Ethrel® stimulant increases the activity of soluble invertase isoforms in rubber tree (Hevea brasiliensis) bark tissues

Abstract

Ethrel® is a commercial stimulant based on ethylene commonly used in exploitation systems for increases sucrose hydrolysis and improve dry rubber production by rubber tree (Hevea brasiliensis). The main enzymes that act on sucrose hydrolysis and provide hexoses for rubber biosynthesis are invertase isoforms: Vacuolar Invertase (VIN), Cell Wall Invertase, (CWIN) and Neutral Invertase (NIN). The aim of this study was to evaluate the contribution of each of the invertase isoforms (VIN, NIN and CWIN) in rubber tree bark tissues stimulated with Ethrel® and its relationship with the rubber production. For this, they were made two Ethrel® applications in commercial planting of RRIM 600 clone rubber trees, a 34-day interval. Ethrel® stimulated rubber trees showed a 40% increase in dry rubber production. This work demonstrated that this increase is due to the higher performance of the NIN and VIN invertase isoforms, which contributed to the availability of hexoses in the intracellular compartment favoring rubber biosynthesis and improving the inflow of water necessary to the latex flow.