Muhammad Sarwar

Bio: Muhammad Sarwar is an academic researcher from National Institute for Biotechnology and Genetic Engineering. The author has contributed to research in topics: Plant virus & Host (biology). The author has an hindex of 4, co-authored 16 publications receiving 45 citations. Previous affiliations of Muhammad Sarwar include National Institute of Biotechnology.

Development and evaluation of double gene transgenic cotton lines expressing Cry toxins for protection against chewing insect pests.

Abstract: Cotton is the main fiber producing crop globally, with a significant impact on the economy of Pakistan. Bt cotton expressing a Cry1Ac gene is grown over a large area in Pakistan, however, there is a major concern that bollworms may develop resistance. Here we have used a durable resistance strategy against bollworms by developing a double gene construct containing Cry1Ac and Cry2Ab (pGA482-12R) for cotton transformation. Both Cry toxin genes have been cloned in the same T-DNA borders and transferred successfully into cotton via Agrobacterium-mediated transformation. Both genes are expressed in transgenic cotton plants and is likely to help breeders in developing new cotton cultivars by incorporating these genes in cotton lines having no Bt genes or expressing Cry1Ac gene (Mon 531). Positive transgenic cotton was identified by PCR using specific primers for the amplification of both Cry1Ac and Cry2Ab genes. Cry1Ac and Cry2Ab expression was confirmed with an immunostrip test and quantified using ELISA that showed significant spatio-temporal expression of Cry2Ab ranging from 3.28 to 7.72 µg/g of the tissue leaf. Insect bioassay with army worm (Spodoptera litura) was performed to check the efficacy of NIBGE (National Institute for Biotechnology and Genetic Engineering) double gene transgenic cotton plants and up to 93% insect mortality was observed.

Insects as transport devices of plant viruses

Abstract: In the class Insecta, there are eight Orders of insects (Orthoptera, Dermaptera, Coleoptera, Lepidoptera, Diptera, Thysanoptera, Hemiptera, and Homoptera) whose members transmit plants viruses. The best-characterized insect vectors that transmit plant viruses are aphids, thrips, leafhoppers, planthoppers, and whiteflies. Plant viruses can interact with their insect hosts in a variety of ways, including both nonpersistent and circulative transmission, but in some cases the latter involves virus replication in the cells of the insect host. Some studies have shown that viruses can modify vector behavior in a way so that transmission is enhanced to seriously reduce crop yield and quality. Virus transmission is also determined by interactions that are associated with alterations in a plant host's morphology and metabolism that favor the attraction or deterrence of vectors. Most often, control of vectored viruses of plants will involve integrated approaches such as interfering with vectors and transmissions, reducing vector populations, reducing virus sources, interfering with vector landing on crops, and interfering with the transmission process, as well as host-plant resistance, cultural control, biological control, chemical control, regulatory measures, and novel biotechnological tools.

Enhanced Electrochemical Performance of Hydrothermally Synthesized NiS/ZnS Composites as an Electrode for Super-Capacitors

Abstract: In this study, nickel sulfide (NiS), zinc sulfide (ZnS), and their composites have been synthesized by using surfactant driven hydrothermal method. Synthesized materials are investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy, UV–Vis and Photoluminescence spectroscopy. XRD results have shown the presence of corresponding structural planes. Crystallite size was much smaller (15 nm) in the case of ZnS nanomaterials, whereas, composite materials have shown size comparable to NiS nanomaterials. SEM images presented morphology of star-like, spherical, and mixture of two for NiS, ZnS, and NiS/ZnS nanocomposites respectively. EDX spectrum of composite materials showed Nickel, Zinc, and Sulfur, indicating the purity of the synthesized composite. Electrochemical measurements i.e. cyclic voltammetry and galvanostatic charge–discharge were determined for all three materials. Maximum specific capacitance is obtained as 1594.68 F g−1 at a scan rate of 5 mV S−1 for NiS/ZnS composite materials whereas a charging/discharging time of 461.97 s is observed. The composite materials have shown 95.4% retention for applied for 3000 charging–discharging cycles. The favorable behavior of NiS/ZnS composites indicated their potential as an electrode material for pseudo-capacitors.

Enhanced photocatalytic activity of La³⁺ and Se⁴⁺ co-doped bismuth ferrite nanostructures

Abstract: Photocatalysis is attracting huge interest for addressing current energy and environmental issues by converting solar light into chemical energy. For this purpose, we investigated the effect of La³⁺ and Se⁴⁺ co-doping on the photocatalytic activity of BiFeO₃. BiFeO₃ and Bi₀.₉₂La₀.₀₈FeO₃ nanoparticles containing different Se⁴⁺ doping content (BiFe₍₁₋ₓ₎SeₓO₃, x = 0.0, 0.02, 0.05, and Bi₀.₉₂La₀.₀₈Fe₍₁₋ₓ₎SeₓO₃, x = 0.0, 0.02, 0.05, 0.075, 0.1) were synthesized by a double solvent sol–gel route. The co-doped nanoparticles were characterized by X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and UV-vis diffuse reflectance spectroscopy (DRS), and their photocatalytic activity was studied by the photocatalytic degradation of Congo Red (CR) in aqueous solution under different wavelengths of light illumination. The band-gap of the pure BiFeO₃ was significantly decreased from 2.06 eV to 1.94 eV. It was found that La³⁺ and Se⁴⁺ co-doping significantly affected the photocatalytic performance of pure BiFeO₃. Moreover, with the increment of Se⁴⁺ doping into Bi₀.₉₂La₀.₀₈FeO₃ up to an optimal value, the photocatalytic activity was maximized. In order to study the photosensitization process, photo-degradation of a colourless organic compound (acetophenone) was also observed. On the basis of these experimental results, the enhanced photocatalytic activities with La³⁺ and Se⁴⁺ co-doping could be attributed to the increased optical absorption, and efficient separation and migration of photo-generated charge carriers with the decreased recombination of electrons–holes resulting from co-doping effects. The possible photocatalytic mechanism of La³⁺ and Se⁴⁺ co-doped BiFeO₃ was critically discussed.

Nanoparticles as Potential Antivirals in Agriculture

Abstract: Viruses are estimated to be responsible for approximately 50% of the emerging plant diseases, which are difficult to control, and in some cases, there is no cure. It is essential to develop therapy practices to strengthen the management of these diseases caused by viruses in economically important crops. Metal nanoparticles (MeNPs) possess diverse physicochemical properties that allow for them to have a wide range of applications in industry, including nanomedicine and nano-agriculture. Currently, there are reports of favorable effects of the use of nanoparticles, such as antibacterial, antifungal, and antiviral effects, in animals and plants. The potential antiviral property of MeNPs makes them a powerful option for controlling these histological agents. It is crucial to determine the dosage of NPs, the application intervals, their effect as a biostimulant, and the clarification of the mechanisms of action, which are not fully understood. Therefore, this review focuses on discussing the ability of metal nanoparticles and metal oxides to control viruses that affect agriculture through an exhaustive analysis of the characteristics of the particles and their interaction processes for a possibly beneficial effect on plants.

Near-Infrared-Activated Efficient Bacteria-Killing by Lignin-Based Copper Sulfide Nanocomposites with an Enhanced Photothermal Effect and Peroxidase-like Activity

Abstract: Lignin has been considered to be an ideal carrier for the construction of lignin-based antibacterial materials by its biocompatibility and environmentally benign feature. Herein, lignosulfonate (LS) was utilized as a growth template and a stabilizing agent to synthesize lignin-copper sulfide (LS-CuS) nanocomposites. Interestingly, the as-prepared LS-CuS nanocomposites show enhanced photothermal performance and peroxidase-like activity with near-infrared (NIR) light activation, which benefits highly efficient bacteria-killing via synergistic photothermal–catalytic effects. The bactericidal tests indicated that LS-CuS nanocomposites (100 μg/mL) cause 5.9-log₁₀ and 5.4-log₁₀ CFU/mL reductions against Escherichia coli and Staphylococcus aureus under NIR light irradiation (808 nm, 1.8 W/cm²) for only 5 min in the presence of H₂O₂. Moreover, LS-CuS nanocomposites can be blended with waterborne polyurethane (WPU) to obtain hybrid films, which also achieves a bactericidal efficacy of more than 90% in 5 min. Considering the low cost, easy preparation, and environmental friendliness of LS-CuS nanocomposites, this study may provide new insights into the design of lignin-based inorganic nanocomposites with high bacteria-killing efficiency in a sustainable manner.