Functional annotation of proteins in Catharanthus roseus shoot cultures under biogenic zinc nanotreatment.

Nano-interactions are well known for their positive as well as negative impacts on the morphological and physiological systems of plants. Keeping in mind, the conformational changes in plant proteins as one of the key mechanisms for stress adaptation responses, the current project was designed to explore the effect of glutathione-capped and uncapped zinc nano-entities on Catharanthus roseus shoot cultures. Zinc nanotreatment (0.05 µg/mL) significantly induced ester production in C. roseus shoots as detected by Gas Chromatography-Mass spectrometry. These nanotreated shoots were further subjected to peptide-centric nano-LC-MS/MS analysis. Mass spectrometry followed by a Heat map revealed a significant effect of zinc nanoparticles on 59 distinct classes of proteins as compared to control. Proteins involved in regulating stress scavenging, transport, and secondary metabolite biosynthesis were robustly altered under capped zinc nanotreatment. UniProt database identified majority of the localization of the abundantly altered protein in cell membranes and chloroplasts. STRING and Cytoscape analysis assessed inter and intra coordination of triosephosphate isomerase with other identified proteins and highlighted its role in the regulation of protein abundance under applied stress. This study highlights the understanding of complex underlying mechanisms and regulatory networks involved in proteomic alterations and interactions within the plant system to cope with the nano-effect.

Antibacterial evaluation of silver nanoparticles synthesized from lychee peel: individual versus antibiotic conjugated effects.

This paper describes the extracellular synthesis of silver nanoparticles from waste part of lychee fruit (peel) and their conjugation with selected antibiotics (amoxicillin, cefixim, and streptomycin). FTIR studies revealed the reduction of metallic silver and stabilization of silver nanoparticles and their conjugates due to the presence of CO (carboxyl), OH (hydroxyl) and CH (alkanes) groups. The size of conjugated nanoparticles varied ranging from 3 to 10 nm as shown by XRD. TEM image revealed the spherical shape of biosynthesized silver nanoparticles. Conjugates of amoxicillin and cefixim showed highest antibacterial activity (147.43 and 107.95%, respectively) against Gram-negative bacteria i.e. Alcaligenes faecalis in comparison with their control counterparts. The highest reduction in MIC was noted against Gram-positive strains i.e. Enterococcus faecium (75%) and Microbacterium oxydans (75%) for amoxicillin conjugates. Anova two factor followed by two-tailed t test showed non-significant results both in case of cell leakage and protein estimation between nanoparticles and conjugates of amoxicillin, cefixime and streptomycin. In case of MDA release, non-significant difference among the test samples against the selected strains. Our study found green-synthesized silver nanoparticles as effective antibacterial bullet against both Gram positive and Gram negative bacteria, but they showed a more promising effect on conjugation with selected antibiotics against Gram negative type.

DAT and PRX1 gene expression modulates vincristine production in Catharanthus roseus L. propagates using Cu, Fe and Zn nano structures.

Underlying mechanism of nanostructures upon monoterpene induction in Catharanthus roseus has not been explored yet. In the current study, Copper, Iron and Zinc nanoparticles were biosynthesized by Eriobotrya japonica seed extract and capped with reduced glutathione. Biosynthesized nanoparticles and their capped analogues were characterized by UV-visible spectrophotometer, FTIR, XRD and SEM. Selected concentration of nanostructures were used in plant tissue culture media which instigated the production of alkaloids, tannins and flavonoids without significantly affecting the growth index of propagated calli and shoots cultures of C. roseus. Accelerated vincristine production was noticed in propagated calli and shoots under copper and zinc nanostress (1645-1865 µg/ml respectively) with the least effect by iron nanostructure. Highest concentration of calcium was recorded in in vitro shoots under capped (3.42 mg/ml ± 7.16) and uncapped (4.41 mg/ml ± 20.44) Zn nanoparticles compared to control (2.82 mg/ml ± 13.41). Real time PCR depicts nano-zinc mediated increased expression of DAT and PRX1 genes of TIA pathway. Significant correlation among PRX1/DAT gene expression with vincristine production and calcium accumulation in the presence of nanostress validate by PCA. This study paved way the opportunities of metal biogenic nanomaterials as an ideal drug modulator in plant tissue culture studies.