scholarly journals Duration and Persistence of Heat Shock Induction of Chilling Tolerance in Cucumber Seedling Roots

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 538E-538
Author(s):  
Hua Zhang ◽  
Paul H. Jennings
Keyword(s):  
Heat Shock ◽  
Root Growth ◽  
Electrolyte Leakage ◽  
Chilling Tolerance ◽  
Shock Duration ◽  
Dependent Manner ◽  
Heat Shocks ◽  
Shock Proteins ◽  
Membrane Peroxidation ◽  
Heat Shock Induction

The effects of heat shock duration and persistence on the induction of chilling tolerance in cucumber roots were studied using total root growth, electrolyte leakage, and membrane peroxidation as injury indices after chilling. Heat shock reduced the chilling induced electrolyte leakage, decreased membrane peroxidation as measured by MDA content, and resulted in a greater total root growth after chilling compared to the control. Heat shocks at 40°C, applied to 36 hr germinated seedlings for time periods from 1 to 15 hr, all resulted in an increase in chilling tolerance in a time-dependent manner. The heat shock induction of chilling tolerance is most effective when heat shock was imposed immediately before chilling, but the effect is persistent even 32 hr after heat shock when seedlings are held at 25°C before chilling. The possible mechanism of heat shock effect and its persistence will be discussed in relation to heat shock proteins and antioxidant enzyme systems.

scholarly journals The Effect of Heat Shock on the Induction of Chilling Tolerance in Cucumber Seedling Roots

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 851F-851 ◽  
Author(s):  
Hua Zhang ◽  
Paul H. Jennings
Keyword(s):  
Molecular Weight ◽  
Heat Shock ◽  
Protein Profile ◽  
Chilling Tolerance ◽  
Low Molecular Weight ◽  
Cucumber Seedling ◽  
Sds Page ◽  
Seedling Roots ◽  
Shock Proteins ◽  
Heat Shock Induction

Heat shock was applied to 32-h-old cucumber seedlings before chilling at 2.5C. Two cultivars, `Poinsett 76' and `Ashley', with different chilling tolerances, were tested. Using root growth after chilling as a measure of chilling tolerance, three heat shock regimes were found to induce chilling tolerance in both cultivars, with the most effective and uniform induction by heat shock at 40C for 3 h. `Ashley', the more chilling tolerant cultivar, exhibited a greater response to heat shock induction of chilling tolerance than `Poinsett 76'. Protein samples from roots were subjected to SDS-PAGE. Three low molecular weight heat shock proteins accumulated to a greater extent in the protein profile of heat-shocked `Ashley' roots. No such increase was found in the `Poinsett 76' roots. The induction of low molecular weight HSPs are discussed in relation to the heat-shock induction of chilling tolerance.

Progesterone enhances target gene transcription by receptor free of heat shock proteins hsp90, hsp56, and hsp70

1991 ◽  
Vol 11 (10) ◽  
pp. 4998-5004
Author(s):  
M K Bagchi ◽  
S Y Tsai ◽  
M J Tsai ◽  
B W O'Malley
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Transcriptional Activation ◽  
Target Gene ◽  
Steroid Hormone ◽  
Receptor Activation ◽  
Target Cells ◽  
Dependent Manner ◽  
Shock Proteins

Steroid receptors regulate transcription of target genes in vivo and in vitro in a steroid hormone-dependent manner. Unoccupied progesterone receptor exists in the low-salt homogenates of target cells as a functionally inactive 8 to 10S complex with several nonreceptor components such as two molecules of 90-kDa heat shock protein (hsp90), a 70-kDa heat shock protein (hsp70), and a 56-kDa heat shock protein (hsp56). Ligand-induced dissociation of receptor-associated proteins such as hsp90 has been proposed as the mechanism of receptor activation. Nevertheless, it has not been established whether, beyond release of heat shock proteins, the steroidal ligand plays a role in modulating receptor activity. To examine whether the release of these nonreceptor proteins from receptor complex results in a constitutively active receptor, we isolated an unliganded receptor form essentially free of hsp90, hsp70, and hsp56. Using a recently developed steroid hormone-responsive cell-free transcription system, we demonstrate for the first time that the dissociation of heat shock proteins is not sufficient to generate a functionally active receptor. This purified receptor still requires hormone for high-affinity binding to a progesterone response element and for efficient transcriptional activation of a target gene. When an antiprogestin, Ru486, is bound to the receptor, it fails to promote efficient transcription. We propose that in the cell, in addition to the release of receptor-associated inhibitory proteins, a distinct hormone-mediated activation event must precede efficient gene activation.

scholarly journals P transposons controlled by the heat shock promoter.

1986 ◽  
Vol 6 (5) ◽  
pp. 1640-1649 ◽  
Author(s):  
H Steller ◽  
V Pirrotta
Keyword(s):  
Heat Shock ◽  
Germ Line ◽  
Fusion Gene ◽  
P Element ◽  
Translational Efficiency ◽  
Heat Shock Promoter ◽  
P Elements ◽  
Heat Shocks ◽  
Neomycin Resistance ◽  
Heat Shock Induction

We have transformed Drosophila melanogaster with modified P-element transposons, which express the transposase function from the heat-inducible hsp70 heat shock promoter. The Icarus transposon, which contains a direct hsp70-P fusion gene, behaved like a very active autonomous P element even before heat shock induction. Although heat shock led to abundant somatic transcription, transposition of the Icarus element was confined to germ line cells. To reduce the constitutive transposase activity observed for the Icarus element, we attenuated the translational efficiency of the transposase RNA by inserting the transposon 5 neomycin resistance gene between the hsp70 promoter and the P-element sequences. The resulting construct, called Icarus-neo, conferred resistance to G418, and its transposition was significantly stimulated by heat shock. Heat shocks applied during the embryonic or third instar larval stage had similar effects, indicating that transposition of P elements is not restricted to a certain developmental stage. Both Icarus and Icarus-neo destabilized snw in a P-cytotype background and thus at least partially overcome the repression of transposition. Our results suggest that the regulation of P-element transposition occurs at both the transcriptional and posttranscriptional levels.

Interaction of Plasminogen and Angiostatin with Heat Shock Proteins.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1622-1622
Author(s):  
Anil K. Dudani ◽  
Jelica Mehic ◽  
Anthony Martyres
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Dependent Manner ◽  
Hsp 70 ◽  
Molar Excess ◽  
Hsp 27 ◽  
Human Plasminogen ◽  
Shock Proteins ◽  
Dose Dependent ◽  
Mcf 7

Abstract Previous studies from this laboratory have demonstrated that plasminogen and angiostatin bind to endothelial cell (EC) surface-associated actin via their kringles in a specific manner. Heat shock proteins (hsps) like hsp 27 are constitutively expressed by vascular ECs and regulate actin polymerization, cell growth and migration. Since many hsps have also been found to be highly abundant on cell surfaces and there is evidence that bacterial surface hsps may interact with human plasminogen, the purpose of this study was to determine whether human plasminogen and angiostatin would interact with human hsps. ELISAs were developed in our laboratory to assess these interactions. It was observed that plasminogen bound to hsps 27, 60 and 70. In all cases, binding was inhibited (85–90%) by excess (50 mM) lysine indicating kringle involvement. Angiostatin predominantly bound to hsp 27 and to hsp 70 in a concentration- and kringle-dependent manner. As observed previously for actin, there was dose-dependent inhibition of angiostatin’s interaction with hsp 27 by plasminogen. In addition, thirty-fold molar excess actin inhibited (up to 50%), the interaction of plasminogen with all hsps. However, thirty-fold molar excess actin could only inhibit the interaction of angiostatin with hsp 27 by 15–20%. FACS analyses indicated the presence of hsps 27, 60 and 70 on the surface of MCF-7 breast cancer cells but not on human umbilical vein ECs. Polyclonal antibodies to hsp 27 significantly inhibited the interaction of plasminogen and angiostatin with MCF-7 surface-associated hsp27 in a dose-dependent manner. Collectively, these data indicate that while plasminogen interacts specifically with hsp 27, 60 and 70, angiostatin interacts predominantly with hsp 27 and to some extent with hsp 70; plasminogen only partially displaces angiostatins binding to hsp 27; actin only partially displaces plasminogen/angiostatin binding to hsps and surface-associated hsp 27 can mediate the binding of both plasminogen and angiostatin to MCF-7 cells.

scholarly journals Involvement of HSP Synthesis and Protease Inhibitors in Heat Shock-induced Cucumber Seedling Chilling Tolerance

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 775F-775
Author(s):  
Paul H. Jennings ◽  
Ann Fitzpatrick
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Protease Inhibitors ◽  
Actinomycin D ◽  
Chilling Tolerance ◽  
Cucumber Seedling ◽  
Shock Effect ◽  
Seedling Roots ◽  
Germinating Seeds ◽  
Heat Shock Induction

Heat shock induction of chilling tolerance in cucumber seedlings is not blocked by inhibitors of protein synthesis. Treatment of germinating seeds with cycloheximide and actinomycin-D, prior to heat shock and chilling, does not block the heat shock induction of chilling tolerance, while the inhibitors alone promote chilling tolerance of seedling roots. To test whether the heat shock effect might be acting on proteases, two protease inhibitors (bestatin and PMSF) were tested for their ability to induce chilling tolerance. Although PMSF slowed germination, it still provided protection against chilling, but bestatin was much more effective.

scholarly journals Sensitivity of Seedling Radicles to Chilling and Heat-shock-induced Chilling Tolerance

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 848C-848
Author(s):  
Abdur Rab ◽  
Mikal E. Saltveit
Keyword(s):  
Heat Shock ◽  
Mung Bean ◽  
Lateral Roots ◽  
Chilling Injury ◽  
Chilling Tolerance ◽  
Shock Temperature ◽  
Chilling Sensitivity ◽  
Hibiscus Esculentus ◽  
Time Required ◽  
Shock Proteins

Chilling sensitivity increased as the radicle of germinating corn (Zea mays L. `Jubilee' hybrid), cucumber (Cucumis sativus L. `Poinsett 76'), mung bean (Phaseolus aureus Roxb. `Berkin'), and tomato (Lycopersicon esculentum Mill. `Rio Grande') seeds increased in length from 1 to 7 mm. In contrast, radicles of germinating okra (Hibiscus esculentus L. `Clemson' spineless) seeds exhibited similar levels of chilling sensitivity at all radicle lengths. The degree of chilling sensitivity varied among the species in relation to time required to elicit a significant response and the magnitude of the elicited response. Based on subsequent radicle elongation, okra and cucumber were the most sensitive species to chilling at 2.5C for 96 h; tomato and corn were relatively less sensitive, and mung bean was the least sensitive. This pattern of sensitivities changed when other criteria were used to evaluate chilling sensitivity. The development of lateral roots decreased with prolonged chilling in all species, except for corn in which the apical tip remained viable even after 192 h of chilling. Heat shock (0 to 10 min at 45C) induced chilling tolerance in all species, except okra. In okra, neither increasing the heat shock temperature nor decreasing the severity of chilling (i.e., temperature and duration of exposure) resulted in a significant reduction in chilling injury. The differential induction of heat shock proteins in okra and the other species is discussed.

scholarly journals 330 Effects of Calcium Salts on Chilling Tolerance in Cucumber Seedling Roots

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 500A-500
Author(s):  
Mustafa Ozden ◽  
Paul H. Jennings
Keyword(s):  
Root Growth ◽  
Electrolyte Leakage ◽  
Calcium Salt ◽  
Chilling Injury ◽  
Calcium Nitrate ◽  
Chilling Tolerance ◽  
Root Growth Inhibition ◽  
Calcium Salts ◽  
Seedling Roots ◽  
Cucumber Roots

The effects of calcium salts and concentrations from 25 to 200 mM on the induction of chilling tolerance in cucumber roots were studied using total root growth, electrolyte leakage, lipid peroxidation, and activities of antioxidant enzymes as indicies of chilling injury. Cucumber seeds `Poinsett 76' germinated at 25 °C for 36 h were treated with calcium sulfate, calcium nitrate, and calcium chloride for 2 h at 25 °C. After incubation, treated seedlings were rinsed with distilled H2O and chilled at 2 °C for 72 or 96 h with or without re-warming at 25 °C. Roots of CaSO4-treated cucumber seedlings exhibited less chilling injury at all concentrations, when exposed to 72- or 96-h chilling periods with a 72-h re-warming period as shown by greater root growth compared to the chilled control. Concentrations of CaCl2 and Ca(NO3)2 above 100 mM resulted in significant root growth inhibition. Electrolyte leakage (EL) was significantly reduced by CaSO4 up to 150 mM under chilling conditions and all calcium salt treatments reduced malondialdehyde (MDA) levels in seedling roots up to 150 mM. However, at 150 mM CaSO4 both EL and MDA values of 72 h chilled and re-warmed roots were at their lowest levels compared to the control and other treatments. Both superoxide dismutase and catalase activities of seedling roots decreased under chilling conditions compared to the nonchilled control, although the reduction was less in the presence of CaSO4. Peroxidase and glutathione reductase activities increased under chilling conditions and were generally reduced in the presence of calcium salts compared to the chilled control.

RNAi Silencing of TEL-AML1 Reveals a Heat Shock Protein Dependent Mechanism in the Development of Leukemia.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2844-2844
Author(s):  
Christofer Diakos ◽  
Christopher Gerner ◽  
Andrea Inthal ◽  
Helmut Gadner ◽  
Renate Panzer-Grümayer
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Heat Shock Protein ◽  
Fusion Gene ◽  
Leukemic Cell ◽  
Leukemia Cell Line ◽  
Cell Phenotype ◽  
Dependent Manner ◽  
Leukemic Clone ◽  
Shock Proteins

Abstract The t(12;21) chromosomal translocation generating the TEL-AML1 fusion product is the most frequent genetic aberration of childhood acute lymphoblastic leukemia. This translocation has been shown to occur in utero and thus represents an early or even initiating event in leukemia development. However, additional molecular changes are necessary for the clinical manifestation of the disease. Despite increasing knowledge on TEL and AML1, the role of the TEL-AML1 fusion gene and its contribution to the malignant transformation is largely unknown. In particular, the mechanisms by which TEL-AML1 influences the biology of the affected cell, and thus survival and expansion, are yet to be defined. The aim of this study was to investigate the functional contribution of TEL-AML1 to the leukemic cell phenotype. We particularly sought to search for TEL-AML1 dependent genes as well as for pathways that function in a fusion gene dependent manner. The t(12;21) positive B cell precursor leukemia cell line REH was used as model system and RNA interference technology, a new and highly specific approach, was employed to block the expression of the TEL-AML1 fusion gene. The successful silencing of TEL-AML1 was demonstrated by Western blot analysis. In order to gain a broad overview of the impact of TEL-AML1 silencing upon the leukemic cell, RNA was isolated and subjected to Affymetrix gene chip analysis. In addition, we studied the proteome by high-resolution 2D electrophoresis. Expression profiling resulted in a specific pattern of differentially regulated genes after TEL-AML1 suppression with a particular emphasis on genes involved in the control of apoptosis. Genes with anti-apoptotic properties were down regulated after TEL-AML1 silencing while those that contribute to apoptosis were largely unaffected. Among the affected anti-apoptotic genes were the heat shock proteins, the most prominent representatives of which were HSP90 and HSP70. Their changes were observed at the mRNA but also at the protein level. This is of special interest, since both heat shock proteins interfere with the intrinsic as well as the extrinsic pathway of apoptosis and hence provide a powerful anti-apoptotic signal. These first data support a model in which TEL-AML1, as an early event, is functionally linked to an anti-apoptotic network and especially to the members of the heat shock protein family. Engagement of these mechanisms might rescue a cell from apoptosis and in consequence give rise to the development of a pre-leukemic clone, a reservoir for the acquisition of further mutations that might eventually give rise to leukemia. Thus, decreasing the apoptosis defence by silencing TEL-AML1 or by inhibiting the heat shock proteins might sensitize TEL-AML1 positive cells to apoptosis. This would not only be an option for future therapy of leukemias but also for the eradication of the pre-leukemic clone as a proposed source of relapse.

The contribution of biotechnology to improving post-harvest chilling tolerance in fruits and vegetables using heat-shock proteins

2013 ◽  
Vol 153 (1) ◽  
pp. 7-24 ◽  
Author(s):  
M. S. AGHDAM ◽  
L. SEVILLANO ◽  
F. B. FLORES ◽  
S. BODBODAK
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Plant Species ◽  
Fruits And Vegetables ◽  
Chilling Injury ◽  
Chilling Tolerance ◽  
Refrigerated Storage ◽  
Post Harvest ◽  
Injury Tolerance ◽  
Shock Proteins

SUMMARYFresh fruits and vegetables have a short post-harvest life and are prone to post-harvest losses due to mechanical injury, physiological causes and decay. Low-temperature storage is widely used as post-harvest treatment applied for delaying senescence in vegetables and ornamentals and ripening in fruits, upholding their post-harvest quality. But the refrigerated storage of tropical and subtropical crop plant species provokes a set of physiological alterations known as chilling injury that negatively affect their quality and frequently renders the product not saleable. Membrane damage and reactive oxygen species (ROS) accumulation are the main adverse effects of chilling injury impact in sensitive horticultural products. The chilling injury tolerance of certain plant species is attributed to their ability to accumulate heat-shock proteins (HSP). The beneficial action of HSP in chilling tolerance is due to their chaperone activity but, besides this biological function, small HSP (sHSP) are able to function as membrane stabilizers and ROS scavengers, or synergistically with cell antioxidant systems. Also, biosynthesis of osmolytes such as raffinose and proline is under the regulation of heat-shock transcription factors (HSTF). These molecules are critical for osmotic adjustment since low temperatures also provoke a secondary osmotic stress. The use of biotechnological strategies can be envisaged, with the aim of generating engineered crop plants of horticultural interest to induce the production and action of HSP and HSTF, in order to assure the beneficial effects of these proteins in promoting chilling injury tolerance during their post-harvest refrigerated storage. In particular, induction of HSTF expression using biotechnology has significant potential and interest for reducing the impact of chilling injury on sensitive produce, avoiding the practical difficulties of applying the classic post-harvest technologies based on heat treatment.

Synergistic impacts of heat shock and spawning on the physiology and immune health ofCrassostrea gigas: an explanation for summer mortality in Pacific oysters

2007 ◽  
Vol 293 (6) ◽  
pp. R2353-R2362 ◽  
Author(s):  
Yan Li ◽  
Jian G. Qin ◽  
Catherine A. Abbott ◽  
Xiaoxu Li ◽  
Kirsten Benkendorff
Keyword(s):  
Heat Shock ◽  
Energy Charge ◽  
Cumulative Effect ◽  
Gill Tissue ◽  
Adenylate Energy Charge ◽  
Pacific Oysters ◽  
The Pacific ◽  
Summer Mortality ◽  
Heat Shocks ◽  
Shock Proteins

Mass mortality is often observed in cultured oysters during the period following spawning in the summer season. To examine the underlying causes leading to this phenomenon, thermotolerance of the Pacific oyster Crassostrea gigas was assessed using pre- and postspawning oysters that were sequentially treated with sublethal (37°C) and lethal heat shocks (44°C). The effects were examined on a range of immune and metabolic parameters in addition to mortality rate. A preventative 37°C significantly reduced oyster mortality after exposure to a second heat shock of 44°C, but in postspawning oysters mortality remained at 80%, compared with < 10% in prespawning oysters. Levels of the 72 kDa and 69 kDa heat shock proteins were low in the gill tissue from postspawning oysters stimulated by heat shock, indicating spawning reduced heat shock protein synthesis. The postspawning oysters had depleted glycogen stores in the mantle tissue and reduced adenylate energy charge after heat shock, indicative of lower energy for metabolic activity. A cumulative effect of spawning and heat shock was observed on the immunocompetence of oysters, demonstrated by reduced hemocyte phagocytosis and hemolymph antimicrobial activity. These results support the hypothesis that the energy expended during reproduction compromises the thermotolerance and immune status of oysters, leaving them easily subject to mortality if heat stress occurs in postspawning stage. This study improves our understanding of oyster summer mortality and has implications for the long-term persistence of mollusks under the influence of global warming.

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