scholarly journals Direct Sunlight Influences Postharvest Temperature Responses and Ripening of Five Avocado Cultivars

2000 ◽  
Vol 125 (3) ◽  
pp. 370-376 ◽  
Author(s):  
Allan B. Woolf ◽  
Asya Wexler ◽  
Dov Prusky ◽  
Elana Kobiler ◽  
Susan Lurie

Effect of direct sunlight on the postharvest behavior of five avocado (Persea americana Mill.) cultivars (Ettinger, Fuerte, Hass, Horshim and Pinkerton) was examined. Probes placed 6 to 7 mm under the peel showed that the temperature an the side exposed to the sun could be as much as 15 to 20 °C higher than the temperature of shade fruit, while the nonexposed side of the fruit was ≈5 °C higher than the shade fruit. With the exception of `Ettinger', sun fruit, and especially the exposed side, were found to be most tolerant to postharvest 50 and 55 °C hot water treatments. Similarly, storage of fruit at 0 °C for between 3 to 6 weeks caused severe chilling injury to shade fruit, with less effect on sun fruit. Furthermore, there was little or no damage on the exposed side of the sun fruit. During postharvest ripening at 20 °C, sun fruit showed a delay of between 2 to 5 days in their ethylene peak compared with shade fruit. The exposed side of the sun fruit was generally firmer than the nonexposed side, and the average firmness was higher than that of shade fruit. Activities of polygalacturonase and cellulase were similar in shade and sun fruit of similar firmness. After inoculation with Colletotrichum gloeosporioides (Penz.) Penz@sacc., the appearance of lesions on sun fruit occurred 2 to 3 days after shade fruit. Levels of heat-shock proteins were examined using western blotting with antibodies for Class I and II cytoplasmic heat-shock proteins. Class I reacted with proteins from the exposed side of sun fruit and Class II with proteins from both sides of sun fruit. Thus, it is clear that preharvest exposure of fruit to the sun can result in a wide range of postharvest responses.

1995 ◽  
Vol 182 (3) ◽  
pp. 885-889 ◽  
Author(s):  
D Arnold ◽  
S Faath ◽  
H Rammensee ◽  
H Schild

Vaccination of mice with heat shock proteins isolated from tumor cells induces immunity to subsequent challenge with those tumor cells the heat shock protein was isolated from but not with other tumor cells (Udono, H., and P.K. Srivastava. 1994. J. Immunol. 152:5398-5403). The specificity of this immune response is caused by tumor-derived peptides bound to the heat shock proteins (Udono., H., and P.K. Srivastava. 1993. J. Exp. Med. 178:1391-1396). Our experiments show that a single immunization with the heat shock protein gp96 isolated from beta-galactosidase (beta-gal) expressing P815 cells (of DBA/2 origin) induces cytotoxic T lymphocytes (CTLs) specific for beta-gal, in addition to minor H antigens expressed by these cells. CTLs can be induced in mice that are major histocompatibility complex (MHC) identical to the gp96 donor cells (H-2d) as well as in mice with a different MHC (H-2b). Thus gp96 is able to induce "cross priming" (Matzinger, P., and M.J. Bevan. 1977. Cell. Immunol. 33:92-100), indicating that gp96-associated peptides are not limited to the MHC class I ligands of the gp96 donor cell. Our data confirm the notion that samples of all cellular antigens presentable by MHC class I molecules are represented by peptides associated with gp96 molecules of that cell, even if the fitting MHC molecule is not expressed. In addition, we extend previous reports on the in vivo immunogenicity of peptides associated gp96 molecules to two new groups of antigens, minor H antigens, and proteins expressed in the cytosol.


2013 ◽  
Vol 12 (5) ◽  
pp. 452-457 ◽  
Author(s):  
George A. Alexiou ◽  
George Vartholomatos ◽  
Kalliopi Stefanaki ◽  
Amalia Patereli ◽  
Lefkothea Dova ◽  
...  

Object Medulloblastoma (MB) is the most common malignant brain tumor in children. Heat shock proteins (HSPs) comprise a superfamily of proteins that serve as molecular chaperones and are overexpressed in a wide range of human cancers. The purpose of the present study was to investigate the expression of HSP27 (pSer82), HSP27 (pSer15), HSP40, HSP60, HSP70, HSP90-α, Akt, and phospho-Akt by multiplex bead array assay of MBs. The results of HSP and Akt expression were correlated with MB subtype; immunohistochemical expression of Ki-67 index, bcl-2, and p53; and patients' prognosis. Methods The authors retrospectively evaluated 25 children with MB who underwent surgery. Immunohistochemical analysis of Ki-67, p53, and bcl-2 expression was performed in all cases. By using multiplex bead array assay, a simultaneous detection of HSP27 (pSer82), HSP27 (pSer15), HSP40, HSP60, HSP70, HSP90-α, Akt, and phospho-Akt was performed. Results Medulloblastoma with extensive nodularity had significantly lower HSP27 (pSer15) expression (p = 0.039) but significantly higher HSP60 expression (p = 0.021) than classic MB. Large-cell MB had significantly higher HSP70 expression (p = 0.028) than classic MB. No significant difference was found between HSP27 (pSer82), HSP40, HSP90-α, Akt, or phospho-Akt expression and MB subtype. Large-cell MBs had significantly higher Ki-67 index compared with classic MBs (p = 0.033). When analyzing all MBs, there was a significant negative correlation between HSP27 (pSer15) and Ki-67 index (r = −0.475, p = 0.016); a significant positive correlation between HSP70 expression and Ki-67 index (r = 0.407, p = 0.043); and a significant positive correlation between HSP70 expression and bcl-2 index (r = 0.491, p = 0.023). Patients with large-cell MB had a worse survival than those with classic MB, but the difference did not reach statistical significance (p = 0.076). Conclusions A substantial expression of several HSPs in MB was observed. Given that HSPs represent an attractive strategy for anticancer therapy, further studies, involving larger series of patients, are obviously necessary to clarify the relationship of HSPs with tumor aggressiveness and prognosis.


2017 ◽  
Vol 373 (1738) ◽  
pp. 20160524 ◽  
Author(s):  
Stuart K. Calderwood

Heat shock proteins (HSPs) are found at elevated concentrations in tumour cells, and this increase reflects the proteotoxic stress experienced by the cells due to expanding levels of the mutated oncoproteins that drive tumorigenesis. The protection of oncogenic proteins by HSPs offers a window of vulnerability in tumour metabolism that has been exploited using Hsp90-targeting drugs. Such compounds have been shown to cause inhibition and degradation of a wide range of proteins essential for oncogenesis. Recently, Hsp90 has also been shown to be secreted by tumour cells and to interact in autocrine or paracrine manners with the surfaces of adjacent cells, leading to increased growth and metastasis. Future studies will address a number of key questions associated with these findings, including the relative importance of intracellular versus extracellular HSPs in tumorigenesis, as well as overcoming potential problems with normal tissue toxicity associated with Hsp90 drugs. Targeting individual members of HSP families and inactivating extracellular HSPs may be desirable future approaches that offer increased selectivity in targeting HSPs in cancer. This article is part of the theme issue ‘Heat shock proteins as modulators and therapeutic targets of chronic disease: an integrated perspective’.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 691c-691
Author(s):  
Robert E. Paull ◽  
Chris B. Watkins

Production of heat shock proteins (HSP) in response to high temperatures are a highly recognizable feature of plant and animal systems. It is thought that such proteins play a critical role in survival under supraoptimal temperature conditions. The use of heat treatments has been examined extensively, especially for disinfestation of fruit and disease control. Heat treatments can affect physiological responses, such as ethylene production, softening, and other ripening factors, as well as reducing physiological disorders, including chilling injury. HSPs have been implicated in a number of stress responses, but the extent that they are involved, especially in amelioration of chilling injury, is a subject of debate. In a number of cases, heat shock proteins do not appear to be involved, and HSPs do not explain long-term adaptation to heat; other systems for which we do not have models may be at work. Resolution of these issues may require the use of transgenic plants with modified heat shock responses.


2013 ◽  
Vol 153 (1) ◽  
pp. 7-24 ◽  
Author(s):  
M. S. AGHDAM ◽  
L. SEVILLANO ◽  
F. B. FLORES ◽  
S. BODBODAK

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.


Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 247
Author(s):  
Miriam Buttacavoli ◽  
Gianluca Di Cara ◽  
Cesare D’Amico ◽  
Fabiana Geraci ◽  
Ida Pucci-Minafra ◽  
...  

Heat shock proteins (HSPs) are a well-characterized molecular chaperones protein family, classified into six major families, according to their molecular size. A wide range of tumors have been shown to express atypical levels of one or more HSPs, suggesting that they could be used as biomarkers. However, the collective role and the possible coordination of HSP members, as well as the prognostic significance and the functional implications of their deregulated expression in breast cancer (BC) are poorly investigated. Here, we used a systematic multi-omics approach to assess the HSPs expression, the prognostic value, and the underlying mechanisms of tumorigenesis in BC. By using data mining, we showed that several HSPs were deregulated in BC and significantly correlated with a poor or good prognosis. Functional network analysis of HSPs co-expressed genes and miRNAs highlighted their regulatory effects on several biological pathways involved in cancer progression. In particular, these pathways concerned cell cycle and DNA replication for the HSPs co-expressed genes, and miRNAs up-regulated in poor prognosis and Epithelial to Mesenchymal Transition (ETM), as well as receptors-mediated signaling for the HSPs co-expressed genes up-regulated in good prognosis. Furthermore, the proteomic expression of HSPs in a large sample-set of breast cancer tissues revealed much more complexity in their roles in BC and showed that their expression is quite variable among patients and confined into different cellular compartments. In conclusion, integrative analysis of multi-omics data revealed the distinct impact of several HSPs members in BC progression and indicate that collectively they could be useful as biomarkers and therapeutic targets for BC management.


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