Open AccessBiodiversity of M imosa pudica rhizobial symbionts ( C upriavidus taiwanensis , R hizobium mesoamericanum ) in N ew C aledonia and their adaptation to heavy metal‐rich soils
Author(s) -
Klonowska Agnieszka,
Chaintreuil Clémence,
Tisseyre Pierre,
Miché Lucie,
Melkonian Rémy,
Ducousso Marc,
Laguerre Gisèle,
Brunel Brigitte,
Moulin Lionel
Publication year - 2012
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2012.01393.x
Subject(s) - biology , rhizobia , rhizobium , botany , symbiosis , mimosa pudica , nitrogen fixation , proteobacteria , 16s ribosomal rna , bacteria , genetics
Rhizobia are soil bacteria able to develop a nitrogen‐fixing symbiosis with legumes. They are taxonomically spread among the alpha and beta subclasses of the P roteobacteria . M imosa pudica , a tropical invasive weed, has been found to have an affinity for beta‐rhizobia, including species within the B urkholderia and C upriavidus genera. In this study, we describe the diversity of M . pudica symbionts in the island of N ew C aledonia, which is characterized by soils with high heavy metal content, especially of N i. By using a plant‐trapping approach on four soils, we isolated 96 strains, the great majority of which belonged to the species C upriavidus taiwanensis (16 S rRNA and recA gene phylogenies). A few R hizobium strains in the newly described species R hizobium mesoamericanum were also isolated. The housekeeping and nod gene phylogenies supported the hypothesis of the arrival of the C . taiwanensis and R . mesoamericanum strains together with their host at the time of the introduction of M . pudica in N ew C aledonia ( NC ) for its use as a fodder. The C . taiwanensis strains exhibited various tolerances to N i, Z n and C r, suggesting their adaptation to the specific environments in NC . Specific metal tolerance marker genes were found in the genomes of these symbionts, and their origin was investigated by phylogenetic analyses.