Influence of Exogenous Auxins on Phenolic Compounds Contents and Polyphenol oxidasic and Peroxidasic Activities in Root Differentiation in <i>Gnetum</i> spp.

Abstract

Root failure is a key limiting factor in Gnetum spp. domestication and production of plants materials for farming. To overcome, root failure in Gnetum spp. may depend on adequate strategies set up and understanding of biochemical markers controlling the rooting process. The present work is principally based on phenolic compounds contents, peroxidasic and polyphenol oxidasic activities during rooting of cuttings (pretreated with IBA, ANA and IAA) at induction, initiation and expression phases of roots formation in Gnetum africanum Welw. and G. buchholzianum Engl. The study revealed that cuttings pretreated with IBA (150 mg/l) were more effective than IAA and NAA. Phenolic compounds analysis revealed that cuttings pretreated with IBA exhibited high phenolic compound contents at initiation and expression phases for both Gnetum species. Indicating that IBA pretreatment promotes phenolic compounds synthesis and accumulation necessary for roots differentiation. Enzyme contents appear to be high during the initiation stage for both species when they are pretreated with IBA (150 mg/l). Peroxidasic and Polyphenol oxidasic activities evolved on the synchroneous maner. This allows us to know that the implication of these enzymes in the rooting process is fundamental makers.