Loading...
M. Sc. Dissertations
Browse
30 results
Search Results
ThesisItem Open Access Lipid peroxidation and oxygen scavenging system in guava (Psidium guajava L.) fruit during ripening and storage(CCSHAU, 2007) Sita Ram; Dhawan, KamalPresent investigation was conducted to study the changes in lipid peroxidation and oxygen scavenging system in guava fruit during ripening and storage. During ripening the fruits of two varieties viz. Lucknow-49 (Long shelf life) and Banarsi Surkha (short shelf life) were collected at five different stages of maturity i.e. immature green (IMG), mature green (MG), colour turning (CT), ripe (R) and overripe (OR). While during storage, the fruits of MG stage were stored in corrugated fibre board boxes at room temperature and analysed at two days interval until complete deterioration. The lipoxygenase (LOX) activity, MDA value and H2O2 content increased throughout ripening in both the varieties. Ascorbate and glutathione content increased initially and then decreased. The ROS scavenging enzymes like superoxide dismutase (SOD), ascorbate peroxidase (ASPX), catalase (CAT) and glutathione reductase (GR) exhibited an initial increase and then decrease in their activities, however peroxidase (POX) showed a continuous decrease throughout ripening. During storage Lipoxygenase activity. MDA value and H2O2 content increased throughout while ascorbate increased upto 8th day of storage in var. L-49 and upto 4th day of storage in var. Banarsi Surkha. The total, oxidized and reduced glutathione decreased continuously throughout storage period. The activities of antioxidative enzymes viz. superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and glutathione reductase decreased throughout storage period. Variety Banarsi Surkha had higher values for LOX, MDA value and H2O2 content and lower activities of free radical scavenging enzymes at all the stages of ripening and storage period which might be the reason for its short shelf life.ThesisItem Open Access Biochemical evaluation of seed storage proteins of cowpea (Vigna unguiculata (L.) Walp.] genotypes(CCSHAU, 2007) Gupta, Prachi; Malhotra, SarlaProtein content of 21 cowpea genotypes viz. HC-3, HC-98-64, LST-II-C-12, CP-16, CP-21, CP-26, LST-II-C-2, COVU-702, GC-119, CP- 11, CP-13, CP-27, CP-22, CP-17, CP-12, HC-5, CP-18, CP-19, CPD-80 and CP-20 ranged from 22.4 (HC-3) to 27.9 (HC-98-64) per cent whereas the four check varieties viz. FS-68, Chirrodi, CS-88 and V-240 contained 25.5 per cent protein on an average. Seven genotypes viz. HC-98-64, HC-6, LST-II C-12, CP-16, CP-21, COVU-702 and HC-5 having protein content higher than the average check value were used for further investigations. Globulin was found to be the major storage protein fraction ranging from 55.6 (LST-II-C-12) to 58.8 (HC-6 and CP-16) per cent of total proteins. Glutelin was the second major protein followed by albumins and prolamins contributing 14.4 (HC-98.64) to 15.6 (HC-6); 8.2 (HC-5) to 11.9 (HC-98-64, CP-16 and CP-21); and 2.3 (CP-16) to 5.0 (HC-98-64) per cent of the total proteins, respectively. xxviii SDS-Polyacrylamide gel electrophoresis separated total proteins and their fractions viz. albumins, globulins, prolamins and glutelins into 14, 7, 10, 4 and 8 polypeptides of Mr ranging from 10 to 141.3, 15.85 to 147.9, 10 to 125.9, 7.94 to 56.23 and from 10 to 79.43 kDa, respectively. Free amino acid content of cowpea genotypes ranged between 1.6 to 3.7 mg/100 g flour being maximum in COVU-702 and minimum in Chirrodi while the total essential amino acid content varied from 24 (Chirrodi) to 34 (V-240) per cent of total proteins. Data on adequacy of individual amino acids in cowpea proteins revealed S-amino acids (met+cys) to be the first limiting amino acids followed by tryptophan.ThesisItem Open Access Characterization of seed storage proteins of moth bean [Vigna aconitifolia (Jacq.) marechal] genotypes(CCSHAU, 2007) Tomar, Pooja; Singal, H.R.Protein content of 21 mothbean genotypes viz. Mb 18, GMO 01-02, Mb 5, RMO 435, Mb 16, Mb 2, MH 61, Mb 15, RMB 101, RMB 100, RMM 103, GMO 9915, Mb 14, RMB 4-1, GMO 01-04, CZM 04-01, GMO 9910, GMO 002, Mb 10, RMB 106, GMO 009 ranged from 21.2 (GMO 009) to 27.6 (RMO 435) per cent whereas in check varieties the protein content was 22.5 (RMO 40), 21.4 (Jwala), 22.5 (Jadia) and 23.5 (RMO 225) per cent with an average of 22.5 per cent. Seven genotypes viz. GMO 01-02, RMO 435, MH 61, Mb 2, RMB 100, GMO 01-04 and GMO 002 having protein content higher than other genotypes as well as the average check value were used for further investigations. Globulin was found to be major fraction of mothbean seed storage proteins. The protein content of globulins ranged from 56.7 (GMO 01-02) to 60.5 (RMO 435) per cent of total proteins. Glutelin was the second major protein fraction followed by albumins and prolamins contributing 13.9 (GMO 01-04, GMO 002) to 15.2 (MH 61, Mb 2); 10.9 (GMO 01-02, RMB 100) to 12.2 (GMO 002) and 2.4 (MH 61, Mb 2) to 4.3 (RMO 435) percent of total proteins, respectively. SDS-Polyacrylamide gel electrophoresis separated total proteins and their protein fractions viz. albumins, globulins, prolamins and glutelins resolved into 13, 5, 12, 4 and 6 polypeptides of Mr ranging from 11.22 to 100 kDa, 10 to 56.23 kDa, 12.59 to 141.3 kDa, 7.94 to 56.23 kDa and 8.91 to 50.12 kDa, respectively. Free amino acid content of mothbean genotypes ranged between 3.4 to 6.4 mg/100g flour, being maximum in RMO 435 and minimum in RMB 100. Histidine content of these genotypes varied from 1.75 (GMO 002, Jadia) to 2.37 (RMB 100) g/16g N; cysteine from 0.85 (RMO 40) to 2.12 (Mb 2) g/16g N; methionine from 0.83 (MH 61) to 1.74 (RMB 100) g/16g N; isoleucine from 3.92 (RMO 40) to 5.02 (MH 61) g/16g N; leucine from 6.55 (Jadia) to 7.99 (RMB 100) g/16g N; threonine from 3.13 (Jadia) to 4.93 (RMO 435) g/16g N; lysine from 7.5 (RMO 435) to 8.53 (Mb 2) g/16g N and tryptophan from 0.98 (Jwala) to 1.37 (MH 61) g/16g N. The total essential amino acid contents in these genotypes ranged between 26.67 (Jadia) to 32.40 (Mb 2) g/16g N. Data on adequacy of individual amino acids in mothbean proteins revealed S-amino acid (methionine and cysteine) to be first limiting amino acids followed by tryptophan.ThesisItem Open Access Effect of zinc on nitrogen metabolism and nutritive value of clusterbean (Cyamopsis tetragonoloba (L.) Taub.)(CCSHAU, 2008) Sonia; Joshi, U.N.The present investigation was designed to evaluate the effect of zinc through soil and foliar spray of 0.5 per cent ZnSO4 on clusterbean. Clusterbean (Cyamopsis tetragonoloba (L.) Taub. Cv. HG563) plants were raised in earthenware pots filled with zinc deficient sandy loam soil and treated with 0.0, 2.5, 5.0 and 10.0 ppm zinc in soil in first experiment where as in second experiment plants were sprayed with 0.5 per cent ZnSO4 at 25, 45 and 25 as well as 45 DAS. Zinc deficiency symptoms appear in control plants after 15 days of sowing as smaller terminal leaves, discoloration between veins, stunted plant growth with reduced leaf number and plant height which was corrected after application of zinc. All morphophysiological parameters increased with zinc application through soil and foliar spray. In general, all the morphophysiological parameters increased with advancement of growth attaining maximum value either at 50 DAS (flowering stage) and declined at 70 DAS (grain filling stage) or increased up to maturity. Pod yield and seed yield on per plant basis was increased in zinc treated plants (by 1.4 fold in ppm zinc treated plants) as compared to control. The magnitude of increase in the morphophysiological parameters are correlated well with the amount of zinc in various plant parts, which was increased with zinc application in both the experiments. This in turn resulted in significant increment in total chlorophyll and chlorophyll ‘a’ content in leaves and thus might increase the rate of photosynthesis. Both soil as well as foliar application of Zn+2 enhanced the activity of key enzymes of nitrogen metabolism viz. nitrogenase, nitrate reductase, nitrite reductase, glutamine synthetase and glutamate dehydrogenase on per plant as well as per mg protein basis. The above increase in the efficiency of nitrogen metabolism results into increased protein content in leaves, shoots, pods and seeds. Gum content was also enhanced in seed at maturity upon the soil application of 2.5, 5.0 and 10.0 ppm Zn+2 and foliar spray of 0.5 per cent ZnSO4. Zinc application also significantly improved the nutritive value of leaves, shoots and pods, by decreasing NDF, ADF, cellulose and lignin content, which resulted into increase in in vitro dry matter digestibility. Hemicellulose and silica content did not follow regular trend with zinc application. Zinc either through soil or foliar application of Zn+2 have both synergistic and antagonistic effects on the Fe, Cu and Mn content. Iron and copper content synergistically increased at lower Zinc dose and decreased at higher doses. Whereas, Mn content was antagonistically related to increased zinc. Application of zinc through soil was more beneficial then through foliar spray. Zinc application through soil and foliar spray ultimately resulted into increase in fodder and seed yield.ThesisItem Open Access Effect of salinity on antioxidant system in rice cultivars(CCSHAU, 2008) Chawla, Sheetal; Jain, VeenaEffect of salinity was studied on osmoregulation, enzymes and metabolites of reactive oxygen species (ROS) scavenging pathway in leaves and roots of Oryza sativa. For this, six cultivars of rice, three each salt-tolerant (Pokkali, CSR-1 and CSR-10) and salt-sensitive (Basmati-370, IR-28 and MI-48) were taken. The relative water content and osmotic potential decreased upon salinization in all the cultivars, however, the magnitude of reduction was more in salt-sensitive cultivars with increase in salt concentration. Na+/K+ also increased with increasing salt stress in all the cultivars, but the increase was much higher in the salt-sensitive cultivars than salt-tolerant cultivars. Similarly, the production of toxic reactive oxygen species (viz. .O2- and H2O2) and malondialdehyde content (MDA), which is an indicator of cell-membrane damage also increased in all the cultivars with higher level of increment in the salt-sensitive cultivars than salt-tolerant cultivars in both the tissues viz. leaves and roots. The salt-stress had differential effects on the antioxidant enzyme activities in leaves and roots of salt-sensitive and salt-tolerant cultivars. There was enhancement in the activities of superoxide dismutase and glutathione reductase in all the tolerant cultivars while the activities of these enzymes decreased with increasing salinity in the sensitive cultivars. Salt-stress induced the activities of catalase and peroxidase in all the cultivars but the magnitude of increase was more pronounced in sensitive cultivars than tolerant cultivars. Ascorbate peroxidase activity increased in both the tissues of the salt-sensitive cultivars and decreased in the salt-tolerant cultivars. However, the basal level was much higher in the tolerant cultivars. Contrarily, GPX activity declined in roots and leaves of sensitive cultivars but remained unaltered in salt-tolerant cultivars upon exposure to salt-stress. The tolerant cultivars had higher ratio of glutathione reduced (GSH)/glutathione oxidized (GSSG). Ascorbic acid content increased in leaves of tolerant cultivars while reduced in both leaves and roots of sensitive cultivars under saline condition.ThesisItem Open Access Lipid peroxidation and antioxidant pathway in specific leaves of Brassica juncea L. infected with Albugo candida(CCSHAU, 2008) Sapna; Jain, SunitaThe present study was undertaken to investigate the lipid peroxidation and antioxidant pathway in specific leaves of resistant and sensitive cultivars of Brassica juncea L. infected with Albugo candida. Following inoculation of third leaf with Albugo candida spores higher electrolyte leakage, MDA and H2O2 content indicating enhanced lipid peroxidation was observed in sensitive cultivar Varuna. Activity of H2O2 scavenging enzyme viz. peroxidase and catalase increased in both the cultivars but more pronounced enhancement was found in resistant cultivar except super oxide dismutase, as its activity was found to increase in Varuna but declined sharply in RH781. The activity of Halliwell- Asada pathway enzymes i.e. ascorbate peroxidase and glutathione reductase enhanced in both the cultivars but the elevation was more in RH781. Ascorbate and reduced glutathione level increased specifically in RH781 whereas, oxidized glutathione was found to be higher in Varuna signifying more oxidative damage. The study shows noticeable enhancement in lipid peroxidation, activities of enzymes of antioxidant pathway and ascorbate and glutathione content in third leaf on 3 DAI. Thereafter, the increase was more in second leaf as compared to fourth leaf in both the varieties indicating that transduction of pathogen attack signal might be towards the upper leaves via phloem than the lower leaves.ThesisItem Open Access Biochemical studies in wheat (Triticum aestivum L.) seedlings under heat stress(CCSHAU, 2009) Reena; Madan, ShashiThe present investigation was carried out to investigate the effect of heat stress and revival on some antioxidative enzymes, metabolites, chlorophyll stability and polypeptide pattern in the leaves of Wheat seedlings of heat susceptible (WH-147 and HS-277) and heat tolerant (WH-1021 and HW-2045) genotypes. Seven days old seedlings grown at 25ºC were exposed to 40ºC for 6 h and these seedlings were brought to 25ºC. The observations were recorded in the leaves of control, stressed and revived seedlings on 2nd and 4th day of revival. Screening of thirty six genotypes for thermo-tolerance was done based on wilting of primary leaf and values of chlorophyll fluorescence. Chlorophyll stability (%) declined in tolerant and susceptible genotypes under heat stress. There was enhancement in the activities of antioxidative enzymes, viz. CAT, POX, GR and APX in the leaves of tolerant and susceptible genotypes under heat stress, however, higher per cent increase was observed in tolerant genotypes. Heat stress increased the SOD activity in tolerant genotypes but activity declined in susceptible genotypes. On revival, the activities of the CAT, POX and GR declined in comparison to stressed seedlings but remained higher as compared to control. Ascorbate peroxidase activity remained higher on 2nd day and 4th day of revival in all the genotypes. The higher accumulation of H2O2, ascorbic acid and malondialdehyde content was observed under heat stress in all the genotypes but their level was more in heat susceptible genotypes as compared to heat tolerant genotypes. SDS-PAGE of seedlings under stress conditions revealed the appearance of polypeptide bands of different molecular weight in tolerant and susceptible genotypes, and these polypeptides bands disappeared on revival of 2nd and 4th day. Based on genotypes screening and antioxidant enzyme activities, out of four genotypes HW-2045 was found to be the most tolerant and WH-147 as the most susceptible genotype.ThesisItem Open Access High temperature induced changes in oxidative stress, antioxidant system and polypeptide pattern in Indian mustard [Brassica juncea (L.) Czern & Coss.](CCSHAU, 2009) Babita Rani; Dhawan, KamalThe present investigations were undertaken to study the changes in lipid peroxidation, antioxidative enzymes, metabolites and protein pattern in Brassica juncea seedling after subjecting to high temperature stress (45±0.5C) and on revival. Two tolerant genotypes viz. BPR-542-6 and NRCDR-02 and two susceptible genotypes viz. NPJ-119 and RGN-152 were screened at 45±0.5C on the basis of time taken to 50% seedling mortality. Lipoxygenase (LOX), malondialdehyde (MDA) and hydrogen peroxide (H2O2) which are indicators of cell membrane damage increased under heat stress in all the genotypes but increase was higher in susceptible genotypes. On recovery, LOX, MDA and H2O2 content decreased in all the genotypes. The activities of antioxidative enzymes viz . superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) increased under high temperature stress . SOD and CAT started decreasing but activity of POX and GR still continued increasing in all the genotypes. But APX enzyme exhibited differential behaviour on revival which increased in tolerant genotypes but decreased in susceptible genotypes. Ascorbic acid and carotenoids increased under heat stress but during recovery, ascorbic acid continued increasing while carotenoids started decreasing in all the genotypes. A major band of 53.12 kDa and minor bands of 100 kDa, 89.12 kDa, 74.13 kDa, 46.76 kDa and 38.9 kDa in tolerant genotypes and protein bands of molecular weight 25.79 kDa and 30.7 kDa in susceptible genotypes appeared under high temperature stress which disappeared when the stress was relieved.ThesisItem Open Access Isolation, partial purification and characterization of sucrose synthase from thermotolerant wheat (Triticum aestivum L.)(CCSHAU, 2009) Ekta; Singal, H.R.Wheat grain is the dominant grain of world commerce and is the staple food of millions of people world wide. High temperature beyond 300C which is usually encountered during later part of grain filling period, affects grain yield (reduction by 20-50 per cent) and grain quality. Starch is the major storage carbohydrate in wheat grains. It is synthesized from sucrose which is the principal product of leaf photosynthesis and transported to the wheat grain. Sucrose synthase is the first enzyme and an important link in sucrose-starch conversion pathway. Keeping above in view, the present investigation was conducted to purify and characterize sucrose synthase from thermotolerant wheat. Sucrose synthase was purified to near homogeneity (as revealed by single band on Native-PAGE) from immature grains (21 days after anthesis) of thermotolerant wheat WH-1021 by using conventional protein purification techniques viz. ammonium sulphate fractionation, gel filtration through sephadex G-100 and DEAE-cellulose ion exchange chromatography. The enzyme was purified about 27 fold with approximately 37 per cent recovery. The molecular weight as determined by gel filtration and subunit molecular weight as determined by SDS-PAGE (single band) were found to be 269 KDa and 63 KDa respectively indicating that enzyme is a homotetramer. The purified enzyme exhibited optimum activity at 370C temperature and pH 6.5. It was thermostable upto 500C. The activity followed Michaelis-Menten kinetics with Km value of 14.28 mM and 1.18 mM for sucrose and UDP, respectively. Among the various nucleotides tested the enzyme was highly specific for UDP as substrate. The kinetic studies revealed that sucrose synthase catalysed the sucrose degradation by ping-pong mechanism. The enzyme activity was inhibited by Mn2+ (38.5 % inhibition) while NO3- stimulated (20.8% stimulation) the activity at 2 mM concentration. Amongst various metabolites tested NADP+ and G-6-P were found to be the potent inhibitors of purified sucrose synthase (inhibiting the enzyme activity by 16 and 34%), respectively. To summarize, higher thermostability of enzyme is suggestive of enzyme’s adaptation to high temperature stress.