Relevant bibliographies by topics / Induced systemic tolerance

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Induced systemic tolerance'

Author: Grafiati
Published: 4 June 2025
Last updated: 23 June 2025

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Journal articles on the topic "Induced systemic tolerance"

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Roth, Joachim, Tunay Aslan, Birgit Störr та Eugen Zeisberger. "Lack of cross tolerance between LPS and muramyl dipeptide in induction of circulating TNF-α and IL-6 in guinea pigs". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 273, № 4 (1997): R1529—R1533. http://dx.doi.org/10.1152/ajpregu.1997.273.4.r1529.

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In guinea pigs, lipopolysaccharide (LPS) from gram-negative bacteria and muramyl dipeptide (MDP) from gram-positive bacteria are potent inducers of systemic production of proinflammatory cytokines and fever. However, there is a striking difference between these two bacterial pyrogens in so far as repeated administration of LPS, but not of MDP, in short-term intervals induces tolerance by a progressive downregulation of the systemic cytokine network. In the present study, we investigated MDP-induced fever and the systemic release of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in LPS-tolerant guinea pigs in comparison with naive animals. Endotoxin tolerance was induced by repeated intramuscular injections of 20 μg/kg LPS at intervals of 3 days. In response to the last of five injections with LPS, systemic production of TNF-α and IL-6 as well as the development of a febrile response was abrogated almost completely. Those guinea pigs that had developed an LPS tolerance could, however, produce the same amounts of TNF-α and IL-6 as naive animals in response to a challenge with MDP. Also, MDP-induced fever was identical in LPS-tolerant and naive guinea pigs. These results provide evidence for a lack of cross tolerance between LPS and MDP in induction of circulating cytokines and fever in guinea pigs.
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Sonoda, Koh-Hei, Mark Exley, Scott Snapper, Steven P. Balk, and Joan Stein-Streilein. "Cd1-Reactive Natural Killer T Cells Are Required for Development of Systemic Tolerance through an Immune-Privileged Site." Journal of Experimental Medicine 190, no. 9 (1999): 1215–26. http://dx.doi.org/10.1084/jem.190.9.1215.

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Systemic tolerance can be elicited by introducing antigen into an immune-privileged site, such as the eye, or directly into the blood. Both routes of immunization result in a selective deficiency of systemic delayed type hypersensitivity. Although the experimental animal model of anterior chamber–associated immune deviation (ACAID) occurs in most mouse strains, ACAID cannot be induced in several mutant mouse strains that are coincidentally deficient in natural killer T (NKT) cells. Therefore, this model for immune-privileged site–mediated tolerance provided us with an excellent format for studying the role of NKT cells in the development of tolerance. The following data show that CD1-reactive NKT cells are required for the development of systemic tolerance induced via the eye as follows: (a) CD1 knockout mice were unable to develop ACAID unless they were reconstituted with NKT cells together with CD1+ antigen-presenting cells; (b) specific antibody depletion of NKT cells in vivo abrogated the development of ACAID; and (c) anti-CD1 monoclonal antibody treatment of wild-type mice prevented ACAID development. Significantly, CD1-reactive NKT cells were not required for intravenously induced systemic tolerance, thereby establishing that different mechanisms mediate development of tolerance to antigens inoculated by these routes. A critical role for NKT cells in the development of systemic tolerance associated with an immune-privileged site suggests a mechanism involving NKT cells in self-tolerance and their defects in autoimmunity.
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Grdic, Dubravka, Elisabeth Hörnquist, Martin Kjerrulf, and Nils Y. Lycke. "Lack of Local Suppression in Orally Tolerant CD8-Deficient Mice Reveals a Critical Regulatory Role of CD8+ T Cells in the Normal Gut Mucosa." Journal of Immunology 160, no. 2 (1998): 754–62. http://dx.doi.org/10.4049/jimmunol.160.2.754.

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Abstract We found that feeding keyhole limpet hemocyanin (KLH) to CD8-deficient (CD8−/−) mice induced oral tolerance that was comparable in both magnitude and quality to that induced in wild-type (wt) mice. The tolerance was dose dependent, and only higher doses of KLH caused significant reduction in specific Ab and T cell responses. Both Th1 and Th2 CD4+ T cell functions were affected. Feeding KLH together with cholera toxin (CT) adjuvant, however, abrogated the induction of oral tolerance equally well in CD8−/− and wt mice. On the contrary, CT adjuvant was unable to abrogate already established oral tolerance in both CD8−/− and wt mice. Most importantly, whereas Ag feeding induced hyporesponsiveness in systemic as well as in local gut IgA responses in wt mice, a lack of local suppression was evident in orally tolerant CD8−/− mice following oral immunizations. Thus, contrary to the situation in wt mice, Ag feeding induces systemic, but not local, gut IgA hyporesponsiveness in CD8−/− mice, suggesting that CD8+ T cells in the normal gut mucosa exert an important down-regulatory function. In wt mice the local suppression extended to an unrelated Ag, OVA, given together with KLH and CT adjuvant, i.e., bystander suppression. Based on these results we propose that tolerance induced by feeding Ag is highly compartmentalized, requiring CD8+ T cells for local suppression of IgA responses, whereas systemic tolerance may affect CD4+ T cells of both Th1 and Th2 types independently of CD8+ T cells. Finally, the adjuvant effect of CT abrogates induction, but not established, oral tolerance through a mechanism that does not require CD8+ T cells.
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Zeng, Zhutian, Lu Li, Yongyan Chen, Haiming Wei, Rui Sun та Zhigang Tian. "Interferon-γ facilitates hepatic antiviral T cell retention for the maintenance of liver-induced systemic tolerance". Journal of Experimental Medicine 213, № 6 (2016): 1079–93. http://dx.doi.org/10.1084/jem.20151218.

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Persistent exposure to liver pathogens leads to systemic antigen-specific tolerance, a major cause of chronicity during hepatotropic infection. The mechanism regarding how this systemic tolerance is maintained remains poorly elucidated. In a well established mouse model of hepatitis B virus (HBV) persistence–induced systemic tolerance, we observed that interferon-γ (IFN-γ) deficiency led to complete loss of tolerance, resulting in robust anti-HBV responses upon peripheral vaccination. The recovery of vaccine-induced anti-HBV responses was mainly caused by the retained antigen-specific CD4+ T cells rather than decreased functional inhibitory cells in the periphery. Mechanistically, HBV persistence induced sustained hepatic CD4+ T cell–derived IFN-γ production. IFN-γ was found to promote CXCL9 secretion from liver-resident macrophages. This T cell chemokine facilitated the retention of antiviral CD4+ T cells in the liver in a CXCR3-dependent manner. Hepatic sequestrated antiviral CD4+ T cells subsequently underwent local apoptotic elimination partially via cytotoxic T lymphocyte–associated protein 4 ligation. These findings reveal an unexpected tolerogenic role for IFN-γ during viral persistence in the liver, providing new mechanistic insights regarding the maintenance of systemic antigen-specific tolerance during HBV persistence.
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Freise, Nicole, Alina Burghard, Theresa Ortkras, et al. "Signaling mechanisms inducing hyporesponsiveness of phagocytes during systemic inflammation." Blood 134, no. 2 (2019): 134–46. http://dx.doi.org/10.1182/blood.2019000320.

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Abstract The inflammatory responsiveness of phagocytes to exogenous and endogenous stimuli is tightly regulated. This regulation plays an important role in systemic inflammatory response syndromes (SIRSs). In SIRSs, phagocytes initially develop a hyperinflammatory response, followed by a secondary state of hyporesponsiveness, a so-called “tolerance.” This hyporesponsiveness can be induced by endotoxin stimulation of Toll-like receptor 4 (TLR4), resulting in an ameliorated response after subsequent restimulation. This modification of inflammatory response patterns has been described as innate immune memory. Interestingly, tolerance can also be triggered by endogenous TLR4 ligands, such as the alarmins myeloid-related protein 8 (MRP8, S100A8) and MRP14 (S100A9), under sterile conditions. However, signaling pathways that trigger hyporesponsiveness of phagocytes in clinically relevant diseases are only barely understood. Through our work, we have now identified 2 main signaling cascades that are activated during MRP-induced tolerance of phagocytes. We demonstrate that the phosphatidylinositol 3-kinase/AKT/GSK-3β pathway interferes with NF-κB–driven gene expression and that inhibition of GSK-3β mimics tolerance in vivo. Moreover, we identified interleukin-10–triggered activation of transcription factors STAT3 and BCL-3 as master regulators of MRP-induced tolerance. Accordingly, patients with dominant-negative STAT3 mutations show no tolerance development. In a clinically relevant condition of systemic sterile stress, cardiopulmonary bypass surgery, we confirmed the initial induction of MRP expression and the tolerance induction of monocytes associated with nuclear translocation of STAT3 and BCL-3 as relevant mechanisms. Our data indicate that the use of pharmacological JAK-STAT inhibitors may be promising targets for future therapeutic approaches to prevent complications associated with secondary hyporesponsiveness during SIRS.
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Shi, Hai Ning, Christian J. Ingui, Ingrid Dodge, and Cathryn Nagler-Anderson. "A Helminth-Induced Mucosal Th2 Response Alters Nonresponsiveness to Oral Administration of a Soluble Antigen." Journal of Immunology 160, no. 5 (1998): 2449–55. http://dx.doi.org/10.4049/jimmunol.160.5.2449.

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Abstract A fascinating feature of the intestinal mucosal immune system is its ability to guard against invasion by pathogens while avoiding a response to the many potential Ags present in food. The phenomenon of systemic tolerance after oral administration of protein Ags is well documented, but the cellular and molecular basis for the observed nonresponsiveness is not fully understood. To gain insight into the role of the mucosal microenvironment in the induction of orally induced nonresponsiveness, we attempted to induce tolerance to OVA in mice primed for a Th2-biased mucosal immune response by infection with the nematode parasite Heligmosomoides polygyrus. We found that oral tolerance for Th1-type responses to OVA is maintained when OVA is fed during the peak of the mucosal immune response to H. polygyrus. Tolerance for Th2 cytokine responses or a Th2-dependent isotype of IgG is not induced in this Th2-biased mucosal environment. Treatment of infected mice with rIL-12 to reverse the Th2 polarity of the parasite-specific immune response restores tolerance of both Th1 and Th2 responses to OVA. We conclude that the polarized Th2 response induced by this enteric infection plays a central role in determining whether or not systemic tolerance is induced. Our results imply that attempts to use oral administration of Ag to suppress systemic immune responses will be influenced strongly by the presence of mucosal infection.
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Cho, Song Mi, Beom Ryong Kang, Song Hee Han, et al. "2R,3R-Butanediol, a Bacterial Volatile Produced by Pseudomonas chlororaphis O6, Is Involved in Induction of Systemic Tolerance to Drought in Arabidopsis thaliana." Molecular Plant-Microbe Interactions® 21, no. 8 (2008): 1067–75. http://dx.doi.org/10.1094/mpmi-21-8-1067.

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Root colonization of plants with certain rhizobacteria, such as Pseudomonas chlororaphis O6, induces tolerance to biotic and abiotic stresses. Tolerance to drought was correlated with reduced water loss in P. chlororaphis O6-colonized plants and with stomatal closure, indicated by size of stomatal aperture and percentage of closed stomata. Stomatal closure and drought resistance were mediated by production of 2R,3R-butanediol, a volatile metabolite of P. chlororaphis O6. Root colonization with bacteria deficient in 2R,3R-butanediol production showed no induction of drought tolerance. Studies with Arabidopsis mutant lines indicated that induced drought tolerance required the salicylic acid (SA)-, ethylene-, and jasmonic acid-signaling pathways. Both induced drought tolerance and stomatal closure were dependent on Aba-1 and OST-1 kinase. Increases in free SA after drought stress of P. chlororaphis O6-colonized plants and after 2R,3R-butanediol treatment suggested a primary role for SA signaling in induced drought tolerance. We conclude that the bacterial volatile 2R,3R-butanediol was a major determinant in inducing resistance to drought in Arabidopsis through an SA-dependent mechanism.
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Issazadeh, Shohreh, ManHua Zhang, Mohamed H. Sayegh, and Samia J. Khoury. "Acquired Thymic Tolerance: Role of CTLA4 in the Initiation and Maintenance of Tolerance in a Clinically Relevant Autoimmune Disease Model." Journal of Immunology 162, no. 2 (1999): 761–65. http://dx.doi.org/10.4049/jimmunol.162.2.761.

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Abstract Injection of Ag into the thymus of adult animals induces specific systemic tolerance. The mechanisms of acquired thymic tolerance include anergy and the deletion of Ag-specific T cells. Here, we report that anergy to nominal Ag induced via acquired thymic tolerance requires CTL-associated Ag 4 (CTLA4) engagement. The role of CTLA4 in the induction and maintenance of tolerance was then investigated in the murine experimental autoimmune encephalomyelitis model. CTLA4 blockade abrogated the induction but not the maintenance phase of acquired thymic tolerance induced by intrathymic injection of myelin Ags. In addition, CTLA4 blockade had a restricted window of action after priming with Ag, which is consistent with the expression patterns of CTLA4 in vivo. We conclude that: 1) the induction of acquired thymic tolerance requires signaling through CTLA4 and 2) CTLA4 does not appear to be required for the maintenance of acquired thymic tolerance. This is the first report documenting the role of a CTLA4 negative signaling pathway in the induction of tolerance in an autoimmune disease model.
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Husby, S., J. Mestecky, Z. Moldoveanu, S. Holland, and C. O. Elson. "Oral tolerance in humans. T cell but not B cell tolerance after antigen feeding." Journal of Immunology 152, no. 9 (1994): 4663–70. http://dx.doi.org/10.4049/jimmunol.152.9.4663.

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Abstract The purpose of this study was to investigate whether oral tolerance, defined as Ag-specific immunologic unresponsiveness after Ag feeding, could be induced in humans after prolonged Ag ingestion. Eight adult volunteers ingested a total dose of 0.5 g of keyhole limpet hemocyanin (KLH) followed by subcutaneous immunization with KLH. Eight controls received only the subcutaneous immunization. In the group fed KLH, there was a significant reduction in KLH-specific T cell proliferation (p = 0.04) and delayed skin test responses (p = 0.07) to KLH. KLH ingestion alone did not induce significant levels of Abs in either serum or secretions. However, after the subsequent subcutaneous immunization, the number of circulating IgG and IgM anti-KLH-producing cells, the titers of serum IgG, IgA, and IgM anti-KLH Abs, and the titers of IgA anti-KLH Abs in saliva and intestinal secretions were significantly greater in the KLH-fed group than in the nonfed group. We conclude that KLH feeding induced systemic T cell tolerance, but B cell priming, at both systemic and mucosal sites. These studies support the concept of using Ag feeding as a treatment for certain immune-mediated diseases.
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Zhang, Jun, Yunxia Wang, and Xin Qi. "Systemic Rapamycin Attenuates Morphine-Induced Analgesic Tolerance and Hyperalgesia in Mice." Neurochemical Research 44, no. 2 (2018): 465–71. http://dx.doi.org/10.1007/s11064-018-2699-0.

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Dissertations / Theses on the topic "Induced systemic tolerance"

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Simpson, Joanne Elizabeth. "Immune regulation induced by apoptotic cells in health and in systemic lupus erythematosus (SLE)." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/23515.

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Systemic lupus erythematosus (SLE) is a chronic autoimmune disease where failure to remove apoptotic cells, due to a defect in phagocytic cells, or deficient opsonisation, leads to secondary necrosis and the release of DNA and chromatin. The nuclear constituents from apoptotic cells are targeted by autoantibodies, which form immune complexes. Immune complex-mediated TLR9 activation of plasmacytoid dendritic cells (pDCs) and subsequent secretion of interferon (IFN-α) is thought to drive inflammation in SLE. It is currently believed that pDCs do not normally respond to apoptotic cells, as self-DNA is hidden from TLR9. However, DNA and chromatin expressed on membrane bound apoptotic bodies is essential for inducing IL-10 secreting regulatory B cells through TLR9 stimulation. The overall objective of this thesis was to understand how apoptotic cells influence immune responses in health and in patients with SLE. Splenic mouse pDCs were activated with the synthetic TLR7 agonist R848 and TLR9 agonists CpGB and CpGA and were co-cultured with apoptotic cells, or with freeze-thawed necrotic cells. PDCs co-cultured with apoptotic cells down-regulated the expression of CD40 and CD86. When pDCs were activated by R848 or CpGB, IL-10, IFN-γ and IL-6 secretion was significantly induced in the presence of apoptotic cells. PDCs so cultured induced T cells to secrete immune-regulatory IL- 10. In contrast, co-culturing apoptotic cells with pDCs activated by CpGA, augmented IFN-α secretion. These cytokine responses by pDCs were only stimulated by DNA on whole apoptotic cells; not by free nucleic acids derived from necrotic cells. This data demonstrates that the inflammatory context in which pDCs sense whole apoptotic cells is crucial to determining the threshold of tolerance to apoptotic self. It questions the perception that pDCs see all apoptotic cells and their necrotic cellular debris as dangerous and suggests that there may be something intrinsically different about SLE apoptotic cells, which causes inflammation. SNPs near ATG5, a protein of the cell survival pathway autophagy, have been linked to SLE susceptibility, but the role of autophagy in SLE pathogenesis is unclear. We hypothesised that dysfunctional autophagy is linked to abnormal apoptosis of SLE lymphocytes. Western blotting revealed that ATG5-ATG12 protein complex expression was significantly reduced in SLE lymphocytes and they failed to convert LC3-I to LC3- II, the hallmark of a functioning autophagy pathway, which caused accelerated secondary necrosis. Apoptotic SLE lymphocytes had an impaired ability to stimulate IL-10 secreting regulatory B cells and they induced pro-inflammatory cytokine secretion by monocyte-derived macrophages. Phagocytosis of apoptotic SLE lymphocytes by healthy macrophages was also impaired; however this was independent of ATG5 protein expression. The novel findings of this thesis suggest SLE apoptotic lymphocytes are intrinsically pro-inflammatory, which may be caused by diminished autophagy leading to an inability of lymphocytes to correctly execute apoptosis. Furthermore, inefficient clearance of SLE apoptotic cells results from a defect in the apoptotic cell, rather than the phagocytic cell.
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Matsunaga, Yoichi. "Oral immunization with size-purified microsphere beads as a vehicle selectivery induces systemic tolerance and sensitization." Kyoto University, 2000. http://hdl.handle.net/2433/151402.

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Books on the topic "Induced systemic tolerance"

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G, Choi, Iyer R. K, and United States. National Aeronautics and Space Administration. Scientific and Technical Information Division., eds. Analog-digital simulation of transient-induced logic errors and upset susceptibility of an advanced control system. National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Division, 1990.

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Carreno, Victor A. Analog-digital simulation of transient-induced logic errors and upset susceptibility of an advanced control system. Langley Research Center, 1990.

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Rogler, Gerhard. Gastrointestinal system. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0021.

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Rheumatic diseases and diseases of the gastrointestinal (GI) tract are connected in two ways. The extraintestinal manifestations of inflammatory GI diseases such as inflammatory bowel disease affect joints in up to one-third of patients. On the other hand, several rheumatic diseases such as vasculitis or systemic lupus erythematosus (SLE) induce a wide spectrum of gastrointestinal manifestations. The GI tract constitutes a huge area in contact with the environment. It is exposed to billions of food antigens, commensal bacteria, and potential pathogens. Some of those antigens are thought to play a role in the pathogenesis of rheumatic diseases. The intestinal barrier function and the gut immune system are tightly regulated, as on one hand tolerance for food antigens and the resident commensal flora needs to be maintained, and on the other hand pathogens need to be rapidly and effectively eliminated. Non-infectious, chronic inflammatory diseases of the small and large intestine with rheumatic manifestations have been well known for decades. Among the susceptibility genes for Crohn's disease and ulcerative colitis are some that also cause susceptibility to rheumatoid arthritis or SLE, indicating a shared susceptibility and overlapping pathological mechanisms. Subsequently, similar therapeutic principles have successfully been applied in autoimmune GI and rheumatological diseases such as steroids, immunosuppressants, and anti-TNF (tumour necrosis factor) antibodies.
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Book chapters on the topic "Induced systemic tolerance"

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Sarma, Birinchi Kumar, Sudheer Kumar Yadav, Dhananjaya Pratap Singh, and Harikesh Bahadur Singh. "Rhizobacteria Mediated Induced Systemic Tolerance in Plants: Prospects for Abiotic Stress Management." In Bacteria in Agrobiology: Stress Management. Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-662-45795-5_11.

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Sevanthi, Amitha Mithra V., Prashant Kale, Chandra Prakash, et al. "National repository of EMS induced mutants of an upland rice cultivar Nagina 22: progress update on characterization and utilization." In Mutation breeding, genetic diversity and crop adaptation to climate change. CABI, 2021. http://dx.doi.org/10.1079/9781789249095.0030.

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Abstract The Indian initiative for creating mutant resources in rice has generated 87,000 mutants in the background of a popular drought- and heat-tolerant upland cultivar, Nagina 22 (N22), through EMS mutagenesis. So far, 541 macro-mutants from this resource have been identified, maintained in the mutant garden and characterized in detail based on 44 descriptors pertaining to distinctness, uniformity and stability (DUS) of rice and other agronomic parameters. The similarity index of the mutants was more than 0.6 for nearly 90% of the mutants with respect to DUS descriptors, further establishing the validity of the mutants. The available high-quality sequence resource of N22 has been improved by reducing the gaps by 0.02% in the coding sequence (CDS) region. This was made possible using the newly synthesized whole-genome data of N22 which helped to remove 9006 'Ns' and replace 12,746 existing nucleotides with the accurate ones. These sequence and morphological details have been updated in the mutant database 'EMSgardeN22'. Further, 1058 mutants have been identified for low-P tolerance, tolerance to sheath blight, blast, drought, heat, higher photosynthetic efficiency and agronomic and root traits from this resource. A novel herbicide-tolerant (imazethapyr) mutant earlier identified and characterized from this resource is now being used in introgressing the herbicide-tolerant trait in eight major rice varieties in India. Further, robust and simpler screening systems have been tested for studying low-P tolerance of the mutants. A grain-size mutant, heat-tolerant mutant, drought-tolerant mutant, stay-green mutant and low-P tolerant and water-use efficient high-root-volume mutants have been characterized at morphological and molecular levels. A brief account of all these mutants, the entire mutant resource and the elaborate trait-based screenings is presented in this chapter.
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Speyer, J. J. "Towards Design-Induced Error Tolerance." In Vigilance and Performance in Automatized Systems/Vigilance et Performance de l’Homme dans les Systèmes Automatisés. Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0981-6_13.

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Saglietti, F. "A Classification of Software Diversity Degrees Induced by an Analysis of Fault Types to be Tolerated." In Fault-Tolerant Computing Systems. Springer Berlin Heidelberg, 1991. http://dx.doi.org/10.1007/978-3-642-76930-6_32.

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Greco, Raffaella, and Dominique Farge. "CART Cells and Other Cell Therapies (ie MSC, Tregs) in Autoimmune Diseases." In The EBMT Handbook. Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-44080-9_93.

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AbstractAuto-immune diseases (AD) are heterogeneous conditions, characterized by polyclonal activation of the immune system with a defect of B or T lymphocyte selection and altered lymphocytic reactions to auto-antigens components (Burnet 1959a, b), although it is rare to identify a single antigenic epitope. The native immune system and its tissue environment play an important role to determine if exposure to a given antigen will induce an immune response or tolerance or anergy. The role of the genes coding for the major histocompatibility system molecules, but also of many other genes, is important in the regulation of the immune response, although this does not explain all the observed phenomena during loss of tolerance (Matzinger 1994; Rioux and Abbas 2005).
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Karlsson, Johan, Ulf Gunneflo, and Jan Torin. "The Effects of Heavy-ion Induced Single Event Upsets in the MC6809E Microprocessor." In Fehlertolerierende Rechensysteme / Fault-tolerant Computing Systems. Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-75002-1_24.

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Le, Thao Duc, and Chung Thi Bao Pham. "Soybean breeding through induced mutation in Vietnam." In Mutation breeding, genetic diversity and crop adaptation to climate change. CABI, 2021. http://dx.doi.org/10.1079/9781789249095.0004.

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Abstract In Vietnam, soybean is one of the traditional crops and plays an important role in crop rotation, soil improvement and meeting the nutritional needs of humans and livestock. With the aim of generating genetic variability in soybean and creating new soybean varieties to meet the needs of production, induced mutation research has been carried out since the 1980s and has gained outstanding achievements. Induction of modified traits and their incorporation into an ideal genotype was achieved by judicious use of the induced mutation technique. So far, outstanding soybean varieties such as DT84, DT90, DT99, DT2008 and several promising lines have been developed in Vietnam by incorporating desirable traits like high and stable yield (2.0-3.5 t/ha), good quality, drought tolerance, disease resistance (rust, powdery mildew, downy mildew), short growth duration (70-100 days), wide adaptability and suitability for cropping systems and ecological regions in the whole country. The most outstanding variety, DT84, occupies over 50% of the total production area and 80% in Central and North Vietnam (about 70,000-80,000 ha/year). These varieties have also been used as materials for developing several additional improved soybean varieties. Thus, induced mutation research has played an important role in improving soybean varieties in Vietnam.
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Denkena, Berend, Heinrich Klemme, Eike Wnendt, and Matthias Meier. "Thermally Induced Clamping Force Deviations in a Sensory Chuck for Thin-Walled Workpieces." In Lecture Notes in Production Engineering. Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-34486-2_15.

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AbstractDeviations between nominal and actual tolerances are a challenging problem during turning processes of thin-walled workpieces. One main cause of these deviations is the clamping force applied by the turning chuck to hold the workpiece. Due to the low stiffness of thin-walled workpieces, large workpiece deformations can occur even when clamping forces are low. For this reason, the clamping force needs to be precisely adjusted. A possible approach are chucks with integrated actuators. As a result of the more direct power transmission, these chucks have a potentially higher clamping force accuracy compared to conventional external actuation. However, integrated actuators are additional heart sources resulting in thermal loads and thermally induced deformations of the chuck components. Due to the resulting mechanical distortion of the chuck system, the precise adjustment of clamping forces is not possible. Thus, this paper evaluates the thermally induced clamping force deviations on a novel turning chuck with four integrated electric drives. A test bench is used to analyse both a single drive and the combination of all four drives regarding the temperature effect on the clamping force adjustability. A clamping force deviation of up to 26% is observed. Based on the measured chuck temperature, a compensation method is introduced leading to a clamping force accuracy of 96.9%.
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Kamada, Naoshi. "Systemic Tolerance Induced by Liver Transplantation." In Experimental Liver Transplantation. CRC Press, 2019. http://dx.doi.org/10.1201/9780429263620-7.

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Jain, Shekhar, Anookul Vaishnav, Amrita Kasotia, Sarita Kumari, and Devendra Kumar Choudhary. "Plant Growth-Promoting Bacteria Elicited Induced Systemic Resistance and Tolerance in Plants." In Emerging Technologies and Management of Crop Stress Tolerance. Elsevier, 2014. http://dx.doi.org/10.1016/b978-0-12-800875-1.00005-3.

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Conference papers on the topic "Induced systemic tolerance"

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Gatti, Jean-Loup, Hugo Anthonioz, David Dayan, and Pierre Fruitet. "System Installation Disparity Between Theory and Practice." In Vertical Flight Society 80th Annual Forum & Technology Display. The Vertical Flight Society, 2024. http://dx.doi.org/10.4050/f-0080-2024-1126.

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When the target value of functional geometrical specification is too tight, its cascade of tolerances is at the feasibility limit of production. In this case, the geometrical Tolerancing method loses its benefits and generates an excessive level of non-Conformity which induces additional costs that are not acceptable. The aim of this paper is first to introduce the background concerning chain of dimension method and tolerances capabilities based on test specimen results. Secondly, demonstrate ability to apply statistical calculation. Thirdly extend conventional chain of dimension in one dimension to multi-holes system installation. And, then analyze potential effect by stress evaluation. And confirm the demonstration of improvement on Tolerancing installation calculations, by onboarding all stakeholder (design, manufacturing, stress) early in design phase (interfaces maturation) and by analyzing more in detail installations constraints. This method should be applied first on "non-critical" junction, because it needs to be further matured and so it is not yet mature enough for primary structure and associated quality checks. In conclusion, as a result, it is possible to increase tolerance specification of parts and manage risks of non-assembly. In conclusion, tolerances for holes localization could be approximatively multiplied by two compared to basic calculation method.
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Barbirotta, Marcello, Marco Angioli, Antonio Mastrandrea, Francesco Menichelli, Abdallah Cheikh, and Mauro Olivieri. "Special Session: SE-UVM, an Integrated Simulation Environment for Single Event Induced Failures Characterization and its Application to the CV32E40P Processor." In 2024 IEEE International Symposium on Defect and Fault Tolerance in VLSI and Nanotechnology Systems (DFT). IEEE, 2024. http://dx.doi.org/10.1109/dft63277.2024.10753534.

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Siahrang, Majid, Josh Brown, Dale Lindemuth, et al. "Challenging AC Interference Mitigation: a Case Study of Mitigation beyond the Pipeline Corridor." In CONFERENCE 2025. AMPP, 2025. https://doi.org/10.5006/c2025-00427.

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Abstract This case study examines a unique installation of AC mitigation for a high-pressure natural gas pipeline system affected by a newly constructed 500 kV overhead powerline. The pipeline system was equipped with corrosion rate probe remote monitoring units (RMUs) shortly after the powerline was energized and before the parallel counterpoise AC mitigation system was installed. Before and after the initial AC mitigation installation, pipeline AC current densities were excessively high and significantly greater than predicted by initial computer modeling. Various field analyses and computer simulations were conducted to determine the cause of the unexpected conditions, refine the computer models, and develop an appropriate solution. The final mitigation involved an uncommon approach, including the installation of 4,500 feet of buried mitigation conductor along the powerline corridor, outside the pipeline right-of-way, to counterbalance the induced voltage on the pipeline. Real-time monitoring of pipeline conditions showed the installed mitigation extension has been effective in reducing AC current densities below the maximum tolerable limit. This project underscores the importance of collaboration between the pipeline and powerline companies and their respective AC interference experts during the design, installation, and ongoing monitoring of AC mitigation systems.
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Fisher, M. S., A. S. Bulygin, V. V. Kurilin, Yu N. Khantakova, and S. V. Sennikov. "INDUCTION OF ANTIGEN-SPECIFIC IMMUNOLOGICAL TOLERANCE BY REGULATORY T-CELLS IN COLLAGEN-INDUCED ARTHRITIS AND TRANSPLANTATION, IN VITRO." In X Международная конференция молодых ученых: биоинформатиков, биотехнологов, биофизиков, вирусологов и молекулярных биологов — 2023. Novosibirsk State University, 2023. http://dx.doi.org/10.25205/978-5-4437-1526-1-383.

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Induction of antigen-specific immunological tolerance with CD25 high FoxP3 hi T-regulatory cells (T-reg), plays an important role in organ transplant rejection, graft-versus-host disease, and autoimmune diseases, and helps to reduce the severity and incidence of adverse reactions associated with systemic immunosuppression in the use of traditional therapy
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Konno, R., AP Velosa, ER Parra, et al. "Decreased Lung Collagen mRNA Synthesis and TGF-B Expression in Experimental Model of Systemic Sclerosis after Collagen V-Induced Nasal Tolerance." In American Thoracic Society 2009 International Conference, May 15-20, 2009 • San Diego, California. American Thoracic Society, 2009. http://dx.doi.org/10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a3422.

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Khiewkamrop, Phuriwat, Chonnavee Manipuntee, Chamraj Kaewraemruaen, et al. "LP-086 Dexamethasone-incorporated immunomodulatory PDMAEMA-PLGA nanoparticles potentially induced tolerogenic dendritic cells and ameliorated lupus disease by mediating antigen-specific immune tolerance." In The 15th International Congress on Systemic Lupus Erythematosus and The 43rd KCR Annual Scientific Meeting & 17th International Symposium (LUPUS & KCR 2023). Lupus Foundation of America, 2023. http://dx.doi.org/10.1136/lupus-2023-kcr.191.

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Patil, Chinmaya B., S. V. Sreenivasan, and Raul G. Longoria. "Robust Design of Flexure Based Nano Precision Compliant Mechanisms With Application to Nano Imprint Lithography." In ASME 2008 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/detc2008-50114.

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Flexure-based compliant mechanisms are the preferred motion guiding systems for small range, nano-precision positioning applications because of excellent characteristics like friction-free continuous motion. These mechanisms are commonly used in nano fabrication equipment and ultra precision instruments. However, machining imperfections induced geometric errors in the mechanisms are known to cause undesirable parasitic motion and significant loss of precision. A systematic design approach to minimize the sensitivity of the flexure mechanisms to geometric errors induced by machining tolerances is presented here. Central to the design approach is the screw systems based analytical model to study the spatial motion characteristics of flexure mechanisms. Using this model, the parasitic motion is classified into those errors which can be corrected by calibration (extrinsic) and those which are coupled with the mechanism motion and cannot be corrected by apriori calibration (intrinsic). Metric to quantify the intrinsic parasitic motion results naturally from the screw systems analysis, and is used to represent the precision capability of the flexure mechanism. The analytical model enables the selection of geometric parameters of flexure joints of the mechanism via an optimization scheme with the aim of minimizing the parasitic motion metric. The statistical nature of the machining tolerances is accounted for by sampling the random variables at every iteration step of the optimization, leading to a stochastic formulation. The robust design approach is illustrated using a one DOF rotational flexure mechanism that is used in nano-imprint lithography equipment. Numerical results of the optimization indicate up to 40% improvement in the precision capability of the mechanism without any change in the manufacturing tolerance limits. Further, it is shown via eigenscrew analysis of mechanism compliance that the robustness resulting from the optimal flexure joint design can be attributed to the improved compliance distribution.
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Radhakrishnan, Satish, Ganesh Subbarayan, Luu Nguyen, and William P. Mazotti. "A Systems Approach for Analyzing Uncertainties in Misalignment of a Fiber-Optic System." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42667.

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Performance of a fiber-optic system depends on the coupling efficiency and the alignment retention capability. The optoelectronic system experiences performance degradation due to uncertainties in the alignment of the optical fibers with the laser beam. The laser devices are temperature sensitive, generate large heat fluxes, are prone to mechanical stresses induced and require stringent alignment tolerance due to their spot sizes. The performance of an optoelectronic system is also affected by many other factors such as geometric tolerances, uncertainties in the properties of the materials, optical parameters such as Numerical Aperture etc. To analyze such a complex system, we need to understand the dependence and inter-relationships between various elements that together make the complex system. In this paper, we develop systematic, formal procedures for identifying the relationships between the critical system level parameters through system decomposition strategies. A novel technique to include the sensitivity of the variables with respect to the functions to assist in the system decomposition is developed. We apply graph partitioning strategies to decompose the system into different subsystems. We also demonstrate system decomposition technique using a simple to implement simulated annealing algorithm. The results of system decomposition using graph partitioning technique and simulated annealing are also compared.
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Namba, Kazuteru, Masatoshi Sakata, and Hideo Ito. "Single Event Induced Double Node Upset Tolerant Latch." In 2010 IEEE International Symposium on Defect and Fault Tolerance in VLSI Systems (DFT). IEEE, 2010. http://dx.doi.org/10.1109/dft.2010.41.

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Simoglou, Stavros, Christos Sotiriou, and Nikolaos Blias. "Static Timing Analysis Induced Simulation Errors for Asynchronous Circuits." In 2021 IEEE International Symposium on Defect and Fault Tolerance in VLSI and Nanotechnology Systems (DFT). IEEE, 2021. http://dx.doi.org/10.1109/dft52944.2021.9568296.

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Reports on the topic "Induced systemic tolerance"

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Freeman, Stanley, Russell Rodriguez, Adel Al-Abed, Roni Cohen, David Ezra, and Regina Redman. Use of fungal endophytes to increase cucurbit plant performance by conferring abiotic and biotic stress tolerance. United States Department of Agriculture, 2014. http://dx.doi.org/10.32747/2014.7613893.bard.

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Major threats to agricultural sustainability in the 21st century are drought, increasing temperatures, soil salinity and soilborne pathogens, all of which are being exacerbated by climate change and pesticide abolition and are burning issues related to agriculture in the Middle East. We have found that Class 2 fungal endophytes adapt native plants to environmental stresses (drought, heat and salt) in a habitat-specific manner, and that these endophytes can confer stress tolerance to genetically distant monocot and eudicot hosts. In the past, we generated a uv non-pathogenic endophytic mutant of Colletotrichum magna (path-1) that colonized cucurbits, induced drought tolerance and enhanced growth, and protected 85% - 100% against disease caused by certain pathogenic fungi. We propose: 1) utilizing path-1 and additional endophtyic microorganisms to be isolated from stress-tolerant local, wild cucurbit watermelon, Citrulluscolocynthis, growing in the Dead Sea and Arava desert areas, 2) generate abiotic and biotic tolerant melon crop plants, colonized by the isolated endophytes, to increase crop yields under extreme environmental conditions such as salinity, heat and drought stress, 3) manage soilborne fungal pathogens affecting curubit crop species growing in the desert areas. This is a unique and novel "systems" approach that has the potential to utilize natural plant adaptation for agricultural development. We envisage that endophyte-colonized melons will eventually be used to overcome damages caused by soilborne diseases and also for cultivation of this crop, under stress conditions, utilizing treated waste water, thus dealing with the limited resource of fresh water.
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Nakagawa, T., E. Poulin, T. Rueppel, et al. Effects of thermal modification on the flexure properties, fracture energy, and hardness of western hemlock. Engineer Research and Development Center (U.S.), 2025. https://doi.org/10.21079/11681/49666.

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This study investigates the effect of thermal modification on the flexural properties, transverse fracture energy, and hardness of western hemlock. Flexure tests on specimens featuring longitudinal and transverse grains showed that thermal modification at 167 °C leads to less statistical variability compared to unmodified samples. Additionally, thermal modification leads to a decrease in the transverse flexural strength. On the other hand, the fracture and Janka hardness tests revealed a more pronounced brittleness of the thermally modified samples. The total mode I fracture energy of modified single-edge notch bending samples was about 47% lower for radial–longitudinal systems and 60% lower for tangential–longitudinal systems. Similarly, the average Janka hardness in the tangential and transverse planes was 8.5% and 9.4% lower in the modified specimens, respectively. The results presented in this work show that thermal modification can have a significant effect on the fracturing behavior of west-ern hemlock and its energy dissipation capabilities. For design, this must be taken into serious consideration as these properties significantly influence the damage tolerance of this wood in the presence of stress concentrations such as those induced in bolted joints and cut outs. Fracture energy and hardness are also strongly correlated to ballistic performance.
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Droby, Samir, Michael Wisniewski, Ron Porat, and Dumitru Macarisin. Role of Reactive Oxygen Species (ROS) in Tritrophic Interactions in Postharvest Biocontrol Systems. United States Department of Agriculture, 2012. http://dx.doi.org/10.32747/2012.7594390.bard.

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To elucidate the role of ROS in the tri-trophic interactions in postharvest biocontrol systems a detailed molecular and biochemical investigation was undertaken. The application of the yeast biocontrol agent Metschnikowia fructicola, microarray analysis was performed on grapefruit surface wounds using an Affymetrix Citrus GeneChip. the data indicated that 1007 putative unigenes showed significant expression changes following wounding and yeast application relative to wounded controls. The expression of the genes encoding Respiratory burst oxidase (Rbo), mitogen-activated protein kinase (MAPK) and mitogen-activated protein kinase kinase (MAPKK), G-proteins, chitinase (CHI), phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) and 4-coumarate-CoA ligase (4CL). In contrast, three genes, peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), were down-regulated in grapefruit peel tissue treated with yeast cells. The yeast antagonists, Metschnikowia fructicola (strain 277) and Candida oleophila (strain 182) generate relatively high levels of super oxide anion (O2−) following its interaction with wounded fruit surface. Using laser scanning confocal microscopy we observed that the application of M. fructicola and C. oleophila into citrus and apple fruit wounds correlated with an increase in H2O2 accumulation in host tissue. The present data, together with our earlier discovery of the importance of H₂O₂ production in the defense response of citrus flavedo to postharvest pathogens, indicate that the yeast-induced oxidative response in fruit exocarp may be associated with the ability of specific yeast species to serve as biocontrol agents for the management of postharvest diseases. Effect of ROS on yeast cells was also studied. Pretreatment of the yeast, Candida oleophila, with 5 mM H₂O₂ for 30 min (sublethal) increased yeast tolerance to subsequent lethal levels of oxidative stress (50 mM H₂O₂), high temperature (40 °C), and low pH (pH 4). Suppression subtractive hybridization analysis was used to identify genes expressed in yeast in response to sublethal oxidative stress. Transcript levels were confirmed using semi quantitative reverse transcription-PCR. Seven antioxidant genes were up regulated. Pretreatment of the yeast antagonist Candida oleophila with glycine betaine (GB) increases oxidative stress tolerance in the microenvironment of apple wounds. ROS production is greater when yeast antagonists used as biocontrol agents are applied in the wounds. Compared to untreated control yeast cells, GB-treated cells recovered from the oxidative stress environment of apple wounds exhibited less accumulation of ROS and lower levels of oxidative damage to cellular proteins and lipids. Additionally, GB-treated yeast exhibited greater biocontrol activity against Penicillium expansum and Botrytis cinerea, and faster growth in wounds of apple fruits compared to untreated yeast. The expression of major antioxidant genes, including peroxisomal catalase, peroxiredoxin TSA1, and glutathione peroxidase was elevated in the yeast by GB treatment. A mild heat shock (HS) pretreatment (30 min at 40 1C) improved the tolerance of M. fructicola to subsequent high temperature (45 1C, 20–30 min) and oxidative stress (0.4 mol-¹) hydrogen peroxide, 20–60 min). HS-treated yeast cells showed less accumulation of reactive oxygen species (ROS) than non-treated cells in response to both stresses. Additionally, HS-treated yeast exhibited significantly greater (P≥0.0001) biocontrol activity against Penicillium expansum and a significantly faster (Po0.0001) growth rate in wounds of apple fruits stored at 25 1C compared with the performance of untreated yeast cells. Transcription of a trehalose-6-phosphate synthase gene (TPS1) was up regulated in response to HS and trehalose content also increased.
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Handa, Avtar K., Yuval Eshdat, Avichai Perl, Bruce A. Watkins, Doron Holland, and David Levy. Enhancing Quality Attributes of Potato and Tomato by Modifying and Controlling their Oxidative Stress Outcome. United States Department of Agriculture, 2004. http://dx.doi.org/10.32747/2004.7586532.bard.

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General The final goal and overall objective of the current research has been to modify lipid hydroperoxidation in order to create desirable phenotypes in two important crops, potato and tomato, which normally are exposed to abiotic stress associated with such oxidation. The specific original objectives were: (i) the roles of lipoxygenase (LOX) and phospholipids hydroperoxide glutathione peroxidase (PHGPx) in regulating endogenous levels of lipid peroxidation in plant tissues; (ii) the effect of modified lipid peroxidation on fruit ripening, tuber quality, crop productivity and abiotic stress tolerance; (iii) the effect of simultaneous reduction of LOX and increase of PHGPx activities on fruit ripening and tuber quality; and (iv) the role of lipid peroxidation on expression of specific genes. We proposed to accomplish the research goal by genetic engineering of the metabolic activities of LOX and PHGPx using regulatable and tissue specific promoters, and study of the relationships between these two consecutive enzymes in the metabolism and catabolism of phospholipids hydroperoxides. USA Significant progress was made in accomplishing all objectives of proposed research. Due to inability to regenerate tomato plants after transforming with 35S-PHGPx chimeric gene construct, the role of low catalase induced oxidative stress instead of PHGPx was evaluated on agronomical performance of tomato plant and fruit quality attributes. Effects of polyamine, that protects DNA from oxidative stress, were also evaluated. The transgenic plants under expressing lipoxygenase (LOX-sup) were crossed with catalase antisense (CAT-anti) plants or polyamine over producing plants (SAM-over) and the lines homozygous for the two transgenes were selected. Agronomical performance of these line showed that low catalase induced oxidative stress negatively affected growth and development of tomato plants and resulted in a massive change in fruit gene expression. These effects of low catalase activity induced oxidative stress, including the massive shift in gene expression, were greatly overcome by the low lipoxygenase activity. Collectively results show that oxidative stress plays significant role in plant growth including the fruit growth. These results also for the first time indicated that a crosstalk between oxidative stress and lipoxygenase regulated processes determine the outcome during plant growth and development. Israel Regarding PHGPx, most of the study has concentrated on the first and the last specific objectives, since it became evident that plant transformation with this gene is not obvious. Following inability to achieve efficient transformation of potato and tomato using a variety of promoters, model plant systems (tobacco and potato cell cultures, tobacco calli and plantlets, and Arabidopsis) were used to establish the factors and to study the obstacles which prohibited the regeneration of plants carrying the genetic machinery for overproduction of PHGPx. Our results clearly demonstrate that while genetic transformation and over-expression of PHGPx occurs in pre-developmental tissue stage (cell culture, calli clusters) or in completed plant (Arabidopsis), it is likely that over-expression of this enzyme before tissue differentiation is leading to a halt of the regeneration process. To support this assumption, experiments, in which genetic engineering of a point-mutated PHGPx gene enable transformation and over-expression in plants of PhSPY modified in its catalytic site and thus inactive enzymatically, were successfully carried out. These combined results strongly suggest, that if in fact, like in animals and as we established in vitro, the plant PHGPx exhibits PH peroxidase activity, these peroxides are vital for the organisms developmental process.
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Steffens, John C., and Eithan Harel. Polyphenol Oxidases- Expression, Assembly and Function. United States Department of Agriculture, 1995. http://dx.doi.org/10.32747/1995.7571358.bard.

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Polyphenol oxidases (PPOs) participate in the preparation of many plant products on the one hand and cause considerable losses during processing of plant products on the other hand. However, the physiological functions of plant PPO were still a subject of controversy at the onset of the project. Preliminary observations that suggested involvement of PPOs in resistance to herbivores and pathogens held great promise for application in agriculture but required elucidation of PPO's function if modulation of PPO expression is to be considered for improving plant protection or storage and processing of plant products. Suggestions on a possible role of PPO in various aspects of chloroplast metabolism were also relevant in this context. The characterization of plant PPO genes opened a way for achieving these goals. We reasoned that "understanding PPO targeting and routing, designing ways to manipulate its expression and assessing the effects of such modifications will enable determination of the true properties of the enzyme and open the way for controlling its activity". The objective of the project was to "obtain an insight into the function and biological significance of PPOs" by examining possible function(s) of PPO in photosynthesis and plant-pest interactions using transgenic tomato plants; extending our understanding of PPO routing and assembly and the mechanism of its thylakoid translocation; preparing recombinant PPOs for use in import studies, determination of the genuine properties of PPOs and understanding its assembly and determining the effect of PPO's absence on chloroplast performance. Results obtained during work on the project made it necessary to abandon some minor objectives and devote the effort to more promising topics. Such changes are mentioned in the 'Body of the report' which is arranged according to the objectives of the original proposal. The complex expression pattern of tomato PPO gene family was determined. Individual members of the family are differentially expressed in various parts of the plant and subjected to developmentally regulated turnover. Some members are differentially regulated also by pathogens, wounding and chemical wound signals. Wounding systemically induces PPO activity and level in potato. Only tissues that are developmentally competent to express PPO are capable of responding to the systemic wounding signal by increased accumulation of PPO mRNA. Down regulation of PPO genes causes hyper susceptibility to leaf pathogens in tomato while over expression regulation of PPO expression in tomato plants is their apparent increased tolerance to drought. Both the enhanced disease resistance conferred by PPO over expression and the increased stress tolerance due to down regulation can be used in the engineering of improved crop plants. Photosynthesis rate and variable fluorescence measurements in wild type, and PPO-null and over expressing transgenic tomato lines suggest that PPO does not enable plants to cope better with stressful high light intensities or reactive oxygen species. Rather high levels of the enzyme aggravate the damage caused under such conditions. Our work suggests that PPO's primary role is in defending plants against pathogens and herbivores. Jasmonate and ethylene, and apparently also salicylate, signals involved in responses to wounding and defense against herbivores and pathogens, enhance markedly and specifically the competence of chloroplasts to import and process pPPO. The interaction of the precursor with thylakoid membranes is primarily affected. The routing of PPO shows other unusual properties: stromal processing occurs in two sites, resulting in intermediates that are translocated across thylakoids by two different mechanisms - a DpH- and a Sec-dependent one. It is suggested that the dual pattern of processing and routing constitutes a'fail safe' mechanism, reflecting the need for a rapid and flexible response to defense challenges. Many of the observations described above should be taken into consideration when manipulation of PPO expression is contemplated for use in crop improvement.
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