Jagoueix S, Bove J M, Garnier M
Laboratoire de Biologie Cellulaire et Moléculaire, INRA, Villenave d'Ornon, France.
Int J Syst Bacteriol. 1994 Jul;44(3):379-86. doi: 10.1099/00207713-44-3-379.
Using the PCR, we amplified the 16S ribosomal DNAs (rDNAs) of an Asian strain and an African strain of the uncultured, gram-negative, walled, phloem-limited bacterium-like organism (BLO) associated with citrus greening disease. We evaded coamplification of chloroplast 16S rDNA by using restriction enzymes; the chloroplast 16S rDNA was sensitive to BclI digestion and resistant to EcoRI digestion, while the 16S rDNA of the BLO was resistant to BclI digestion and sensitive to EcoRI digestion. The 16S rDNA of the African BLO strain was amplified from BclI-digested DNA extracted from infected periwinkle leaf midribs. The Asian strain was isolated from plant extract by using a specific monoclonal antibody coated onto the surface of a PCR tube. The 16S rDNAs of the two BLO strains were cloned and sequenced. Comparisons with sequences of 16S rDNAs obtained from the GenBank data base revealed that the two citrus greening disease BLOs belong to the alpha subdivision of the class Proteobacteria. Even though their closest relatives are members of the alpha-2 subgroup, these BLOs are distinct from this subgroup as we observed only 87.5% homology between the 16S rDNAs examined. Therefore, the two BLOs which we studied probably are members of a new lineage in the alpha subdivision of the Proteobacteria. We propose the trivial name "liberobacter" for this new group of bacteria and will wait until additional characteristics have been determined before we propose a formal name.
我们利用聚合酶链反应（PCR）扩增了与柑橘黄龙病相关的未培养、革兰氏阴性、有细胞壁、韧皮部受限的类细菌生物（BLO）的亚洲菌株和非洲菌株的16S核糖体DNA（rDNA）。我们通过使用限制酶避免了叶绿体16S rDNA的共扩增；叶绿体16S rDNA对BclI消化敏感，对EcoRI消化有抗性，而BLO的16S rDNA对BclI消化有抗性，对EcoRI消化敏感。非洲BLO菌株的16S rDNA是从感染长春花叶片中脉提取的经BclI消化的DNA中扩增得到的。亚洲菌株是通过使用包被在PCR管表面的特异性单克隆抗体从植物提取物中分离出来的。对这两个BLO菌株的16S rDNA进行了克隆和测序。与从GenBank数据库获得的16S rDNA序列进行比较后发现，这两种柑橘黄龙病BLO属于变形菌纲α亚纲。尽管它们最亲近的亲属是α-2亚群的成员，但这些BLO与该亚群不同，因为我们观察到所检测的16S rDNA之间只有87.5%的同源性。因此，我们研究的这两种BLO可能是变形菌纲α亚纲中的一个新谱系的成员。我们为这一新的细菌群体提议了一个俗名“韧皮杆菌”，并将等待确定更多特征后再提议一个正式名称。
