Tariq Aftab
Research interests
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InterestsOxidative Stress, Artemisia annua, Elemental, Phytochemistry
Publications
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2.13Impact points
Exogenous nitric oxide donor protects Artemisia annua from oxidative stress generated by boron and aluminium toxicity.
Ecotoxicology and environmental safety. 03/2012;
Nitric oxide (NO) is an important signal molecule modulating the response of plants to environmental stress. Here we report the effects of boron (B) and aluminium (Al) contamination in soil, carried out with or without application of exogenous SNP (NO donor), on various plant processes in Artemisia ... [more] Nitric oxide (NO) is an important signal molecule modulating the response of plants to environmental stress. Here we report the effects of boron (B) and aluminium (Al) contamination in soil, carried out with or without application of exogenous SNP (NO donor), on various plant processes in Artemisia annua, including changes in artemisinin content. The addition of B or Al to soil medium significantly reduced the yield and growth of plants and lowered the values of net photosynthetic rate, stomatal conductance, internal CO(2) concentration and total chlorophyll content. The follow-up treatment of NO donor favoured growth and improved the photosynthetic efficiency in stressed as well as non-stressed plants. Artemisinin content was enhanced by 24.6% and 43.8% at 1mmole of soil-applied B or Al. When SNP was applied at 2mmole concentration together with either 1mmole of B and/or Al, it further stimulated artemisinin biosynthesis compared to the control. Application of B+Al+SNP proved to be the best treatment combination for the artemisinin content in Artemisia annua leaves.
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Triacontanol-mediated regulation of growth and other physiological attributes, active constituents and yield of Mentha arvensis L.
Plant Growth Regulation. 01/2011; DOI 10.1007/s10725-011-9588-8.
Triacontanol (TRIA) has been realized as a potent plant growth promoting substance for a number of agricultural and horticultural crops. Out of a large number of essential oil bearing plants, mint (Mentha arvensis L.) constitutes the most important source of therapeutic agents used in the alternativ... [more] Triacontanol (TRIA) has been realized as a potent plant growth promoting substance for a number of agricultural and horticultural crops. Out of a large number of essential oil bearing plants, mint (Mentha arvensis L.) constitutes the most important source of therapeutic agents used in the alternative systems of medicine. The mint plant has marvelous medicinal properties. In view of enhancing growth, yield and quality of this medicinally important plant, a pot experiment was conducted according to simple randomized block design. The experiment was aimed at studying the effect of four concentrations of TRIA (10-0, 10-7, 10-6 and 10-5 M) on the performance of mint with regard to growth and other physiological attributes, crop yield and quality attributes and the yield and contents of active constituents of the plant. The growth and other physiological parameters as well as yield and quality attributes were studied at 100 and 120 DAP. The foliar application of TRIA at 10-6 M concentration significantly enhanced most of the growth and other physiological attributes, crop herbage yield and the yield and content of active constituents (menthol, L-methone, isomenthone and menthyl acetate) of mint at both the stages. However, the next higher concentration of TRIA (10-5 M) exhibited slightly negative effect and did not further increase the values of the attributes studied, but it proved significantly better than the control. Application of TRIA significantly enhanced the yield and content of all the active constituents determined by GLC technique.
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Enhancing the Growth, Photosynthetic Capacity and Artemisinin Content in Artemisia annua L. by Irradiated Sodium Alginate
Radiation Physics and Chemistry. 01/2011; DOI: 10.1016/j.radphyschem.2011.03.004.
Degrading the natural bioactive agents by ionizing radiation and then using them as growth promoting substances is a novel emerging technology to exploit the genetic potential of crops in terms of growth, yield, and quality. Polysaccharides, such as sodium alginate, have proven wonderful growth prom... [more] Degrading the natural bioactive agents by ionizing radiation and then using them as growth promoting substances is a novel emerging technology to exploit the genetic potential of crops in terms of growth, yield, and quality. Polysaccharides, such as sodium alginate, have proven wonderful growth promoting substances in their depolymerized form for various plants. The effect of depolymerized form of sodium alginate, produced by irradiating the latter by Co-60 gamma rays, was studied on Artemisia annua L with regard to growth attributes, physiological and biochemical parameters and artemisinin content. The study revealed that the irradiated sodium alginate (ISA), applied as leaf-sprays at a concentration of 20 to 120 mg L-1, improved the growth attributes, photosynthetic capability, enzyme activities, and artemisinin content of the plant significantly. Application of ISA at 80 mg L-1 increased the values of the attributes studied to the maximum extent. The enhancement of leaf-artemisinin content was ascribed to the ISA-enhanced H2O2 content in the leaves.
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Role of salicylic acid in promoting salt stress tolerance and enhanced artemisinin production in Artemisia annua L.
Journal of Plant Growth Regulation. 01/2011; DOI 10.1007/s00344-011-9205-0.
In the present investigation, the role of salicylic acid (SA) in inducing salinity tolerance was studied in Artemisia annua L., which is a major source of antimalarial drug artemisinin. The SA, applied at 1.00 mM, provided considerable protection against salt stress imposed by adding 50, 100 or 200 ... [more] In the present investigation, the role of salicylic acid (SA) in inducing salinity tolerance was studied in Artemisia annua L., which is a major source of antimalarial drug artemisinin. The SA, applied at 1.00 mM, provided considerable protection against salt stress imposed by adding 50, 100 or 200 mM of NaCl to the soil. Salt stress negatively affected the plant growth as assessed by length and dry weight of shoot and root. Salinity also reduced the values of photosynthetic attributes and total chlorophyll content and inhibited the activities of nitrate reductase and carbonic anhydrase. Further, salt stress significantly increased the electrolyte leakage and proline contents. Salt stress also induced oxidative stress, as indicated by the elevated levels of lipid peroxidation compared to the control. Foliar spray treatment using SA at 1.00 mM concentration promoted the growth of plants, independent of salinity levels. The activity of antioxidant enzymes, namely, catalase, peroxidase and superoxide dismutase, was upregulated by salt stress and was further enhanced by SA treatment. Artemisinin content increased at NaCl concentrations of 50 and 100 mM, while it decreased at 200 mM of NaCl. Application of SA further enhanced the artemisinin content when applied with 50 and 100 mM of NaCl by 18.3 and 52.4%, respectively. The results indicated that moderate saline conditions might be exploited to obtain higher artemisinin content in A. annua plants, while the application of SA can be used to protect plant growth and induce its antioxidant defence system under salt stress.
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Use of Radiolytically Derived Oligomers for Artemisinin Production
01/2011; LAMBERT Academic Publishing & Company, Germany.
ISBN: ISBN 978-3-8443-8374-4
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Optimizing nitrogen levels combined with gibberellic acid for enhanced yield, photosynthetic attributes, enzyme activities and artemisinin content in Artemisia annua
Frontiers of Agriculture in China. 01/2011; 5(1):51–59.
Artemisia annua L. is an aromatic-antibacterial herb that destroys malarial parasites, lowers fever and checks bleeding, and of which the secondary compound of interest is artemisinin. It has become increasingly popular as an effective and safe alternative therapy against malaria and its derivatives... [more] Artemisia annua L. is an aromatic-antibacterial herb that destroys malarial parasites, lowers fever and checks bleeding, and of which the secondary compound of interest is artemisinin. It has become increasingly popular as an effective and safe alternative therapy against malaria and its derivatives are effective against multi-drug resistant Plasmodium falciparum strains. Nitrogen is required by the plants in largest quantity and is most limiting where biomass production is desired. On the other hand, gibberellic acid play important role in flowering, growth and development and also in other physiologic and biochemical processes. The feasibility of foliar GA3 (75 mg L1) alone and with varying levels of soil applied nitrogen (40, 80 and 120 mg kg1 soil) was tested on A. annua in the present study. Application of GA3 proved effective in alleviating the growth, photosynthesis and enzyme activities of A. annua. However, nitrogen levels combined with GA3 showed better response and further improvement in these parameters was observed. Furthermore, the most important task we were interested in, to increase the artemisinin content and its yield on per plant basis. The combination of nitrogen (80 mg kg1 soil) together with GA3 augmented the content (21.8% more) and yield (55.8% more), both in the treated plants over the control.
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Study on application of irradiated sodium alginate and macronutrients on growth, yield and artemisinin content of Artemisia annua L.
01/2011
Degree: PhD (persuing)
Supervisor: Dr. M. Masroor A. Khan
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Phosphorus ameliorates crop productivity, photosynthetic efficiency, nitrogen-fixation, activities of the enzymes and content of nutraceuticals of Lablab purpureus L.
Scientia Horticulturae. 01/2010;
Hyacinth bean (Lablab purpureus L.) serves as a good source of vegetable proteins in human diet. Its seeds and pods contain as much as 20–28% protein. Besides, it contains tyrosinase enzyme, which has potential use in the treatment of hypertension. Phosphorus deficiency causes a serious yield and qu... [more] Hyacinth bean (Lablab purpureus L.) serves as a good source of vegetable proteins in human diet. Its seeds and pods contain as much as 20–28% protein. Besides, it contains tyrosinase enzyme, which has potential use in the treatment of hypertension. Phosphorus deficiency causes a serious yield and quality constraint of beans at Aligarh, Western Uttar Pradesh, India. To address the problem, a pot experiment was conducted to study the effect of basal phosphorus application on the agricultural performance of this medicinal legume. The plants were grown in pots containing soil supplied with five levels of phosphorus viz. 0, 25, 50, 75 and 100 mg P kg−1 soil as potassium dihydrogen orthophosphate (KH2PO4). The growth and other physiological attributes, leaf nutrient contents, nodule-nitrogen and leghemoglobin content were studied at 60, 90 and 120 days after sowing (DAS), photosynthesis and other related parameters were measured at 90 DAS and yield and quality attributes were recorded at harvest (150 DAS). Nitrate reductase and carbonic anhydrate activities, leaf-N, -P, -K and -Ca contents and nodule-nitrogen and leghemoglobin contents reached the maximum extent at 60 DAS. At 90 and 120 DAS, the values decreased significantly. Chlorophyll content, carotenoids content, and photosynthesis were at maximum level at 90 DAS. At various growth stages, phosphorus application at 75mgP kg−1 soil resulted in maximum amelioration of most of the parameters studied. It increased the seed-yield by 38.3%, seed-protein content by 14.9% and seed-carbohydrate content by 5.0%, relative to the control. It was concluded that there was a hidden hunger of hyacinth bean for phosphorus owing to soil-phosphorus deficiency that was ameliorated effectively by its basal dressing at 75 mg P kg−1 soil.
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Stimulation of Crop Productivity, Photosynthesis and Artemisinin Production in Artemisia annua L. by Triacontanol and Gibberellic Acid Application
Journal of Plant Interactions. 01/2010;
Artemisia annua L. is an aromatic-antibacterial herb that destroys malarial parasites, lowers fevers and checks bleeding, and of which the secondary compound of interest is artemisinin. Enhanced production of the artemisinin content in the whole plant is highly desirable. Keeping in mind, the import... [more] Artemisia annua L. is an aromatic-antibacterial herb that destroys malarial parasites, lowers fevers and checks bleeding, and of which the secondary compound of interest is artemisinin. Enhanced production of the artemisinin content in the whole plant is highly desirable. Keeping in mind, the importance of this valuable antimalarial plant, a field experiment was conducted to investigate the effects of triacontanol alone and in combination with gibberellic acid on growth attributes, photosynthesis, enzymatic activities, essential oil and artemisinin content and yield of Artemisia. The results indicate that combination of triacontanol and gibberellic acid (1.5 mg L-1 + 75 mg L-1) significantly increased activities of nitrate reductase and carbonic anhydrase by 25.9% and 21.5% higher, and net photosynthetic rate, stomatal conductance and internal CO2 by 25.4%, 14.1% and 15.4% higher, respectively when compared to unsprayed plants. This combined treatment also significantly enhanced artemisinin content and yield (29% and 61% higher values).
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Salicylic acid-induced physiological and biochemical changes in lemongrass varieties under water stress
Journal of Plant Interactions. 01/2010;
Salicylic acid (SA) treatment reduces the damaging action by water deficit on growth and accelerates a restoration of growth processes. The aim of the present work was to study the physiological and biochemical alteration induced by SA in lemongrass plants under stress conditions. Therefore, a pot c... [more] Salicylic acid (SA) treatment reduces the damaging action by water deficit on growth and accelerates a restoration of growth processes. The aim of the present work was to study the physiological and biochemical alteration induced by SA in lemongrass plants under stress conditions. Therefore, a pot culture experiment was conducted to test whether SA application at concentration of (10�5 M) through foliar spray could protect lemongrass (Cymbopogon flexuosus Steud. Wats.) varieties (Neema and Krishna), subjected to drought stress on the basis of growth parameters and biochemical constituents, proline metabolism and quality attributes including citral content. The treatments were as follows: (i) 100% FC�0 SA; (ii) 75% FC�0 SA; (iii) 50% FC�0 SA; (iv) 75% FC�10�5 M SA; and (v) 50% FC�10�5 M SA. The growth parameters were significantly reduced under the applied water stress levels; however, foliar application of salicylic acid (10 -5M) improved the growth parameters in stress-affected plants. The plants under water stress exhibited a significant increase in activities of nitrate reductase and carbonic anhydrase, and electrolyte leakage, proline content, free amino acid and in PEP carboxylase activity. Content and yield of essential oil also significantly decreased in plants that faced water stress. Thus, it was concluded that variety Neema is the more tolerant variety as compared to Krishna on the basis of content and oil yield and well adapted to drought stress conditions.
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Boron Induced Oxidative Stress, Antioxidant Defense Response and Changes in Artemisinin Content in Artemisia annua L.
Journal of Agronomy and Crop Science. 01/2010;
Boron is an essential plant micronutrient and the range between deficient and toxic levels of boron is narrow for most of the plants. Like other elements, boron becomes toxic to growth at high concentrations. High boron concentrations in soil reduce crop productivity in many areas of the world. The ... [more] Boron is an essential plant micronutrient and the range between deficient and toxic levels of boron is narrow for most of the plants. Like other elements, boron becomes toxic to growth at high concentrations. High boron concentrations in soil reduce crop productivity in many areas of the world. The effect of increasing levels of boron (0, 0.50, 1.00, 1.50, 2.00mM) on oxidative stress, antioxidant defense response and changes in artemisinin content in Artemisia annua were investigated in the present study. Boron toxicity reduced the growth parameters viz. stem height, fresh weight and dry weight. Treatments induced oxidative stress resulting in lower net photosynthetic rate, stomatal conductance, internal CO2 and total chlorophyll content. The increased activities of antioxidant enzymes like CAT, POX and SOD were also noted in response to increasing levels of boron stress. However, H2O2 and artemisinin content were found to be high upto 1.00mM concentration of boron compared to control, and on applying higher doses, further reduced contents were obtained. Thus, the results suggest that a mild stress of boron can be utilized for enhanced artemisinin production.
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Methyl jasmonate counteracts boron toxicity by preventing oxidative stress and regulating antioxidant enzyme activities and artemisinin biosynthesis in Artemisia annua L.
Protoplasma. 01/2010;
Boron (B) is an essential plant micronutrient, but it is phytotoxic if present in excessive amounts in soil for certain plants such as Artemisia annua L. that contains artemisinin (an important antimalarial drug) in its areal parts. Artemisinin is a sesquiterpene lactone with an endoperoxide bridge.... [more] Boron (B) is an essential plant micronutrient, but it is phytotoxic if present in excessive amounts in soil for certain plants such as Artemisia annua L. that contains artemisinin (an important antimalarial drug) in its areal parts. Artemisinin is a sesquiterpene lactone with an endoperoxide bridge. It is quite expensive compound because the only commercial source available is A. annua and the compound present in the plant is in very low concentration. Since A. annua is a major source of the antimalarial drug, and B stress is a deadly threat to its cultivation, the present research was conducted to determine whether the exogenous application of methyl jasmonate (MeJA) could combat the ill effects of excessive B present in the soil. According to the results obtained, the B toxicity induced oxidative stress and reduced the stem height as well as fresh and dry masses of the plant remarkably. The excessive amounts of soil-B also lowered the net photosynthetic rate, stomatal conductance, internal CO2 concentration and total chlorophyll content in the leaves. In contrast, the foliar application of MeJA enhanced the growth and photosynthetic efficiency both in the stressed and non-stressed plants. The excessive B levels also increased the activities of antioxidant enzymes, such as CAT, POX and SOD. Endogenous H2O2 and O2- levels were also high in the stressed plants. However, the MeJA application to the stressed plants reduced the amount of lipid peroxidation and stimulated the synthesis of antioxidant enzymes, enhancing the content and yield of artemisinin as well. Thus, it was concluded that MeJA might be utilized in mitigating the B toxicity and improving the content and yield of artemisinin in A. Annua plant.
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Effects of aluminium exposures on growth, photosynthetic efficiency, lipid peroxidation, antioxidant enzymes and artemisinin content of Artemisia annua L.
Journal of Phytology. 01/2010;
Acid soils are widely distributed at a global scale; under acidic conditions, the solubility of aluminium (Al) increases and the elevated concentration of toxic Al3+ in soil solution seriously limits crop production. There is no information on the effects of aluminium (Al) on Artemisia annua L., whi... [more] Acid soils are widely distributed at a global scale; under acidic conditions, the solubility of aluminium (Al) increases and the elevated concentration of toxic Al3+ in soil solution seriously limits crop production. There is no information on the effects of aluminium (Al) on Artemisia annua L., which is a most important antimalarial plant in the recent time being artemisinin; responsible for its antimalarial activity. In this report, we describe the effects of Al contamination on growth, photosynthetic efficiency, membrane damage, antioxidant enzyme activities and changes in artemisinin content in A. annua. Al addition to the soil medium significantly reduced the yield and growth of the plants. Lower values of net photosynthetic rate, stomatal conductance, internal CO2 and total chlorophyll content were observed as a result of different Al concentrations applied. The activities of nitrate reductase (NR) and carbonic anhydrase (CA) were also found to be hampered by Al exposure to the plants. Al enhanced lipid peroxidation rate (TBRAS content) and activated the activities of catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) enzymes in the treated plants. The elicitation in the endogenous ROS levels, due to the Al treatments, was also noticed in the present study. Furthermore, enhanced artemisinin content and yield was obtained at 0.10mM concentration of soil applied Al. Our study provides evidence that excess Al in soil hamper the growth and yield, slow down the activities of NR and CA, induce lipid peroxidation and antioxidant enzymes but a low level of Al-toxicity can induce artemisinin content in A. annua plants.
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Effect of Salt Stress on Growth, Membrane Damage, Antioxidant Metabolism and Artemisinin Accumulation in Artemisia annua L.
Plant Stress. 01/2010;
Salinity in soil and irrigation water is one of the major factors that limit crop productivity. The effects of salinity on growth, lipid peroxidation, the antioxidant defence system and changes in artemisinin content were studied in Artemisia annua L. Salinity treatments were established by adding 0... [more] Salinity in soil and irrigation water is one of the major factors that limit crop productivity. The effects of salinity on growth, lipid peroxidation, the antioxidant defence system and changes in artemisinin content were studied in Artemisia annua L. Salinity treatments were established by adding 0, 50, 100, 150 and 200 mM of sodium chloride (NaCl) to the soil. Salt stress negatively affected the growth of plants, measured in terms of shoot and root length and dry weight. Photosynthetic attributes and total chlorophyll content were also reduced by salinity stress. Salinity treatments inhibited the activity of carbonic anhydrase and significantly increased electrolyte leakage and proline content. Moreover, salt stress induced oxidative stress, as indicated by the level of lipid peroxidation. The activities of antioxidant enzymes viz. catalase (CAT), peroxidase (POX) and superoxide dismutase (SOD) were upregulated by salt stress. Most importantly, a synergistic relationship was noted between endogenous H2O2 and artemisinin content i.e. both contents increased under low levels of salinity (50 and 100 mM) and thereafter decreased. Thus, it can be concluded that A. annua species is very sensitive to soil salinity; however, moderate saline conditions can be utilized to obtain more artemisinin.
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Salicylic acid mitigates salinity stress by improving antioxidant defence system and enhances vincristine and vinblastine alkaloids production in periwinkle [Catharanthus roseus (L.) G. Don]
Acta Physiologiae Plantarum. 01/2010;
A pot experiment was conducted to find out whether the foliar spray of salicylic acid (SA) could successfully ameliorate the adverse effects of salinity stress on periwinkle. Thirty-day-old plants were supplied with Control; 0 mM NaCl + 10-5 M SA (T1); 50 mM NaCl + 0 SA (T2); 100 mM NaCl + 0 SA (T3)... [more] A pot experiment was conducted to find out whether the foliar spray of salicylic acid (SA) could successfully ameliorate the adverse effects of salinity stress on periwinkle. Thirty-day-old plants were supplied with Control; 0 mM NaCl + 10-5 M SA (T1); 50 mM NaCl + 0 SA (T2); 100 mM NaCl + 0 SA (T3); 150 mM NaCl + 0 SA (T4); 50 mM NaCl + 10-5 M SA (T5); 100 mM NaCl + 10-5 M SA (T6); 150 mM NaCl + 10-5 M SA (T7). The plants were sampled 90 days after sowing to assess the effect of SA on stressed and unstressed plants. Salt stress significantly reduced the growth attributes including plant height, leaf-area index, shoot and root fresh weights, shoot and root dry weights. Increasing NaCl concentrations led to a gradual decrease in photosynthetic parameters and activities of nitrate reductase and carbonic anhydrase. Ascorbic acid, total alkaloids and antioxidants enzymes superoxide dismutase, catalase and peroxidase also declined in NaCl-treated plants. The plants, undergoing NaCl stress, exhibited a significant increase in electrolyte leakage and proline content. Foliar application of SA (10-5 M) reduced the damaging effect of salinity on plant growth and accelerated the restoration of growth processes. It not only improved the growth parameters but also reversed the effects of salinity. Total alkaloid content was improved by SA application both in unstressed and stressed plants. The highest level of total alkaloid content recorded in leaves of SA-treated stressed plants was 11.1%. Foliar spray of SA overcame the adverse effect of salinity by improving the content of vincristine (14.0%) and vinblastine (14.6%) in plants treated with 100 M NaCl.
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Salicylic Acid acts as Potent Enhancer of Growth, Photosynthesis and Artemisinin Production in Artemisia annua L.
Journal of Crop Science and Biotechnology. 01/2010;
Plant secondary metabolites constitute the most important class of natural products with diverse and valuable chemical properties and biological activities. Artemisinin, isolated from Artemisia annua L., is potentially a drug that could be effective against multidrug-resistant strains of the malaria... [more] Plant secondary metabolites constitute the most important class of natural products with diverse and valuable chemical properties and biological activities. Artemisinin, isolated from Artemisia annua L., is potentially a drug that could be effective against multidrug-resistant strains of the malarial parasite, Plasmodium. Salicylic acid (SA) acts as a potential plant growth regulator and plays an important role in regulating a number of plant physiological and biochemical processes. The present study was conducted to assess the alterations in plant growth, photosynthetic capacity, enzyme activities, and content and yield of artemisinin in Artemisia annua L. in response to foliar application of SA. Four levels of SA (0.00, 0.25, 0.50, and 1.00 mM SA) were applied on the aboveground plant parts. Plant height and dry weight were altered significantly as the level of SA increased. Besides, application of SA positively improved chlorophyll and carotenoid contents. Furthermore, significant enhancement in net photosynthetic rate (31.7%) and the activity of nitrate reductase (17.2%) and carbonic anhydrase (10.9%) was noticed as the level of SA was increased from 0.00 to 1.00 mM SA. Most importantly, the content and yield of artemisinin was positively regulated by the SA. In comparison to no SA application (control), SA at 1.00 mM increased the content and yield of artemisinin by 25.8 and 50.0%, respectively.
Following (277)
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Laura H.
Universität Bremen -
Maryam Amini
Kerman Graduate University of Technology -
Sweeti Ahlawat
G. B. Pant University of Agriculture and Technology -
Amina Daqiqi Khodashahri
Islamic Azad University of Central Tehran Branch -
Elçin Ekşi
Middle East Technical University
