scholarly journals 992 STRESS TOLERANCE INDUCTION: THE ROLE OF ABA AND HEAT STABLE PROTEINS

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 571c-571
Author(s):  
L. V. Gusta

Plants acclimate to abiotic stresses, e.g. heat, freezing drought and salinity, in response to environmental cues such as temperature, daylength and water. Plants can respond within minutes to the cue e.g. heat tolerance or within hours or days, e.g. drought and freezing tolerance. Heat shock proteins are measurable within 20 to 30 minutes of a heat stress and the plants aclimate almost immediately. In contrast, proteins related to freezing tolerance are measurable within hours but days are required before a measurable increase in freezing tolerance can be detected. In almost all stresses it appears that the environmental cue effects the water status of the plant which in turn affects the level of endogenous abscisic acid (ABA). ABA has been implicated to ameliorate the stress by inducing genes to produce stress proteins. There is a certain degree of commodity between stresses in ragards to stress proteins, however each stress has their own unique set of stress proteins. For example heat shock proteins did not confer stress tolerance. Proteins involved in water and osmotic stress tolerance share a high degree of commonality. I” all stresses a unique class of proteins are synthesized which are classified as heat or boiling stable (do not coagulate at 100°). These proteins are suggested to be involved in the stress response. Many of these heat stable proteins are induced by ABA alone or in combination with jasmonic acid (JA). Analogs of ABA which are either slowly converted to ABA or are degraded slowly or taken up at a faster rate than ABA have been tested for the efficacy in inducing the stress responses. Analogs have also been identified which inhibit the ABA induced response. How these analogs may have practical significance will be discussed.

Parasitology ◽  
2001 ◽  
Vol 122 (5) ◽  
pp. 583-588 ◽  
Author(s):  
L. VARGAS-PARADA ◽  
C. F. SOLÍS ◽  
J. P. LACLETTE

Heat shock and stress responses are documented for the first time in larval stages of the cestodes Taenia solium and Taenia crassiceps. Radioactive metabolic labelling after in vitro incubation of cysts at 43 °C, revealed the induction of heat shock proteins. In T. crassiceps, the major heat shock proteins were 80, 70 and 60 kDa. After prolonged incubation, a set of low molecular weight heat shock proteins (27, 31, 33 and 38 kDa), were also induced. In vitro incubation of cysts at 4 °C, induced the synthesis of stress proteins ranging from 31 to 80 kDa, indicating the parasite is also able to respond to cold shock. T. solium cysts exposure to temperature stress also resulted in an increased synthesis of 2 major heat shock proteins of 80 and 70 kDa. Western blots using the excretory–secretory products of T. solium showed that 2 heat shock proteins were recognized by antibodies in the sera of cysticercotic patients: one of 66 kDa and another migrating close to the run front. The T. solium 66 kDa protein was also recognized by specific antibodies directed to a 60 kDa bacterial heat shock protein, suggesting that it belongs to this family of proteins.


2002 ◽  
Vol 92 (5) ◽  
pp. 2177-2186 ◽  
Author(s):  
Kevin C. Kregel

Cells from virtually all organisms respond to a variety of stresses by the rapid synthesis of a highly conserved set of polypeptides termed heat shock proteins (HSPs). The precise functions of HSPs are unknown, but there is considerable evidence that these stress proteins are essential for survival at both normal and elevated temperatures. HSPs also appear to play a critical role in the development of thermotolerance and protection from cellular damage associated with stresses such as ischemia, cytokines, and energy depletion. These observations suggest that HSPs play an important role in both normal cellular homeostasis and the stress response. This mini-review examines recent evidence and hypotheses suggesting that the HSPs may be important modifying factors in cellular responses to a variety of physiologically relevant conditions such as hyperthermia, exercise, oxidative stress, metabolic challenge, and aging.


2019 ◽  
Vol 20 (21) ◽  
pp. 5321 ◽  
Author(s):  
ul Haq ◽  
Khan ◽  
Ali ◽  
Khattak ◽  
Gai ◽  
...  

Due to the present scenario of climate change, plants have to evolve strategies to survive and perform under a plethora of biotic and abiotic stresses, which restrict plant productivity. Maintenance of plant protein functional conformation and preventing non-native proteins from aggregation, which leads to metabolic disruption, are of prime importance. Plant heat shock proteins (HSPs), as chaperones, play a pivotal role in conferring biotic and abiotic stress tolerance. Moreover, HSP also enhances membrane stability and detoxifies the reactive oxygen species (ROS) by positively regulating the antioxidant enzymes system. Additionally, it uses ROS as a signal to molecules to induce HSP production. HSP also enhances plant immunity by the accumulation and stability of pathogenesis-related (PR) proteins under various biotic stresses. Thus, to unravel the entire plant defense system, the role of HSPs are discussed with a special focus on plant response to biotic and abiotic stresses, which will be helpful in the development of stress tolerance in plant crops.


2003 ◽  
Vol 66 (11) ◽  
pp. 2045-2050 ◽  
Author(s):  
YI ZHANG ◽  
MANSEL W. GRIFFITHS

Heat shock proteins play an important role in protecting bacterial cells against several stresses, including starvation. In this study, the promoters for two genes encoding heat shock proteins involved in many stress responses, UspA and GrpE, were fused with the green fluorescent protein (gfp) gene. Thus, the expression of the two genes could be quantified by measuring the fluorescence emitted by the cells under different environmental conditions. The heat resistance levels of starved and nonstarved cells during storage at 5, 10, and 37°C were compared with the levels of expression of the uspA and grpE genes. D52-values (times required for decimal reductions in count at 52°C) increased by 11.5, 14.6, and 18.5 min when cells were starved for 3 h at 37°C, for 24 h at 10°C, and for 2 days at 5°C, respectively. In all cases, these increases were significant (P < 0.01), indicating that the stress imposed by starvation altered the ability of E. coli O157:H7 to survive subsequent heat treatments. Thermal tolerance was correlative with the induction of UspA and GrpE. At 5°C, the change in the thermal tolerance of the pathogen was positively linked to the induced expression of the grpE gene but negatively related to the expression of the uspA gene. The results obtained in this study indicate that UspA plays an important role in starvation-induced thermal tolerance at 37°C but that GrpE may be more involved in regulating this response at lower temperatures. An improvement in our understanding of the molecular mechanisms involved in these cross-protection responses may make it possible to devise strategies to limit their effects.


Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 940-943 ◽  
Author(s):  
Daryl J. Somers ◽  
Randal W. Giroux ◽  
W. Gary Filion

Opuntia ficus indica roots grown hydroponically at 20 or 30 °C were subjected to a range of heat-shock temperatures as high as 50 °C for 2 h. Roots grown at 30 °C sustained a greater level of total protein synthesis than did 20 °C-grown roots following heat-shock treatments ≥ 45 °C. The 30 °C-grown roots synthesized 31 families of heat-shock proteins between 38 and 47 °C in comparison with 20 °C-grown roots, which synthesized 19 families of heat-shock proteins at 45 °C. In both groups of roots, the heat-shock response was dominated equally by the 71–75 and a 62 kDa heat-shock protein families. In addition, the 20 °C-grown roots expressed 11 families of cold-shock proteins following 2 h at 4 °C, five of which had similar relative molecular masses to heat-shock protein families. There were numerous qualitative differences in the heat shock protein profiles between the roots grown at 20 and 30 °C; the 30 °C-grown roots expressed several unique heat shock protein families.Key words: heat-shock protein(s), cactus, thermal stress, acclimation.


Sign in / Sign up

Export Citation Format

Share Document