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Your search keyword '"Shweta, Guleria"' showing total 3 results
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3 results on '"Shweta, Guleria"'

1. Synergistic effect of graphene oxide and silver nanoparticles as biostimulant improves the postharvest life of cut flower bird of paradise (Strelitzia reginae L.)

Author

Meenakshi Thakur, Anjali Chandel, Shweta Guleria, Vipasha Verma, Raghawendra Kumar, Gurpreet Singh, Anjali Rakwal, Diksha Sharma, and Bhavya Bhargava

Subjects
antioxidant, cut flower, enzymes, nanoparticles, senescence, vase life, Plant culture, SB1-1110
Abstract

The bird of paradise (Strelitzia reginae L.) is one of the important tropical cut flowers. Generally, flowers like bird of paradise (BOP) grown for the commercial ornamental market must be of high pre and postharvest quality. Thus, to improve the postharvest longevity and increase marketability, the relative efficacy of two different biologically synthesized nanoparticles (NPs) was evaluated. The novel proprietary stimulants were graphene oxide (GO) and silver nanoparticles (SNPs). The NP treatments were applied as a vase (lower concentrations) solutions. Among all the applied treatments, the synergistic effect of GO + SNPs at 1 µL L−1 vase solution significantly (p =0.05) prolongs the post-harvest life of cut flowers of BOP. Increased vase life over the deionized water (DI) control was associated with better maintenance of relative water uptake, relative fresh weight, suppressed microbial density at stem-end and delay of stem blockage, reduced electrolyte leakage, malondialdehyde (MDA), SOD, and POD activity. In contrast to control, administration of NPs gave better results for all analyzed parameters. Application of biologically synthesized NPs in combination (GO + SNPs at 1 µL L−1) extended the vase life of cut flowers by 6 days compared with control flowers, and overall, showed better results than the control. The findings of the studies revealed that the standardized NPs could have more potential in prolonging the postharvest life of cut flowers in BOP. Thus, this technique can be used as a novel postharvest technology for commercial application in cut flowers.

Published
2022
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3. Site-directed mutagenesis (P61G) of copper, zinc superoxide dismutase enhances its kinetic properties and tolerance to inactivation by H2O2

Author

Anish Kaachra, Sanjay Kumar, Arun Kumar, Sachin Kumar, Rituraj Purohit, Vijay Kumar Bhardwaj, and Shweta Guleria

Subjects
chemistry.chemical_classification, biology, Physiology, Mutant, Plant Science, Superoxide dismutase, chemistry.chemical_compound, Enzyme, chemistry, Biochemistry, Glycine, Genetics, biology.protein, Proline, Hydrogen peroxide, Site-directed mutagenesis, Thermostability
Abstract

Superoxide dismutases (SODs) protect the cells by catalyzing the dismutation of harmful superoxide radicals (O2•-) into molecular oxygen (O2) and hydrogen peroxide (H2O2). Here, a Cu, Zn SOD (WT) from a high altitude plant (Potentilla atrosanguinea) was engineered by substituting a conserved residue proline to glycine at position 61 (P61G). The computational analysis showed higher structural flexibility and clusters in P61G than WT. The P61G exhibited moderately higher catalytic efficiency (Km = 0.029 μM, Vmax = 1488) than WT protein (Km = 0.038 μM, Vmax = 1290.11). P61G showed higher thermostability as revealed from residual activity (72.25% for P61G than 59.31% for WT after heating at 80 °C for 60 min), differential calorimetry scanning and CD-spectroscopic analysis. Interestingly, the P61G mutation also resulted in enhanced tolerance to H2O2 inactivation than WT protein. The finding on enhancing the biophysico-chemical properties by mutating conserved residue could stand as an example to engineer other enzymes. Also, the reported mutant can be exploited in food and pharmaceutical industries.

Published
2021

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