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Papers by samra irem

International Journal of Agriculture and Biology, 2015

ABSTRACT

Chemosphere, Jan 20, 2018

Hydroponics experiment was conducted to investigate the effects of different levels of Pb on Para... more Hydroponics experiment was conducted to investigate the effects of different levels of Pb on Para Grass (Brachiaria mutica) and Castorbean (Ricinus communis L). Generally, Para Grass exhibited higher tolerance to excessive concentrations of Pb in nutrient solution, whereas a consistent decline was observed in growth of Castorbean plants exposed to similar Pb levels. Malondialdehyde (MDA) and HOcontents exhibited contrasting results with a general decrease in Para Grass and a linear increase in case of Castorbean. In both species a decrease was noticed in the activities of superoxide dismutase (SOD) and guaiacol peroxidase (G-POD) while catalase (CAT) activity was significantly increased. Ultrastructural studies revealed increased starch grains and adversely affected thylakoid membranes in chloroplasts of leaf cells of plants treated with 500 μM Pb. Photosynthetic parameters such as COassimilation rate, stomatal conductance (gs) and transpiration rate (E) decreased in both plant spec...

Water Science and Technology: Water Supply, 2017

The biosorption potential of orange waste (OW) was investigated using synthetic solutions of arse... more The biosorption potential of orange waste (OW) was investigated using synthetic solutions of arsenic and contaminated drinking water under different parameters, e.g. biosorbent dose, initial concentrations of solution, contact time, and pH in a batch system. The optimum conditions were identified as a contact time of 30 minutes, pH 6, biosorbent dose of 1 g L−1, and initial arsenic concentration of 250 ppb. A fluidized bed column was used to study the removal of arsenic in the column. The results showed that biosorption of arsenic gave promising results in batch and continuous system, lowering the arsenic concentration down to WHO standards (10 ppb) for drinking water. The Fourier transform infrared spectra indicated that hydroxyl and carboxyl groups were major active sites for biosorption, while the results of scanning electron microscopy showed obvious changes in surface morphology of OW after the biosorption process. With 90% removal efficiency, results indicated that OW is a cos...

Pakistan Journal of Biological Sciences, 2016

International Journal of Agriculture and Biology

ABSTRACT

Environmental Chemistry for a Sustainable World, 2015

Genomic technologies started in the early 1980s to improve the genomes of cultivated crop species... more Genomic technologies started in the early 1980s to improve the genomes of cultivated crop species. For example the term “Bt” comes from the soil bacterium Bacillus thuringiensis containing genes, e.g. Cry1Ac, Cry2Ab, Cry1F, Cry3Bb1, that provides protection against lepidopteran insect pests. Those genes have been inserted in crops such as corn, cotton, soybean, rice, potato and canola released for cultivation in mid 1990s in USA, and later in many other countries like China and India. About 29 countries commercialized genetically-modified (GM) or ‘transgenic’ crops while 30 countries granted regulatory approvals for planting GM-crops; together making 75 % of the world population. Potential harmful effects of the Bt-crops on non-targets were quantified before releasing such non-conventional crops into the environment. The cultivation of Bt-crops were most commonly found safe, based on various studies including the insertional impact of transgene and its regulatory elements on plant phenotype and agronomic performance, effect on non-target organisms (NTOs) and nutritional impacts on multiple experimental models. Albeit the studies were conducted for limited durations. However, the skeptics always claim for conducting extensive clinical as well as field trials, and also doubt on methods and procedures of calculating the ecological risks. This debate is still on-going, especially after reports on substantial reduction of monarch butterfly caterpillars exposed to Bt-maize pollen, though later nullified; and detection of traces of transgene in various tissues of experimental animals. Procedures, methods and protocols for evaluating potential risks of GM-crops and foods should be standardized as the first step to build trust of researchers and end-users. Many efforts should be exerted in deploying genes of interest, marker genes and regulatory sequences invoking no or little issues of potential risks to the ecosystem.

Ecotoxicology and environmental safety, Jan 28, 2015

Plants are the ultimate food source for humans, either directly or indirectly. Being sessile in n... more Plants are the ultimate food source for humans, either directly or indirectly. Being sessile in nature, they are exposed to various biotic and abiotic stresses because of changing climate that adversely effects their growth and development. Contamination of heavy metals is one of the major abiotic stresses because of anthropogenic as well as natural factors which lead to increased toxicity and accumulation in plants. Arsenic is a naturally occurring metalloid toxin present in the earth crust. Due to its presence in terrestrial and aquatic environments, it effects the growth of plants. Plants can tolerate arsenic using several mechanisms like phytochelation, vacuole sequestration and activation of antioxidant defense systems. Several signaling mechanisms have evolved in plants that involve the use of proteins, calcium ions, hormones, reactive oxygen species and nitric oxide as signaling molecules to cope with arsenic toxicity. These mechanisms facilitate plants to survive under metal...

Chemosphere, 2019

High concentration of arsenic (As) in rice is a serious problem worldwide. Pot experiments were c... more High concentration of arsenic (As) in rice is a serious problem worldwide. Pot experiments were conducted to assess the potential dietary toxicity of arsenic and effect of various soil amendments on arsenic accumulation in rice grains. Two basmati rice genotypes were used to conduct pot experiments using various levels of arsenic (10, 25, 50 and 100 mg kg-1 soil). In addition, plants were exposed to soil collected from a well documented arsenic contaminated site. Contrasting results for growth, yield and grain arsenic concentration were obtained for basmati-385 (Bas-385), exhibiting tolerance (56% yield improvement at 10 mg As kg-1), while genotype BR-1 showed 18% yield decline under same conditions. Furthermore, application of soil amendments such as iron (Fe), phosphate (PO 4) and farmyard manure (FYM) at 50 mg kg-1 , 80 kg ha-1 and 10 t ha-1 , respectively improved the plant height and biomass in both genotypes. Accumulation of arsenic in rice grain followed a linear trend in BR-1 whereas a parabolic relationship was observed in Bas-385. Both genotypes exhibited a positive response to iron sulfate amendment with significant reduction in grain arsenic concentrations. Regression analysis gave soil arsenic threshold values of 12 mg kg-1 in Bas-385 and 10 mg kg-1 in BR-1 for potential dietary toxicity. This study suggests that genotype Bas-385 can be used for safe rice production in areas with soil arsenic contamination up to 12 mg kg-1 and that appropriate dose of iron sulfate for soil amendment can be used effectively to reduce translocation of arsenic to rice grain.

High concentration of arsenic (As) in rice is a serious problem worldwide. Pot experiments were c... more High concentration of arsenic (As) in rice is a serious problem worldwide. Pot experiments were conducted to assess the potential dietary toxicity of arsenic and effect of various soil amendments on arsenic accumulation in rice grains. Two basmati rice genotypes were used to conduct pot experiments using various levels of arsenic (10, 25, 50 and 100 mg kg−1 soil). In addition, plants were exposed to soil collected from a well documented arsenic contaminated site. Contrasting results for growth, yield and grain arsenic concentration were obtained for basmati-385 (Bas-385), exhibiting tolerance (56% yield improvement at 10 mg As kg−1), while genotype BR-1 showed 18% yield decline under same conditions. Furthermore, application of soil amendments such as iron (Fe), phosphate (PO4) and farmyard manure (FYM) at 50 mg kg−1, 80 kg ha−1 and 10 t ha−1, respectively improved the plant height and biomass in both genotypes. Accumulation of arsenic in rice grain followed a linear trend in BR-1 whereas a parabolic relationship was observed in Bas-385. Both genotypes exhibited a positive response to iron sulfate amendment with significant reduction in grain arsenic concentrations. Regression analysis gave soil arsenic threshold values of 12 mg kg−1 in Bas-385 and 10 mg kg−1 in BR-1 for potential dietary toxicity. This study suggests that genotype Bas-385 can be used for safe rice production in areas with soil arsenic contamination up to 12 mg kg−1 and that appropriate dose of iron sulfate for soil amendment can be used effectively to reduce translocation of arsenic to rice grain.

Research Paper, 2018

Hydroponics experiment was conducted to investigate the effects of different levels of Pb on Para... more Hydroponics experiment was conducted to investigate the effects of different levels of Pb on Para Grass (Brachiaria mutica) and Castorbean (Ricinus communis L). Generally, Para Grass exhibited higher tolerance to excessive concentrations of Pb in nutrient solution, whereas a consistent decline was observed in growth of Castorbean plants exposed to similar Pb levels. Malondialdehyde (MDA) and H2O2 contents exhibited contrasting results with a general decrease in Para Grass and a linear increase in case of Castorbean. In both species a decrease was noticed in the activities of superoxide dismutase (SOD) and guaiacol peroxidase (G-POD) while catalase (CAT) activity was significantly increased. Ultrastructural studies revealed increased starch grains and adversely affected thylakoid membranes in chloroplasts of leaf cells of plants treated with 500 μM Pb. Photosynthetic parameters such as CO2 assimilation rate, stomatal conductance (gs) and transpiration rate (E) decreased in both plant species under different levels of Pb. Maximum concentrations of Pb in shoots of Para Grass and Castorbean were 1.29 and 0.352 g kg−1, respectively while in roots maximum values were 8.88 and 49.86 g kg−1, respectively. The high concentrations of Pb (about 5%) in the roots of Castorbean plants suggest its possible role in the phytoremediation/rhizofiltration of Pb contaminated water.

Environmental Chemistry Letters

Your article is protected by copyright and all rights are held exclusively by Springer Internatio... more Your article is protected by copyright and all rights are held exclusively by Springer International Publishing Switzerland. This eoffprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".

Ecological Engineering, 2013

The aim of the present research was to evaluate the suitability of low-cost, ecofriendly and free... more The aim of the present research was to evaluate the suitability of low-cost, ecofriendly and freely available orange waste (OW) biosorbent for the removal of reactive navy blue dye. The biosorption potential of OW was investigated using synthetic solutions of textile dye (reactive navy blue) at different parameters, e.g. biosorbent dose, initial concentrations of solution, contact time, pH and particle size in a batch system. The optimum conditions were identified as contact time of 160 min, pH 2, biosorbent dose of 4 g L −1 , agitation speed of 80 rpm and initial dye concentration of 100 ppm. The biosorbent was analyzed by surface area analyzer (SAA), Fourier transform infra-red spectroscopy (FT-IR) and scanning electron microscopy (SEM) for its physical and chemical characterization. The FT-IR spectra indicated that hydroxyl and carboxyl groups were major active sites for biosorption, while the results of SEM showed obvious changes in surface morphology after biosorption. Experimental data were fitted in Langmuir and Freundlich equilibrium isotherms and found to follow the Langmuir equation. Adsorption capacity was 30.28 mg g −1 with the dye removal efficiency of 82%. The application of pseudo-first order equation, pseudo-second order kinetics, Elovich sorption model and intraparticle diffusion kinetics revealed that pseudo-second order kinetic model best explained the experimental process. The results indicated that orange waste is a cost-effective and eco-friendly biosorbent and competitive to the current wastewater treatment technologies.

Genomic technologies started in the early 1980s to improve the genomes of cultivated crop species... more Genomic technologies started in the early 1980s to improve the genomes of cultivated crop species. For example the term "Bt" comes from the soil bacterium Bacillus thuringiensis containing genes, e.g. Cry1Ac, Cry2Ab, Cry1F, Cry3Bb1, that provides protection against lepidopteran insect pests. Those genes have been inserted in crops such as corn, cotton, soybean, rice, potato and canola released for cultivation in mid 1990s in USA, and later in many other countries like China and India. About 29 countries commercialized genetically-modified (GM) or 'transgenic' crops while 30 countries granted regulatory approvals for planting GM-crops; together making 75 % of the world population. Potential harmful effects of the Bt-crops on non-targets were quantified before releasing such non-conventional crops into the environment. The cultivation of Bt-crops were most commonly found safe, based on various studies including the insertional impact of transgene and its regulatory elements on plant phenotype and agronomic performance, effect on non-target organisms (NTOs) and nutritional impacts on multiple experimental models. Albeit the studies were conducted for limited durations. However, the skeptics always claim for conducting extensive clinical as well as field trials, and also doubt on methods and procedures of calculating the ecological risks. This debate is still on-going, especially after reports on substantial reduction of monarch butterfly caterpillars exposed to Bt-maize pollen, though later nullified; and detection of traces of transgene in various tissues of experimental animals. Procedures, methods and protocols for evaluating potential risks of GM-crops and foods should be standardized as the first step to build trust of researchers and end-users. Many efforts should be exerted in deploying genes of interest, marker genes and regulatory sequences invoking no or little issues of potential risks to the ecosystem.

Like many other cotton growing countries, area under the cultivation of genetically modified cott... more Like many other cotton growing countries, area under the cultivation of genetically modified cotton containing Cry1Ac gene has been increased tremendously in Pakistan because of its added advantage towards conferring resistance to bollworms especially Helicoverpa armigera. It has been reported that this gene derived from Bacillus thuringiensis has no negative impact on the soil ecosystem. Studies covering biosafety aspect of transgene involving Bt gene are non-existent in our ecological system. Every country has different microbiota which is the compelling factor to design studies for estimating the negative impact, if any, in our indigenous environment. In the present study, the concentration of Cry 1Ac protein in leaf tissues have shown increasing trend from 60 DAS to 90 DAS, and decreased at 120 DAS. Similar results were observed during each cropping season. Variation in protein concentration was found non-significant over different cropping years but it was significant at different sampling stages. We also observed that the Cry 1Ac toxin in the soil was stumpy low (78 times) when we compare it to leaf. Experiments related to the colony farming units (CFUs) of culturable bacteria, actinomycetes and fungi were undertaken in the rhizosphere of Bt-and non-Bt-cotton plants at various growth stages at 30 days interval from sowing till maturity for three consecutive years (2006)(2007)(2008). A cotton variety IR-NIBGE-901 (containing Cry 1Ac gene, bred at NIBGE) and its non-Bt isogenic variety (FH-901) were sown in NIBGE cotton field, Faisalabad Pakistan. The concentration of Cry 1Ac protein released in the soil through root exudates, and in the terminal leaves was measured 60, 90 and 120 DAS. Results showed no significant impact (P<0.05) on CFUs of bacteria, actinomycetes and fungus between the Bt and non-Bt cotton rhizosphere during cropping season at one particular stage. However, the temporal and spatial variations for microbes were observed significant among the different time interval (30, 60, 90, 120, 150 and 180 DAS) and the year of cultivation. Thus, our studies have demonstrated that the repeated cultivation of Bt cotton had no significant impact on soil health of Pakistan.

International Journal of Agriculture and Biology, 2015

ABSTRACT

Chemosphere, Jan 20, 2018

Water Science and Technology: Water Supply, 2017

Pakistan Journal of Biological Sciences, 2016

International Journal of Agriculture and Biology

ABSTRACT

Environmental Chemistry for a Sustainable World, 2015

Ecotoxicology and environmental safety, Jan 28, 2015

Chemosphere, 2019

High concentration of arsenic (As) in rice is a serious problem worldwide. Pot experiments were c... more High concentration of arsenic (As) in rice is a serious problem worldwide. Pot experiments were conducted to assess the potential dietary toxicity of arsenic and effect of various soil amendments on arsenic accumulation in rice grains. Two basmati rice genotypes were used to conduct pot experiments using various levels of arsenic (10, 25, 50 and 100 mg kg−1 soil). In addition, plants were exposed to soil collected from a well documented arsenic contaminated site. Contrasting results for growth, yield and grain arsenic concentration were obtained for basmati-385 (Bas-385), exhibiting tolerance (56% yield improvement at 10 mg As kg−1), while genotype BR-1 showed 18% yield decline under same conditions. Furthermore, application of soil amendments such as iron (Fe), phosphate (PO4) and farmyard manure (FYM) at 50 mg kg−1, 80 kg ha−1 and 10 t ha−1, respectively improved the plant height and biomass in both genotypes. Accumulation of arsenic in rice grain followed a linear trend in BR-1 whereas a parabolic relationship was observed in Bas-385. Both genotypes exhibited a positive response to iron sulfate amendment with significant reduction in grain arsenic concentrations. Regression analysis gave soil arsenic threshold values of 12 mg kg−1 in Bas-385 and 10 mg kg−1 in BR-1 for potential dietary toxicity. This study suggests that genotype Bas-385 can be used for safe rice production in areas with soil arsenic contamination up to 12 mg kg−1 and that appropriate dose of iron sulfate for soil amendment can be used effectively to reduce translocation of arsenic to rice grain.

Research Paper, 2018

Hydroponics experiment was conducted to investigate the effects of different levels of Pb on Para... more Hydroponics experiment was conducted to investigate the effects of different levels of Pb on Para Grass (Brachiaria mutica) and Castorbean (Ricinus communis L). Generally, Para Grass exhibited higher tolerance to excessive concentrations of Pb in nutrient solution, whereas a consistent decline was observed in growth of Castorbean plants exposed to similar Pb levels. Malondialdehyde (MDA) and H2O2 contents exhibited contrasting results with a general decrease in Para Grass and a linear increase in case of Castorbean. In both species a decrease was noticed in the activities of superoxide dismutase (SOD) and guaiacol peroxidase (G-POD) while catalase (CAT) activity was significantly increased. Ultrastructural studies revealed increased starch grains and adversely affected thylakoid membranes in chloroplasts of leaf cells of plants treated with 500 μM Pb. Photosynthetic parameters such as CO2 assimilation rate, stomatal conductance (gs) and transpiration rate (E) decreased in both plant species under different levels of Pb. Maximum concentrations of Pb in shoots of Para Grass and Castorbean were 1.29 and 0.352 g kg−1, respectively while in roots maximum values were 8.88 and 49.86 g kg−1, respectively. The high concentrations of Pb (about 5%) in the roots of Castorbean plants suggest its possible role in the phytoremediation/rhizofiltration of Pb contaminated water.

Environmental Chemistry Letters

Ecological Engineering, 2013

Genomic technologies started in the early 1980s to improve the genomes of cultivated crop species... more Genomic technologies started in the early 1980s to improve the genomes of cultivated crop species. For example the term "Bt" comes from the soil bacterium Bacillus thuringiensis containing genes, e.g. Cry1Ac, Cry2Ab, Cry1F, Cry3Bb1, that provides protection against lepidopteran insect pests. Those genes have been inserted in crops such as corn, cotton, soybean, rice, potato and canola released for cultivation in mid 1990s in USA, and later in many other countries like China and India. About 29 countries commercialized genetically-modified (GM) or 'transgenic' crops while 30 countries granted regulatory approvals for planting GM-crops; together making 75 % of the world population. Potential harmful effects of the Bt-crops on non-targets were quantified before releasing such non-conventional crops into the environment. The cultivation of Bt-crops were most commonly found safe, based on various studies including the insertional impact of transgene and its regulatory elements on plant phenotype and agronomic performance, effect on non-target organisms (NTOs) and nutritional impacts on multiple experimental models. Albeit the studies were conducted for limited durations. However, the skeptics always claim for conducting extensive clinical as well as field trials, and also doubt on methods and procedures of calculating the ecological risks. This debate is still on-going, especially after reports on substantial reduction of monarch butterfly caterpillars exposed to Bt-maize pollen, though later nullified; and detection of traces of transgene in various tissues of experimental animals. Procedures, methods and protocols for evaluating potential risks of GM-crops and foods should be standardized as the first step to build trust of researchers and end-users. Many efforts should be exerted in deploying genes of interest, marker genes and regulatory sequences invoking no or little issues of potential risks to the ecosystem.