Insight into Recent Progress and Perspectives in Improvement of Antioxidant Machinery upon PGPR Augmentation in Plants under Drought Stress: A Review

Agriculture has a lot of responsibility as the rise in the world’s population demands more food requirements. However, more than one type of biotic and abiotic stress continually impacts agricultural productivity. Drought stress is a major abiotic stress that significantly affects agricultural productivity every year as the plants undergo several morphological, biochemical, and physiological modifications, such as repressed root and shoot growth, reduced photosynthesis and transpiration rate, excessive production of reactive oxygen species (ROS), osmotic adjustments, and modified leaf senescence regulating and stress signaling pathways. Such modifications may permanently damage the plants; therefore, mitigation strategies must be developed. The use of drought resistant crop cultivars is more expensive and labor-intensive with few advantages. However, exploiting plant growth promoting rhizobacteria (PGPR) is a proven alternative with numerous direct and indirect advantages. The PGPR confers induced systemic tolerance (IST) mechanisms in plants in response to drought stress via multiple mechanisms, including the alteration of root architecture, maintenance of high relative water content, improvement of photosynthesis rate, production of phytohormones, exopolysaccharides, ACC deaminase, carotenoids and volatiles, induction of antioxidant defense system, and alteration in stress-responsive gene expression. The commercial application of PGPR as bioinoculants or biostimulants will remain contingent on more robust strain selection and performance under unfavorable environmental conditions. This review highlights the possible mechanisms of PGPR by activating the plant adaptive defense systems for enhancing drought tolerance and improving overall growth and yield

Cinnamomum verum Bark Extract Mediated Green Synthesis of ZnO Nanoparticles and Their Antibacterial Potentiality

Cinnamomum verum plant extract mediated propellant chemistry route was used for the green synthesis of zinc oxide nanoparticles. Prepared samples were confirmed for their nano regime using advanced characterization techniques such as powder X-ray diffraction and microscopic techniques such as scanning electron microscopy and transmission electron microscopy. The energy band gap of the green synthesized zinc oxide (ZnO)-nanoparticles (NPs) were found between 3.25-3.28 eV. Fourier transmission infrared spectroscopy shows the presence of Zn-O bond within the wave number of 500 cm(-1). SEM images show the specific agglomeration of particles which was also confirmed by TEM studies. The green synthesized ZnO-NPs inhibited the growth of Escherichia coli and Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 125 mu g mL(-1) and 62.5 mu g mL(-1), respectively. The results indicate the prepared ZnO-NPs can be used as a potential antimicrobial agent against harmful pathogens

Insight into Recent Progress and Perspectives in Improvement of Antioxidant Machinery upon PGPR Augmentation in Plants under Drought Stress: A Review

Agriculture has a lot of responsibility as the rise in the world’s population demands more food requirements. However, more than one type of biotic and abiotic stress continually impacts agricultural productivity. Drought stress is a major abiotic stress that significantly affects agricultural productivity every year as the plants undergo several morphological, biochemical, and physiological modifications, such as repressed root and shoot growth, reduced photosynthesis and transpiration rate, excessive production of reactive oxygen species (ROS), osmotic adjustments, and modified leaf senescence regulating and stress signaling pathways. Such modifications may permanently damage the plants; therefore, mitigation strategies must be developed. The use of drought resistant crop cultivars is more expensive and labor-intensive with few advantages. However, exploiting plant growth promoting rhizobacteria (PGPR) is a proven alternative with numerous direct and indirect advantages. The PGPR confers induced systemic tolerance (IST) mechanisms in plants in response to drought stress via multiple mechanisms, including the alteration of root architecture, maintenance of high relative water content, improvement of photosynthesis rate, production of phytohormones, exopolysaccharides, ACC deaminase, carotenoids and volatiles, induction of antioxidant defense system, and alteration in stress-responsive gene expression. The commercial application of PGPR as bioinoculants or biostimulants will remain contingent on more robust strain selection and performance under unfavorable environmental conditions. This review highlights the possible mechanisms of PGPR by activating the plant adaptive defense systems for enhancing drought tolerance and improving overall growth and yield

Repositioning Therapeutics for SARS-CoV-2: Virtual Screening of Plant-based Anti-HIV Compounds as Possible Inhibitors against COVID-19 Viral RdRp

Background: Coronavirus disease 2019 (COVID-19) has caused a global pandemic with a high mortality and morbidity rate worldwide. The COVID-19 vaccines that are currently in development or already approved are expected to provide at least some protection against the emerging variants of the virus, but the mutations may reduce the efficacy of the existing vaccines. Purified phytochemicals from medicinal plants provide a helpful framework for discovering new therapeutic leads as they have long been employed in traditional medicine to treat many disorders. Objective: The objectives of the study are to exploit the anti-HIV bioactive compounds against SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) through molecular docking studies and to evaluate the Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) properties of potential compounds. Methods: Molecular docking was performed to study the interaction of ligands with the target sites of RdRp protein (PDB: 6M71) using AutoDock Vina. The ADMET properties of potential compounds were predicted using the pkCSM platform. Results: A total of 151 phytochemicals derived from the medicinal plants with recognized antiviral activity and 18 anti-HIV drugs were virtually screened against COVID-19 viral RdRp to identify putative inhibitors that facilitate the development of potential anti-COVID-19 drug candidates. The computational studies identified 34 compounds and three drugs inhibiting viral RdRp with binding energies ranging from -10.2 to -8.5 kcal/mol. Among them, five compounds, namely Michellamine B, Quercetin 3-O-(2'',6''-digalloyl)-beta-Dgalactopyranoside, Corilagin, Hypericin, and 1,2,3,4,6-Penta-O-galloyl-beta-D-glucose residues, bound efficiently with the binding site of RdRp. Besides, Lopinavir, Maraviroc, and Remdesivir drugs also inhibited SARS-CoV-2 polymerase. In addition, the ADMET properties of top potential compounds were also predicted in comparison to the drugs. Conclusion: The present study suggested that these potential drug candidates can be further subjected to in vitro and in vivo studies that may help develop effective anti-COVID-19 drugs.Fil: Murali, Mahadevamurthy. University of Mysore; IndiaFil: Gowtham, Hittanahallikoppal Gajendramurthy. University of Mysore; IndiaFil: Ansari, Mohammad Azam. Bin Faisal University; Arabia SauditaFil: Alomary, Mohammad N.. King Abdulaziz City for Science and Technology; Arabia SauditaFil: Alghamdi, Saad. Umm Al qura University; Arabia SauditaFil: Almehmadi, Mazen. Taif Universisty; Arabia SauditaFil: Singh, Sudarshana Brijesh. University of Mysore; IndiaFil: Shilpa, Natarajamurthy. University of Mysore; IndiaFil: Aiyaz, Mohammed. University of Mysore; IndiaFil: Kalegowda, Nataraj. University of Mysore; IndiaFil: Ledesma, Ana Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Centro de Investigación en Biofísica Aplicada y Alimentos. - Universidad Nacional de Santiago del Estero. Centro de Investigación en Biofísica Aplicada y Alimentos; ArgentinaFil: Amruthesh, Kestur Nagaraj. University of Mysore; Indi