@article{fdi:010080965,
  title = {{R}ib{BX} of {B}radyrhizobium {ORS}285 plays an important role in intracellular persistence in various {A}eschynomene host plants},
  author = {{N}ouwen, {N}ico and {A}rrighi, {J}ean-{F}ran{\c{c}}ois and {G}ully, {D}jamel and {G}iraud, {E}ric},
  editor = {},
  language = {{ENG}},
  abstract = {{B}radyrhizobium {ORS}285 forms a nitrogen-fixating symbiosis with both {N}od factor ({NF})-dependent and {NF}-independent {A}eschynomene spp. {T}he {B}radyrhizobium {ORS}285 rib{BA} gene encodes for a putative bifunctional enzyme with 3,4-dihydroxybutanone phosphate (3,4-{DHBP}) synthase and guanosine triphosphate ({GTP}) cyclohydrolase {II} activities, catalyzing the initial steps in the riboflavin biosynthesis pathway. {I}n this study, we show that inactivating the rib{BA} gene does not cause riboflavin auxotrophy under free-living conditions and that, as shown for {R}ib{BA}s from other bacteria, the {GTP} cyclohydrolase {II} domain has no enzymatic activity. {F}or this reason, we have renamed the annotated rib{BA} as rib{BX}. {B}ecause we were unable to identify other rib{BA} or rib{A} and rib{B} homologs in the genome of {B}radyrhizobium {ORS}285, we hypothesize that the {ORS}285 strain can use unconventional enzymes or an alternative pathway for the initial steps of riboflavin biosynthesis. {I}nactivating rib{BX} has a drastic impact on the interaction of {B}radyrhizobium {ORS}285 with many of the tested {A}eschynomene spp. {I}n these {A}eschynomene spp., the {ORS}285 rib{BX} mutant is able to infect the plant host cells but the intracellular infection is not maintained and the nodules senesce early. {T}his phenotype can be complemented by reintroduction of the 3,4-{DHBP} synthase domain alone. {O}ur results indicate that, in {B}radyrhizobium {ORS}285, the {R}ib{BX} protein is not essential for riboflavin biosynthesis under free-living conditions and we hypothesize that its activity is needed to sustain riboflavin biosynthesis under certain symbiotic conditions.},
  keywords = {bacteria-plant symbiosis ; mutualism ; nodule organogenesis ; rhizobium ; rhizobium-legume symbiosis ; vitamin {B}2},
  booktitle = {},
  journal = {{M}olecular {P}lant-{M}icrobe {I}nteractions},
  volume = {34},
  numero = {1},
  pages = {88--99},
  ISSN = {0894-0282},
  year = {2021},
  DOI = {10.1094/mpmi-07-20-0209-r},
  URL = {https://www.documentation.ird.fr/hor/fdi:010080965},
}