The XadA Trimeric Autotransporter Adhesins in Xylella fastidiosa Differentially Contribute to Cell Aggregation, Biofilm Formation, Insect Transmission and Virulence to Plants

Author(s):Show less -

Feitosa-Junior, Oseias R. ; Souza, Ana Paula S. ; Zaini, Paulo A. ; Baccari, Clelia ; Ionescu, Michael ; Pierry, Paulo M. ; Uceda-Campos, Guillermo ; Labroussaa, Fabien ; Almeida, Rodrigo P. P. ; Lindow, Steven E. ; da Silva, Aline M.

• Document type: Journal article
• Source: MOLECULAR PLANT-MICROBE INTERACTIONS; v. 35, n. 9, p. 10-pg., 2022-09-01.

Abstract

Surface adhesion strategies are widely employed by bacterial pathogens during establishment and systemic spread in their host. A variety of cell-surface appendages such as pili, fimbriae, and afimbrial adhesins are involved in these processes. The phytopathogen Xylella fastidiosa employs several of these structures for efficient colonization of its insect and plant hosts. Among the adhesins encoded in the X. fastidiosa genome, three afimbrial adhesins, XadA1, Hsf/XadA2, and XadA3, are predicted to be trimeric autotransporters with aC-terminalYadA-anchor membrane domain. We analyzed the individual contributions of XadA1, XadA2, andXadA3 to various cellular behaviors both in vitro and in vivo. Using isogenic X. fastidiosa mutants, we found that cell-cell aggregation and biofilm formation were severely impaired in the absence of XadA3. No significant reduction of cell-surface attachment was found with any mutant under flow conditions. Acquisition by insect vectors and transmission to grapevines were reduced in the XadA3 deletion mutant. While the XadA3 mutant was hypervirulent in grapevines, XadA1 or XadA2 deletion mutants conferred lower disease severity than the wild-type strain. This insight of the importance of these adhesive proteins and their individual contributions to different aspects of X. fastidiosa biology should guide new approaches to reduce pathogen transmission and disease development. (AU)

• FAPESP's process: 11/09409-3 - Microfluidic technology to study phytopathogenic bacteria adhesion mechanisms
• Grantee: Paulo Adriano Zaini
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 11/24091-0 - Transcriptome analysis of Xylella fastidiosa strains isolated from distinct hosts and search for regulatory RNAs
• Grantee: Paulo Marques Pierry
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 14/03617-1 - Biochemical and functional characterization of Xylella fastidiosa XadA3 adhesin
• Grantee: Ana Paula Silva de Souza
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 10/16409-7 - Molecular aspects of Xylella fastidiosa-plant interaction
• Grantee: Aline Maria da Silva
• Support Opportunities: Scholarships abroad - Research
• FAPESP's process: 08/11703-4 - Identification of genes potentially involved in adaptation, evolution and virulence of Xylella fastidiosa
• Grantee: Aline Maria da Silva
• Support Opportunities: Regular Research Grants