Ethylene and jasmonate as stimulants of latex yield in rubber trees (Hevea brasiliensis): Molecular and physiological mechanisms. A systematic approximation review

The rubber tree Hevea brasiliensis (Willd. Ex Adr. De Juss.) Müell Arg.] is an important source of latex for the production natural rubber. Natural rubber is an important biopolymer used in various industries, but aspects related to hormonal regulation in biosynthesis are still unknown, which would allow optimizing its production. We review the molecular and physiological mechanisms of increases latex regeneration and flow by the stimulation of rubber trees with exogenous applications of ethylene and jasmonate. We found that the increase in latex regeneration by ethylene is due to the increase in gene level expression and enzymatic activity of key photosynthesis and glycolysis enzymes for the generation of precursors in the first phase of rubber biosynthesis. Latex flow is supported by up-regulated genes in sucrose metabolism such as invertases, induction of sucrose transporters (SUT), and aquaporins (PIP) to maintain flow and turgor pressure in laticifers. Meanwhile, the increase in latex yield mediated by jasmonate may be due to the induction of laticifer differentiation in the long term and in the short term be mediated by the induction of small rubber particles (SRPP) as non-enzymatic cofactors in the production of latex. This information contributes to the knowledge of latex biosynthesis, which allows for a greater support for the exogenous application of jasmonates and ethylene to regulate its production.