Electrolyte Leakage Induced by Chilling in Passiflora Species Tolerant to Different Climates

1976 ◽  
Vol 3 (4) ◽  
pp. 435 ◽  
Author(s):  
BD Patterson ◽  
T Murata ◽  
D Graham
Keyword(s):  
Electrolyte Leakage ◽  
Slow Rate ◽  
Time Course ◽  
Gradual Increase ◽  
Chilling Injury ◽  
High Rate ◽  
Chilling Sensitivity ◽  
Stage 1 ◽  
Tropical Lowlands ◽  
Different Climates

A method was devised to measure chilling sensitivity in a series of species and hybrids of Passiflora having a range of climatic requirements. Leaves from plants which had been grown under 25°C day/18°C night were chilled at 0°C in the dark. At the same time, leakage of electrolyte from thin strips of these leaves was measured at 0°C using conductivity. Two main stages of leakage were found: a relatively slow rate (stage 1) which was followed by a high rate (stage 2), during which most of the electrolyte was lost from the tissue. Potassium was the principal cation lost from the tissue, and its leakage was proportional to that of total electrolyte during the time course of leakage. Stage 2 occurred at about the same time as obvious lesions appeared on whole leaves, and apparently signified lethal chilling injury. When different species were compared, those which had originated from the tropical lowlands (P. maliformis L. and P. edulis Sims forma flavicarpa Degener) were killed in less than 10 days, but those tolerant of cooler climates (P. caerulea L. and P. edulis Sims) survived much longer. From the behaviour of a number of species and hybrids, the rate of leakage during stage 1 was related to the time taken to reach stage 2. Resistance to chilling in the species and hybrids examined was not an all-or-nothing property, but showed a gradual increase in the series: P. edulis forma flavicarpa < P. maliformis < P. cincinnata Masters < P. edulis < P. caerulea, with some hybrids occupying intermediate positions.

scholarly journals CULTIVAR RESPONSE OF OKRA TO CHILLING AND PACKAGING

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 854c-854
Author(s):  
P. Perkins-Veazie ◽  
J. K. Collins
Keyword(s):  
Weight Loss ◽  
Membrane Permeability ◽  
Respiration Rate ◽  
Electrolyte Leakage ◽  
Storage Temperature ◽  
Chilling Injury ◽  
Chilling Sensitivity ◽  
High Respiration Rate ◽  
And Storage

Okra pods are highly perishable due to a high respiration rate and chilling sensitivity. The purpose of this experiment was to evaluate okra cultivar response to package and storage temperature. Freshly harvested `Annie Oakley', `Blondy', `Burgundy', `Clemson Spineless' and `Emerald' okra pods were placed in plastic boxes and shrink-wrap bags. Pods were evaluated for weight loss, chilling injury and electrolyte leakage during 8 days of storage at 12.5 and 3°C. Weight loss was similar for all cultivars at both temperatures, but it was much less when pods were stored in bags compared to boxes. Percent electrolyte leakage was similar for all cultivars before storage. `Blondy' displayed the most severe chilling injury after 8 days of storage at 3C while `Emerald' had few symptoms of chilling injury. After 8 days of storage, all cultivars except `Emerald' had increased electrolyte leakage. These results indicate that okra pods have increased membrane permeability with chilling injury, and the degree of chilling injury may differ with cultivar.

Fast-phase transvascular fluid flux and the Fahraeus effect

1987 ◽  
Vol 62 (4) ◽  
pp. 1513-1520 ◽  
Author(s):  
W. N. Richardson ◽  
D. Bilan ◽  
M. Hoppensack ◽  
L. Oppenheimer
Keyword(s):  
Mechanical Properties ◽  
Slow Rate ◽  
Time Course ◽  
Rate Of Change ◽  
Distributed Model ◽  
Slow Phase ◽  
Fluid Flux ◽  
Fast Phase ◽  
Constant Rate ◽  
Fahraeus Effect

Transvascular fluid flux was induced in six isolated blood-perfused canine lobes by increasing and decreasing hydrostatic inflow pressure (Pi). Fluid flux was followed against the change in concentration of an impermeable tracer (Blue Dextran) measured directly with a colorimetric device. The time course of fluid flux was biphasic with an initial fast transient followed by a slow phase. Hematocrit changes unrelated to fluid flux occurred due to the Fahraeus effect, and their contribution to the total color signal was subtracted to determine the rate of fast fluid flux (Qf). Qf was related to Pi to derive fast-phase conductance (Kf). Slow-phase Kf was calculated from the constant rate of change of lobe weight. For a mean change in Pi of 7 cmH2O, 40% of the color signal was due to fluid flux. Fast- and slow-phase Kf's were 0.86 +/- 0.15 and 0.27 +/- 0.05 ml X min-1. cmH2O–1 X 100 g dry wt-1. The fast-phase Kf is smaller than that reported for plasma-perfused lobes. Possible explanations discussed are the nature of the perfusate, the mechanical properties of the interstitium, and the slow rate of rise of the driving pressure at the filtration site on the basis of a distributed model of pulmonary vascular compliance.

scholarly journals Features of immunopathogenesis of atopic dermatitis

2020 ◽  
Vol 17 (2) ◽  
pp. 74-80
Author(s):  
Olga O. Pobezhimova ◽  
Alexsander V. Zhestkov ◽  
Olga S. Sidorova ◽  
Vera V. Kulagina
Keyword(s):  
Early Childhood ◽  
Atopic Dermatitis ◽  
Immune Cells ◽  
Gradual Increase ◽  
Allergic Diseases ◽  
High Rate ◽  
Skin Disorders ◽  
Traditional Therapies ◽  
Genetically Determined ◽  
Chronic Course

Atopic dermatitis is one of the most common allergic diseases with severe course, which affects the skin. This disease is genetically determined and has a chronic course. Atopic dermatitis is also one of the commonest diseases (between 20% and 40% of all skin disorders) and affects patients of both sexes across the globe. Such high rate of morbidity, onset in early childhood, often continuous relapsing course and a trend toward gradual increase of tolerance to traditional therapies makes the issue of detalization of pathogenesis of atopic dermatitis particularly topical. Immune cells play one of the major roles in the pathogenesis of atopic dermatitis. This article will systematically review the main available to date information on participation immune cells in the pathogenesis of atopic dermatitis.

Quantitative aspects of RNA synthesis and polyadenylation in 1-cell and 2-cell mouse embryos

Development ◽  
1983 ◽  
Vol 74 (1) ◽  
pp. 169-182
Author(s):  
Kerry B. Clegg ◽  
Lajos Pikó
Keyword(s):  
Time Course ◽  
Specific Activity ◽  
Average Length ◽  
State Level ◽  
Mouse Embryos ◽  
High Rate ◽  
Rna Sequences ◽  
Cell Stage ◽  
New Synthesis ◽  
Cell Embryo

Mouse embryos at the late 1-cell and late 2-cell stages were labelled with [3H]adenosine for periods of up to 320 min during which the specific activity of the ATP pool was constant. The time course of the molar accumulation of adenosine was calculated for tRNA, high-molecular-weight poly(A)− RNA and poly(A) tails versus internal regions of poly(A)+ RNA. Most of the adenosine incorporation into tRNA is due to turnover of the 3′-terminal AMP but some new synthesis of tRNA also appears to take place in both 1-cell and 2-cell embryos at a rate of about 0·2 pg/embryo/h. In the poly(A)- RNA fraction, an unstable component which is assumed to be heterogeneous nuclear RNA is synthesized at a high rate and accumulates at a steady-state level of about 1·5 pg/embryo in the 1-cell embryo and about 3·0 pg/embryo in the 2-cell embryo. Both 1-cell and 2-cell embryos synthesize relatively stable heterogeneous poly(A)− RNA, assumed to be mRNA, at a rate of about 0·3 pg/embryo/h; 2-cell embryos also synthesize mature ribosomal RNA at a rate of about 0·4 pg/embryo·h. Internally labelled poly(A)+ RNA is synthesized at a low rate in the 1-cell embryo, about 0·045 pg/embryo/h, but the rate increases to about 0·2 pg/embryo/h by the 2-cell stage. A striking feature of the 1-cell embryo is the high rate of synthesis of poly(A) tails, about 2·5 × 106 tails/embryo/h of an average length of (A)43, due almost entirely to cytoplasmic polyadenylation. This and other evidence suggests a turnover of the poly(A)+ RNA population in 1-cell embryos as a result of polyadenylation of new RNA sequences and degradation of some of the pre-existing poly(A)+ RNA. In the 2-cell embryo, the rate of synthesis of poly(A) tails (average length (A)93) is estimated at about 0·8 × 106tails/embryo/h and a significant fraction of poly(A) synthesis appears to be nuclear.

scholarly journals Proteolytic processing of potyviral proteins and polyprotein processing intermediates in insect and plant cells

2002 ◽  
Vol 83 (5) ◽  
pp. 1211-1221 ◽  
Author(s):  
Andres Merits ◽  
Minna-Liisa Rajamäki ◽  
Päivi Lindholm ◽  
Pia Runeberg-Roos ◽  
Tuija Kekarainen ◽  
...  
Keyword(s):  
Virus Replication ◽  
Time Course ◽  
Infected Plant ◽  
Plant Cells ◽  
Proteolytic Processing ◽  
High Rate ◽  
Detectable Effect ◽  
Virus Infectivity ◽  
Polyprotein Processing ◽  
Baculovirus System

Processing of the polyprotein encoded by Potato virus A (PVA; genus Potyvirus) was studied using expression of the complete PVA polyprotein or its mutants from recombinant baculoviruses in insect cells. The time-course of polyprotein processing by the main viral proteinase (NIaPro) was examined with the pulse–chase method. The sites at the P3/6K1, CI-6K2 and VPg/NIaPro junctions were processed slowly, in contrast to other proteolytic cleavage sites which were processed at a high rate. The CI-6K2 polyprotein was observed in the baculovirus system and in infected plant cells. In both cell types the majority of CI-6K2 was found in the membrane fraction, in contrast to fully processed CI. Deletion of the genomic region encoding the 6K1 protein prevented proper proteolytic separation of P3 from CI, but did not affect processing of VPg, NIaPro, NIb or CP from the polyprotein. The 6K2-encoding sequence could be removed without any detectable effect on polyprotein processing. However, deletion of either the 6K1 or 6K2 protein-encoding regions rendered PVA non-infectious. Mutations at the 6K2/VPg cleavage site reduced virus infectivity in plants, but had a less pronounced, albeit detectable, effect on proteolytic processing in the baculovirus system. The results of this study indicate that NIaPro catalyses proteolytic cleavages preferentially in cis, and that the 6K1/CI and NIb/CP sites can also be processed in trans. Both 6K peptides are indispensable for virus replication, and proteolytic separation of the 6K2 protein from the adjacent proteins by NIaPro is important for the rate of virus replication and movement.

CHILLING INJURY AND ELECTROLYTE LEAKAGE IN COLD STORED MANGO AND AVOCADO FRUITS

1989 ◽  
pp. 303-308 ◽  
Author(s):  
Y. Fuchs ◽  
G. Zauberman ◽  
I. Rot ◽  
A. Weksler
Keyword(s):  
Electrolyte Leakage ◽  
Chilling Injury

Photoinhibition at Chilling Temperatures

1988 ◽  
Vol 15 (2) ◽  
pp. 207 ◽  
Author(s):  
RM Smillie ◽  
SE Hetherington ◽  
J He ◽  
R Nott
Keyword(s):  
Low Temperatures ◽  
Chilling Injury ◽  
Leaf Tissue ◽  
Pigeon Pea ◽  
Tropical Fruit ◽  
Fruit Species ◽  
Wide Range ◽  
Chilling Sensitivity ◽  
Chilling Temperatures ◽  
Warm Temperate

Relative susceptibilities of chilled leaves to photoinhibition were determined for 15 species of crop annuals showing a wide range of chilling tolerance. Leaf tissue at 7°C was exposed to a moderate photon irradiance of 300 �mol m-2 s-1 and photoinhibition was measured by the decrease in chlorophyll fluorescence (Fv/Fm) measured at 77K. All chilling-resistant plants surveyed (barley, broad bean, oat, pea and wheat) were photoinhibited at chilling temperatures. The chilling-sensitive plants (bean, cucumber, lablab, maize, pearl millet, pigeon pea, sesame, sorghum and tomato) were more susceptible, the mean of values for susceptibility to photoinhibition being twice that of the chilling-resistant plants. Rice, however, showed a tolerance to photoinhibition at 7°C comparable to that of some of the chilling- resistant plants. Indica rices were more susceptible than japonica rices. Photoinhibition increased with decreasing temperature and with increasing photon irradiance in both the chilling-resistant and sensitive plants. In pea and cucumber, photoinhibition at 7°C was correlated linearly with the decrease in photosystem II activity assayed in chloroplast thylakoids isolated from similarly treated tissue. Relative tolerances of leaves of the same 15 species to chilling injury in the dark were also measured. No linear correlation was found between susceptibility of chilled leaves to photoinhibition and susceptibility to dark chilling injury. The pattern of differences between species for photoinhibition at 7°C was largely preserved when photoinhibitory treatments were given at a non-chilling temperature (21°C) by increasing the photon irradiance to 900 �mol m-2 s-1. We conclude that, while the chilling-sensitive plants were generally more susceptible than the chilling-resistant ones to photoinhibition at low temperatures, this arose from a greater sensitivity to the irradiance rather than from the chilling sensitivity. Photoinhibition associated with low temperatures was also demonstrated in the tropical fruit species, banana, pawpaw and Monstera. Low values of Fv/Fm recorded in leaves exposed to full sunlight during the winter month of July (range 0.39-0.56 compared with 0.70-0.79 in January) indicated that photoinhibition could adversely affect some tropical perennial fruit species cultivated in semitropical or warm temperate areas experiencing recurrent cool to cold winters.

scholarly journals AMELIORATION OF CHILLING INJURY IN PHASEOLUS VULGARIS BY GLK-8903.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 657b-657
Author(s):  
Agnes A. Flores-Nimedez ◽  
Paul H. Li ◽  
Charles C. Shin
Keyword(s):  
Plasma Membrane ◽  
Electrolyte Leakage ◽  
Stress Condition ◽  
Chilling Injury ◽  
Plasma Membrane Atpase ◽  
Protection Mechanism ◽  
Bean Plants ◽  
Membrane Atpase ◽  
Application Potential ◽  
High Application

Protection mechanism of a new compound, coded as GLK-8903, from chilling injury in bean plants was assessed by measuring several physiological parameters. The decline in leaf water potential caused by the chilling exposure to 4°C (day/night) was minimized when GLK-8903 was applied to the plants as compared to the non-treated control. Chilling causes an increase in electrolyte leakage, an indication of chilling injury that occurs at the site of plasma membrane. An increased electrolyte leakage was reduced in the GLK-8903-treated plants during chilling. Data from plasmolysis and deplasmolysis studies of epidermal cells suggest that GLK-8903 is able to stabilize the plasma membrane under stress condition by determining the permeability coefficients plasmometrically (1.96 cm s-1 × 10-4 for GLK-8903-treated plants vs. 4.00 for the controls 3 d at 4°C) with less decreased activity of the plasma membrane ATPase (9.36 μmol ATP.mg chl-1·h-1 for GLK-8903-treated plants vs. 5.04 for the controls 3 d at 4°C). GLK-8903 appears to have high application potential in protecting bean plants from chilling injury with improved yield.

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 Bell Pepper (Capsicum annuum L.) Fruits are Susceptible to Chilling Injury at the Breaker Stage of Ripeness

HortScience ◽  
2007 ◽  
Vol 42 (7) ◽  
pp. 1659-1664 ◽  
Author(s):  
Chae Shin Lim ◽  
Seong Mo Kang ◽  
Jeoung Lai Cho ◽  
Kenneth C. Gross ◽  
Allan B. Woolf
Keyword(s):  
Capsicum Annuum ◽  
Water Loss ◽  
Ethylene Production ◽  
Electrolyte Leakage ◽  
Color Change ◽  
Chilling Injury ◽  
Bell Pepper ◽  
Low Temperature Storage ◽  
Bell Peppers ◽  
Temperature Storage

To study ripening-related chilling injury (CI) of bell pepper (Capsicum annuum L.), fruit at mature green, breaker, and red-ripe stages were stored at 1, 5, 7, and 10 °C for 4 weeks. Surface pitting was evaluated after storage at 1 °C for 2 weeks followed by a 2-day exposure to room temperature (20 °C). Exposing fruit to 1 °C enhanced water loss, respiration, ethylene production, and electrolyte leakage, but slowed color change. Weight loss, respiration, ethylene production, electrolyte leakage, and color change increased more in breaker than in mature green and red-ripe fruit. No pitting symptom was observed at temperatures of 5 to 10 °C. After storing peppers at 1 °C for 2 weeks, breaker stage fruit exhibited chilling symptoms of severe surface pitting with more sheet pitting and deeper peel depression. Mature green fruit showed only moderate pitting. However, red-ripe peppers showed no injury and cells showed a normal appearance after low-temperature storage (1 °C). These results show that bell peppers tended to be more susceptible to chilling temperature while at the breaker stage and that the increase in visible CI is correlated with increased water loss, respiration, ethylene production, electrolyte leakage, and color change during storage.

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