Highly nutritive and antioxidants-enriched okra (Abelmoschus esculentus) gets sub-optimal field yield due to the irregular germination coupled with non-synchronized harvests. Hence, the research ...aimed at assessing the combined impact of seed priming and field-level gibberellic acid (GA3) foliar spray on the yield and post-harvest quality of okra. The lab studies were conducted using a complete randomized design (CRD), while the field trials were performed following a factorial randomized complete block design (RCBD) with three replications. Okra seeds were subjected to ten different priming methods to assess their impact on seed germination and seeding vigor. In the premier step, okra seeds were subjected to ten different priming methods, like hydro priming for 6, 12, and 18 h, halo priming with 3% NaCl at 35 ℃, 45 ℃, and 60 ℃, acid priming with 80% H2SO4 for 2.5, 5, and 10 min. Based on the observation, hydro priming for 12 h exhibited the best germination rate (90%), followed by halo seed priming at 60 ℃ and acid priming for 5 min. Furthermore, the halo priming at 60 ℃ demonstrated the greatest seedling vigor index (1965), whereas acid priming for 5 min resulted in favorable outcomes in terms of early emergence in 2.66 days. In addition, varying concentrations of GA3 (0, 100, 200, and 300 ppm) were also administered to the best three primed seedlings for evaluating their field performance. The findings indicated that applying GA3 at a concentration of 300 ppm to seedlings raised through acid priming (80% H2SO4 for 5 min) resulted in improved leaf length, reduced time to flowering (first and 50%) and harvest, increased pod diameter, individual pod weight, and yield per plant (735.16 g). Additionally, the treatment involving GA3 at 300 ppm with halo priming (3% NaCl) at 60 ℃ exhibited the longest shelf life (21 days) of okra with the lowest levels of rotting (6.73%) and color change (1.12) in the polyethylene storage condition.
Paederia foetida L. is an important medicinal herb harboring lots of essential drug producing metabolites and the plant has been going to be endangered due to lack of proper strategies for ...conservation. Since, indirect organogenesis by tissue culture is considered as the valuable tools for rapid multiplication and improvement of plant genetic resources, application of this technique should be very imperative for the conservation of this valuable and rare medicinal plant. Hence, the research effort was made to develop a suitable protocol for indirect organogenesis in-vitro using nodal explants of P. foetida. After surface sterilization, the explants were submitted to MS medium supplemented with different concentrations and combinations of plant growth regulators for showing the performance in terms of callus induction, shoot proliferation and root initiation. Among the surface sterilants used, 0.1% HgCl2 treated for 2 minutes and 3% NaOCl treated for 10 minutes showed better performance and maintained 100% and 80% survivability respectively. MS medium supplemented with 2, 4-D at 1.5 mg L-1 showed better performance than others in terms of initiation of callus from nodal explants. In contrast, NAA at 0.5 mg L-1 and BAP 0.2 mg L-1 showed highest rate of callus proliferation with somatic embryos from proliferated callus. During shoot organogenesis, MS medium supplemented with BAP 2 mg L-1 showed better results for the regeneration of shoots from embryogenic calli. The shoots derived from callus produced roots by half strength MS medium supplemented with IAA. After acclimatization, the plantlets were allowed to ambient condition for further establishment. Our findings claim the establishment of a suitable protocol for indirect organogenesis of P. foetida that could be employed for rapid multiplication, conservation and sustainable utilization of P. foetida as valuable genetic resource. Fundam Appl Agric 2019; 4(2.000): 806-814
Acclimation of plants to a great variety of environmental conditions is mediated by a phytohormoneabscisic acid (ABA), which induces accumulation of stress-associated transcripts such as those ...encodingLEA-like proteins in both vascular and non-vascular land plants. Transient assays by particle bombardmentwith reporter genes have been employed for studies of ABA-induced gene expression in angiosperms, butsuch assay system has not been established in liverworts representing basal non-vascular plants. We usedgemmalings of Marchantia polymorpha, which show ABA-induced desiccation tolerance, for establishmentof the transient assay system in liverworts. We introduced the β-glucuronidase (GUS) reporter gene fusedwith the wheat Em promoter or the endogenous MpDHN1 promoter into gemmalings of M. polymorpha byparticle bombardment and showed that GUS activity was increased by exogenous ABA for the bothpromoter constructs. Furthermore, we observed that exogenous ABA induced accumulation of LEA-liketranscripts in the gemmalings. The results suggest that the transient assay system of the gemmalings of M.polymorpha is useful for monitoring ABA and stress responses in liverworts.
Effect of abscisic acid (ABA) on chloroplast relocation in gemmae cells of the liverwort Marchantia polymorpha was examined. Cold incubation of gemmae of wild-type plants in a liquid medium under dim ...light caused relocation of chloroplasts from the periclinal to anticlinal position, but presence of 1 μM or greater concentrations of ABA inhibited this movement as observed by light and fluorescent microscopy. Gemma cells of the transgenic MT-2 line overexpressing MpABI1A encoding a group A protein phosphatase 2C known as a negative regulator of ABA signaling were also used for chloroplast observation. It was found that the cold-induced chloroplast relocation was observed at any ABA concentration tested in MT-2, indicating that the cells exhibited ABA insensitivity. These results indicated that ABA specifically acts on inhibition of the chloroplast movement.
The growing need of antimicrobial agent for novel therapies against multi-drug resistant bacteria has drawn researchers to green nanotechnology. Especially, eco-friendly biosynthesis of silver ...nanoparticles (Ag NPs) has shown its interesting impact against bacterial infection in laboratory research. In this study, a simple method was developed to form Ag NPs at room temperature, bio-reduction of silver ions from silver nitrate salt by leaf extract from Ocimum gratissimum. The Ag NPs appear to be capped with plant proteins, but are otherwise highly crystalline and pure. The Ag NPs have a zeta potential of −15mV, a hydrodynamic diameter of 31nm with polydispersity index of 0.65, and dry sizes of 18±3nm and 16±2nm, based on scanning and transmission electron microscopy respectively. The minimum inhibitory concentration (MIC) of the Ag NPs against a multi-drug resistant Escherichia coli was 4μg/mL and the minimum bactericidal concentration (MBC) was 8μg/mL, while the MIC and MBC against a resistant strain of Staphylococcus aureus were slightly higher at 8μg/mL and 16μg/mL respectively. Further, the Ag NPs inhibited biofilm formation by both Escherichia coli and S. aureus at concentrations similar to the MIC for each strain. Treatment of E. coli and S. aureus with Ag NPs resulted in damage to the surface of the cells and the production of reactive oxygen species. Both mechanisms likely contribute to bacterial cell death. In summary, this new method appears promising for green biosynthesis of pure Ag NPs with potent antimicrobial activity.
Abstract Recently bio-inspired experimental processes for synthesis of nanoparticles are receiving significant attention in nanobiotechnology. Silver nanoparticles (Ag NPs) have been used very ...frequently in recent times to the wounds, burns and bacterial infections caused by drug-resistant microorganisms. Though, the antibacterial effects of Ag NPs on some multi drug-resistant bacteria specially against Gram positive bacteria has been established, but further investigation is needed to elicit its effectiveness against Gram negatives and to identify the probable mechanism of action. Thus, the present study was conducted to synthesize Ag NPs using Andrographis paniculata leaf extract and to investigate its antibacterial efficacy. After synthesis process the biosynthesized nanoparticles were purified and characterized with the help of various physical measurement techniques which raveled their purity, stability and small size range. The antimicrobial activity of Ag NPs was determined against both Gram-positive Enterococcus faecalis and Gram-negative Proteus vulgaris . Results showed comparatively higher antibacterial efficacy of Ag NPs against Gram positive Enterococcus faecalis strains. It was found that greater difference in zeta potential values between Gram positive bacteria and Ag NPs triggers better internalization of the particles. Thus the cell surface charge played vital role in cell killing which was confirmed by surface zeta potential study. Finally it may be concluded that green synthesized Ag NPs using Andrographis paniculata leaf extract can be very useful against both multi drug resistant Gram-positive and Gram-negative bacteria.
A mononucleating (HL1) and a dinucleating (HL2) “end-off” compartmental ligand have been designed and synthesized by controlled Mannich reaction using p-cresol and bis(2-methoxyethyl)amine, and their ...formation has been rationalized. Six complexes have been prepared on treating HL1 and HL2 with ZnIIX2 (X = Cl–, Br–, I–) with the aim to investigate their hydrolytic activity on phosphoester bond cleavage. Interestingly, the mononucleating ligand was observed to yield dinuclear complexes, Zn2(L1)2X2 (1–3), while the potential dinucleating ligand generated mononuclear complexes, Zn(HL2)X2 (4–6). Four (1–4), out of six complexes studied, were characterized by single-crystal X-ray diffraction (XRD): the Zn ion exhibits trigonal bipyramidal and tetrahedral coordination spheres in the di- and mononuclear complex, respectively. The hydrolytic kinetics, followed spectrophotometrically with 4-nitrophenylphosphate (4-NPP) in buffered dimethylformamide (DMF) (97.5% DMF, v/v) because of solubility reasons, under excess substrate conditions (substrate:complex = 20:1), indicated that the complexes enormously accelerate the rate of phosphomonoester hydrolysis with first order rate constants (k cat) in the range 2–10 s–1 at 25 °C. In each case kinetic data analyses have been run by Michaelis–Menten treatment. The efficacy in the order of conversion of substrate to product (p-nitrophenolate ion) follows the trend 1 > 2 > 3 > 4 > 5 > 6, and the ratio of k cat of an analogous dinuclear to mononuclear complex is ≃2. An electrospray ionization-mass spectrometry (ESI-MS) study has revealed the dissociation of the centrosymmetric dinuclear complex to two mononuclear species instead of a syn-cooperative catalysis. Density functional theory (DFT) calculations have been performed to rationalize our proposed mechanistic pathway for phosphatase activity. The comparative analysis concludes the following facts under experimental conditions: (1) the halide bound to the active site affects the overall rate in the order: Cl– > Br– > I– regardless of nuclearity; (2) dinuclear complexes prevail over the mononuclear ones.
In the study, leaf extract of Carica papaya was utilized for the biogenic fabrication process of chitosan functionalized silver nanoparticles (Ag-Chito NPs). HRTEM analysis revealed that the ...fabricated Ag-Chito NPs was spherical in shape, with an average particle size of 13.31 (±0.07) nm. FTIR, UV–Vis, DLS, and other characterizations were also performed to analyze the diverse physicochemical properties of the particles. The antibacterial potency of the synthesized Ag-Chito NPs was tested against the two clinically isolated multidrug resistant uropathogenic bacterial strains, i.e. MLD 2 (Escherichia coli) and MLD 4 (Staphylococcus aureus) through MIC, MBC, time and concentration dependent killing kinetic assay, inhibition of biofilm formation assay, fluorescence and SEM imaging. Significantly, Ag-Chito NPs showed the highest sensitivity against the MLD 2 (MIC value of 12.5 μg/mL) strain, as compared to the MLD 4 (MIC value of 15 μg/mL) strain. From the hemolysis assay, it was revealed that Ag-Chito NPs exerted no significant toxicity up to 50 μg/mL against healthy human blood cells. Additionally, in silico analysis of chitosan (functionalized on the surface of AgNPs) and bacterial cell membrane protein also evidently suggested a strong interaction between Ag-Chito NPs and bacterial cells, which might be responsible for bacterial cell death.
•Biogenic fabrication of chitosan functionalized silver nanoparticles.•Promising antibacterial potency against multidrug resistant bacterial strain•Fabricated nanoparticles hold promising cytocompatibility.•Molecular docking explains the interaction of the particle with bacterial proteins.
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