Sugar metabolism ofVetiveria zizanioidescells cultured with Amberlite XAD-4. Uptake of radiolabelled sugars, cell wall invertase activity and gene expression

Abstract

Activated and non-activated Amberlite XAD-4 was added to the cell cultures of vetiver (Vetiveria zizanioides Stapf.) in order to study its effects as abiotic growth promoter. Amberlite XAD-4 increased vetiver cell viability, especially when used in the activated form. Results from labelling experiments in cell suspensions showed that XAD-4 prompted a significant decrease of sucrose Km, accompanied by an increased Vmax. Glucose uptake from the medium was almost doubled, as demonstrated by the increase of the radiolabelled fraction (25-fold the controls) in vetiver cells cultured with XAD-4. Affinity for fructose uptake by cells was not altered by the use of activated XAD-4, even though its uptake and Vmax increased. These results were further supported by a significant 7.5-fold increase in cell wall invertases (CWI) activity in XAD-4 elicited cells. Vetiver CWI gene expression was characterized by transcript RT-PCR analysis. The identity of the transcripts was confirmed by sequencing analysis. These results indicated the use of XAD-4 as an effective tool for vetiver cell biomass optimization.

Aloe vera transformation: the role of Amberlite XAD-4 resin and antioxidants during selection and regeneration

“…Although gene transfer by particle bombardment is widely used in monocots, several factors were found to play a major role specifically in Aloe vera transformation: (1) the appropriate explants being competent for transformation and regeneration, (2) pretreatment of the explants using DTT and GA 3 before bombardment, (3) establishment of an appropriate stepwise increased liquid selection system, and (4) post-bombardment recovery procedure utilizing medium supplemented with amberlite XAD resin entrapped in alginate beads. Although amberlite is mainly used to trap and extract different secondary metabolite produce in vitro (Falk et al 1990), we cannot rule out the possibility that the beneficial effect of Amberlite can be attributed also to the possibility that medium-organic compounds are also trapped by the amberlite resin (Mucciarelli et al 2009). …”

“…Amberlite XAD-4 is mainly used for the removal of aromatic hydrocarbons such as phenols and pesticides from wastes. However, they have also been utilized for both extraction of specific phytochemicals produced in vitro and removal of toxic compounds negatively affecting explant viability in plant cell cultures (Strobel et al 1991;Ui et al 1993;Georgiev et al 2006;Mucciarelli et al 2009).…”