Mendes Juliano S, Santiago André S, Toledo Marcelo A S, Horta Maria A C, de Souza Alessandra A, Tasic Ljubica, de Souza Anete P
Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas Campinas, Brazil.
Instituto Agronômico, Centro de Citricultura Sylvio Moreira Cordeirópolis, Brazil.
Front Microbiol. 2016 Dec 26;7:2090. doi: 10.3389/fmicb.2016.02090. eCollection 2016.
The phytopathogen causes economic losses in important agricultural crops. Xylem vessel occlusion caused by biofilm formation is the major mechanism underlying the pathogenicity of distinct strains of . Here, we provide a detailed characterization of the extracellular proteins of . 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 of in 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 of biofilm development, including proteases, quorum-sensing proteins, biofilm formation proteins, hypothetical proteins, phage-related proteins, chaperones, toxins, antitoxins, and extracellular vesicle membrane components.
这种植物病原体在重要农作物中造成经济损失。生物膜形成导致的木质部导管堵塞是不同菌株致病性的主要机制。在此，我们对该病原体的细胞外蛋白质进行了详细表征。基于这些结果，我们与菌株J1a12进行了比较，该菌株接种到柑橘植株中时不会引发柑橘杂色黄化症状。然后，我们扩展了这种方法，以分析在添加钙的培养基中该病原体的细胞外蛋白质。我们证实细胞外蛋白质随着生长天数以及生物膜发育（3 - 30天）而增加。在9a5c菌株生长10天时开始鉴定出携带毒素的外膜囊泡。此外，在两种菌株中均观察到添加钙的培养基中细胞外蛋白质减少。使用质谱分析，在该病原体生物膜发育的30天内鉴定出71种不同蛋白质，包括蛋白酶、群体感应蛋白、生物膜形成蛋白、假定蛋白、噬菌体相关蛋白、伴侣蛋白、毒素、抗毒素以及细胞外囊泡膜成分。
