Symbiotic nitrogen fixation in legumes: perspectives on the diversity and evolution of nodulation by Rhizobium and Burkholderia species

Abstract

–legume symbiosis asking the question “whatmakes this symbiosis so special?” (Hirsch et al., 2001).Sincethattime,wehavelearnedagreatdealmoreaboutthisimportantplant–microbeassociation.However,thestoryofsymbioticnitrogenfixationinlegumeshasbecomemorecomplicatedduetothediscoveryofseveralBetaproteobac-teria, namely species of