Cadmium toxicity in plants: Impacts and remediation strategies.

The use of nanomaterials in agriculture as nanofertilizers, nanopesticides, or nano-enabled sensors to increase crop yield is gaining increasing interest. Engineered nanomaterials (ENMs) can improve crop productivity by influencing fertilizer nutrient availability in soil and uptake by plants. These materials can suppress crop diseases by directly acting on pathogens through a variety of mechanisms, including the generation of reactive oxygen species (ROS). ENMs may also suppress disease indirectly by improving crop nutrition and enhancing plant defense pathways. Efficient use of ENMs may complement or replace conventional fertilizers and pesticides, subsequently reducing the environmental impact of agricultural practices. This review evaluates the current literature on ENMs used as pesticides and fertilizers, and highlights critical knowledge gaps that must be addressed to ensure sustainable application of nanotechnology in agriculture so as to achieve global food security.

Recent advances in nano-enabled fertilizers and pesticides: a critical review of mechanisms of action

Plants facing oxidative challenges—A little help from the antioxidant networks

Bioremediation is an inventive and optimistic technology which is applicable for the retrieval and reduction of heavy metals in water and polluted lands. Microorganism plays an essential part in bioremediation of heavy metals. By using genetic engineering, genetically modified organisms can be generated which can likely reduce different types of polycyclichydrocarbons (PAHs). Flavobacterium, Pseudomonas, Bacillus, Arthrobacter, Corynebacterium, Methosinus, Rhodococcus, Mycobacterium, Stereum hirsutum, Nocardia, Methanogens, Aspergilus niger, Pleurotus ostreatus, Rhizopus arrhizus, Azotobacter, Alcaligenes, Phormidium valderium, Ganoderma applantus are some microbial species that help in bioremediation of heavy metals. This review not only discussed about the importance of microbes for bioremediation of heavy metals but also discussed about the challenges and limitations of native and engineered bacteria for bioremediation. Significance of bioremediation with the help of genetically engineered bacteria is in light because of its eco-friendly nature and minimum health hazards other than the physio-chemical dependent strategies, which are less eco friendly and dangerous to life.

Bioremediation of heavy metals by microbial process

Regulation of L-proline biosynthesis, signal transduction, transport, accumulation and its vital role in plants during variable environmental conditions.

Role of sugars under abiotic stress.

The present study was carried out to assess the role of zinc oxide nanoparticles (ZnO-NPs) in tomato plants on growth, photosynthetic efficiency, and antioxidant system. At 20-d stage of growth, roots of tomato plants were dipped into 0, 2, 4, 8, or 16 mg(ZnO-NPs) L–1 for 15, 30, and 45 min and then seedlings were transplanted in their respective cups and allowed to grow under natural environmental conditions. At 45-d stage of growth, the ZnO-NPs treatments significantly increased growth, photosynthetic efficiency together with activities of carbonic anhydrase and antioxidant systems in a concentration- and duration-dependent manner. Moreover, the treatment by 8 mg(ZnO-NPs) L–1 for 30 min proved to be the most effective and resulted in maximum activities of antioxidant enzymes, proline accumulation and the photosynthetic rate. We concluded that presence of ZnO-NPs improved the antioxidant systems and speeded up proline accumulation that could provide stability to plants and improved photosynthetic efficiency.

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Zinc oxide nanoparticle-mediated changes in photosynthetic efficiency and antioxidant system of tomato plants

Nitric oxide-mediated integrative alterations in plant metabolism to confer abiotic stress tolerance, NO crosstalk with phytohormones and NO-mediated post translational modifications in modulating diverse plant stress.

The reported study investigated the interaction between salicylic acid (SA) and citric acid (CA) in cadmium (Cd)-stressed Brassica juncea plants. Seedling received Cd (0.6 mM) stress through soil at 5-day stage of growth. SA (0.01 mM) and CA (0.6 mM) treatments were applied at 25 days after sowing. Growth, photosynthesis, oxidative burst, and antioxidant systems were examined at 30-day stage of growth. Growth and photosynthetic parameters reduced significantly in the presence of Cd, and elevated levels of H2O2 were indicative of oxidative burst which resulted in decline of cell viability. Foliar spray of SA and CA alone or in combination mitigated the toxic effects generated by Cd and enhanced plant growth parameters. The inhibitory effects of Cd toxicity on width of stomatal pore resulted in reduced internal CO2 concentration and carbonic anhydrase activity which consequently limited the photosynthetic rate. SA and CA alleviated the inhibitory effect of Cd on photosynthesis by stimulating the stomatal activity and pore size. The Cd-generated oxidative burst was reduced via enhanced antioxidant activity (catalase, peroxidase, and superoxide dismutase) upon follow-up treatment with SA and CA alone or in combination. A combined dose of SA and CA countered Cd-induced damage by reducing levels of reactive oxygen species and strengthening plant antioxidant defense systems, which resulted in membrane stabilization and recovery from stress. Combined dose of SA and CA proved more effective than their individual application towards Cd stress which suggests an effective synergism between the two acids.

Supplementation of Salicylic Acid and Citric Acid for Alleviation of Cadmium Toxicity to Brassica juncea

In this article, a Riga plate is exhibited with an electric magnetization actuator consisting of permanent magnets and electrodes assembled alternatively. This exhibition produces electromagnetic hydrodynamic phenomena over a fluid flow. A new study model is formed with the Sutterby nanofluid flow through the Riga plate, which is crucial to the structure of several industrial and entering advancements, including thermal nuclear reactors, flow metres and nuclear reactor design. This article addresses the entropy analysis of Sutterby nanofluid flow over the Riga plate. The Cattaneo–Christov heat and mass flux were used to examine the behaviour of heat and mass relaxation time. The bioconvective motile microorganisms and nanoparticles are taken into consideration. The system of equations for the current flow problems is converted from a highly non-linear partial system to an ordinary system through an appropriate transformation. The effect of the obtained variables on velocity, temperature, concentration and motile microorganism distributions are elaborated through the plots in detail. Further, the velocity distribution is enhanced for a greater Deborah number value and it is reduced for a higher Reynolds number for the two cases of pseudoplastic and dilatant flows. Microorganism distribution decreases with the increased magnitude of Peclet number, Bioconvection Lewis number and microorganism concentration difference number. Two types of graphical outputs are presented for the Sutterby fluid parameter (β = −2.5, β = 2.5). Finally, the validation of the present model is achieved with the previously available literature.

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Mohammad Faizan

Papers

Role of sugars under abiotic stress.

Zinc oxide nanoparticle-mediated changes in photosynthetic efficiency and antioxidant system of tomato plants

Nitric oxide-mediated integrative alterations in plant metabolism to confer abiotic stress tolerance, NO crosstalk with phytohormones and NO-mediated post translational modifications in modulating diverse plant stress.

Supplementation of Salicylic Acid and Citric Acid for Alleviation of Cadmium Toxicity to Brassica juncea

Entropy Analysis of Sutterby Nanofluid Flow over a Riga Sheet with Gyrotactic Microorganisms and Cattaneo–Christov Double Diffusion