Exogenous ascorbic acid as a potent regulator of antioxidants, osmo-protectants, and lipid peroxidation in pea under salt stress.

Pea (Pisum sativum L.), a globally cultivated leguminous crop valued for its nutritional and economic significance, faces a critical challenge of soil salinity, which significantly hampers crop growth and production worldwide. A pot experiment was carried out in the Botanical Garden, The Islamia University of Bahawalpur to alleviate the negative impacts of sodium chloride (NaCl) on pea through foliar application of ascorbic acid (AsA). Two pea varieties Meteor (V1) and Sarsabz (V2) were tested against salinity, i.e. 0 mM NaCl (Control) and 100 mM NaCl. Three levels of ascorbic acid 0 (Control), 5 and 10 mM were applied through foliar spray. The experimental design was completely randomized (CRD) with three replicates. Salt stress resulted in the suppression of growth, photosynthetic activity, and yield attributes in pea plants. However, the application of AsA treatments effectively alleviated these inhibitory effects. Under stress conditions, the application of AsA treatment led to a substantial increase in chlorophyll a (41.1%), chl. b (56.1%), total chl. contents (44.6%) and carotenoids (58.4%). Under salt stress, there was an increase in Na+ accumulation, lipid peroxidation, and the generation of reactive oxygen species (ROS). However, the application of AsA increased the contents of proline (26.9%), endogenous AsA (23.1%), total soluble sugars (17.1%), total phenolics (29.7%), and enzymatic antioxidants i.e. SOD (22.3%), POD (34.1%) and CAT (39%) in both varieties under stress. Salinity reduced the yield attributes while foliarly applied AsA increased the pod length (38.7%), number of pods per plant (40%) and 100 seed weight (45.2%). To sum up, the application of AsA alleviated salt-induced damage in pea plants by enhancing photosynthetic pigments, both enzymatic and non-enzymatic activities, maintaining ion homeostasis, and reducing excessive ROS accumulation through the limitation of lipid peroxidation. Overall, V2 (Sarsabz) performed better as compared to the V1 (Meteor).

Molecular insights into expression and silencing of resistance determinants in Staphylococcus aureus.

OBJECTIVE: This study aimed to investigate the status of antimicrobial-resistant strains of Staphylococcus aureus in Pakistan, their association in terms of co-occurrence with the biofilm-forming genes, resistance profiling and associated discrepancies in diagnostic methods. METHODOLOGY: A total of 384 milk samples from bovine was collected by using convenient sampling technique and were initially screened for subclinical mastitis, further preceded by isolation and confirmation of S. aureus. The S. aureus isolates were subjected to evaluation of antimicrobial resistance by phenotypic identification using Kirby-Bauer disc diffusion method, while the genotypic estimation was done by polymerase chain reaction to declare isolates as methicillin, beta-lactam, vancomycin, tetracycline, and aminoglycoside resistant S. aureus (MRSA, BRSA, VRSA, TRSA, and ARSA), respectively. RESULTS: The current study revealed an overall prevalence of subclinical mastitis and S. aureus to be 59.11% and 46.69%, respectively. On a phenotypic basis, the prevalence of MRSA, BRSA, VRSA, TRSA, and ARSA was found to be 44.33%, 58.49%, 20.75%, 35.84%, and 30.18%, respectively. The results of PCR analysis showed that 46.80% of the tested isolates were declared as MRSA, 37.09% as BRSA, and 36.36% as VRSA, while the occurrence of TRSA and ARSA was observed in 26.31% and 18.75%, respectively. The current study also reported the existence of biofilm-producing genes (icaA and icaD) in 49.06% and 40.57% isolates, respectively. Lastly, this study also reported a high incidence of discrepancies for both genotypic and phenotypic identification methods of resistance evaluation, with the highest discrepancy ratio for the accA-aphD gene, followed by tetK, vanB, blaZ, and mecA genes. CONCLUSION: The study concluded that different antibiotic resistance strains of S. aureus are prevalent in study districts with high potential to transmit between human populations. The study also determined that there are multiple resistance determinants and mechanisms that are responsible for the silencing and expression of antibiotic resistance genes.

Genotypic insights to Panton-Valentine leukocidin positive methicillin-resistant Staphylococcus aureus isolated from cattle mastitis.

In this research communication we investigate the prevalence and antimicrobial susceptibility of S. aureus harboring virulent genes responsible for mastitis in cattle of Punjab, Pakistan. A total of 690 milk samples were collected from commercial dairy farms for analysis of the prevalence of subclinical and clinical mastitis and isolation of S. aureus. Virulence ability and methicillin resistance in S. aureus (MRSA) was determined by targeting the pvl (the gene for Panton-Valentine leukocidin) and mecA genes, respectively. A total of 175 S. aureus isolates exhibiting prevalence of pvl gene (6.28%) and mecA gene (22.28%) were determined. Antimicrobial susceptibility testing of pvl positive and negative MRSA against different classes of antibiotics revealed 100% resistance against ß-lactams while 100% sensitivity towards tylosin and linezolid.

Non-Invasive Multi-Gas Detection Enabled by Cu-CuO/PEDOT Microneedle Sensor.

Metal-oxide-based gas sensors are extensively utilized across various domains due to their cost-effectiveness, facile fabrication, and compatibility with microelectronic technologies. The copper (Cu)-based multifunctional polymer-enhanced sensor (CuMPES) represents a notably tailored design for non-invasive environmental monitoring, particularly for detecting diverse gases with a low concentration. In this investigation, the Cu-CuO/PEDOT nanocomposite was synthesized via a straightforward chemical oxidation and vapor-phase polymerization. Comprehensive characterizations employing X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and micro Raman elucidated the composition, morphology, and crystal structure of this nanocomposite. Gas-sensing assessments of this CuMPES based on Cu-CuO/PEDOT revealed that the response current of the microneedle-type CuMPES surpassed that of the pure Cu microsensor by nearly threefold. The electrical conductivity and surface reactivity are enhanced by poly (3,4-ethylenedioxythiophene) (PEDOT) polymerized on the CuO-coated surface, resulting in an enhanced sensor performance with an ultra-fast response/recovery of 0.3/0.5 s.

Environmental implications of phosphate-based fertilizer industrial waste and its management practices.

During the green revolution in the mid-twentieth century, the consumption of inorganic phosphorous and phosphate-based fertilizers (P-fertilizers) in the developing world skyrocketed, resulting in a proliferation of P-fertilizer industries. Phosphate-based fertilizer industries are ranked among the most environment-polluting industries. The worldwide phosphorus market, which was 68.5 million metric tons in 2020, is expected to increase at a compound annual growth rate (CAGR) of 2.5% to 81 million metric tons by 2027. The release of untreated hazardous pollutants from these fertilizer industries into the soil, water, and atmosphere has resulted in severe environmental health issues. Excessive surface runoff of phosphorus from agricultural fields and its deposition in water promote the growth of algae and macrophytes and lower dissolved oxygen concentration through eutrophication, which is detrimental to aquatic life. Fluorides (F-) and sulfur dioxide (SO2) and/or heavy metals (potentially toxic elements, PTEs) are also detected in the emissions from these fertilizer industries. The main solid waste generated from the phospho-gypsum plant produced up to 5 tons of di-hydrogen phosphate (H2PO4), including PTEs and radioactive substances. Phosphates and fluorenes from these industries are usually disposed of as sludge in storage ponds or trash piles. Humans inhaling poisonous gases released from the P-fertilizer industries can develop hepatic failure, autoimmune diseases, pulmonary disorders, and other health problems. The objectives of this review are to provide guidelines for eliminating the bottleneck pollutions that occur from the phosphate-based fertilizer industries and explore the management practices for its green development.

The rising menace of antifungal resistance in dermatophytes among the patients of tinea capitis.

OBJECTIVE: To determine the epidemiological profile of dermatophytes among patients of tinea capitis and their susceptibility pattern to fluconazole and terbinafine. METHODS: The cross-sectional study was conducted at the Department of Microbiology, Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi, from August to December 2019, and comprised samples of hair and skin from the scalp of tinea capitis patients regardless of age and gender. Demographic details were collected and the samples were processed for direct microscopy and mycological culture. Antifungal susceptibility testing for fluconazole and terbinafine was performed using broth microdilution method. Data was analysed using SPSS 21. RESULTS: Of the 207 patients, 115(55.5%) were males, and 114(55.1%) were children. Alopecia was the most common presenting complaint 141(68.1%), while grey patch tinea was the most characteristic clinical form 53(25.6%). Dermatophytes were yielded in 61(29.5%) cases, non-dermatophytes were isolated in 45(21.7%) specimens, and 101(48.8%) were culture-negative. Among the dermatophytes, trichophyton violaceum was the most common pathogen 21(34.4%), followed by trichophyton mentagrophytes 18(29.5%). Resistance to fluconazole and terbinafine among dermatophytes was recorded in 12(19.7%) and 7(11.5%) isolates, respectively. CONCLUSIONS: The frequency of dermatophytes among tinea capitis patients was higher compared to non-dermatophyte species. Antifungal resistance was predominantly seen in trichophyton violaceum and trichophyton mentagrophytes.

Alleviation of adverse effects of nickel on growth and concentration of copper and manganese in wheat through foliar application of ascorbic acid.

We investigated the role of ascorbic acid (AsA) to alleviate nickel (Ni) induced adverse effects on growth and concentration of Ni, copper (Cu), and manganese (Mn) in hydroponically grown wheat varieties viz. Galaxy, Punjab-2011, and FSD-08. Plants were exposed to five levels of Ni viz. 0, 5, 10, 15, and 20 mg L-1. After 1 week, AsA (1 mM) was sprayed onto the Ni-stressed plants. FSD-08 produced the maximum SDW with and without AsA compared to other varieties. FSD-08, Galaxy, and Punjab-2011 witnessed 2.61-, 2.83-, and 7.5-fold increases in SDW with AsA, respectively. Wheat plants contained the maximum Ni in shoots and roots with a Ni level of 20 mg L-1 irrespective of varieties. Nickel in shoots decreased with AsA witnessing 13, 12, and 10% decrease in FSD-08, Punjab-2011, and Galaxy, respectively. Nickel in roots of FSD-08 decreased by 18% while increased by 3.34-fold and 3.50-fold in Galaxy and Punjab-2011, respectively with AsA. Nickel decreased Cu in shoot and Mn in shoot and root while Cu in roots of all wheat varieties increased. It was concluded that AsA improved the growth of Ni-stressed and FSD-08 performed better by maintaining good growth and less Ni in shoots compared to other varieties.

Exploiting plant internal mechanisms with foliar application of different organic substances have widely been investigated to decrease metal accumulation and their adverse effects on plants. However, the differential response of different varieties to metal accumulation in response to foliar application of ascorbic acid is not well documented. This study was conducted to investigate the effect of exogenous application of ascorbic acid on growth response, the concentration of Ni, Cu, and Mn in three wheat varieties.

Immobilization of cadmium in soil-plant system through soil and foliar applied silicon.

We conducted a pot experiment to evaluate the potential for soil- and foliar-applied silicon (Si), alone and in combination, to a Cd-contaminated soil in order to evaluate the effects on such amendments on the Cd translocation from soil to wheat root, shoot and grains. Five treatments were used, T1) control with no external factor added, T2 received only Cd, while T3-T5 treatments received Cd in combination with soil, foliar and soil plus foliar applied Si. Except control (T1), soil was contaminated with Cd at 10 mg kg-1 in all the treatments and 1% solution of Si as an amendment was used for soil and/or foliar application or their combination. Overall, while Si application improved both plant growth and yield in Cd-contaminated soil. Control and combined soil- and foliar-applied Si in Cd contaminated treatments showed equally positive (2.5%) increase in plant height over Cd contaminated treatment. Grain yield was also highest in the treatment receiving Cd plus soil-applied Si (29%) followed by control (26%). It was concluded that Si can alleviate Cd toxicity in wheat irrespective of whether the Si was soil-applied or applied via a foliar method, but soil applied Si proved the best in this regard.Novelty statement Immobilization of metals i.e., cadmium (Cd) with soil-applied amendments like biomaterials and organic manure to decrease Cd concentration in plants have already been widely investigated. Silicon (Si) is a cheap in-organic and readily available element in the nature and also used for the same purpose. It can be applied both in soil as well as by foliar and soil + foliar application to decrease the metals concentration in soil and plants. However, comparative effectiveness of these three methods have not been checked simultaneously. In this study, we have studied the comparative effectiveness of Si application to soil, foliar and their combination (soil + foliar) to decrease Cd concentration during wheat crop.

Arsenic concentrations in soil, water, and rice grains of rice-growing areas of Punjab, Pakistan: multivariate statistical analysis.

Arsenic (As), a class-A human carcinogen, is ubiquitously present in the earth's crust and soil and may enter the air, water, and surface environments through different natural and anthropogenic sources. In this experiment, soil, irrigation water, and rice grains were sampled from conventional rice-growing areas of Punjab, Pakistan. Soil samples were collected from 0 to 15 cm surface soil of rice growing fields, and rice grains were collected from the same field at crop maturity. Irrigation water samples were collected from the source used to irrigate the respective rice fields. Coordinates of sampling locations were noted using a global positioning system, and a locations map was made using ArcGIS. Soil samples were digested in a microwave digester using aqua regia, and plant samples were block digested using nitric acid. Arsenic concentration was determined using an inductively coupled plasma mass spectrometer coupled with an auto-sampler and integrated samples introduction system. The mean concentration of As in rice grains, soil, and water samples was found within the safe limit set by WHO except for a sample from Narowal (148.54 µg l-1) that exceeded the irrigation water standard limit, i.e., 100 µg l-1 for irrigation water. Principal component analysis was performed to reduce the multidimensional space of variables and samples. Through the calculations of estimated daily intake, it has been revealed that the As levels measured in this study would only contribute a small amount (less than 5%) of the total recommended daily intake allowance.

Predictors of sleep paralysis and relationship of sleep paralysis with sleep quality in university students of Islamabad.

OBJECTIVE: To determine the frequency of sleep paralysis among university students, and to determine the association between sleep paralysis and sleep quality along with different predictive factors leading to sleep paralysis. METHODS: The descriptive cross-sectional study was conducted at the National University of Modern Languages, Islamabad, Pakistan, from June to October, 2019, and comprised adult students of either gender who had experienced at least one episode of sleep paralysis in the past. Demographic variables were obtained using Google Form, while experiences of sleep paralysis were assessed using the Waterloo Unusual Sleep Experience Questionnaire, and sleep quality was assessed with the Sleep Condition Indicator. Data was analysed using SPSS 20. RESULTS: Initially, 440 students were assessed/ Of them, 233(53%) were males, 207(47%) were females, 208(47.3%) were aged 20-23 years, and 129(29.3%) were studying in the third year of their university programme. Of the total, 130(29.5%) subjects had experienced sleep paralysis at least once in their lifetime. The most frequent sensation experienced was feeling of floating 22(16.9%). Mean age at the time of the first experience was 9.7±3.1 years, and 66(50.8%) had experienced the episodes while lying on their back, while 32(24.6%) had positive family history of sleep paralysis. Sleep paralysis had significant relationship with sleep quality (p<0.001). CONCLUSIONS: About one-third of the sample had experienced sleep paralysis once in their lifetime. The relationship between sleep paralysis and insomnia was significant.

Comparative in vitro activity of selected antibacterial agents against Escherichia coli isolated from hospitalized patients suffering UTI.

Escherichia coli is the most studied among those bacteria causing urinary tract infections. This study was aimed to find out antibacterial activity and minimum inhibitory concentration of selected antibacterial agents against E. coli isolates of hospitalized UTI patients. The specimens were inoculated on Eosin Methylene Blue medium. E. coli isolates were identified via colonial morphology, biochemical testing and API-20 kit. The susceptibility pattern of antibacterial agents was determined applying disc diffusion method (Kirby-Bauer) and dilution tube method. Among all, 38.82% (n=158/407) specimens were positive for E. coli, while the rest showed either no growth or exhibited colonies other than E. coli. while observing the susceptibility pattern, Imipenem was found the most effective (73.42%) antibacterial agent, followed by nitrofurantoin (52.53%), cefpirome (44.94%) and tazobactam/ piperacillin (44.94%), whereas the E. coli isolates were highly resistant to sulfamethoxazole/trimethoprim (71.52%), followed by Amoxicillin-clavulanic acid (67.72%), nalidixic acid (66.46%) and Tobramycin (62.03%), when tested by disc diffusion method. The isolates were susceptible to cefpirome (39.87%) and tobramycin (39.87%) and resistant to sulfamethoxazole/trimethoprim (75.32%), followed by levofloxacin (61.39%), when tested by tube dilution method. The study concluded high degree of resistance against Sulfamethoxazole/trimethoprim, in contrast, cephalosporin and Imipenem exhibited good potency which can be recommended for UTI.

The evaluation of antibiotic susceptibility pattern and associated risk factors of UTI in tertiary care hospital of Peshawar.

UTIs are majorly caused by species of bacteria in patients of almost all ages. The study was aimed to determine the prevalence rate of uropathogens, its antibiotic susceptibility pattern and associated risk factors. Urine samples were collected from n=470 participants using sterilized containers and were inoculated on culture media. The isolates were identified via gram-staining and biochemical characterization. A total of 43.20% samples were positive. Female contributed the highest prevalence rate, 78.82% as compared to male, 21.18%. The highest prevalence 40.90% was observed in the age-group 31-45, followed by 16-30 with 36.90%. Escherichia coli (47.80%) was the most prevalent, followed by Klebsiella pneumoniae (18.2%), Enterococcus faecalis (12.80%), Pseudomonas aeruginosa (10.30%) and Proteus mirabilis (7.40%). Staphylococcus aureus showed high sensitivity (100%) to amikacin, meropenem, imipenem, fosfomycin, vancomycin, clindamycin and linezolid while in case of E. faecalis, vancomycin and linezolid were highly potent. Amikacin and meropenem showed the highest (100%) potency followed by imipenem While Fosfomycin was highly potent to E. coli, K. pneumoniae, P. mirabilis and P. aeruginosa with potency rate 89.97%, 92.31%, 100% and 100% respectively. In the current study, the positivity rate was highly observed in female. E. coli and K. pneumoniae were found the most ubiquitous for UTI.

Comparative Effect of Fertilization Practices on Soil Microbial Diversity and Activity: An Overview.

Continuously increasing human population demands increased food production, which needs greater fertilizer's input in agricultural lands to enhance crop yield. In this respect, different fertilization practices gained acceptance among farmers. We reviewed effect of three main fertilization practices (Conventional-, Organic-, and Bio-fertilization) on soil microbial diversity, activity, and community composition. Studies reported that over application of inorganic fertilizers decline soil pH, change soil osmolarity, cause soil degradation, disturb taxonomic diversity and metabolism of soil microbes and cause accumulation of extra nutrients into the soil such as phosphorous (P) accumulation. On the contrary, organic fertilizers increase organic carbon (OC) input in the soil, which strongly encourage growth of heterotrophic microbes. Organic fertilizer vermicompost application provides readily available nutrients to both plants as well as microbes and encourage overall microbial number in the soil. Most recently, role of beneficial bacteria in long-term sustainable agriculture attracted attention of scientists towards their use as biofertilizer in the soil. Studies documented favorable effect of biofertilization on microbial Shannon, Chao and ACE diversity indices in the soil. It is concluded from intensive review of literature that all the three fertilization practices have their own way to benefit the soil with nutrients, but biofertilization provides long-term sustainability to crop lands. When it is used in integration with organic fertilizers, it makes the soil best for microbial growth and activity and increase microbial diversity, providing nutrients to soil for a longer time, thus improving crop productivity.

An overview of self-medication: A major cause of antibiotic resistance and a threat to global public health.

Self-medication is the use of medicines by people on the basis of their own experience without consulting a doctor. People use medicines for pain management or to cure a disease and sometime this may be unnecessary. There are a lot of public and professional health concerns about misuse of medicines and globally physicians agree upon this rising issue that leads to antibiotic resistance. In developing countries, medicines without prescription are easily available which results in many adverse outcomes, especially bacterial resistance. Insufficient healthcare services and socioeconomic factors result in increased proportion of self-medication compared to drugs prescribed by physicians. The current narrative review was planned to focus on indicating prevalence rate of self-medication in different developed and under-developed countries, major risk factors and control of self-medication due to which antibiotic resistance rate can be minimised. The issue needs urgent attention of representative authorities for taking serious actions. Furthermore, arranging awareness seminars and implementing new policies/regulations to prevent the sale of any drug/antibiotic without prescription could play a vital role in bringing this alarming issue under control.

Observer and descriptor satisfying incremental quadratic constraint for class of chaotic systems and its applications in a quadrotor chaotic system.

A drone based on four rotors is considered in this research paper. Its chaotic solution is shown bounded in an inscribed sphere whose vertices are tangent to faces of octahedron. Based on concept of constrained optimization; Linear Matrix Inequalities (LMIs) satisfying quadratic constraint increment multiplier matrix σm , state observers and descriptors with estimated parameter is calculated. Moreover, an image file is decrypted by designing description for mentioned chaotic system and then encrypted on its receiver end. Furthermore, an electric circuit is designed for chaotic quadrotor using LTspice and is fitted into wireless flying robot to observe its dynamics in bounded rectangular region.

Comparative residual effect of activated carbon and other organic amendments on immobilization and phytoavailability nickel and other metals to Egyptian Clover (Trifolium alexandrinum) in contaminated soil.

The effect of organic amendments on phytoavailability of nickel (Ni) and other metals in soil may change with time due to transformation of organic matter. We investigated the residual effect of organic amendments (farm manure [FM], poultry manure [PM], pressmud [PrM], and activated carbon [AC]) to immobilize Ni and other metals in soil and absorption of metals by Egyptian clover. Fresh and dry weights of Egyptian clover increased significantly (p < 0.05) due to residual effect of amendments compared to control. Extractable Ni and other metals had significant positive correlation with residual organic matter in soil. Extractable manganese (Mn) in post-harvest soil of Egyptian clover increased compared with that of post-harvest soil of maize (previous crop). However, extractable copper (Cu) decreased with amendments. Copper was the maximum in control followed by AC. Zinc in soil decreased in FM and PrM treated pots but increased in pots amended with PM and AC. Concentration of Ni, Mn, and Cu was the minimum in shoots of those plants grown with AC amended pots compared to the control. It was concluded that AC was the most effective for immobilization of metals in soil which consequently decreased the concentration of metals in shoots of Egyptian clover.

Frequency and comparison among antibiotic resistant Staphylococcus aureus strains in selected hospitals of Peshawar, Pakistan.

OBJECTIVE: To assess and compare the frequency of antibiotic-resistant staphylococcus aureus strains. METHODS: A retrospective study was conducted at the privately-owned Welfare Medical Laboratory, Peshawar, Pakistan, and comprised record related to the period between 07th February 2017 and 23rd March 2018 of patients referred for pus-testing from Khyber Teaching Hospital, Lady Reading Hospital and the Hayatabad Medical Complex. Pus samples were obtained from various parts of body with cotton swabs. The samples were cultured and the isolated staphylococcus aureus strains were analysed against selected antibiotics. The frequency of the isolated strains was tested and compared using Prism 7 software. RESULTS: Of the 6780 samples, staphylococcus aureus was found in 4315(63.64%). Wild-type staphylococcus aureus strains were 2133(31.46%), followed by 825(12.16%) methicillin resistant, 792(11.68%) vancomycin intermediate, and 565(8.33%) vancomycin-resistant staphylococcus aureus strains. The isolated strains were significant (p<0.0001) for operated wounds, and non-significant (p=0.8915) for diabetic foot cases. CONCLUSIONS: The frequency of antibiotic-resistant staphylococcu saureus strains was high.

A multivariate analysis of health risk assessment, phytoremediation potential, and biochemical attributes of Spinacia oleracea exposed to cadmium in the presence of organic amendments under hydroponic conditions.

Cadmium (Cd) phytoremediation potential and its accumulation in edible and nonedible plant tissues is the function of various biochemical processes taking place inside plants. This study assessed the impact of organic ligands on Cd phyto uptake and different biophysiochemical processes of Spinacia oleracea L., and associated health hazards. Plants were exposed to Cd alone and chelated with citric acid (CA) and ethylenediaminetetraacetic acid (EDTA). Results revealed that the effect of Cd on lipid peroxidation, H2O2 production and pigment contents varied greatly with its applied level and the type of organic ligand. Moreover, the effect was more prominent in root tissues than leaf tissues and for high concentrations of Cd and organic ligands. Cadmium accumulation increased by 90 and 74% in roots and leaves, respectively, with increasing Cd levels (25-100 µM). Cadmium exposure at high levels caused lipid peroxidation in roots only. Application of both CA and EDTA slightly diminished Cd toxicity with respect to pigment contents, lipid peroxidation and hydrogen peroxide (H2O2) contents. Hazard quotient (HQ) of Cd was <1.00 for all the treatments. Under nonlinear effect of treatments, multivariate analysis can be an effective tool to trace overall effects/trends.

Assessment of trace elements in urban topsoils of Rawalpindi-Pakistan: a principal component analysis approach.

Assessment of trace elements is inevitable to reduce stress on environment due to urbanization and industrialization. Rawalpindi, the fourth largest city of Pakistan, rapidly moving towards industrialization and has a large number of automobiles. In the present study, the urban area of Rawalpindi was divided into five parts: Gawal Mandi, Pir Wadhai, Soan Adda, Chah Sultan, and Central Ordinance Depot (COD), to determine distribution of trace elements. Soil samples were collected from 5 to 20 cm depth. After drying and sieving, samples were digested using di-acid (HNO3 and HClO4 at 2:1). Concentrations of heavy metals were determined using atomic absorption spectrophotometer (AAS). Principal component analysis (PCA) was performed to reduce multidimensional space of variables and samples. Observed mean concentrations of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn were 164, 33.4, 295, 336, 634, 236, 1572, and 546 mg kg-1, respectively. Mean concentrations of all the heavy metals in urban area soil were higher than the WHO permissible limits. Correlation coefficient analysis showed positive correlation among Cd, Co, Cu, Ni, and Pb, whereas no obvious correlation for Cr and Mn was found with any other heavy metal. Zn was positively correlated with Co, Ni, and Mn, whereas negative correlation was found with Cr. Results showed that Pir Wadhai and COD were the most and least contaminated parts of the city, respectively, and this is attributed to the presence and absence of heavy traffic loads and industrial effluents. Graphical abstract ᅟ.

Effect of organic amendments on cadmium stress to pea: A multivariate comparison of germinating vs young seedlings and younger vs older leaves.

Despite significant recent advancement in research, biogeochemical behavior of heavy metals with respect to their applied form is still topical. Moreover, metal toxicity to plants may vary with their stage of development/maturity. Therefore, this study for the first time evaluated the influence of ethylenediaminetetraacetic acid (EDTA) and citric acid (CA) on cadmium (Cd) accumulation and toxicity to germinating and young pea seedlings as well as in younger and older leaves. The experimental setup of current study consisted of two separate studies. The first study was performed on germinating seedlings grown in a Cd-contaminated sand media. Pea seeds were treated with two levels of Cd (Cd-25 and Cd-100) alone and combined with different levels of EDTA and CA. The second study was carried out in hydroponic solution. The influence of organic amendments on Cd accumulation and toxicity to pea plants was evaluated by determining Cd contents in pea seedlings, H2O2 contents, chlorophyll contents and lipid peroxidation in younger and older leaves. Cadmium stress caused overproduction of H2O2 in roots and leaves of pea seedlings. Cadmium-induced overproduction of H2O2 caused a decrease in the pigment contents and increased lipid peroxidation. Application of EDTA at higher levels (81 and 200µM) increased Cd accumulation by pea plants. However, CA did not affect Cd accumulation by pea. Both EDTA and CA increased Cd-induced H2O2 production and lipid peroxidation. Younger pea leaves showed more sensitivity to Cd stress compared to older leaves. Similarly, Cd toxicity was more pronounced in germinating seedlings than young seedlings. Moreover, Pearson correlation and principal component analysis (PCA) showed very interesting correlations between treatments and stress responses of germination and young seedlings as well as younger and older leaves. Based on multivariate analysis, it is proposed that the Cd toxicity to pea plants greatly vary with its growth stage and the maturity of organs (younger or older leaves).