a cold-shock protein Homolog in Xylella fastidiosa is involved in biofilm formation, stress sesponse and virulence. American Phytopathological Society Abstracts.
Technical Abstract: Bacterial cold shock proteins are conserved nucleic acid binding chaperones. Csp1 is a temperature-independent cold shock protein homolog in Xylella fastidiosa, a bacterial pathogen of grapevine and other economically important crops. Csp1 contributes to stress tolerance and virulence in X. fastidiosa. However, little is known about the specific function(s) of Csp1. To investigate the role(s) of Csp1, phenotypic differences between wild type X. fastidiosa strain Stag’s Leap and a csp1 deletion mutant ('csp1) were compared. A significant decrease in cellular aggregation and surface attachment was observed in 'csp1. The 'csp1 strain was also less viable than wild type after long term growth, in vitro. The role of Csp1 on gene expression was also investigated. Transcriptomes of wild type and 'csp1 grown under standard conditions were sequenced with Nanopore’s MinION. RNA-Seq analysis showed changes in expression of several motility and biofilm-related genes. One gene of intertest, pilA1, encodes a type IV pili subunit protein and was up regulated in 'csp1. Type IV pili contribute to virulence by facilitating bacterial movement inside host vascular tissue. Deleting pilA1 from the Stag’s Leap genome increased biofilm formation in vitro and reduced virulence in grapevines. X. fastidiosa virulence depends on attachment and movement within xylem vessels. Studies in other bacteria have also linked biofilm formation with stress responses. These results suggest Csp1 may play roles in virulence and stress tolerance by influencing expression of genes involved in biofilm formation.