Laser diffraction : A new tool for identification and studies of the physiological effectors involved in aggregation-coagulation of rubber particles from hevea latex

Coagulation of latex is the first limiting factor of rubber yield in Hevea brasiliensis. Using laser diffraction, we set up a new method allowing to monitor the kinetics of rubber particles (RP) aggregation. Contrary to the previous methods used (visual observation and more recently spectrophotometry), laser diffraction allows to continuously follow the changes in size of RP and aggregates, then to quantify and characterize the phenomena involved in the aggregation-coagulation processes. Using this technique we confirmed that the major RP aggregating factors are proteins compartmentalized within the latex cells vacuoles. Opposite, the latex cytosol is confirmed to harbour anti-aggregating proteins. Lutoidic serum alone can induce formation of RP loose aggregates which can be large enough to provoke the obstruction of the severed latex vessels extremities, but not irreversible RP coagulation. Using this new method, identification and characterization of the other proteins, as well as their corresponding genes, involved (as +/- effectors) in latex destabilisation/coagulation, hence in rubber yield, are on the process. (Résumé d'auteur