@article{fdi:010048254,
  title = {{I}nvolvement of {H}b{PIP}2;1 and {H}b{TIP}1;1 aquaporins in ethylene stimulation of latex yield through regulation of water exchanges between inner liber and latex cells in {H}evea brasiliensis},
  author = {{T}ungngoen, {K}. and {K}ongsawadworakul, {P}. and {V}iboonjun, {U}. and {K}atsuhara, {M}. and {B}runel, {N}. and {S}akr, {S}. and {N}arangajavana, {J}. and {C}hrestin, {H}erv{\'e}},
  editor = {},
  language = {{ENG}},
  abstract = {{N}atural rubber is synthesized in specialized articulated cells (laticifers) located in the inner liber of {H}evea brasiliensis. {U}pon bark tapping, the laticifer cytoplasm (latex) is expelled due to liber tissue turgor pressure. {I}n mature virgin (untapped) trees, short-term kinetic studies confirmed that ethylene, the rubber yield stimulant used worldwide, increased latex yield, with a concomitant decrease in latex total solid content, probably through water influx in the laticifers. {A}s the mature laticifers are devoid of plasmodesmata, the rapid water exchanges with surrounding liber cells probably occur via the aquaporin pathway. {T}wo full-length aquaporin c{DNA}s ({H}b{PIP}2;1 and {H}b{TIP}1;1, for plasma membrane intrinsic protein and tonoplast intrinsic protein, respectively) were cloned and characterized. {T}he higher efficiency of {H}b{PIP}2;1 than {H}b{TIP}1;1 in increasing plasmalemma water conductance was verified in {X}enopus laevis oocytes. {H}b{PIP}2;1 was insensitive to {H}g{C}l2. {I}n situ hybridization demonstrated that {H}b{PIP}2;1 was expressed in all liber tissues in the young stem, including the laticifers. {H}b{PIP}2;1 was up-regulated in both liber tissues and laticifers, whereas {H}b{TIP}1;1 was down-regulated in liber tissues but up-regulated in laticifers in response to bark {E}threl treatment. {E}thylene-induced {H}b{PIP}2;1 up-regulation was confirmed by western-blot analysis. {T}he promoter sequences of both genes were cloned and found to harbor, among many others, ethylene-responsive and other chemical-responsive (auxin, copper, and sulfur) elements known to increase latex yield. {I}ncrease in latex yield in response to ethylene was emphasized to be linked with water circulation between the laticifers and their surrounding tissues as well as with the probable maintenance of liber tissue turgor, which together favor prolongation of latex flow.},
  keywords = {},
  booktitle = {},
  journal = {{P}lant {P}hysiology},
  volume = {151},
  numero = {2},
  pages = {843--856},
  ISSN = {0032-0889},
  year = {2009},
  DOI = {10.1104/pp.109.140228},
  URL = {https://www.documentation.ird.fr/hor/fdi:010048254},
}