Modified Monosaccharides Content of Xanthan Gum Impairs Citrus Canker Disease by Affecting the Epiphytic Lifestyle of Xanthomonas citri subsp. citri

Autor(es)

Picchi, Simone Cristina ^[1] ; Granato, Lais Moreira ^[1] ; Franzini, Maria Julia Festa ^[1] ; Andrade, Maxuel Oliveira ^[2] ; Takita, Marco Aurelio ^[1] ; Machado, Marcos Antonio ^[1] ; de Souza, Alessandra Alves ^[1]

Afiliação do(s) autor(es)

^[1] Inst Agron Campinas, Ctr Citricultura Sylvio Moreira, Biotechnol Lab, BR-1349070 Sao Paulo - Brazil

^[2] Ctr Nacl Pesquisa Energia & Mat, Biosci Natl Lab, BR-13083100 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MICROORGANISMS; v. 9, n. 6 JUN 2021.
• Citações Web of Science: 0

Resumo

Xanthomonas citri subsp. citri (X. citri) is a plant pathogenic bacterium causing citrus canker disease. The xanA gene encodes a phosphoglucomutase/phosphomannomutase protein that is a key enzyme required for the synthesis of lipopolysaccharides and exopolysaccharides in Xanthomonads. In this work, firstly we isolated a xanA transposon mutant (xanA::Tn5) and analyzed its phenotypes as biofilm formation, xanthan gum production, and pathogenesis on the sweet orange host. Moreover, to confirm the xanA role in the impaired phenotypes we further produced a non-polar deletion mutant (Delta xanA) and performed the complementation of both xanA mutants. In addition, we analyzed the percentages of the xanthan gum monosaccharides produced by X. citri wild-type and xanA mutant. The mutant strain had higher ratios of mannose, galactose, and xylose and lower ratios of rhamnose, glucuronic acid, and glucose than the wild-type strain. Such changes in the saccharide composition led to the reduction of xanthan yield in the xanA deficient strain, affecting also other important features in X. citri, such as biofilm formation and sliding motility. Moreover, we showed that xanA::Tn5 caused no symptoms on host leaves after spraying, a method that mimetics the natural infection condition. These results suggest that xanA plays an important role in the epiphytical stage on the leaves that is essential for the successful interaction with the host, including adaptive advantage for bacterial X. citri survival and host invasion, which culminates in pathogenicity. (AU)

• Processo FAPESP: 13/10957-0 - Interação Xylella fastidiosa-inseto vetor-planta hospedeira e abordagens para o controle da clorose variegada dos citros e cancro cítrico
• Beneficiário: Alessandra Alves de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/18570-9 - Análise funcional de CsMAF1, um repressor da RNA polimerase III envolvida no controle do crescimento celular e resposta a patógeno em plantas
• Beneficiário: Maxuel de Oliveira Andrade
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/50880-0 - INCT 2014: de genômica comparativa e funcional e melhoramento assistido de citros
• Beneficiário: Marcos Antonio Machado
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 13/01395-9 - N-acetil-cisteina (NAC): uma molécula com potencial antimicrobiano para o manejo do cancro cítrico.
• Beneficiário: Simone Cristina Picchi
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/01901-8 - Silenciamento gênico do floema cítrico: modulação da hipersensibilidade à infecção por Candidatus liberibacter spp
• Beneficiário: Laís Moreira Granato
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado