http://nopr.niscair.res.in/handle/123456789/10518 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/10527 Title: Age-associated changes in erythrocyte glutathione peroxidase activity: Correlation with total antioxidant potential <br/> <br/>Authors: Maurya, Pawan Kumar; Kumar, Prabhanshu; Siddiqui, Nahid; Tripathi, Preeti; Rizvi, Syed Ibrahim <br/> <br/>Abstract: Oxidative stress is believed to play a central role in aging and age-associated diseases. It leads to oxidative changes in human red blood cells (RBCs) <i>in vivo</i> and <i>in vitro</i>. In this study, we evaluated the oxidative damage to the erythrocytes during aging in the humans using RBC as a model, by measuring the cytosolic antioxidant enzyme glutathione peroxidase (GPx) activity. GPx activity was found to be significantly decreased as a function of human age and positively correlated with total antioxidant capacity, while negatively correlated with SOD activity. Thus, results of the present study showed involvement of oxidative stress as one of the risk factors, which can initiate and/or promote human aging. <br/> <br/>Page(s): 319-321 http://nopr.niscair.res.in/handle/123456789/10526 Title: Characterization of water distribution and activities of enzymes during germination in magnetically-exposed maize (<i style="">Zea mays </i>L) seeds <br/> <br/>Authors: Vashisth, Ananta; Nagarajan, Shantha <br/> <br/>Abstract: Magnetic seed treatment is one of the physical pre-sowing seed treatments to enhance the performance of crop plants. In our earlier experiment, we found significant increase in germination and vigour characteristics of maize (<i>Zea mays</i> L.) seeds subjected to magnetic fields. Among various combinations of magnetic field (MF) strength and duration, best results were obtained with MF of 100 mT for 2 h and 200 mT for 1 h exposure. The quicker germination in magnetically-exposed seeds might be due to greater activities of germination related enzymes, early hydration of membranes as well as greater molecular mobility of bulk and hydration water fractions. Thus, in the present study, changes in water uptake during imbibition and its distribution and activities of germinating enzymes during germination were investigated in maize seeds exposed to static magnetic fields of 100 and 200 mT for 2 and 1 h respectively by nuclear magnetic resonance (NMR) spectroscopy. The magnetically-exposed seed showed higher water uptake in phase II and III than unexposed seed. The longitudinal relaxation time T₁ of seed water showed significantly higher values and hence greater molecular mobility of cellular water in magnetically-exposed seeds as compared to unexposed. Component analysis of T₂ relaxation times revealed the early appearance of hydration water with least mobility and higher values of relaxation times of cytoplasmic bulk water and hydration water in magnetically-exposed over unexposed seeds. Activities of <img src='/image/spc_char/alpha.gif' border=0> -amylase, dehydorgenase and protease during germination were higher in magnetically-exposed seeds as compared to unexposed. The quicker germination in magnetically-exposed seeds might be due to greater activities of germination related enzymes, early hydration of membranes as well as greater molecular mobility of bulk and hydration water fractions. <br/> <br/>Page(s): 311-318 http://nopr.niscair.res.in/handle/123456789/10525 Title: Reinstate hydrogen peroxide as the product of alternative oxidase of plant mitochondria <br/> <br/>Authors: Bhate, Radha; Ramasarma, T <br/> <br/>Abstract: Chill treatment of potato tubers for 8 days induced mitochondrial O₂ consumption by cyanide-insensitive alternative oxidase (AOX). About half of the total O₂ consumption in such mitochondria was found to be sensitive to salicylhydroxamate (SHAM), a known inhibitor of AOX activity. Addition of catalase to the reaction mixture of AOX during the reaction decreased the rate of SHAM-sensitive O₂ consumption by nearly half, and addition at the end of the reaction released half of the O₂ consumed by AOX, both typical of catalase action on H₂O₂. This reaffirmed that the product of reduction of O₂ by plant AOX was H₂O₂as found earlier and not H₂O as reported in some recent reviews. <br/> <br/>Page(s): 306-310 http://nopr.niscair.res.in/handle/123456789/10524 Title: Isolation of choline monooxygenase (CMO) gene from <i style="">Salicornia europaea</i> and enhanced salt tolerance of transgenic tobacco with CMO genes <br/> <br/>Authors: Wu, S; Su, Q; An, L J <br/> <br/>Abstract: Glycinebetaine (GB) is an osmoprotectant accumulated by certain plants in response to high salinity, drought, and cold stress. Plants synthesize GB via the pathway choline → betaine aldehyde → glycinebetaine, and the first step is catalyzed by choline monooxygenase (CMO). In the present study, by using RT-PCR and RLM-RACE, a full-length CMO cDNA (1844 bp) was cloned from a halophyte <i style="">Salicornia europaea</i>, which showed high homology to other known sequences. In order to identify its function, the ORF of CMO cDNA was inserted into binary vector PBI121 to construct the chimeric plant expression vector PBI121-CMO. Using<i> Agrobacterium</i> (LBA4404) mediation, the recombinant plasmid was transferred into tobacco (<i>Nicotiana tabacum</i>). The PCR, Southern blot and RT-PCR analysis indicated the CMO gene was integrated into the tobacco genome, as well as expressed on the level of transcription. The transgenic tobacco plants were able to survive on MS medium containing 300 mmol/L NaCl and more vigorous than those of wild type with the same concentration salt treatment. In salt-stress conditions, transgenic plants had distinctly higher chlorophyll content and betaine accumulation than that of the control, while relative electrical conductivity of transgenic plants was generally lower. The results suggested the CMO gene transformation could effectively contribute to improving tobacco salt-resistance. <br/> <br/>Page(s): 298-305