title: In vitroDetermination of Extracellular Proteins fromXylella fastidiosa.
abstract: The phytopathogenXylella fastidiosacauses economic losses in important agricultural crops. Xylem vessel occlusion caused by biofilm formation is the major mechanism underlying the pathogenicity of distinct strains ofX. fastidiosa. Here, we provide a detailedin vitrocharacterization of the extracellular proteins ofX. fastidiosa. Based on the results, we performed a comparison with a strain J1a12, which cannot induce citrus variegated chlorosis symptoms when inoculated into citrus plants. We then extend this approach to analyze the extracellular proteins ofX. fastidiosain media supplemented with calcium. We verified increases in extracellular proteins concomitant with the days of growth and, consequently, biofilm development (3-30 days). Outer membrane vesicles carrying toxins were identified beginning at 10 days of growth in the 9a5c strain. In addition, a decrease in extracellular proteins in media supplemented with calcium was observed in both strains. Using mass spectrometry, 71 different proteins were identified during 30 days ofX. fastidiosabiofilm development, including proteases, quorum-sensing proteins, biofilm formation proteins, hypothetical proteins, phage-related proteins, chaperones, toxins, antitoxins, and extracellular vesicle membrane components.
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas Campinas, Brazil.
authors.forename: Juliano S
authors.initials: JS
authors.lastname: Mendes
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas Campinas, Brazil.
authors.forename: André S
authors.initials: AS
authors.lastname: Santiago
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas Campinas, Brazil.
authors.forename: Marcelo A S
authors.initials: MA
authors.lastname: Toledo
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas Campinas, Brazil.
authors.forename: Maria A C
authors.initials: MA
authors.lastname: Horta
authors.affiliation: Instituto Agronômico, Centro de Citricultura Sylvio Moreira Cordeirópolis, Brazil.
authors.forename: Alessandra A
authors.initials: AA
authors.lastname: de Souza
authors.affiliation: Departamento de Química Orgânica, Instituto de Química, Universidade Estadual de Campinas Campinas, Brazil.
authors.forename: Ljubica
authors.initials: L
authors.lastname: Tasic
authors.affiliation: Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de CampinasCampinas, Brazil; Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de CampinasCampinas, Brazil.
authors.forename: Anete P
authors.initials: AP
authors.lastname: de Souza
keywords: LC-MS/MS; PW medium; Xylella fastidiosa; biofilm; calcium; extracellular proteins