Publications by authors named "Waheed Ullah Khan"

19 Publications

  • Page 1 of 1

Karrikinolide alleviates BDE-28, heat and Cd stressors in Brassica alboglabra by correlating and modulating biochemical attributes, antioxidative machinery and osmoregulators.

Ecotoxicol Environ Saf 2021 Apr 16;213:112047. Epub 2021 Feb 16.

Vegetable Research Institute, Guangdong Academy of Agricultural Sciences/Guangdong Key Laboratory for New Technology Research of Vegetables, Guangzhou 510640, China. Electronic address:

In this study, we have evaluated the role of karrikin (KAR) against the absorption and translocation of a persistent organic pollutant (POP), 2,4,4'-Tribromodiphenyl ether (BDE-28) in plants, in the presence of two other stressors, cadmium (Cd) and high temperature. Furthermore, it correlates the physiological damages of Brassica alboglabra with the three stresssors separately. The results revealed that the post-germination application of KAR successfully augmented the growth (200%) and pertinent physiochemical parameters of B. alboglabra. KAR hindered air absorption of BDE-28 in plant tissues, and reduced its translocation coefficient (TF). Moreover, BDE-28 was the most negatively correlated (-0.9) stressor with chlorophyll contents, while the maximum mitigation by KAR was also achieved agaist BDE-28. The effect of temperature was more severe on soluble sugars (0.51), antioxidative machinery (-0.43), and osmoregulators (0.24). Cd exhibited a stronger inverse interrelation with the enzymatic antioxidant cascade. Application of KAR mitigated the deleterious effects of Cd and temperature stress on plant physiological parameters along with reduced aero-concentration factor, TF, and metal tolerance index. The phytohormone reduced lipid peroxidation by decreasing synthesis of ROS and persuading its breakdown. The stability of cellular membranes was perhaps due to the commotion of KAR as a growth-promoting phytohormone. In the same way, KAR supplementation augmented the membrane stability index, antioxidant defense factors, and removal efficiency of the pollutants. Consequently, the exogenously applied KAR can efficiently alleviate Cd stress, heat stress, and POP toxicity.
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http://dx.doi.org/10.1016/j.ecoenv.2021.112047DOI Listing
April 2021

Water-soluble green-emitting carbon nanodots with enhanced thermal stability for biological applications.

Nanoscale 2021 Feb;13(7):4301-4307

National and Local Joint Engineering Laboratory of Optical-Conversion Materials and Technology & School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P.R. China.

High stability and water solubility of fluorescent nanomaterials are considered key factors to evaluate their feasibility for fundamental applications. Herein, water-soluble and thermally stable, green-emitting carbon nanodots (CNDs) have been synthesized via a facile hydrothermal method with an average size of 1.9 nm. CNDs showed green emission centered at 544 nm with the photo-luminescence quantum yield (PLQY) of up to 10.1% under the excitation of 400 nm. The obtained CNDs demonstrated high resistance towards photo-bleaching and an ionic (KCl) environment. Moreover, the aqueous solution of CNDs exhibited excellent stability under harsh thermal conditions from 10 °C to 80 °C. The as-prepared CNDs showed stable performance at high temperatures, even after keeping them at 80 °C for 30 min. Furthermore, the green emissive CNDs were incubated in T-ca cancer cells for bio-imaging applications. The results indicated that CNDs can served as an effective thermally-stable bio-imaging agent in T-ca cells at the physiological temperature range of 25 °C-45 °C. Green emission and excellent thermal stability make these CNDs promising fluorescent materials for potential applications in the medical field, which requires long-wavelength fluorescence and high-temperature imaging.
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http://dx.doi.org/10.1039/d0nr09131fDOI Listing
February 2021

Ameliorative role of Bacillus subtilis FBL-10 and silicon against lead induced stress in Solanum melongena.

Plant Physiol Biochem 2021 Jan 25;158:486-496. Epub 2020 Nov 25.

Botany Department, University of Gujrat, Pakistan.

The continuous deterioration of arable lands by metal pollution compels finding suitable strategies to increase plant tolerance under contaminated regimes. Current study was designed to examine the synergistic role of Bacillus subtilis FBL-10 and silicon (Si) with respect to mitigation of lead (Pb) induced phytotoxicity in Solanum melongena L. Lead stress (75 mg kg) reduced chlorophyll (Chl) content, photosynthetic rate and gas exchange characteristics of S. melongena plants. The Si and B. subtilis FBL-10 individually upgraded all the above-mentioned growth attributes. However, co-application of Si (50 mg kg) and B. subtilis FBL-10 significantly improved biochemical and growth attributes of Pb challenged plants. The abridged levels of oxidative markers including hydrogen peroxide (HO), and malondialdehyde (MDA) besides reduced Pb accumulation in foliage tissues, were recorded in Si and microbe assisted plants. Furthermore, plants inoculated with B. subtilis FBL-10 alone or in combination with Si showed increment in total soluble proteins, photosynthetic rate and gas exchange attributes. The inoculated plants treated with Si exhibited higher level of auxins and improved activity of antioxidant enzymes under Pb stress. Present research elucidates interactive role of B. subtilis FBL-10 and Si in reduction of Pb toxicity in S. melongena plants. Alone application of Si or B. subtilis FBL-10 was less effective for attenuation of Pb stress; however, synergism between both phyto-protectants demonstrated fabulous ability for Pb stress assuagement. Consequently, executions of field studies become indispensable to comprehend the efficacy of Si applied alone or in combination with plant growth promoting bacteria (PGPB) like B. subtilis FBL-10. From current research, it is concluded that the interaction of Si and PGPB seems an auspicious technique and eco-friendly approach to enhance metal tolerance in crop plants.
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http://dx.doi.org/10.1016/j.plaphy.2020.11.037DOI Listing
January 2021

Hydrogen sulfide mitigates cadmium induced toxicity in Brassica rapa by modulating physiochemical attributes, osmolyte metabolism and antioxidative machinery.

Chemosphere 2021 Jan 29;263:127999. Epub 2020 Aug 29.

National Agriculture Research Centre, Islamabad, Pakistan.

Hydrogen sulfide (HS) is helpful for maintaining plant growth under abiotic stresses. The current study elucidated the physiological and biochemical strategies by which sodium hydrosulfide (NaHS), a donor of HS, alleviated cadmium (Cd) toxicity in Brassica rapa. B. rapa plants growing under 50 mgkg Cd stress showed reduced leaf relative water contents (LRWC), photosynthetic pigments, total soluble proteins, minerals uptake, antioxidants and growth. Furthermore, enhanced accumulation of Cd contents caused augmentation in levels of electrolyte leakage (EL) and methylglyoxal (MG). Nevertheless, improved physiochemical parameters in B. rapa seedlings obtained from seeds primed with 1.5 mM NaHS resulted better phenotype, growth and biomass production in Cd stressed plants. Protective stimulus of HS regulated minerals and Cd homeostasis besides increased activity of antioxidants which decreased level of reactive oxygen species (ROS), EL, malondialdehyde (MDA) and MG in Cd regimes. Furthermore, HS treated seedlings exhibited reduction in Cd content and revealed an active participation in the indole acetic acid (IAA) mediated pathway during stress. The findings of current study propose that HS improved stress tolerance and mitigated Cd stress in B. rapa by modulating growth biomarkers and antioxidative system.
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http://dx.doi.org/10.1016/j.chemosphere.2020.127999DOI Listing
January 2021

Combined effect of Bacillus fortis IAGS 223 and zinc oxide nanoparticles to alleviate cadmium phytotoxicity in Cucumis melo.

Plant Physiol Biochem 2021 Jan 12;158:1-12. Epub 2020 Nov 12.

Department of Environmental Science and Engineering, Government College University, Faisalabad, Pakistan.

Cadmium (Cd), prevailing in most of the agricultural lands of the world contaminates food chain, thereby causing several health implications. It has become the main heavy metal contaminant in most of the agricultural lands of Pakistan due to the widespread use of phosphate fertilizers besides application of irrigation water contaminated with industrial and mining effluents. Plant growth promoting bacteria (PGPB) are capable to enhance growth and metal stress tolerance in supplemented plants. Zinc oxide nanoparticles (ZnO-NPs) are capable to alleviate various abiotic stresses when applied to plants. During current research, the efficacy of single and combined application of Bacillus fortis IAGS 223 and ZnO-NPs was evaluated for alleviation of Cd (75 mg kg) induced phytotoxicity in Cucumis melo plants. For this purpose, C. melo plants, subjected to Cd stress were treated with B. fortis IAGS 223 and ZnO-NPs (20 mg kg), either alone or in combination. The growth relevant characteristics including photosynthetic pigments, hydrogen peroxide (HO), malondialdehyde (MDA), and activities of antioxidative enzymes as well as Zn and Cd contents in treated plants were examined. The individual application of ZnO-NPs and B. fortis IAGS 223 slightly enhanced all the above-mentioned growth characteristics in plants under Cd stress. However, the combined application of ZnO-NPs and B. fortis IAGS-223 considerably modulated the activity of antioxidant enzymes besides upgradation of the biochemicals and growth parameters of Cd stressed plants. The decreased amount of stress markers such as HO, and MDA in addition with reduction of Cd contents was observed in shoots of ZnO-NPs and B. fortis IAGS-223 applied plants. B. fortis IAGS-223 inoculated plants supplemented with ZnO-NPs, exhibited reduced amount of Cd as well as protein bound thiols and non-protein bound thiols under Cd stress. Subsequently, the reduced Cd uptake improved growth of ZnO-NPs and B. fortis IAGS-223 applied plants. Henceforth, field trials may be performed to formulate appropriate combination of ZnO-NPs and B. fortis IAGS-223 to acquire sustainable crop production under Cd stress.
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http://dx.doi.org/10.1016/j.plaphy.2020.11.011DOI Listing
January 2021

Synergistic effects of nitric oxide and silicon on promoting plant growth, oxidative stress tolerance and reduction of arsenic uptake in Brassica juncea.

Chemosphere 2021 Jan 21;262:128384. Epub 2020 Sep 21.

Department of Zoology, University of Sargodha, Pakistan.

Arsenic (As) polluted food chain has become a serious issue for the growth and development of humans, animals and plants. Nitric oxide (NO) or silicon (Si) may mitigate As toxicity. However, the combined application of NO and Si in mitigating As uptake and phytotoxicity in Brassica juncea is unknown. Hence, the collegial effect of sodium nitroprusside (SNP), a NO donor and Si application on B. juncea growth, gas exchange parameters, antioxidant system and As uptake was examined in a greenhouse experiment. Arsenic toxicity injured cell membrane as signposted by the elevated level of malondialdehyde (MDA) and hydrogen peroxide (HO), thus decreasing the growth of stressed plants. Moreover, As stress negatively affected gas exchange parameters and antioxidative system of plants. However, NO or/and Si alleviated As induced oxidative stress through increasing the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST), glutathione (GSH), along with thiol and proline synthesis. Furthermore, plants treated with co-application of NO and Si showed improved growth, gas attributes and decreased As uptake under As regimes. The current study highlights that NO and Si synergistically interact to mitigate detrimental effects of As stress through reducing As uptake. Our findings recommend combined NO and Si application in As spiked soils for improvement of plant growth and stress alleviation.
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http://dx.doi.org/10.1016/j.chemosphere.2020.128384DOI Listing
January 2021

Dopamine Alleviates Hydrocarbon Stress in Brassica oleracea through Modulation of Physio-Biochemical Attributes and Antioxidant Defense Systems.

Chemosphere 2021 May 14;270:128633. Epub 2020 Oct 14.

Department of Environmental Science and Engineering, Govt. College University Faisalabad, 38000, Pakistan; Department of Biological Sciences and Technology, China Medical University, Taichung, 40402, Taiwan.

Hydrocarbon stress has become one of the most restrictive factors for crop choice and productivity in most parts of the world. Dopamine (DA) has positively influenced the metabolic, physiological and biochemical activities besides the growth of plants under numerous abiotic stress conditions. The current study was performed to analyze the potential of DA to alleviate hydrocarbon stress and improve growth of Brassica oleracea plants. Hydrocarbon stress in plants was induced by growing in 5% and 10% crude oil contaminated soil. Crude oil stressed plants exhibited reduced growth besides decreased level of photosynthetic pigments and gas exchange attributes. Moreover, oil stressed plants showed elevated level of hydrogen peroxide (HO), electrolyte leakage (EL), malondialdehyde (MDA) and superoxide radical (O). However, exogenous application of 50, 100 and 200 μmol L DA improved photosynthesis, shoot and root dry weight of B. oleracea seedlings growing in hydrocarbon amended soil. Additionally, DA100 treatments improved non-enzymatic and enzymatic antioxidants of treated seedlings. Our results demonstrate that increased gas exchange attributes, modulation of osmoregulators and improved activity of the antioxidative enzymes alleviated hydrocarbon stress in DA supplemented B. oleracea plants. Consequently, the first time observed ameliorative role of DA in hydrocarbon stress opens a new arena for application of this dynamic biomolecule for sustainable crop production.
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http://dx.doi.org/10.1016/j.chemosphere.2020.128633DOI Listing
May 2021

Butanolide alleviated cadmium stress by improving plant growth, photosynthetic parameters and antioxidant defense system of brassica oleracea.

Chemosphere 2020 Dec 23;261:127728. Epub 2020 Jul 23.

National Agriculture Research Centre, Islamabad, Pakistan.

Current study was performed to explore the effect of butanolide (KAR1) in mitigation of cadmium (Cd) induced toxicity in Brussels sprout (Brassica oleracea L.). Brussels sprout seeds, treated with 10-5 M, 10-7 M and 10-10 M solution of KAR1 were allowed to grow in Cd-contaminated (5 mg L-1) regimes for 25 d. Cadmium toxicity decreased seed germination and growth in B. oleracea seedlings. Elevated intensity of electrolyte leakage (EL), malondialdehyde (MDA) and hydrogen peroxide (HO) were observed in Cd-stressed seedlings. Additionally, reduced level of stomatal conductivity, transpiration rate, photosynthesis rate, intercellular carbon dioxide concentration, and leaf relative water content (LRWC) was also observed in Cd-stressed seedlings. Nevertheless, KAR1 improved seed germination, seedling growth and biomass production in Cd stressed plants. KAR1 application showed elevated LRWC, osmotic potential, and higher membranous stability index (MSI) in seedlings under Cd regime. Furthermore, seedlings developed by KAR1 treatment exhibited higher stomatal conductivity, and intercellular carbon dioxide concentration together with improved rate of transpiration and photosynthetic rate in B. oleracea under Cd stress. These findings elucidate that the reduced level of MDA, EL and HO, as well as improvement in antioxidative machinery increased growth and alleviated Cd toxicity in KAR1 treated seedlings under Cd stress.
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http://dx.doi.org/10.1016/j.chemosphere.2020.127728DOI Listing
December 2020

Eu , Sm Deep-Red Phosphors as Novel Materials for White Light-Emitting Diodes and Simultaneous Performance Enhancement of Organic-Inorganic Perovskite Solar Cells.

Small 2020 Jun 27;16(25):e2001551. Epub 2020 May 27.

Department of Chemistry, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia.

The luminous efficiency of inorganic white light-emitting diodes, to be used by the next generation as light initiators, is continuously progressing and is an emerging interest for researchers. However, low color-rendering index (Ra), high correlated color temperature (CCT), and poor stability limit its wider application. Herein, it is reported that Sm - and Eu -doped calcium scandate (CaSc O (CSO)) are an emerging deep-red-emitting material with promising light absorption, enhanced emission properties, and excellent thermal stability that make it a promising candidate with potential applications in emission display, solid-state white lighting, and the device performance of perovskite solar cells (PSCs). The average crystal structures of Sm -doped CSO are studied by synchrotron X-ray data that correspond to an extremely rigid host structure. Samarium ion is incorporated as a sensitizer that enhances the emission intensity up to 30%, with a high color purity of 88.9% with a 6% increment. The impacts of hosting the sensitizer are studied by quantifying the lifetime curves. The CaSc O :0.15Eu ,0.03Sm phosphor offers significant resistance to thermal quenching. The incorporation of lanthanide ion-doped phosphors CSOE into PSCs is investigated along with their potential applications. The CSOE-coated PSCs devices exhibit a high current density and a high power conversion efficiency (15.96%) when compared to the uncoated control devices.
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http://dx.doi.org/10.1002/smll.202001551DOI Listing
June 2020

Cross-Sectional Survey of Musculoskeletal Disorders in Workers Practicing Traditional Methods of Underground Coal Mining.

Int J Environ Res Public Health 2020 04 9;17(7). Epub 2020 Apr 9.

College of Earth and Environmental Sciences, New campus, University of the Punjab, Lahore 54590, Pakistan.

In subcontinental underground mines, coal mining is carried out manually and requires many laborers to practice traditional means of coal excavation. Each task of this occupation disturbs workers' musculoskeletal order. In order to propose and practice possible ergonomic interventions, it is necessary to know what tasks (drilling and blasting, coal cutting, dumping, transporting, timbering and supporting, loading and unloading) cause disorder in either upper limbs, lower limbs, or both. To this end, R-programming, version R 3.1.2 and SPSS, software 20, were used to calculate data obtained by studying 260 workers (working at different tasks of coal mining) from 20 mines of four districts of Punjab, Pakistan. In addition, a Standard Nordic Musculoskeletal Questionnaire (SNMQ) and Rapid Upper Limb Assessment (RULA) sheet were used to collect data and to analyze postures respectively. In multi regression models, significance of the five tasks for upper and lower limb disorder is 0.00, which means that task based prevalence of upper and lower limb disorders are common in underground coal mines. The results of the multiple bar chart showed that 96 coal cutters got upper limb disorders and 82 got lower limb disorders. The task of timbering and supporting was shown to be dangerous for the lower limbs and relatively less dangerous for the upper limbs, with 25 workers reporting pain in their lower limbs, and 19 workers reporting pain in their upper limbs. Documented on the RULA sheet, all tasks got the maximum possible score (7), meaning that each of these tasks pose a threat to the posture of 100% of workers. The majority of participants (182) fell in the age group of 26 to 35 years. Of those workers, 131 reported pain in the lower limbs and slight discomfort (128) in the upper limbs. The significance value of age was 0.00 for upper limb disorder and was 0.012 for lower limb disorder. Frequency graphs show age in direct proportion to severity of pain while in inverse proportion with number of repetitions performed per min. All findings infer that each task of underground coal mining inflicts different levels of disorder in a workers' musculoskeletal structure of the upper and lower limbs. It highlighted the need for urgent intervention in postural aspects of each task.
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http://dx.doi.org/10.3390/ijerph17072566DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7177932PMC
April 2020

Highly Green Emissive Nitrogen-Doped Carbon Dots with Excellent Thermal Stability for Bioimaging and Solid-State LED.

Inorg Chem 2018 Dec 29;57(24):15229-15239. Epub 2018 Nov 29.

National and Local Joint Engineering Laboratory of Optical-Conversion Materials and Technology & School of Physical Science and Technology , Lanzhou University , Lanzhou 730000 , P.R. China.

In this study, nitrogen-doped green emissive carbon dots (N-doped CDs) are synthesized via a convenient one-step solid state reaction method. The N-doped CDs show excitation-dependent fluorescence behavior with a maximum emission of 540 nm. Upon the optimum excitation at 400 nm, the quantum yield (QY) of the green emissive CDs is determined to be 13.4% and 50.3% in deionized water and ethanol, respectively. The higher quantum yield of N-doped CDs in ethanol could be caused by a strong hydrogen-bonding. In addition, the obtained N-doped CDs demonstrate excellent thermal stability, which is supported by the fact that the emission intensity nearly has no change after keeping the sample at 90 °C for 120 min. Moreover, the N-doped CDs exhibit green emission after entering into the HeLa cell membrane, indicating their potential to be used as bioimaging agent. Furthermore, the N-doped CDs are dispersed in PVA matrix for solid state film, where the solid-state quenching  is effectively avoided. A green LED is fabricated by packing the CDs-PVA composite on the top of a 395 nm n-UV-Chip, which provides a potentially healthy green light.
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http://dx.doi.org/10.1021/acs.inorgchem.8b02524DOI Listing
December 2018

Halotolerant plant-growth promoting rhizobacteria modulate gene expression and osmolyte production to improve salinity tolerance and growth in Capsicum annum L.

Environ Sci Pollut Res Int 2018 Aug 4;25(23):23236-23250. Epub 2018 Jun 4.

Department of Botany, University of Sargodha, Sargodha, Pakistan.

Some rhizobacteria have demonstrated a noteworthy role in regulation of plant growth and biomass production under biotic and abiotic stresses. The present study was intended to explicate the ameliorative consequences of halotolerant plant growth-promoting rhizobacteria (HPGPR) on growth of capsicum plants subjected to salt stress. Salt stress was ascertained by supplementing 1 and 2 g NaCl kg soil. The HPGPR positively invigorated growth attributes, chlorophyll, protein contents, and water use efficiency (WUE) of supplemented capsicum plants under salinity stress conditions. Bacillus fortis strain SSB21 caused highest significant increase in shoot length, root length, and fresh and dry biomass production of capsicum plants grown under saline conditions. This multi-trait bacterium also increased biosynthesis of proline and up-regulated the expression profiles of stress related genes including CAPIP2, CaKR1, CaOSM1, and CAChi2. On the other hand, B. fortis strain SSB21 inoculated plants exhibited reduced level of ethylene, lipid peroxidation, and reactive oxygen species (ROS). All these together contribute to activate physiological and biochemical processes involved in the mitigation of the salinity induced stress in capsicum plants.
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http://dx.doi.org/10.1007/s11356-018-2381-8DOI Listing
August 2018

Role of Burkholderia cepacia CS8 in Cd-stress alleviation and phytoremediation by Catharanthus roseus.

Int J Phytoremediation 2018 May;20(6):581-592

e Department of Microbiology and Molecular Genetics , University of the Punjab , Lahore , Pakistan.

The current study was performed to assess the effect of Burkholderia cepacia CS8 on the phytoremediation of cadmium (Cd) by Catharanthus roseus grown in Cd-contaminated soil. The plants cultivated in Cd amended soil showed reduced growth, dry mass, gas-exchange capacity, and chlorophyll contents. Furthermore, the plants exhibited elevated levels of malondialdehyde (MDA) and hydrogen peroxide (HO) under Cd stress. The bacterized plants showed higher shoot length, root length; fresh and dry weight. The improved stress tolerance in inoculated plants was attributed to the reduced quantity of MDA and HO, enhanced synthesis of protein, proline, phenols, flavonoids, and improved activity of antioxidant enzymes including peroxidase, superoxide dismutase, ascorbate peroxidase, and catalase. Similarly, the 1-aminocyclopropane-1-carboxylate deaminase activity, phosphate solubilization, auxin, and siderophore production capability of B. cepacia CS8 improved growth and stress alleviation in treated plants. The bacterial inoculation enhanced the amount of water extractable Cd from soil. Furthermore, the inoculated plants showed higher bioconcentration factor and translocation factor. The current study exhibits that B. cepacia CS8 improves stress alleviation and phytoextraction potential of C. roseus plants growing under Cd stress.
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http://dx.doi.org/10.1080/15226514.2017.1405378DOI Listing
May 2018

Imperative roles of halotolerant plant growth-promoting rhizobacteria and kinetin in improving salt tolerance and growth of black gram (Phaseolus mungo).

Environ Sci Pollut Res Int 2018 Feb 28;25(5):4491-4505. Epub 2017 Nov 28.

College of Earth and Environmental Sciences, University of the Punjab, Lahore, Pakistan.

The salinity stress causes a major threat for plant growth, yield, and biomass production. The present study was designed to assess the effect of exogenously applied kinetin and halotolerant plant growth-promoting rhizobacteria (H-PGPR) on alleviation of salt stress in black gram (Phaseolus mungo). A total of 15 rhizobacterial isolates obtained from a salt-affected area were analyzed for their capability to improve growth of P. mungo plants growing in greenhouse conditions. Out of the tested rhizobacteria, the two bacterial isolates which exhibited maximum growth potential were screened and their growth-promoting attributes were evaluated. The role of screened H-PGPR and/or kinetin (8 and 10 μM) was evaluated in P. mungo plants irrigated with three levels of brackish water (S1 = 3, S2 = 5, and S3 = 7 dSm) under field condition. Salt stress reduced transpiration rate, stomatal conductance, salt tolerance index, growth, leaf area, photosynthetic pigments, leaf relative water content (LRWC), biomass production, and seed yield in subjected plants. Conversely, the salinized plants treated with kinetin and/or H-PGPR exhibited improved levels of chlorophyll contents, LRWC, root growth, shoot growth, biomass production, and seed yield. The H-PGPR and/or kinetin supplementation also reduced electrolyte leakage in salt-stressed plants. Overall, the present findings will be of great value to recognize the mechanism of salt stress alleviation in P. mungo plants under the influence of H-PGPR and/or kinetin.
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http://dx.doi.org/10.1007/s11356-017-0761-0DOI Listing
February 2018

High Quantum Yield Green-Emitting Carbon Dots for Fe(ІІІ) Detection, Biocompatible Fluorescent Ink and Cellular Imaging.

Sci Rep 2017 11 1;7(1):14866. Epub 2017 Nov 1.

School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, P. R. China.

In the present work, we reported the luminescence of a green-emitting carbon dots (CDs) synthesized via solid state reaction method using diammonium hydrogen citrate and urea as a starting materials. The obtained green-emitting CDs shows strong absorption in the 350-450 nm region and gives intense green emission (λ = 537 nm) with quantum yield as high as 46.4% under 420 nm excitation. The obtained green-emitting CDs also demonstrates high photo-stability, which is evidenced by the fact that its emission intensity almost has no change under irradiation by a 365 nm UV lamp for 2 hours. Moreover, the obtained green-emitting CDs shows high sensitivity and selectivity for the detection of Fe, and their emission intensity response towards Fe ions is highly linear (R = 0.995) over the concentration range from 25 to 300 µM, which could provide an effective platform for detection of Fe. Mostly important, we further demonstrate that such photoluminescent green-emitting CDs exhibits low toxicity and are biocompatible for use with in cellular imaging. Combining with low cytotoxicity, good water solubility and excellent luminescence properties, green-emitting CDs could be used as a biocompatible fluorescent ink in future applications.
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http://dx.doi.org/10.1038/s41598-017-15054-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5665951PMC
November 2017

The beneficial role of potassium in Cd-induced stress alleviation and growth improvement in Gladiolus grandiflora L.

Int J Phytoremediation 2018 Feb;20(3):274-283

a University of the Punjab , Lahore , Pakistan.

Heavy metal contaminated agricultural soils are one of the most important constraints for successful cultivation of crops. The current research was conducted to evaluate the role of potassium (K) on plant growth and amelioration of cadmium (Cd) stress in Gladiolus grandiflora under greenhouse conditions. G. grandiflora corms were sown in media contaminated with 0 (C), 50 (Cd50) and 100 (Cd100) mg Cd kg soil. The plants growing in Cd-contaminated media exhibited reduced gas exchange attributes, chlorophyll (Chl) contents, vegetative and reproductive growth as compared to control. The plants raised in Cd contaminated media showed reduced nutrition yet higher Cd contents. However, supplementation of 60 mg Kg K in treated plants (C+K, Cd50+K and Cd100+K) improved quantity of total soluble protein and proline (Pro) along with activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) under Cd stress. Similarly, K supplementation reduced the level of malondialdehyde (MDA) and hydrogen peroxide (HO) in treated plants. Potassium supplemented plants exhibited better vegetative and reproductive growth. The improved stress tolerance in K supplemented plants was attributed to the reduced quantity of MDA and HO, enhanced synthesis of protein, proline, phenols, flavonides and improved activity of antioxidant enzymes. The present research supports the application of K for alleviation of Cd stress in G. grandiflora.
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http://dx.doi.org/10.1080/15226514.2017.1374337DOI Listing
February 2018

Application of Bacillus megaterium MCR-8 improved phytoextraction and stress alleviation of nickel in Vinca rosea.

Int J Phytoremediation 2017 Sep;19(9):813-824

c Institute for Medicinal Plants, College of Plant Science and Technology, Huazhong Agricultural University , Wuhan , China.

The current research was performed to evaluate the effect of Bacillus megaterium MCR-8 on mitigation of nickel (Ni) stress in Vinca rosea grown on Ni-contaminated soil (50, 100, and 200 mg Ni kg soil). The treated plants exhibited reduced growth, biomass, gas exchange capacity, and chlorophyll (Chl) content under Ni stress. The inoculated plants growing in Ni-contaminated media exhibited relatively higher growth, total soluble protein, and proline contents. Similarly, bacterial inoculation improved the activity of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) under Ni stress. The Ni stress alleviation in inoculated plants was attributed to the reduced level of malondialdehyde (MDA) and hydrogen peroxide (HO), enhanced synthesis of protein, proline, phenols, and flavonides in conjunction with improved activity of antioxidant enzymes. The growth-promoting characteristics of microbe such as 1-aminocyclopropane-1-carboxylate deaminase (ACCD) and phosphate solubilization activity, siderophore, and auxin production capability also improved the growth and stress mitigation in inoculated plants. Furthermore, the inoculated plants exhibited higher value for bioconcentration factor (BCF), translocation factor (TF), and resulted in higher loss of Ni content from soil. The current results exhibited the beneficial role of B. megaterium MCR-8 regarding stress alleviation and Ni phytoextraction by V. rosea.
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http://dx.doi.org/10.1080/15226514.2017.1290580DOI Listing
September 2017

Effect of Pseudomonas fluorescens RB4 and Bacillus subtilis 189 on the phytoremediation potential of Catharanthus roseus (L.) in Cu and Pb-contaminated soils.

Int J Phytoremediation 2017 Jun;19(6):514-521

d Institute for Medicinal Plants, College of Plant Science and Technology , Huazhong Agricultural University , Wuhan , China.

The remediation of heavy metal-contaminated soils has become a critical issue due to toxic effects of these metals on living organisms. The current research was conducted to study the effect of Pseudomonas fluorescens RB4 and Bacillus subtilis 189 on the growth and phytoremediation potential of Catharanthus roseus in Cu- and Pb-contaminated soils. The bacterial strains exhibited significantly higher level of water-extractable Pb and Cu in Pb, Cu, and Cu+Pb-contaminated. The P. fluorescens RB4 inoculated plants, produced 102%, 48%, and 45% higher fresh weight (FW) in soils contaminated with Cu, Pb, and both elements, respectively, as compared to un-inoculated control plants. Similarly, B. subtilis 189 inoculated plants produced 108%, 43%, and 114% more FW in the presence of Cu, Pb, and both elements. The plants co-cultivated with both bacteria exhibited 121%, 102%, and 177% higher FW, in Cu, Pb, and both elements contaminated soils, as compared to respective un-inoculated control. Co-cultivation of P. fluorescens RB4, B. subtilis 189, and P. fluorescens RB4 + B. subtilis 189 resulted in higher accumulation of Cu and Pb in shoots of the C. roseus grown in contaminated soils as compared to un-inoculated control. Bacterial treatments also improved the translocation and metal bioconcentration factors. The growth and phytoextraction capability of C. roseus was improved by inoculation of P. fluorescens RB4 and B. subtilis 189.
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http://dx.doi.org/10.1080/15226514.2016.1254154DOI Listing
June 2017

Role of Ni-tolerant Bacillus spp. and Althea rosea L. in the phytoremediation of Ni-contaminated soils.

Int J Phytoremediation 2017 May;19(5):470-477

e Institute of Agricultural Sciences, University of the Punjab , Lahore , Pakistan.

In our current study, four nickel-tolerant (Ni-tolerant) bacterial species viz, Bacillus thuringiensis 002, Bacillus fortis 162, Bacillus subtilis 174, and Bacillus farraginis 354, were screened using Ni-contaminated media. The screened microbes exhibited positive results for synthesis of indole acetic acid (IAA), siderophore production, and phosphate solubilization. The effects of these screened microbes on Ni mobility in the soil, root elongation, plant biomass, and Ni uptake in Althea rosea plants grown in Ni-contaminated soil (200 mg Ni kg) were evaluated. Significantly higher value for water-extractable Ni (38 mg kg) was observed in case of Ni-amended soils inoculated with B. subtilis 174. Similarly, B. thuringiensis 002, B. fortis 162, and B. subtilis 174 significantly enhanced growth and Ni uptake in A. rosea. The Ni uptake in the shoots and roots of B. subtilis 174-inoculated plants enhanced up to 1.7 and 1.6-fold, respectively, as compared to that in the un-inoculated control. Bacterial inoculation also significantly improved the root and shoot biomass of treated plants. The current study presents a novel approach for bacteria-assisted phytoremediation of Ni-contaminated areas.
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http://dx.doi.org/10.1080/15226514.2016.1244167DOI Listing
May 2017