Short‐term hypobaric treatment enhances chilling tolerance in peaches

Author(s):  
Xuedan zhang ◽  
Li Xin ◽  
Chao Wang ◽  
Shan Sun ◽  
Yanhui Lyu
2014 ◽  
Vol 26 (2) ◽  
pp. 109-115
Author(s):  
Krzysztof Górnik

ABSTRACT The aim of the present study was to improve the chilling tolerance of cucumber seedlings. The conditioned seeds in solutions of salicylic or jasmonic acid in concentrations of 10-2, 10-3 or 10-4 M or brassinolide in concentrations of 10-6, 10-8 or 10-10 M were subjected to temperature shock of 0, 2.5, 5, 35, 40 or 45°C for 1, 2 or 4 hours. Seedlings with 3 mm roots were chilled at 0°C for three days. The chilling susceptibility was evaluated by measurements of roots lengths, electrolyte leakage and total dehydrogenase activity. The obtained results indicated that cucumber tolerance to chilling conditions depended on the plant growth regulators used during seed imbibition and its concentration as well as the temperature initiating thermal shock and its duration. The highest tolerance to chilling, expressed by the subsequent growth of roots, was observed after seed conditioning in salicylic acid solutions in a concentration of 10-4 M for 16 h at 25°C, then exposed for 4 h to a shock temperature of 5°C. The length of seedling roots after such treatment was over 12 times longer than the control (imbibed in distilled water and not subjected to short-term temperature impact). An increased chilling tolerance of cucumber seedlings may result from enhanced membrane integrity and total dehydrogenase activity. Further research is needed to explain the mechanism of the positive effects of salicylic acid, jasmonic acid or brassinolide application to reduce the injurious effects of chilling on cucumber seedlings.


2015 ◽  
Vol 71 (1) ◽  
pp. 3-11
Author(s):  
Krzysztof Górnik

AbstractThe aim of the research was to investigate the chilling sensitivity of cucumber seedlings and to alleviate its negative effects by short-term shock temperature applied during seeds imbibition, before radicle protrusion. The chilling sensitivity was investigated depending on initial root length (1, 3, 5 and 7 mm) and duration of chilling exposure (0, 1, 3, 7, 14, 21 days) at 0°C and was evaluated by measurements of roots and hypocotyls growth, electrolyte leakage and dehydrogenases activity. To assess whether short-term shock temperature applied before radicle protrusion can increase chilling tolerance in cucumber seedlings the seeds were imbibed at 25°C for 16 h, exposed to temperatures of 0; 2,5; 5; 35; 40, 45°C for 0; 0,5; 1; 2; 4 h.The obtained results indicated that cucumber seedlings sensitivity depended on duration of chilling expo-sure and initial root length during which the seedlings were subjected to these conditions. Chilling sensitivity were manifested by drop in the roots and hypocotyls elongation, reduction in dehydrogenases activity and membrane integrity expressed by electrolyte leakage. Seedlings with 1 mm roots was relatively tolerant to 3 days of chilling at 0°C. Their chilling sensitivity increased as roots elongated. Seedling with 3, 5, 7 mm of roots subjected to chilling suffered a subsequent 71, 75 and 81% of growth inhibition, respectively.The presented results showed that a short-term of low (0; 2,5 or 5°C) or high (35; 40 or 45°C) temperature treatments applied before radicle protrusion i.e. after 16 h of seeds imbibition significantly counteracted the negative effects of chilling on seedlings. The best results expressed by increased length and the number of roots were obtained when imbibed seeds were exposed to 45°C for 2 and 4 h. The increased chilling tolerance of cucumber seedlings induced as early as at the stage of seed imbibition, before radicle protrusion indicates on the possibility of application of this method in practice. The positive response of such treatment on cucumber chilling tolerance are discussed.


2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.


Author(s):  
M. O. Magnusson ◽  
D. G. Osborne ◽  
T. Shimoji ◽  
W. S. Kiser ◽  
W. A. Hawk

Short term experimental and clinical preservation of kidneys is presently best accomplished by hypothermic continuous pulsatile perfusion with cryoprecipitated and millipore filtered plasma. This study was undertaken to observe ultrastructural changes occurring during 24-hour preservation using the above mentioned method.A kidney was removed through a midline incision from healthy mongrel dogs under pentobarbital anesthesia. The kidneys were flushed immediately after removal with chilled electrolyte solution and placed on a LI-400 preservation system and perfused at 8-10°C. Serial kidney biopsies were obtained at 0-½-1-2-4-8-16 and 24 hours of preservation. All biopsies were prepared for electron microscopy. At the end of the preservation period the kidneys were autografted.


Author(s):  
D.N. Collins ◽  
J.N. Turner ◽  
K.O. Brosch ◽  
R.F. Seegal

Polychlorinated biphenyls (PCBs) are a ubiquitous class of environmental pollutants with toxic and hepatocellular effects, including accumulation of fat, proliferated smooth endoplasmic recticulum (SER), and concentric membrane arrays (CMAs) (1-3). The CMAs appear to be a membrane storage and degeneration organelle composed of a large number of concentric membrane layers usually surrounding one or more lipid droplets often with internalized membrane fragments (3). The present study documents liver alteration after a short term single dose exposure to PCBs with high chlorine content, and correlates them with reported animal weights and central nervous system (CNS) measures. In the brain PCB congeners were concentrated in particular regions (4) while catecholamine concentrations were decreased (4-6). Urinary levels of homovanillic acid a dopamine metabolite were evaluated (7).Wistar rats were gavaged with corn oil (6 controls), or with a 1:1 mixture of Aroclor 1254 and 1260 in corn oil at 500 or 1000 mg total PCB/kg (6 at each level).


Author(s):  
S.S. Poolsawat ◽  
C.A. Huerta ◽  
S.TY. Lae ◽  
G.A. Miranda

Introduction. Experimental induction of altered histology by chemical toxins is of particular importance if its outcome resembles histopathological phenomena. Hepatotoxic drugs and chemicals are agents that can be converted by the liver into various metabolites which consequently evoke toxic responses. Very often, these drugs are intentionally administered to resolve an illness unrelated to liver function. Because of hepatic detoxification, the resulting metabolites are suggested to be integrated into the macromolecular processes of liver function and cause an array of cellular and tissue alterations, such as increased cytoplasmic lysis, centrilobular and localized necroses, chronic inflammation and “foam cell” proliferation of the hepatic sinusoids (1-4).Most experimentally drug-induced toxicity studies have concentrated primarily on the hepatic response, frequently overlooking other physiological phenomena which are directly related to liver function. Categorically, many studies have been short-term effect investigations which seldom have followed up the complications to other tissues and organs when the liver has failed to function normally.


Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.


2008 ◽  
Vol 45 ◽  
pp. 147-160 ◽  
Author(s):  
Jörg Schaber ◽  
Edda Klipp

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.


1999 ◽  
Vol 97 (3) ◽  
pp. 319 ◽  
Author(s):  
D.A. DUPREZ ◽  
M.L. DE BUYZERE ◽  
B. DRIEGHE ◽  
F. VANHAVERBEKE ◽  
Y. TAES ◽  
...  

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