The leaf, inner bark and latex cyanide potential of Hevea brasiliensis: Evidence for involvement of cyanogenic glucosides in rubber yield

Linamarin (1), the major cyanogenic glucoside synthesized in the young mature leaves of Hevea, accumulates particularly in parenchyma cells of the tree bark. The cyanide potential (CNp) of leaves and trunk bark were shown to be positively correlated with the yield potential of the rubber clones. The decrease in bark CNp in the trunk of the tapped trees, the very low CNp of latex cells and the presence of all enzymes needed to hydrolyze the cyanogenic glucosides and to detoxify the free cyanide, led to the conclusion that the cyanogenic glucosides-derived glucose and asparagine may contribute to the latex metabolism and regeneration, thus to latex yield.