@article{fdi:010091008,
  title = {{T}he cepacian-like exopolysaccharide of {P}araburkholderia ultramafica {STM}10279({T}) enhances growth and metal adaptation of {T}etraria comosa on {N}ew {C}aledonian ultramafic soil},
  author = {{B}ourles, {A}. and {P}ierre, {G}. and {A}mir, {H}. and {L}e {F}loc'h, {A}. and {C}halkiadakis, {E}. and {M}{\'e}devielle, {V}. and {J}ourand, {P}hilippe and {M}ichaud, {P}. and {B}urtet-{S}arram{\'e}gna, {V}. and {G}uentas, {L}.},
  editor = {},
  language = {{ENG}},
  abstract = {{P}araburkholderia ultramafica {STM}10279({T}) is a metal-tolerant rhizobacterium that promotes plant growth. {I}t was isolated from the roots of {T}etraria arundinaceae, a pioneer endemic tropical herb growing on ultramafic soils in {N}ew {C}aledonia. {W}e have recently shown that the main mechanism of metal tolerance of {P}. ultramafica is related to the production of an acidic exopolysaccharide ({EPS}). {T}o explore the potential role of this {EPS} in the plant's environmental adaptation, we first elucidated its structure by employing a combination of chromatography and mass spectrometry techniques. {T}hese analyses revealed that the {EPS} is highly branched and composed of galactosyl (35.8%), glucosyl (33.2%), rhamnosyl (19.5%), mannosyl (7.2%), and glucuronosyl residues (4.4%), similar to the {EPS} of the {B}urkholderia cepacia complex known as cepacian. {W}e subsequently conducted greenhouse experiments on {T}etraria comosa plantlets inoculated with {P}. ultramafica or a solution of its {EPS} during transplanting onto ultramafic substrate. {T}he data showed that the dry weight of {T}. comosa shoots was 2.5 times higher in the plants treated with the {EPS} compared to the unexposed plants. {I}n addition, inductively coupled plasma-optical emission spectrometry ({ICP}-{OES}) analysis revealed that exposure to the {EPS} significantly increased {C}a, {M}g, {K}, and {P} uptake as well as {K} content in roots. {I}n vitro experiments using the {P}ikovskaya method showed that the {EPS} was able to solubilize phosphorus. {C}onsistent with the retention of metals in roots and a reduction in shoots, our data revealed a significant decrease in metal translocation factors ({TF}s) in the plants inoculated with the {EPS}. {T}hese results suggest a beneficial effect of the rhizobacterial {EPS} on plant growth and abiotic stress mitigation. {I}n addition, the data suggest that the reduced levels of trace metals in plants exposed to {P}. ultramafica {STM}10279({T}) are due to metal chelation by the {EPS}. {F}urther investigations are needed to firmly demonstrate whether this {EPS} could be used as a biostimulant for plant growth and adaptation to ultramafic soils.},
  keywords = {{PGPR} ; exopolysaccharides ; biostimulant ; {P}araburkholderia ; plant metal ; alleviation ; ultramafic soil ; phosphate solubilization ; {NOUVELLE} {CALEDONIE}},
  booktitle = {},
  journal = {{F}rontiers in {P}lant {S}cience},
  volume = {15},
  numero = {},
  pages = {1349724 [13 p.]},
  ISSN = {1664-462{X}},
  year = {2024},
  DOI = {10.3389/fpls.2024.1349724},
  URL = {https://www.documentation.ird.fr/hor/fdi:010091008},
}