Phenotype Overlap in Xylella fastidiosa Is Controlled by the Cyclic Di-GMP Phosphodiesterase Eal in Response to Antibiotic Exposure and Diffusible Signal Factor-Mediated Cell-Cell Signaling

Autor(es)

de Souza, Alessandra A. ^{[1, 2]} ; Ionescu, Michael ^[2] ; Baccari, Clelia ^[2] ; da Silva, Aline M. ^[3] ; Lindow, Steven E. ^[2]

Afiliação do(s) autor(es)

^[1] Inst Agron Campinas, Ctr APTA Citros Sylvio Moreira, Cordeiropolis, SP - Brazil

^[2] Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 - USA

^[3] Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-01498 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Applied and Environmental Microbiology; v. 79, n. 11, p. 3444-3454, JUN 2013.
• Citações Web of Science: 14

Resumo

Eal is an EAL domain protein in Xylella fastidiosa homologous to one involved in resistance to tobramycin in Pseudomonas aeruginosa. EAL and HD-GYP domain proteins are implicated in the hydrolysis of the secondary messenger bis-(3'-5')-cyclic dimeric GMP (cyclic di-GMP). Cell density-dependent communication mediated by a Diffusible Signal Factor (DSF) also modulates cyclic di-GMP levels in X. fastidiosa, thereby controlling the expression of virulence genes and genes involved in insect transmission. The possible linkage of Eal to both extrinsic factors such as antibiotics and intrinsic factors such as quorum sensing, and whether both affect virulence, was thus addressed. Expression of eal was induced by subinhibitory concentrations of tobramycin, and an eal deletion mutant was more susceptible to this antibiotic than the wild-type strain and exhibited phenotypes similar to those of an rpfF deletion mutant blocked in DSF production, such as hypermotility, reduced biofilm formation, and hypervirulence to grape. Consistent with that, the rpfF mutant was more susceptible than the wild-type strain to tobramycin. Therefore, we propose that cell-cell communication and antibiotic stress can apparently lead to similar modulations of cyclic di-GMP in X. fastidiosa, resulting in similar phenotypes. However, the effect of cell density is dominant compared to that of antibiotic stress, since eal is suppressed by RpfF, which may prevent inappropriate behavioral changes in response to antibiotic stress when DSF accumulates. (AU)

• Processo FAPESP: 10/16409-7 - Aspectos moleculares da interação de Xylella fastidiosa com seus hospedeiros vegetais
• Beneficiário: Aline Maria da Silva
• Modalidade de apoio: Bolsas no Exterior - Pesquisa
• Processo FAPESP: 08/03626-0 - Quorum sensing em Xylella fastidiosa: papel do DSF na modulação das respostas a estresse e controle da população bacteriana
• Beneficiário: Alessandra Alves de Souza
• Modalidade de apoio: Bolsas no Exterior - Novas Fronteiras