New betaproteobacterial Rhizobium strains able to efficiently nodulate Parapiptadenia rigida (Benth.) Brenan.
Among the leguminous trees native to Uruguay, Parapiptadenia rigida (Angico), a Mimosoideae legume, is one of the most promising species for agroforestry. Like many other legumes, it is able to establish symbiotic associations with rhizobia and belongs to the group known as nitrogen-fixing trees, which are major components of agroforestry systems. Information about rhizobial symbionts for this genus is scarce, and thus, the aim of this work was to identify and characterize rhizobia associated with P. rigida. A collection of Angico-nodulating isolates was obtained, and 47 isolates were selected for genetic studies. According to enterobacterial repetitive intergenic consensus PCR patterns and restriction fragment length polymorphism analysis of their nifH and 16S rRNA genes, the isolates could be grouped into seven genotypes, including the genera Burkholderia, Cupriavidus, and Rhizobium, among which the Burkholderia genotypes were the predominant group. Phylogenetic studies of nifH, nodA, and nodC sequences from the Burkholderia and the Cupriavidus isolates indicated a close relationship of these genes with those from betaproteobacterial rhizobia (beta-rhizobia) rather than from alphaproteobacterial rhizobia (alpha-rhizobia). In addition, nodulation assays with representative isolates showed that while the Cupriavidus isolates were able to effectively nodulate Mimosa pudica, the Burkholderia isolates produced white and ineffective nodules on this host.
Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, MEC, Unidad Asociada a la Facultad de Ciencias, Montevideo, Uruguay.
Cecilia
C
Taulé
María
M
Zabaleta
Cintia
C
Mareque
Raúl
R
Platero
Lucía
L
Sanjurjo
Margarita
M
Sicardi
Lillian
L
Frioni
Federico
F
Battistoni
Elena
E
Fabiano
D019117:Burkholderia / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D016000:Cluster Analysis; D049921:Cupriavidus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D007887:Fabaceae / Q000382:microbiology*; D005838:Genotype; D031298:Mimosa / Q000382:microbiology; D008969:Molecular Sequence Data; D058889:Molecular Typing; D009586:Nitrogen Fixation; D010088:Oxidoreductases / Q000235:genetics; D010802:Phylogeny; D055170:Plant Root Nodulation; D018517:Plant Roots / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D017422:Sequence Analysis, DNA; D014583:Uruguay
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D010088:Oxidoreductases; C029130:nitrogenase reductase