Rhizobial extrachromosomal replicon variability, stability and expression in natural niches.
In bacteria, niche adaptation may be determined by mobile extrachromosomal elements. A remarkable characteristic of Rhizobium and Ensifer (Sinorhizobium) but also of Agrobacterium species is that almost half of the genome is contained in several large extrachromosomal replicons (ERs). They encode a plethora of functions, some of them required for bacterial survival, niche adaptation, plasmid transfer or stability. In spite of this, plasmid loss is common in rhizobia upon subculturing. Rhizobial gene-expression studies in plant rhizospheres with novel results from transcriptomic analysis of Rhizobium phaseoli in maize and Phaseolus vulgaris roots highlight the role of ERs in natural niches and allowed the identification of common extrachromosomal genes expressed in association with plant rootlets and the replicons involved.
Centro de Ciencias Genómicas, UNAM, Av. Universidad SN, Cuernavaca, Morelos, Mexico.
Martha G
MG
López-Guerrero
Ernesto
E
Ormeño-Orrillo
José Luis
JL
Acosta
Alfredo
A
Mendoza-Vargas
Marco A
MA
Rogel
Miguel Angel
MA
Ramírez
Mónica
M
Rosenblueth
Julio
J
Martínez-Romero
Esperanza
E
Martínez-Romero
D060054:Agrobacterium / Q000235:genetics / Q000378:metabolism; D005111:Extrachromosomal Inheritance; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000382:microbiology; D018517:Plant Roots / Q000235:genetics*; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D012336:RNA, Ribosomal, 16S; D012093:Replicon; D012231:Rhizobium / Q000235:genetics / Q000378:metabolism; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D020579:Sinorhizobium / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000382:microbiology
D012336:RNA, Ribosomal, 16S