Elucidating the efficacy of functionalized multi-walled carbon nanotube in the biogenesis of L-Dopa and antioxidant metabolites in cell cultures of Hybanthus enneaspermus.

Hybanthus enneaspermus (L.)F.Muell. is a highly indispensable medicinal herb yielding L-Dopa, deemed the gold standard drug among the therapeutic options for Parkinson's disease. This investigation is the first attempt to evaluate the eliciting influence of carboxylic acid functionalized multi-walled carbon nanotube (MWCNT-COOH) on the biosynthesis of L-Dopa and on biomass aggregation and antioxidant metabolites in H. enneaspermus cell suspension cultures. Suspension cells were accomplished from friable calli generated from the nodal segments of H. enneaspermus in Murashige and Skoog (MS) liquid medium infused with 2 mg L-1 2, 4-Dichlorophenoxyacetic acid (2, 4-D), and 0.3 mg L-1meta-Topolin (mT). The influence of MWCNTs on L-Dopa synthesis, biomass accumulation, and biochemical parameters was examined on the basis of the exposure time and in a concentration-dependent manner of MWCNTs. The inclusion of 30 mg L-1 MWCNTs increased the biomass and the L-Dopa level by 2.00 and 16.37-folds, respectively, compared with that of the control. Furthermore, the effect of MWCNTs on physiological parameters such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPX), ascorbate peroxidase (APX), hydrogen peroxide (H2O2), malondialdehyde (MDA) content, 2-diphenylpicrylhydrazyl (DPPH), and ferric-reducing ability of plasma (FRAP) was examined over the elicited cells. Among the antioxidant enzymatic activities, CAT enhanced 8.0 fold compared with that of the control. MDA and DPPH content enhanced 2.60 and 1.12 folds, respectively, compared with that of the control. The current study showed that MWCNTs offer new possibilities for their usage over in vitro by acting as potential innovative plant metabolite elicitors and stress-protecting entities.

ß-D-Glucan nanoparticle pre-treatment induce resistance against Pythium aphanidermatum infection in turmeric.

In vitro experiments were carried out to test the efficacy of GNP (ß-D-glucan nanoparticle prepared from mycelium of Pythium aphanidermatum) against rhizome rot disease of turmeric (Curcuma longa L.) caused by P. aphanidermatum. GNP (0.1%, w/v) was applied to rhizome prior to inoculation with P. aphanidermatum (0 h, 24 h). Cell death, activities of defense enzymes such as peroxidase, polyphenol oxidase, protease inhibitor and ß-1,3 glucanase were monitored. Prior application of GNP (24 h) to turmeric rhizome effectively controls P. aphanidermatum infection. The increase in defense enzyme activities occurred more rapidly and was enhanced in P. aphanidermatum infected rhizomes that were pre-treated with GNP. Pre-treatment also induced new isoforms of defense enzymes. Increased activities of defense enzymes suggest that they play a key role in restricting the development of disease symptoms in the rhizomes as evidenced by a reduction in cell death. The results demonstrated that GNP can be used as a potential agent for control of rhizome rot disease.