Browsing by Author "Shahid, Muhammad"

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    Metal-tolerant morganella morganii isolates can potentially mediate nickel stress tolerance in Arabidopsis by upregulating antioxidative enzyme activities
    (Landes Bioscience, 2024-03) Naqqash, Tahir; Aziz, Aeman; Baber, Muhammad; Shahid, Muhammad; Sajid, Muhammad; Emanuele, Radicetti; Gaafar, Abdel-Rhman Z; Hodhod, Mohamed S; Haider, Ghulam
    Plant growth-promoting rhizobacteria (PGPRs) have been utilized to immobilize heavy metals, limiting their translocation in metal contaminated settings. However, studies on the mechanisms and interactions that elucidate how PGPRs mediate Nickel (Ni) tolerance in plants are rare. Thus, in this study we investigated how two pre-characterized heavy metal tolerant isolates of Morganella morganii (ABT9 and ABT3) improve Ni stress tolerance in Arabidopsis while enhancing its growth and yield. Arabidopsis seedlings were grown for five weeks in control/Ni contaminated (control, 1.5 mM and 2.5 mM) potted soil, in the presence or absence of PGPRs. Plant growth characteristics, quantum yield, and antioxidative enzymatic activities were analyzed to assess the influence of PGPRs on plant physiology. Oxidative stress tolerance was quantified by measuring MDA accumulation in Arabidopsis plants. As expected, Ni stress substantially reduced plant growth (shoot and root fresh weight by 53.25% and 58.77%, dry weight by 49.80% and 57.41% and length by 47.16% and 64.63% over control), chlorophyll content and quantum yield (by 40.21% and 54.37% over control). It also increased MDA content by 84.28% at higher (2.5 mM) Ni concentrations. In contrast, inoculation with M. morganii led to significant improvements in leaf chlorophyll,­quantum­yield,­and­Arabidopsis­biomass­production.­The­mitigation­of­adverse­effects­of­Ni­stresson­biomass­observed­in­M. morganii-inoculated­plants­was­attributed­to­the­enhancement­of­antioxidative­ enzyme­ activities­ compared­ to­ Ni-treated­ plants.­ This­ upregulation­ of­ the­ antioxidative­ defensemechanism­ mitigated­ Ni-induced­ oxidative­stress,­ leading­to­ improved­ performance­ of­the­ photosynthetic­machinery,­which,­ in­turn,­enhanced­ chlorophyll­ content­ and­quantum­yield.­Understanding­theunderlying­mechanisms­of­these­tolerance-inducing­processes­will­help­to­complete­the­picture­of­PGP s-­ mediated­defense­signaling.­Thus,­it­suggests­that­M. morganii PGP s­candidate­can­potentially­be­utilizedfor­plant­growth­promotion­by­reducing­oxidative­stress­via­upregulating­antioxidant­defense­systems­inNi-contaminated­soils­and­reducing­Ni­metal­uptake.
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    Remediation of wastewater by biosynthesized manganese oxide nanoparticles and its effects on development of wheat seedlings
    (Frontiers Media S.A., 2023-12) Ishfaq, Aneeza; Shahid, Muhammad; Nawaz, Muhammad; Ibrar, Danish; Hussain, Sabir; Shahzad, Tanvir; Mahmood, Faisal; Rais, Afroz; Gul, Safia; Gaafar, Abdel-Rhman Z; Hodhod, Mohamed S; Khan, Shahbaz
    Introduction: Nanoparticles play a vital role in environmental remediation on a global scale. In recent years, there has been an increasing demand to utilize nanoparticles in wastewater treatment due to their remarkable physiochemical properties. Methods: In the current study, manganese oxide nanoparticles (MnO-NPs) were synthesized from the Bacillus flexus strain and characterized by UV/Vis spectroscopy, X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. Results: The objective of this study was to evaluate the potential of biosynthesized MnO-NPs to treat wastewater. Results showed the photocatalytic degradation and adsorption potential of MnO-NPs for chemical oxygen demand, sulfate, and phosphate were 79%, 64%, and 64.5%, respectively, depicting the potential of MnO-NPs to effectively reduce pollutants in wastewater. The treated wastewater was further utilized for the cultivation of wheat seedlings through a pot experiment. It was observed that the application of treated wastewater showed a significant increase in growth, physiological, and antioxidant attributes. However, the application of treated wastewater led to a significant decrease in oxidative stress by 40%. Discussion: It can be concluded that the application of MnO-NPs is a promising choice to treat wastewater as it has the potential to enhance the growth, physiological, and antioxidant activities of wheat seedlings.