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Littérature scientifique sur le sujet « Reductase (SDR) »

Auteur : Grafiati

Publié le 14 mars 2023

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Articles de revues sur le sujet "Reductase (SDR)"

Gallego, Oriol, Olga V. Belyaeva, Sergio Porté, F. Xavier Ruiz, Anton V. Stetsenko, Elena V. Shabrova, Natalia V. Kostereva, Jaume Farrés, Xavier Parés et Natalia Y. Kedishvili. « Comparative functional analysis of human medium-chain dehydrogenases, short-chain dehydrogenases/reductases and aldo-keto reductases with retinoids ». Biochemical Journal 399, n^o 1 (13 septembre 2006) : 101–9. http://dx.doi.org/10.1042/bj20051988.

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Retinoic acid biosynthesis in vertebrates occurs in two consecutive steps: the oxidation of retinol to retinaldehyde followed by the oxidation of retinaldehyde to retinoic acid. Enzymes of the MDR (medium-chain dehydrogenase/reductase), SDR (short-chain dehydrogenase/reductase) and AKR (aldo-keto reductase) superfamilies have been reported to catalyse the conversion between retinol and retinaldehyde. Estimation of the relative contribution of enzymes of each type was difficult since kinetics were performed with different methodologies, but SDRs would supposedly play a major role because of their low Km values, and because they were found to be active with retinol bound to CRBPI (cellular retinol binding protein type I). In the present study we employed detergent-free assays and HPLC-based methodology to characterize side-by-side the retinoid-converting activities of human MDR [ADH (alcohol dehydrogenase) 1B2 and ADH4), SDR (RoDH (retinol dehydrogenase)-4 and RDH11] and AKR (AKR1B1 and AKR1B10) enzymes. Our results demonstrate that none of the enzymes, including the SDR members, are active with CRBPI-bound retinoids, which questions the previously suggested role of CRBPI as a retinol supplier in the retinoic acid synthesis pathway. The members of all three superfamilies exhibit similar and low Km values for retinoids (0.12–1.1 μM), whilst they strongly differ in their kcat values, which range from 0.35 min−1 for AKR1B1 to 302 min−1 for ADH4. ADHs appear to be more effective retinol dehydrogenases than SDRs because of their higher kcat values, whereas RDH11 and AKR1B10 are efficient retinaldehyde reductases. Cell culture studies support a role for RoDH-4 as a retinol dehydrogenase and for AKR1B1 as a retinaldehyde reductase in vivo.

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Gabrielli, Franco, Marco Antinucci et Sergio Tofanelli. « Gene Structure Evolution of the Short-Chain Dehydrogenase/Reductase (SDR) Family ». Genes 14, n^o 1 (30 décembre 2022) : 110. http://dx.doi.org/10.3390/genes14010110.

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SDR (Short-chain Dehydrogenases/Reductases) are one of the oldest and heterogeneous superfamily of proteins, whose classification is problematic because of the low percent identity, even within families. To get clearer insights into SDR molecular evolution, we explored the splicing site organization of the 75 human SDR genes across their vertebrate and invertebrate orthologs. We found anomalous gene structures in members of the human SDR7C and SDR42E families that provide clues of retrogene properties and independent evolutionary trajectories from a common invertebrate ancestor. The same analyses revealed that the identity value between human and invertebrate non-allelic variants is not necessarily associated with the homologous gene structure. Accordingly, a revision of the SDR nomenclature is proposed by including the human SDR40C1 and SDR7C gene in the same family.

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Li, Aipeng, Lidan Ye, Xiaohong Yang, Chengcheng Yang, Jiali Gu et Hongwei Yu. « Structure-guided stereoselectivity inversion of a short-chain dehydrogenase/reductase towards halogenated acetophenones ». Chemical Communications 52, n^o 37 (2016) : 6284–87. http://dx.doi.org/10.1039/c6cc00051g.

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Joles, Jaap, Nel Willekes-Koolschijn, Hein Koomans, Arie van Tol, Tini Geelhoed-Mieras, Daan Crommelin, Louis van Bloois et al. « Subcutaneous administration of HMG-CoA reductase inhibitors in hyperlipidaemic and normal rats ». Laboratory Animals 26, n^o 4 (1 octobre 1992) : 269–80. http://dx.doi.org/10.1258/002367792780745689.

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Recent reports demonstrate a hypocholesterolaemic effect of daily subcutaneous injections of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors in different rat models of hyperlipidaemia. However, this effect is not seen after oral administration of HMG-CoA reductase inhibitors in rats. We found that oral administration of the HMG-CoA reductase inhibitor Simvastatin also had no effect on plasma cholesterol in severely hyperlipidaemic Nagase analbuminaemic rats (NAR). Simvastatin (an apolar compound dissolved in propylene glycol) was infused continuously for 28 days into the subcutis of control Sprague-Dawley rats (SDR) and NAR using an implanted osmotic pump. All doses which were effective in reducing cholesterol in the NAR (reductions up to -60%), reduced apolipoprotein AI but not apolipoprotein B and caused a severe inflammatory reaction in the dermis. Similar toxicity was observed in the SDR. Subcutaneous administration of the vehicle (propylene glycol) did not cause this reaction and did not affect plasma lipids. Administration of Lovastatin in osmotic pumps resulted in a similar inflammatory reaction. Incorporation of Simvastatin into liposomes did not diminish the toxic effect. On the other hand, infusion of Pravastatin (a polar HMG-CoA reductase inhibitor dissolved in isotonic saline) caused no changes in the dermis and had no effect on plasma lipids in NAR or SDR. Liver microsomes prepared from the Pravastatin-treated rats demonstrated a 3- to 4-fold increase in HMG-CoA reductase activity as compared to untreated rats, confirming uptake of the drug. We conclude that continuous subcutaneous administration of the HMG-CoA reductase inhibitors Simvastatin, Lovastatin and Pravastatin for 28 days may not reduce plasma cholesterol in rats by a mechanism which is related to inhibition of HMG-CoA reductase activity in the liver. The decrease of plasma cholesterol effected by subcutaneous infusion of Simvastatin or Lovastatin in NAR coincides with, and may be related to inflammatory changes caused by administering these compounds into the dermis.

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Davidson, Jaysón, Kyndall Nicholas, Jeremy Young, Deborah G. Conrady, Stephen Mayclin, Sandhya Subramanian, Bart L. Staker, Peter J. Myler et Oluwatoyin A. Asojo. « Crystal structure of a putative short-chain dehydrogenase/reductase from Paraburkholderia xenovorans ». Acta Crystallographica Section F Structural Biology Communications 78, n^o 1 (1 janvier 2022) : 25–30. http://dx.doi.org/10.1107/s2053230x21012632.

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Paraburkholderia xenovorans degrades organic wastes, including polychlorinated biphenyls. The atomic structure of a putative dehydrogenase/reductase (SDR) from P. xenovorans (PxSDR) was determined in space group P21 at a resolution of 1.45 Å. PxSDR shares less than 37% sequence identity with any known structure and assembles as a prototypical SDR tetramer. As expected, there is some conformational flexibility and difference in the substrate-binding cavity, which explains the substrate specificity. Uniquely, the cofactor-binding cavity of PxSDR is not well conserved and differs from those of other SDRs. PxSDR has an additional seven amino acids that form an additional unique loop within the cofactor-binding cavity. Further studies are required to determine how these differences affect the enzymatic functions of the SDR.

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Nguyen, Giang Thu, Shinae Kim, Hyeonseok Jin, Dong-Hyung Cho, Hang-Suk Chun, Woo-Keun Kim et Jeong Ho Chang. « Crystal Structure of NADPH-Dependent Methylglyoxal Reductase Gre2 from Candida Albicans ». Crystals 9, n^o 9 (10 septembre 2019) : 471. http://dx.doi.org/10.3390/cryst9090471.

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Gre2 is a key enzyme in the methylglyoxal detoxification pathway; it uses NADPH or NADH as an electron donor to reduce the cytotoxic methylglyoxal to lactaldehyde. This enzyme is a member of the short-chain dehydrogenase/reductase (SDR) superfamily whose members catalyze this type of reaction with a broad range of substrates. To elucidate the structural features, we determined the crystal structures of the NADPH-dependent methylglyoxal reductase Gre2 from Candida albicans (CaGre2) for both the apo-form and NADPH-complexed form at resolutions of 2.8 and 3.02 Å, respectively. The CaGre2 structure is composed of two distinct domains: the N-terminal cofactor-binding domain and the C-terminal substrate-binding domain. Extensive comparison of CaGre2 with its homologous structures reveals conformational changes in α12 and β3′ of the NADPH-complex forms. This study may provide insights into the structural and functional variation of SDR family proteins.

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Sameeullah, Muhammad, Muhammet Yildirim, Noreen Aslam, Mehmet Cengiz Baloğlu, Buhara Yucesan, Andreas G. Lössl, Kiran Saba, Mohammad Tahir Waheed et Ekrem Gurel. « Plastidial Expression of 3β-Hydroxysteroid Dehydrogenase and Progesterone 5β-Reductase Genes Confer Enhanced Salt Tolerance in Tobacco ». International Journal of Molecular Sciences 22, n^o 21 (29 octobre 2021) : 11736. http://dx.doi.org/10.3390/ijms222111736.

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The short-chain dehydrogenase/reductase (SDR) gene family is widely distributed in all kingdoms of life. The SDR genes, 3β-hydroxysteroid dehydrogenase (3β-HSD) and progesterone 5-β-reductases (P5βR1, P5βR2) play a crucial role in cardenolide biosynthesis pathway in the Digitalis species. However, their role in plant stress, especially in salinity stress management, remains unexplored. In the present study, transplastomic tobacco plants were developed by inserting the 3β-HSD, P5βR1 and P5βR2 genes. The integration of transgenes in plastomes, copy number and transgene expression at transcript and protein level in transplastomic plants were confirmed by PCR, end-to-end PCR, qRT-PCR and Western blot analysis, respectively. Subcellular localization analysis showed that 3β-HSD and P5βR1 are cytoplasmic, and P5βR2 is tonoplast-localized. Transplastomic lines showed enhanced growth in terms of biomass and chlorophyll content compared to wild type (WT) under 300 mM salt stress. Under salt stress, transplastomic lines remained greener without negative impact on shoot or root growth compared to the WT. The salt-tolerant transplastomic lines exhibited enhanced levels of a series of metabolites (sucrose, glutamate, glutamine and proline) under control and NaCl stress. Furthermore, a lower Na+/K+ ratio in transplastomic lines was also observed. The salt tolerance, mediated by plastidial expression of the 3β-HSD, P5βR1 and P5βR2 genes, could be due to the involvement in the upregulation of nitrogen assimilation, osmolytes as well as lower Na+/K+ ratio. Taken together, the plastid-based expression of the SDR genes leading to enhanced salt tolerance, which opens a window for developing saline-tolerant plants via plastid genetic engineering.

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Jacob, Asha I., Sirin A. I. Adham, David S. Capstick, Scott R. D. Clark, Tara Spence et Trevor C. Charles. « Mutational Analysis of the Sinorhizobium meliloti Short-Chain Dehydrogenase/Reductase Family Reveals Substantial Contribution to Symbiosis and Catabolic Diversity ». Molecular Plant-Microbe Interactions® 21, n^o 7 (juillet 2008) : 979–87. http://dx.doi.org/10.1094/mpmi-21-7-0979.

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The short-chain dehydrogenase/reductase (SDR) family is one of the largest and most ubiquitous protein families in bacterial genomes. Despite there being a few well-characterized examples, the substrate specificities or functions of most members of the family are unknown. In this study, we carried out a large-scale mutagenesis of the SDR gene family in the alfalfa root nodule symbiont Sinorhizobium meliloti. Subsequent phenotypic analysis revealed phenotypes for mutants of 21 of the SDR-encoding genes. This brings the total number of S. meliloti SDR-encoding genes with known function or associated phenotype to 25. Several of the mutants were deficient in the utilization of specific carbon sources, while others exhibited symbiotic deficiencies on alfalfa (Medicago sativa), ranging from partial ineffectiveness to complete inability to form root nodules. Five of the mutants had both symbiotic and carbon utilization phenotypes. These results clearly demonstrate the importance of the SDR family in both symbiosis and saprotrophy, and reinforce the complex nature of the interaction of S. meliloti with its plant hosts. Further analysis of the genes identified in this study will contribute to the overall understanding of the biology and metabolism of S. meliloti in relation to its interaction with alfalfa.

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Stambergova, Hana, Lucie Skarydova, James E. Dunford et Vladimir Wsol. « Biochemical properties of human dehydrogenase/reductase (SDR family) member 7 ». Chemico-Biological Interactions 207 (janvier 2014) : 52–57. http://dx.doi.org/10.1016/j.cbi.2013.11.003.

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Bryndová, J., P. Klusoňová, M. Kučka, K. Mazancová-Vagnerová, I. Mikšík et J. Pácha. « Cloning and expression of chicken 20-hydroxysteroid dehydrogenase ». Journal of Molecular Endocrinology 37, n^o 3 (décembre 2006) : 453–62. http://dx.doi.org/10.1677/jme.1.02025.

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The ligand specificity and activation of steroid receptors depend considerably on the enzymatic activities involved in local pre-receptor synthesis and the metabolism of the steroids. Several enzymes in particular, steroid dehydrogenases have been shown to participate in this process. Here we report the isolation of 20-hydroxysteroid dehydrogenase (ch20HSD) cDNA from chicken intestine and the distribution of ch20HSD mRNA and 20-reductase activity in various avian tissues. Using a reverse transcription PCR and comparison with the known sequences of mammalian 20βHSDs, we have isolated a new ch20HSD cDNA. This cDNA predicted 276 amino acid residues that shared about 75% homology with mammalian 20βHSD. Sequences specific to the short-chain dehydrogenase/reductase superfamily (SDR) were found, the Gly-X-X-X-Gly-X-Gly cofactor-binding motif (residues 11–17) and the catalytic activity motif Tyr-X-X-X-Lys (residues 193–197). The cDNA coding for ch20HSD was expressed in Escherichia coli by placing it under isopropylthiogalactoside (IPTG) inducible control. Both the IPTG cells of E. coli and the isolated recombinant protein reduced progesterone to 20-dihydroprogesterone, corticosterone to 20-dihydrocorticosterone and 5α-dihydrotestosterone to its 3-ol derivative. The 20-reductase and 3-reductase activities of ch20HSD catalyzed both 3α/β- and 20α/20β-epimers. The mRNA transcripts of ch20HSD were found in the kidney, colon, and testes; weaker expression was also found in the heart, ovaries, oviduct, brain, liver, and ileum. 20-Reductase activity has been proven in tissue slices of kidney, colon, ileum, liver, oviduct, testis, and ovary; whereas the activity was nearly absent in the heart and brain. A similar distribution of 20-reductase activity was found in tissue homogenates measured under Vmax conditions. These results suggest that chicken 20HSD is the latest member of the SDR superfamily to be found, is expressed in many avian tissues and whose precise role remains to be determined.

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Thèses sur le sujet "Reductase (SDR)"

Olandersson, Sandra. « Evaluation of Machine Learning Algorithms for Classification of Short-Chain Dehydrogenase/Reductase Protein Sequences ». Thesis, Blekinge Tekniska Högskola, Institutionen för programvaruteknik och datavetenskap, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3828.

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The classification of protein sequences is a subfield in the area of Bioinformatics that attracts a substantial interest today. Machine Learning algorithms are here believed to be able to improve the performance of the classification phase. This thesis considers the application of different Machine Learning algorithms to the classification problem of a data set of short-chain dehydrogenases/reductases (SDR) proteins. The classification concerns both the division of the proteins into the two main families, Classic and Extended, and into their different subfamilies. The results of the different algorithms are compared to select the most appropriate algorithm for this particular classification problem.
Klassificeringen av proteinsekvenser är ett område inom Bioinformatik, vilket idag drar till sig ett stort intresse. Maskininlärningsalgoritmer anses här kunna förbättra utförandet av klassificeringsfasen. Denna uppsats rör tillämpandet av olika maskininlärningsalgoritmer för klassificering av ett dataset med short-chain dehydrogenases/reductases (SDR) proteiner. Klassificeringen rör både indelningen av proteinerna i två huvudklasser, Classic och Extended, och deras olika subklasser. Resultaten av de olika algoritmerna jämförs för att välja ut den mest lämpliga algoritmen för detta specifika klassificeringsproblem.
Sandra Olandersson Blåbärsvägen 27 372 38 Ronneby home: 0457-12084

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ROTONDO, ROSSELLA. « New enzymatic pathway(s) in 4-hydroxynonenal metabolism ». Doctoral thesis, Università di Siena, 2017. http://hdl.handle.net/11365/1007903.

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The main effect of lipid peroxidation, which often occurs in response to oxidative stress, is the production of different toxic aldehydes. In particular, over the years, the lipid peroxidation-derived aldehyde 4-hydroxy-trans-2-nonenal (HNE) has received much attention for its dual role in the pathogenesis of several diseases and as signaling molecule. HNE metabolism is reported to mainly occur through its conjugation with glutathione (GSH) and the subsequent formation of 3-glutathionyl-4-hydroxynonanal (GSHNE) [1, 2]. This molecule is susceptible to both oxidative and reductive transformations, which occur through the action of either the NADPH-dependent activity of aldose reductase (AKR1B1) [1] or through the NAD(P)+ -dependent activity of aldehyde dehydrogenase, respectively [3, 4]. Recently, we have demonstrated the implication of a new NADP+-dependent enzymatic activity able to oxidize GSHNE to its corresponding acid 3-glutathionyl-nonanoic-γ-lactone (GSHNA-γ-lactone) [5]. The enzyme was purified from a human astrocytoma cells line (ADF) to electrophoretic homogeneity as protein doublet in SDS-PAGE, with an apparent molecular weight of 31-32 kDa. Proteomic analysis identified both proteins as human CBR1, also known as NADP+ 15-hydroxyprostaglandine dehydrogenase with 74% of homology and proved their migration differences due to the occurrence of a carboxyethyl moiety at Lys239 [5]. This modification has been already described for the human enzyme and has been demonstrated to have no effect on the protein activity and specificity [6, 7]. The enzyme efficiently catalyzes the oxidation of GSHNE, while it is practically inactive towards 4-hydroxy trans-2-nonenal and other HNE-S-thiolated adducts containing an incomplete glutathionyl moiety [5]. Nucleotide sequence analysis of hCBR1 cDNA from ADF cells completely matched with the human wild type counterpart [5], excluding any gain-of-function mutations in the cDNA-derived protein sequence of hCBR1 [8, 9]. Highly purified human recombinant carbonyl reductase 1 (E.C. 1.1.1.184, hCBR1), which preserves its ability to oxidize specifically GSHNE, is also shown to efficiently act as aldehyde reductase on glutathionylated alkanals, namely 3-glutathionyl-4-hydroxynonanal (GSHNE), 3-glutathionyl-nonanal, 3-glutathionyl-hexanal and 3-glutathionyl-propanal [10]. The presence of the glutathionyl moiety appears as a necessary requirement for the susceptibility of these compounds to the NADPH-dependent reduction by hCBR1. In fact the corresponding alkanals and alkenals, and the cysteinyl and γ-glutamyl-cysteinyl alkanals adducts were either ineffective or very poorly active as CBR1 substrates [10]. Mass spectrometry analysis reveals the ability of hCBR1 to reduce GSHNE to the corresponding 3-glutathionyl-1,4-dihydroxynonane (GSDHN) and at the same time to catalyze the oxidation of the hemiacetal form of GSHNE, generating the 3-glutathionylnonanoic-γ-lactone. These data are indicative of the ability of the enzyme to catalyze a disproportion reaction of the substrate through the redox recycle of the pyridine cofactor [10]. A rationale for the observed preferential activity of hCBR1 on different GSHNE diastereoisomers is given by molecular modelling. These results evidence the potential of hCBR1 acting on GSHNE to accomplish a dual role, both in terms of HNE detoxification and, through the production of GSDHN, in terms of involvement into the signalling cascade of the cellular inflammatory response.

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Heyno, Eiri. « Enzymes impliqués dans la production des formes réactives de l'oxygène dans les membranes plasmiques, les mitochrondries et les chloroplastes ». Phd thesis, Université Paris Sud - Paris XI, 2009. http://tel.archives-ouvertes.fr/tel-00447102.

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Les formes réactives de l'oxygène (FRO) ont été analysées dans différents compartiments cellulaires en utilisant des méthodes spectroscopiques (UV/VIS, fluorescence, infrarouge, résonance paramagnétique électronique). L'identité et les mécanismes catalytiques des enzymes qui produisent les FRO dans les membranes plasmiques (MP) et les mitochondries ont été étudiés, ainsi que le rôle protectif de l'oxydase terminale plastidiale (PTOX) des chloroplastes. Cd2+ s'est révélé être un inhibiteur de la NADPH oxydase des MP. In vivo Cd2+ inhibait la production extracellulaire de O2•- mais stimulait l'accumulation de H2O2. Dans des mitochondries isolées, Cd2+ a augmenté la production de FRO. Antimycin A a entraîné une élévation du H2O2 extracellulaire, confirmant que la mitochondrie est le site principal de production de l'H2O2 extracellulaire induite par Cd2+ in vivo. Une quinone réductase (QR) génératrice de FRO a été isolée des MP. La déprotonation pH-dépendante du quinole a produit des formes intermédiaires instables qui génèrent des FRO par réaction avec O2. Des espèces quinoniques ont été détectées dans la MP et pourraient servir de substrat aux QR in vivo. La protection de la chaine photosynthétique de transfert d'électron par la plastoquinol:O2 oxydoréductase a été étudiée chez des plantes PTOX+ surexprimant PTOX. En raison de leur réponse altérée en conditions de faible et forte intensité lumineuse, il a été proposé que pour fonctionner comme enzyme protectrice, PTOX est couplée à une SOD. Chez les lignées PTOX+, le niveau de SOD chloroplastique n'était pas plus élevé, limitant probablement leur capacité à détoxifier les taux élevés de O2•- généré.

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lson, Timothy Simbarashe Wilson Timothy. « HC-SCR of NOˣ emissions over Ag-Al₂O₃ catalysts using diesel fuel as a reductant ». Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/1338/.

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Hydrocarbon selective catalytic reduction (HC-SCR) of nitrogen oxides (NOˣ) over silver-alumina (Ag-Al₂O₃) catalysts, in diesel exhaust gas, has been investigated and presented in this research thesis. The work involved the use of H₂ to activate diesel-type HC reductants. Numerous HC-SCR studies have been conducted (to date) by various authors and research groups in an effort to improve the low temperature (< 350 °C) NOˣ reduction activity of the catalyst, but mainly at laboratory scale, using simulated diesel exhaust gases and the pelletized form of the catalyst. Conversely, the work presented and discussed herein is based on Ag-Al₂O₃ coated monolith substrates for the examination of the NOˣ reduction efficiency when utilizing the full diesel exhaust gas. The activity of the pelletized form of the catalyst and that of a coated monolith substrate could vary according to various characteristics, such as, the chemical (reaction kinetics) and physical (mass transfer, species filtration) processes. These effects were examined under 'passive' and 'active' operation of the respective catalysts. Diesel oxidation catalysts (DOCs) and unique prototype catalysts were also utilized in order to reduce possible poisoning species, which can lead to the deactivation of the Ag-based catalyst. Furthermore, variations in exhaust gas temperature and composition, by continually changing engine load and speed, were explored and the effects on catalyst activity presented. It was suspected that the fluctuating temperature profiles of the exhaust gas could limit the amount of poison species accumulation onto the catalyst active surface and, as a result, could slow down the deactivation mechanisms. Finally, fuel reforming of conventional diesel, RME and GTL fuels was conducted for the production of hydrogen (H₂). The produced H₂ could then be utilized in the combustion process itself or in a HC-SCR reactor, for reduced engine out or tailpipe emissions.

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Gaziola, Salete Aparecida. « Isolamento, purificação, caracterização e estudo dos mecanismos de regulação das enzimas lisina oxoglutarato reductase (LOR) e sacaropina desidrogenase (SDH) em arroz (Oriza sativa L.) ». [s.n.], 1999. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317253.

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Orientador: Ricardo Antunes Azevedo
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-07-28T15:50:03Z (GMT). No. of bitstreams: 1 Gaziola_SaleteAparecida_D.pdf: 4051671 bytes, checksum: 69f5c5ae7cb94c0486211b621052970f (MD5) Previous issue date: 1999
Doutorado
Genetica Vegetal e Melhoramento
Doutor em Genetica e Biologia Molecular

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Gong, Wenjie [Verfasser]. « Characterization of the LysR-type Transcriptional Regulator HsdR Gene and Its Adjacent Short-chain Dehydrogenase, Reductase SDRx Gene in Comamonas testosteroni ATCC 11996 / Wenjie Gong ». Kiel : Universitätsbibliothek Kiel, 2011. http://d-nb.info/1020244666/34.

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Ayella, Allan K. « Wheat lignans and cancer prevention ». Diss., Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/335.

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Rosa, Joana Alexandra Teixeira. « Identification of novel molecular determinants of tissue mineralization in fish ». Doctoral thesis, 2015. http://hdl.handle.net/10400.1/8756.

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Tese de doutoramento, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2015
The identification of genes involved in signaling and regulatory pathways, and matrix formation is paramount to the better understanding of the complex mechanisms of bone formation and mineralization, and critical to the successful development of therapies for human skeletal disorders. To achieve this objective, in vitro cell systems derived from skeletal tissues and able to mineralize their extracellular matrix have been used to identify genes differentially expressed during mineralization and possibly new markers of bone and cartilage homeostasis. Using cell systems of fish origin and techniques such as suppression subtractive hybridization and microarray hybridization, three genes never associated with mechanisms of calcification were identified: the calcium binding protein S100-like, the short-chain dehydrogenase/reductase sdr-like and the betaine homocysteine S-methyltransferase bhmt3. Analysis of the spatial-temporal expression of these 3 genes by qPCR and in situ hybridization revealed: (1) the up-regulation of sdr-like transcript during in vitro mineralization of gilthead seabream cell lines and its specificity for calcified tissues and differentiating osteoblasts; (2) the up-regulation of S100-like and the down-regulation of bhmt3 during in vitro mineralization and the central role of both genes in cartilaginous tissues undergoing endo/perichondral mineralization in juvenile fish. While expression of S100-like and bhmt3 was restricted to calcified tissues, sdr-like transcript was also detected in soft tissues, in particular in tissues of the gastrointestinal tract. Functional analysis of gene promoters revealed the transcriptional regulation of the 3 genes by known regulators of osteoblast and chondrocyte differentiation/mineralization: RUNX2 and RAR (sdr-like), ETS1 (s100-like; bhmt3), SP1 and MEF2c (bhmt3). The evolutionary relationship of the different orthologs and paralogs identified within the scope of this work was also inferred from taxonomic and phylogenetic analyses and revealed novel protein subfamilies (S100-like and Sdr-like) and the explosive diversity of Bhmt family in particular fish groups (Neoteleostei). Altogether our results contribute with new data on SDR, S100 and BHMT proteins, evidencing for the first time the role for these three proteins in mechanisms of mineralization in fish and emphasized their potential as markers of mineralizing cartilage and bone in developing fish.

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Jacob, Asha Ivy. « STUDY OF SHORT CHAIN DEHYDROGENASE / REDUCTASES (SDRs) IN SINORHIZOBIUM MELILOTI ». Thesis, 2007. http://hdl.handle.net/10012/3346.

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Sinorhizobium meliloti maintains a complex lifestyle, including saprotrophy, rhizophere colonization and root hair infection leading to the formation of root nodules in which the plant provides sustenance in return for nitrogen fixation. S. meliloti cells use a variety of carbon substrates for growth; this omnivory probably contributes to competitive ability in the soil. Several candidates for contribution to the catabolic capacity are found within the family of short chain dehydrogenases /reductases (SDR), which catalyze NAD(P)(H) dependent oxidation / reduction reactions. The 6.7 Mb genome of S. meliloti contains 78 SDR-encoding genes distributed on all three replicons. In this work each of these genes were disrupted by single crossover mutagenesis. These mutants were screened for growth on 93 different compounds as carbon source, and phenotypes were found for 17 of the mutants, providing suggestions for potential substrates of the corresponding enzymes. Carbon sources for which phenotype was observed include sugar alcohols, leucine, lysine, ornithine, galactitol, rhamnose, arabinose, mono-methyl succinate and ribono-γ-lactone. In addition, one of the mutants was found to be a proline auxotroph. In several cases, the phenotypes were consistent with the phenotypes of deletion mutants in which large sections of pSymB were absent. Eight of the mutants exhibited symbiotic deficiency after inoculation of alfalfa, while viable cells of three of the mutants could not be isolated from the nodules even though nitrogen fixation occurred. The results suggest that the corresponding SDR enzymes are involved in a pathway that is required for maintenance of viability by cells throughout infection and nodule development. This work demonstrates that members of the SDR family contribute to both the catabolic capacity and the symbiotic interactions of S. meliloti. Further experiments will address the details of the biochemical pathways involved. Knowledge of the substrate specificities of these enzymes should also prove informative in the description and annotation of orthologs that are identified in other genome sequences.

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陳定威. « Synthesis of vitamin K 2,3-epoxide reductase inhibitors and SAR studies ». Thesis, 2003. http://ndltd.ncl.edu.tw/handle/49974423267304640953.

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Chapitres de livres sur le sujet "Reductase (SDR)"

Furnham, Nicholas, Gemma L. Holliday et Janet M. Thornton. « The NAD Binding Domain and the Short-Chain Dehydrogenase/Reductase (SDR) Superfamily ». Dans Protein Families, 191–206. Hoboken, NJ, USA : John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118743089.ch8.

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« Carboxylic Acid Reductase ». Dans Biocatalysis in Organic Synthesis, sous la direction de Faber, Fessner et Turner. Stuttgart : Georg Thieme Verlag, 2015. http://dx.doi.org/10.1055/sos-sd-215-00257.

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« Imine Reductases ». Dans Biocatalysis in Organic Synthesis, sous la direction de Faber, Fessner et Turner. Stuttgart : Georg Thieme Verlag, 2015. http://dx.doi.org/10.1055/sos-sd-215-00205.

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Nubbemeyer, U. « Reductive Defluorination ». Dans X-Ene-X (X=F, Cl, Br, I, O, S, Se, Te, N, P), Ene-Hal, and Ene-O Compounds, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-032-00081.

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Nubbemeyer, U. « Reductive Dechlorination ». Dans X-Ene-X (X=F, Cl, Br, I, O, S, Se, Te, N, P), Ene-Hal, and Ene-O Compounds, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-032-00082.

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Nubbemeyer, U. « Reductive Coupling ». Dans X-Ene-X (X=F, Cl, Br, I, O, S, Se, Te, N, P), Ene-Hal, and Ene-O Compounds, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-032-00084.

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Nubbemeyer, U. « Reductive Alkylation ». Dans X-Ene-X (X=F, Cl, Br, I, O, S, Se, Te, N, P), Ene-Hal, and Ene-O Compounds, 1. Georg Thieme Verlag KG, 2008. http://dx.doi.org/10.1055/sos-sd-032-00184.

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Toyota, S., et T. Iwanaga. « Reductive Cyclization ». Dans Monocyclic Arenes, Quasiarenes, and Annulenes, 1. Georg Thieme Verlag KG, 2010. http://dx.doi.org/10.1055/sos-sd-045-00722.

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Donohoe, T. J. « Reductive Cyclization ». Dans Fused Five-Membered Hetarenes with One Heteroatom, 1. Georg Thieme Verlag KG, 2001. http://dx.doi.org/10.1055/sos-sd-010-00817.

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Aitken, R. A. « Reductive Elimination ». Dans Fused Five-Membered Hetarenes with One Heteroatom, 1. Georg Thieme Verlag KG, 2001. http://dx.doi.org/10.1055/sos-sd-010-01138.

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Actes de conférences sur le sujet "Reductase (SDR)"

Newburry, Don, Pat Runnels et Mike Owings. « Selective Catalytic Reduction (SCR) System Installation and Commissioning at the Chow II Power Plant in Chowchilla, California ». Dans ASME 2003 Internal Combustion Engine Division Spring Technical Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ices2003-0594.

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Lean burn, natural gas, reciprocating engines are becoming widely utilized for stationary industrial applications due to their high efficiency and low emissions. However, despite the low engine emissions, some locations still require exhaust after-treatment to meet the local emissions requirements. Due to the high oxygen content (greater than 4%) in the exhaust of lean burn engines, 3-Way (non-selective) catalysts are not suitable to reduce NOx. Selective catalytic reduction (SCR), which utilizes a consumable reductant to reduce NOx over a catalyst, is very effective at reducing NOx and is becoming an accepted technology for large, stationary engine applications. In the summer of 2001, Stewart & Stevenson installed 16 Deutz TGB632V16 natural gas fired engines for NEO Corporation at the Chow II power plant. MIRATECH SCR provided and commissioned 16 selective catalytic reduction systems for these engines using a 40% urea solution as the reductant. This paper describes the installed SCR systems and reports some of the emissions testing results and costs. With the SCR systems in place, the engines were successfully able to meet the permitted exhaust emissions requirements of 0.07 g/bhp-hr of NOx, 0.1 g/bhp-hr of CO, and 0.15 g/bhp-hr of VOC’s (volatile organic compounds) with less than 10 ppmvd of ammonia slip @ 15% O2. Additional measurements were made of formaldehyde and acrolein. Very low levels of these emissions were found after the SCR.

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Shuai, Shijin, Jianxin Wang, Rulong Li, Jianjun Sun, Licheng Xiang, Hong He et Xiaoyan Shi. « Performance Evaluation and Application of Diesel NOx-SCR Catalyst by Ethanol Reductant ». Dans SAE 2005 World Congress & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States : SAE International, 2005. http://dx.doi.org/10.4271/2005-01-1089.

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van Vuuren, Nic. « Initial Evaluations of Injector Compatibility with an Alternative SCR Reductant Carrier - Guanidinium Formate ». Dans SAE 2014 World Congress & Exhibition. 400 Commonwealth Drive, Warrendale, PA, United States : SAE International, 2014. http://dx.doi.org/10.4271/2014-01-1532.

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Li, Jie, et Jian Li. « A New Proposal on Reductant Utilization in Flue Gas SCR De-NOx Process ». Dans 2nd International Conference on Material Science, Energy and Environmental Engineering (MSEEE 2018). Paris, France : Atlantis Press, 2018. http://dx.doi.org/10.2991/mseee-18.2018.42.

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Chuang Wang, Xinmei Yuan et Jian Zhang. « On-board detection of SCR system insufficient and improper reductant by magnetically coupled resonators ». Dans 2015 IEEE International Wireless Symposium (IWS). IEEE, 2015. http://dx.doi.org/10.1109/ieee-iws.2015.7164546.

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Lacin, Figen, Adam Kotrba, Granville Hayworth, Henry Sullivan, Marek Tatur, Jason Jacques, Dean Tomazic et Hoon Cho. « SOLID SCR® : Demonstrating an Improved Approach to NOx Reduction via a Solid Reductant ». Dans Commercial Vehicle Engineering Congress. 400 Commonwealth Drive, Warrendale, PA, United States : SAE International, 2011. http://dx.doi.org/10.4271/2011-01-2207.

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Liu, Yue, Zaixia Teng, Yafeng Yin et Guo-Zheng Li. « Using Rough Reducts Based SVM Ensemble for SAR of the Ethofenprox Analogous of Pesticide ». Dans 2008 International Multi-symposiums on Computer and Computational Sciences (IMSCCS). IEEE, 2008. http://dx.doi.org/10.1109/imsccs.2008.34.

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Reihani, Amin, Brent Patterson, John Hoard, Galen B. Fisher, Joseph R. Theis, Christine K. Lambert, Evgeny Smirnov et Dirk Roemer. « Rapidly Pulsed Reductants for Diesel NOx Reduction With Lean NOx Traps : Comparison of Alkanes and Alkenes as the Reducing Agent ». Dans ASME 2016 Internal Combustion Engine Division Fall Technical Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icef2016-9475.

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Lean NOx Traps (LNTs) are often used to reduce NOx on smaller diesel passenger cars where urea-based Selective Catalytic Reduction (SCR) systems may be difficult to package. However, the performance of LNTs at temperatures above 400°C needs to be improved. The use of Rapidly Pulsed Reductants (RPR) is a process in which hydrocarbons are injected in rapid pulses ahead of the LNT in order to improve its performance at higher temperatures and space velocities. This approach was developed by Toyota and was originally called Di-Air (Diesel NOx aftertreatment by Adsorbed Intermediate Reductants) [1]. There is a vast parameter space that needs to be explored in order to maximize the NOx conversion at high temperatures and flow rates while minimizing the fuel penalty associated with the hydrocarbon injections. Four parameters were identified as important for RPR operation: (1) the flow field and reductant mixing uniformity; (2) the pulsing parameters including the pulse frequency, duty cycle, and rich magnitude; (3) the reductant type; and (4) the catalyst composition, including the type and loading of precious metal, the type and loading of NOx storage material, and the amount of oxygen storage capacity (OSC). In this study, RPR performance was assessed between 150°C and 650°C with several reductants including dodecane, propane, ethylene, propylene, H2, and CO. A novel injection and mixer system was designed that allowed for the investigation of previously unexplored areas of high frequency injections up to f = 100Hz. Under RPR conditions, H2, CO, dodecane, and C2H4 provided approximately 80% NOx conversion at 500°C, but at 600°C the conversions were significantly lower, ranging from 40 to 55%. The NOx conversion with C3H8 was low across the entire temperature range, with a maximum conversion of 25% near 300°C and essentially no conversion at 600°C. In contrast, C3H6 provided greater than 90% NOx conversion over a broad range of temperature between 280°C and 630°C. Among the hydrocarbons, this suggested that the high temperature NOx conversion with RPR improves as the reactivity of the hydrocarbon increases.

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Benjamin, S. F., M. Gall et C. A. Roberts. « Modelling of NOx Conversion in a 1D Diesel Engine Exhaust SCR Catalyst System under Transient Conditions Using Ammonia Gas as the Reductant ». Dans SAE 2012 International Powertrains, Fuels & Lubricants Meeting. 400 Commonwealth Drive, Warrendale, PA, United States : SAE International, 2012. http://dx.doi.org/10.4271/2012-01-1743.

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Benjamin, S. F., M. Gall et C. A. Roberts. « Tuning the Standard SCR Reaction Kinetics to Model NO Conversion in a Diesel Engine Exhaust SCR Catalyst System Under Steady State Conditions in 1D and 3D Geometries Using Ammonia Gas as the Reductant ». Dans SAE 2012 International Powertrains, Fuels & Lubricants Meeting. 400 Commonwealth Drive, Warrendale, PA, United States : SAE International, 2012. http://dx.doi.org/10.4271/2012-01-1636.

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Rapports d'organisations sur le sujet "Reductase (SDR)"

Or, Etti, David Galbraith et Anne Fennell. Exploring mechanisms involved in grape bud dormancy : Large-scale analysis of expression reprogramming following controlled dormancy induction and dormancy release. United States Department of Agriculture, décembre 2002. http://dx.doi.org/10.32747/2002.7587232.bard.

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The timing of dormancy induction and release is very important to the economic production of table grape. Advances in manipulation of dormancy induction and dormancy release are dependent on the establishment of a comprehensive understanding of biological mechanisms involved in bud dormancy. To gain insight into these mechanisms we initiated the research that had two main objectives: A. Analyzing the expression profiles of large subsets of genes, following controlled dormancy induction and dormancy release, and assessing the role of known metabolic pathways, known regulatory genes and novel sequences involved in these processes B. Comparing expression profiles following the perception of various artificial as well as natural signals known to induce dormancy release, and searching for gene showing similar expression patterns, as candidates for further study of pathways having potential to play a central role in dormancy release. We first created targeted EST collections from V. vinifera and V. riparia mature buds. Clones were randomly selected from cDNA libraries prepared following controlled dormancy release and controlled dormancy induction and from respective controls. The entire collection (7920 vinifera and 1194 riparia clones) was sequenced and subjected to bioinformatics analysis, including clustering, annotations and GO classifications. PCR products from the entire collection were used for printing of cDNA microarrays. Bud tissue in general, and the dormant bud in particular, are under-represented within the grape EST database. Accordingly, 59% of the our vinifera EST collection, composed of 5516 unigenes, are not included within the current Vitis TIGR collection and about 22% of these transcripts bear no resemblance to any known plant transcript, corroborating the current need for our targeted EST collection and the bud specific cDNA array. Analysis of the V. riparia sequences yielded 814 unigenes, of which 140 are unique (keilin et al., manuscript, Appendix B). Results from computational expression profiling of the vinifera collection suggest that oxidative stress, calcium signaling, intracellular vesicle trafficking and anaerobic mode of carbohydrate metabolism play a role in the regulation and execution of grape-bud dormancy release. A comprehensive analysis confirmed the induction of transcription from several calcium–signaling related genes following HC treatment, and detected an inhibiting effect of calcium channel blocker and calcium chelator on HC-induced and chilling-induced bud break. It also detected the existence of HC-induced and calcium dependent protein phosphorylation activity. These data suggest, for the first time, that calcium signaling is involved in the mechanism of dormancy release (Pang et al., in preparation). We compared the effects of heat shock (HS) to those detected in buds following HC application and found that HS lead to earlier and higher bud break. We also demonstrated similar temporary reduction in catalase expression and temporary induction of ascorbate peroxidase, glutathione reductase, thioredoxin and glutathione S transferase expression following both treatments. These findings further support the assumption that temporary oxidative stress is part of the mechanism leading to bud break. The temporary induction of sucrose syntase, pyruvate decarboxylase and alcohol dehydrogenase indicate that temporary respiratory stress is developed and suggest that mitochondrial function may be of central importance for that mechanism. These finding, suggesting triggering of identical mechanisms by HS and HC, justified the comparison of expression profiles of HC and HS treated buds, as a tool for the identification of pathways with a central role in dormancy release (Halaly et al., in preparation). RNA samples from buds treated with HS, HC and water were hybridized with the cDNA arrays in an interconnected loop design. Differentially expressed genes from the were selected using R-language package from Bioconductor project called LIMMA and clones showing a significant change following both HS and HC treatments, compared to control, were selected for further analysis. A total of 1541 clones show significant induction, of which 37% have no hit or unknown function and the rest represent 661 genes with identified function. Similarly, out of 1452 clones showing significant reduction, only 53% of the clones have identified function and they represent 573 genes. The 661 induced genes are involved in 445 different molecular functions. About 90% of those functions were classified to 20 categories based on careful survey of the literature. Among other things, it appears that carbohydrate metabolism and mitochondrial function may be of central importance in the mechanism of dormancy release and studies in this direction are ongoing. Analysis of the reduced function is ongoing (Appendix A). A second set of hybridizations was carried out with RNA samples from buds exposed to short photoperiod, leading to induction of bud dormancy, and long photoperiod treatment, as control. Analysis indicated that 42 genes were significant difference between LD and SD and 11 of these were unique.

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