Rana Pratap Singh

Arsenate Exposure Affects Amino Acids, Mineral Nutrient Status and Antioxidants in Rice (Oryza sativa L.) Genotypes

Simulated pot experiments were conducted on four rice (Oryza sativa L.) genotypes (Triguna, IR-36, PNR-519, and IET-4786) to examine the effects of As(V) on amino acids and mineral nutrient status in grain along with antioxidant response to arsenic exposure. Rice genotypes responded differentially to As(V) exposure in terms of amino acids and antioxidant profiles. Total amino acid content in grains of all rice genotypes was positively correlated with arsenic accumulation. While, most of the essential amino acids increased in all cultivars except IR-36, glutamic acid and glycine increased in IET-4786 and PNR-519. The level of nonprotein thiols (NPTs) and the activities of superoxide dismutase (SOD; EC 1.15.1.1), glutathione reductase (GR; EC 1.6.4.2) and ascorbate peroxidase (APX; EC 1.11.1.11) increased in all rice cultivars except IET-4786. A significant genotypic variation was also observed in specific arsenic uptake (SAU; mg kg(-1)dw), which was in the order of Triguna (134) > IR-36 (71) > PNR-519 (53) > IET-4786 (29). Further, application of As(V) at lower doses (4 and 8 mg L(-1) As) enhanced the accumulation of selenium (Se) and other nutrients (Fe, P, Zn, and S), however, higher dose (12 mg L(-1) As) limits the nutrient uptake in rice. In conclusion, low As accumulating genotype, IET-4786, which also had significantly induced level of essential amino acids, seems suitable for cultivation in moderately As contaminated soil and would be safe for human consumption.

Cadmium Tolerance and Its Phytoremediation by Two Oil Yielding Plants Ricinus Communis (L.) and Brassica Juncea (L.) From The Contaminated Soil

The effect of increasing level of cadmium in soil was investigated on biomass production, antioxidants, Cd bioaccumulation and translocation in Ricinus communis vis-à-vis a commonly studied oil crop Brassica juncea. The plants were exposed to 25, 50, 75, 100, and 150 mg Cd/Kg soil for up to 60 days. It was found that R. communis produced higher biomass at all the contamination levels than that of B. juncea. Proline and malondialdehyde in the leaves increased with increase in Cd level in both the species, whereas soluble protein decreased. The bioaccumulation of Cd was higher in B. juncea on the basis of the per unit biomass, total metal accumulation per plant was higher in R. communis. The translocation of Cd from roots to shoot was also higher in B. juncea at all Cd concentrations. R. communis appeared more tolerant and capable to clean Cd contaminated soil for longer period in one sowing than B. juncea and the former can grow in wasteland soil also in which later cannot be cultivated.

Nitrate assimilation and biomass production in Sesamum indicuml. Seedlings in a lead enriched environment

Seed germination was delayed and seedling growth inhibited by 0.04 to 1.9 mM Pb+2 in Sesamum indicum L. var HT-I. In root, shoot and leaf Pb+2 accumulation increased with increasing Pb+2 concentration in the nutrient solution. In root and leaf tissues in vivo and in vitro nitrate reductase activity was inhibited significantly which was well correlated with the concentration of Pb+2 supplied and its accumulation in the plant parts. The inhibition of the NR enzyme activity could be, however, reversed by simultaneous treatment of Sesamum seedlings with K2HPO4, CaCl2 and KNO3 dissolved in nutrient solution. Total organic N and soluble protein of roots and shoots/leaves, on the other hand, increased with increasing concentration of Pb+2 while the same treatment caused a decrease in the N content of cotyledons. It appears therefore, that the increase in N and protein in the roots, shoots/leaves may be a result of increased translocation of N from the cotyledons to the roots and shoots/leaves during early seedling growth in a Pb+2 enriched environment.

Degradation of γ-HCH spiked soil using stabilized Pd/Fe0 bimetallic nanoparticles: pathways, kinetics and effect of reaction conditions.

This study investigates the degradation pathway of gamma-hexachlorocyclohexane (γ-HCH) in spiked soil using carboxymethyl cellulose stabilized Pd/Fe(0) bimetallic nanoparticles (CMC-Pd/nFe(0)). GC-MS analysis of γ-HCH degradation products showed the formation of pentachlorocyclohexene, tri- and di-chlorobenzene as intermediate products while benzene was formed as the most stable end product. On the basis of identified intermediates and final products, degradation pathway of γ-HCH has been proposed. Batch studies showed complete γ-HCH degradation at a loading of 0.20 g/L CMC-Pd/nFe(0) within 6h of incubation. The surface area normalized rate constant (k(SA)) was found to be 7.6 × 10(-2) L min(-1)m(-2). CMC-Pd/nFe(0) displayed ≈ 7-fold greater efficiency for γ-HCH degradation in comparison to Fe(0) nanoparticles (nFe(0)), synthesized without CMC and Pd. Further studies showed that increase in CMC-Pd/nFe(0) loading and reaction temperature facilitates γ-HCH degradation, whereas a declining trend in degradation was noticed with the increase in pH, initial γ-HCH concentration and in the presence of cations. The data on activation energy (33.7 kJ/mol) suggests that γ-HCH degradation is a surface mediated reaction. The significance of the study with respect to remediation of γ-HCH contaminated soil using CMC-Pd/nFe(0) has been discussed.

Assessment of heavy metal tolerance in native plant species from soils contaminated with electroplating effluent

Heavy metals concentrations of (Cr, Zn, Fe, Cu and Ni) were determined in plants and soils contaminated with electroplating industrial effluent. The ranges of total soil Cr, Zn, Fe, Cu and Ni concentrations were found to be 1443-3240, 1376-3112, 683-2228, 263-374 and 234-335 mg kg⁻¹, respectively. Metal accumulation, along with hyperaccumulative characteristics of the screened plants was investigated. Present study highlighted that metal accumulation in different plants varied with species, tissues and metals. Only one plant (Amaranthus viridis) accumulated Fe concentrations over 1000 mg kg⁻¹. On the basis of TF, eight plant species for Zn and Fe, three plant species for Cu and two plant species for Ni, could be used in phytoextraction technology. Although BAF of all plant species was lesser than one, these species exhibited high metal adaptability and could be considered as potential hyperaccumulators. Phytoremediation potential of these plants can be used to remediate metal contaminated soils, though further investigation is still needed.

Differential toxicity of heavy metals to growth and nitrate reductase activity of Sesamum indicum seedlings

Abstract The response observed for biomass accumulation in Sesamum indicum L cv PB-1 seedlings during early growth phase induced by 1.0 mM Pb 2+ supply in our earlier studies was not persistent when 1.0 mM Cu 2+ and Cd 2+ were supplied either alone or in the various combinations of Pb 2+ , Cu 2+ and Cd 2+ . Root and leaf fresh weights of the seedlings were hardly affected due to supply of 1.0 mM Pb 2+ , whereas Cu 2+ and Cd 2+ caused a drastic decrease in the tissue fresh weight which was more pronounced in the roots. The dry weight of the roots showed a similar effect, however, leaf dry weight was increased with the metal supply. In vivo nitrate reductase activity (NRA, EC 1.6.6.1) was significantly inhibited in roots in the order Pb 2+ >Cu 2+ >Cd 2+ . Leaf NRA was inhibited with Cu 2+ supply and with the combinations of the metals. The in vitro enzyme activity, on the other hand, was increased in most of the cases due to the metal supply. Further, total organic nitrogen of the young roots and in several cases in the leaves also increased with the metal supply, possibly because of increased translocation of nitrogen from seed to growing seedlings. The results show that growth and nitrate reduction of this cultivar of sesame respond differentially to Pb 2+ , Cu 2+ and Cd 2+ , and the effect was specific to the tissue examined.

Effect of calcium chloride on heavy metal induced alteration in growth and nitrate assimilation of Sesamum indicum seedlings

Abstract In the early growth phase of Sesamum indicum cv. PB-1, the decrease in fresh and dry mass was higher with 1.0 mM Cd 2+ than with the same level of Pb 2+ and Cu 2+ . Recovery from the metal stress was considerable in the root fresh weight and almost completely in the root dry weight when 10.0 mM (1.9 EC), calcium chloride was supplied to the growing seedlings along with the metal salts in various combinations. Accumulation of Pb 2+ , Cd 2+ and Cu 2+ was differential to the metals and the plant parts when supplied without or with 10.0 mM calcium chloride. The order of endogenous metal accumulation was Cu 2+ Cd 2+ Pb 2+ and roots accumulated more metal than the leaves in the absence, as well as in the presence, of calcium chloride. Calcium chloride could recover loss of in vivo NRA in roots caused by either of the metal combinations, whereas the salt could recover the loss in leaf NRA caused only by Pb 2+ Cd 2+ (1.0 mM each). Response of root and leaf NRA was on the other hand, different when the enzyme was assayed directly using an in vitro assay method, and the salt accelerated the loss in enzyme activity drastically. The organic-N content of root and leaf was, however, increased significantly ( p 2+ , Cd 2+ and Pb 2+ in roots and leaves the metal toxicity is recovered to a great extent in the presence of 10.0 mM calcium chloride in the root environment regarding growth and nitrate reduction of the roots and leaves of young sesame seedlings.

Applied genetics of leguminosae biotechnology

Foreword. Preface. Part I: Grain Legumes. 1. Recent advances in soybean transformation R.D. Dinkins, M.S. Srinivsa Reddy, C.A. Meurer, C.T. Redmond, G.B. Collins. 2. Genetic transformation in pea J.E. Grant, P.A. Cooper. 3. Genetic transformation of common bean by particle bombardment F.J.L. Aragao. 4. In vitro regeneration and genetic transformation of pigeonpea N. Dolendro Singh, P.A. Kumar, P.K. Jaiwal. 5. In vitro regeneration and genetic transformation of chickpea S. Rana P. Singh, K.K. Sharma, P.K. Jaiwal. 6. In vitro regeneration and genetic transformation of cowpea, mungbean, urdbean and azuki bean L. Sahoo, T. Sugla, P.K. Jaiwal. 7. In vitro regeneration and genetic transformation of Vicea species T. Pickardt. 8. In vitro regeneration and genetic transformation of lentil A. Gulati, A. McHughen. 9. Transformation and regeneration of guar M. Joersbo. 10. In vitro regeneration of winged bean S. Dutta Gupta. 11. Regeneration and genetic transformation in peanut: current status and future prospects S. Eapen. 12. Microprojectile-mediated transformation of peanut S. Eapen. 13. Transformation of lupins C.A. Atkins, P.M.C. Smith. 14. Nutritional improvement of lupin seed protein using gene technology L. Molvig, L.M. Tabe, J. Hamblin, V. RAvindran, W.L. Bryden, C.L. White, T.J.V. Higgins. Part II: Forage Legumes. 15. Genetic transformation of Medicago species R.J. Rose, K.E. Nolan, Chen Niu. 16.Molecular genetics of white clover K.J. Webb, M.T. Abberton, S.R. Young. 17. Agrobacterium-mediated transformation of Lotus species P. Oger, Y. Dessaux. Part III: Tree Legumes. 18. Regeneration and genetic transformation of tree legumes with special reference to Albizzia species P. Khurana, J. Khurana, M. Jani. 19. Regeneration and genetic transformation of tree legumes with special reference to Leucaena species S. Rastogi, U.N. Dwivedi. Index. Subject Index.

Antagonistic effect of sodium chloride to differential heavy metal toxicity regarding biomass accumulation and nitrate assimilation in Sesamum indicum seedlings

Abstract Combinations of 1.0 mM Pb2+, Cu2+ and Cd2+ (1:1) differentially inhibited growth, biomass accumulation and in vivo nitrate reductase activity (NRA, EC 1.6.6.1) in root and leaves of five-day-old Sesamum indicum L cv PB-1 seedlings. Addition of 2 EC and 10 EC NaCl to the nutrient media slightly inhibited root fresh weight of the seedlings (statistically not significant), whereas it increased the leaf fresh weight and dry weight of the plant parts with a variable magnitude. The presence of NaCl could abolish the negative effect of the metal combinations on the root fresh weight to a good extent, and it caused an increase in the tissue dry mass in the presence of the metals in most of the cases. However, recovery in the leaf fresh weight was observed only if NaCl was added with Cu2++Cd2+ in the nutrient media. In vivo NRA of root and leaf in this cultivar was increased two-three-fold with the supply of NaCl and this increase was maintained even in the presence of the metal combinations by counteracting the toxic effect of the metals on the enzyme activity. A corresponding increase in total organic nitrogen content of the roots was also recorded. In vitro NRA, in either of the tissues, on the other hand, was drastically inhibited by the addition of 10 EC NaCl to the nutrient media. Our results show that toxic effect of Cd2+, Cu2+ and Pb2+ combinations on the seedling growth and nitrate assimilation especially in the roots of sesame PB-1 was not persistent in the NaCl affected growth environment. However, in vitro NRA was drastically inhibited by some modulating effect of the salt on the enzyme.

Assessment of Metal Uptake Capacity of Castor Bean and Mustard for Phytoremediation of Nickel from Contaminated Soil

ABSTRACT The effect of increasing level of nickel (Ni) in soil was studied on biomass production, antioxidants, and Ni bioaccumulation and its translocation in castor bean (Ricinus communis) as well as Indian mustard (Brassica juncea) in similar agroclimatic conditions. The plants were exposed to 25, 50, 75, 100, and 150 mg Ni kg−1 soil for up to 60 days. It was found that R. communis produced higher biomass during the same period at all the contamination levels than B. juncea, and reduction in fresh and dry weights due to the metal contamination in soil was significantly lower in R. communis than in B. juncea. Proline and malondialdehyde in the leaves increased with increase in Ni level in both the species, whereas soluble protein content was found decreased. A correlation between the protein and MDA contents in the leaves and Ni contamination levels revealed that higher r2 values for protein and MDA were found in case of B. juncea, which indicates more toxic effects of the metal in this species. R. communis was found to have enhanced proline accumulation (higher correlation value, r2) at different Ni contamination levels. The bioaccumulation of Ni was higher in B. juncea on the basis of the per unit biomass; however, the total metal accumulation per plant was much higher in R. communis than in B. juncea during the same growing periods. The translocation of Ni from roots to shoots was higher in B. juncea at all Ni concentrations. R. communis appeared more tolerant and capable to clean more Ni from the contaminated soil in a given time and also in one crop cycle.