scholarly journals Heat Shocks Reduce Chilling Sensitivity of Cotton, Kenaf, Okra, and Rice Seedling Radicles

2000 ◽  
Vol 125 (3) ◽  
pp. 377-382 ◽  
Author(s):  
Mary E. Mangrich ◽  
Mikal E. Saltveit
Keyword(s):  
Heat Shock ◽  
Chilling Injury ◽  
Rice Seedling ◽  
Hibiscus Cannabinus ◽  
Wheat Seedlings ◽  
Chilling Sensitivity ◽  
Heat Shocks ◽  
Chilling Temperatures ◽  
Hibiscus Esculentus ◽  
Triticum Sativum

Seeds of cotton (Gossypium hirsutum L.), kenaf (Hibiscus cannabinus L.), okra [Abelmoschus esculentus (L.) Moench. `Clemson Spineless' (syn. Hibiscus esculentus L.)], rice (Oryza sativa L.), and wheat (Triticum sativum (L.) Lam.) were germinated and grown at 25 °C until their radicles reached 10 mm in length. They were then exposed to chilling temperatures for 0 to 5 days followed by 3 days at 25 °C. Radicle length was measured periodically and inhibition of elongation was used as an indicator of the severity of chilling injury. Exposure to chilling reduced radicle elongation in all species except chilling insensitive wheat. When seedlings were heat-shocked at 45 °C for 1 to 12 min before being chilled, radicles of the chilling sensitive okra, kenaf, cotton, and rice seedlings elongated more than seedlings not heat-shocked before chilling. The method of heat-shock application and the stringency (i.e., time× temperature) of the heat-shock and chilling treatments all affected the response of the tissue. In comparison to nonheat-shocked wheat seedlings, the radicles of chilling insensitive wheat seedlings did not elongate more than seedlings in which the heat shocks were applied before chilling. A brief heat shock ameliorates chilling injury in these chilling sensitive species.

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 Heat-shock-induced Chilling Tolerance in Malvaceous Seedlings

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 601b-601
Author(s):  
M.E. Mangrich ◽  
M.E. Saltveit
Keyword(s):  
Heat Shock ◽  
Chilling Injury ◽  
Chilling Tolerance ◽  
Heat Treatments ◽  
Sensitive Species ◽  
Immersion Method ◽  
Heated Water ◽  
Chilling Sensitivity ◽  
Heat Shocks ◽  
The Tropics

Crops indigenous to the tropics and subtropics and some temperate crops suffer physiological injury when exposed to temperatures <12°C. Heat shock has induced chilling tolerance in a number of sensitive species (e.g., corn, cucumber, and tomato), but not in okra. To study this anomaly, we investigated the chilling sensitivity and heat shock response of a variety of Malvaceous species (i.e., cotton, hibiscus, kenaf, and okra). Seedlings with 8- to 12-mm long radicles were exposed to heat shock temperatures of 40 to 45°C for 2 to 12 minutes. Heat shocks were applied by two methods, floating the seeds in petri dishes on heated water and immersing the seeds in the heated water. The seedlings were held at 20°C for 2 hours after the heat treatments and then chilled at 2.5°C for 3 days. After chilling, seedlings were placed at 25°C for 3 additional days. The growth at 25°C was used as an assessment of chilling injury. Although there was a great deal of variability among the seedlings, a significant number of the okra and kenaf seedlings were more tolerant to chilling after heat shock: (i.e., more growth subsequent to chilling) compared to nonheat-shocked controls. More chilling tolerance was induced by the floating method than the immersion method. The response of cotton seedlings to heat-shock was variable, and the seedlings appeared damaged by even slight heat treatments (i.e., 4 minutes at 40°C). The variability in the capacity of heat-shocks to induce chilling tolerance in seedlings of Malvaceous species will be discussed.

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 Aglaonema Cultivars Differ in Resistance to Chilling Temperatures

2001 ◽  
Vol 19 (4) ◽  
pp. 198-202
Author(s):  
Jianjun Chen ◽  
Richard W. Henley ◽  
Richard J. Henny ◽  
Russell D. Caldwell ◽  
Cynthia A. Robinson
Keyword(s):  
Genetic Variation ◽  
Chilling Injury ◽  
Visible Injury ◽  
Ornamental Foliage Plants ◽  
Chilling Sensitivity ◽  
Young Leaves ◽  
Chilling Temperatures ◽  
Chilling Response ◽  
High Degree ◽  
New Cultivars

Abstract Aglaonema is considered one of the most chilling sensitive tropical ornamental foliage plants. However, information on resistance of the ever-increasing number of new cultivars to chilling temperatures is not available. In this study, the chilling response of 12 Aglaonema cultivars was evaluated after exposure to 1.7, 7.2, or 12.8C (35, 45, or 55F) for 24 hours. Results showed that a high degree of genetic variation existed among the cultivars. The cultivar ‘Silver Queen’ demonstrated the greatest sensitivity to chilling with 30% of leaves injured at 12.8C (55F). In contrast, three new cultivars, ‘Emerald Star’, ‘Stars’, and ‘Jewel of India’, were the most resistant, each showing no visible injury at 1.7C (35F). Data also indicated that chilling injury to young leaves was much less pronounced than in either mature or old leaves. Additionally, chilling sensitivity of the cultivars was reduced by pre-exposure to cooler temperatures that were slightly above the chilling range.

scholarly journals Cucumber Cultivars Differ in Their Response to Chilling Temperatures

1992 ◽  
Vol 117 (5) ◽  
pp. 802-807 ◽  
Author(s):  
Roberto M. Cabrera ◽  
Mikal E. Saltveit ◽  
Ken Owens
Keyword(s):  
Enzyme Activity ◽  
Physiological Responses ◽  
Chilling Injury ◽  
Dry Weight ◽  
Ion Leakage ◽  
Fresh Weight ◽  
Resistant Lines ◽  
Chilling Sensitivity ◽  
Chilling Temperatures ◽  
Highly Correlated

The physiological responses associated with chilling of horticulturally mature cucumber (Cucumis sativus L.) fruit were examined using 13 lines that differ in chilling sensitivity. The low correlation coefficient between pitting and decay suggested that these two early manifestations of chilling injury are not significantly related. Likewise, fruit pitting and decay were not highly correlated with the tolerance of seedlings to chilling, suggesting that fruit and seedlings of the same line may have dissimilar sensitivity to chilling temperatures. Exudates from fruit cut in half transversely were collected on filter paper. The amount of exudate showed a significant correlation with pitting, decay, and percent ion leakage after 10 days of chilling. The fresh and dry weight of the exudates from fruit kept for 8 days at 12.5C ranged from 141- to 346-mg fresh weight and from 15 to 47-mg dry weight, respectively. Cucumber lines that were more sensitive to chilling had watery exudate, as indicated by their lower dry weight and percent solids. The conductivity of exudates from sensitive lines was higher (60 μsiemen/cm) than from chilling resistant lines (30 μsiemen/cm). Chilling-induced ethylene production was higher in sensitive than in resistant lines, and chilling caused a greater loss of ethylene forming enzyme activity in resistant lines than from chilling sensitive lines.

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

1996 ◽  
Vol 121 (4) ◽  
pp. 711-715 ◽  
Author(s):  
Abdur Rab ◽  
Mikal E. Saltveit
Keyword(s):  
Heat Shock ◽  
Mung Bean ◽  
Lateral Roots ◽  
Chilling Injury ◽  
Chilling Tolerance ◽  
Significant Response ◽  
Tomato Seedling ◽  
Shock Temperature ◽  
Chilling Sensitivity ◽  
Time Required

The sensitivity of corn, cucumber, mung bean, and tomato seedling radicles to chilling (i.e., inhibition of subsequent elongation at 25 C after chilling at 2.5 C) was greater for radicles 5 to 7 mm long than for radicles 1 mm long. In contrast, radicles of germinating okra seeds had a similar level of chilling inhibition (i.e., 70% to 90%) at lengths of 1 to 7 mm. For seeds with 1-mm-long radicles, subsequent radicle elongation for cucumber was inhibited only 2% by 72 hours of chilling at 2.5 C, while it was inhibited about 20% for corn, mung bean, and tomato. For seeds with 5- to 7-mm-long radicles, chilling inhibition was 50% to 70% for corn, mung bean, and tomato and 80% to 90% for cucumber and okra. The degree of chilling sensitivity varied among species in relation to time required to elicit a significant response and the magnitude of the elicited response. The development of lateral roots decreased with prolonged chilling in all species. Heat shock (i.e., 4 to 10 minutes at 45 C) 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) significantly reduced chilling injury.

scholarly journals Evaluation of Caladium Cultivars for Sensitivity to Chilling

2006 ◽  
Vol 16 (1) ◽  
pp. 172-176 ◽  
Author(s):  
Zhanao Deng ◽  
Brent K. Harbaugh
Keyword(s):  
Chilling Injury ◽  
Growing Season ◽  
Cultivar Differences ◽  
Greenhouse Production ◽  
Potted Plants ◽  
Mature Leaves ◽  
Air Temperatures ◽  
Chilling Sensitivity ◽  
Chilling Temperatures ◽  
Fuel Costs

Caladium (Caladium ×hortulanum) leaves can be injured at air temperatures below 15.5 °C. This chilling sensitivity restricts the geographical use of caladiums in the landscape, and leads to higher fuel costs in greenhouse production of pot plants because warmer conditions have to be maintained. This study was conducted to develop procedures to evaluate differences among caladium cultivars for chilling sensitivity and to identify cultivars that might be resistant to chilling injury. The effects of two chilling temperatures (12.1 and 7.2 °C) and three durations (1, 3, and 5 days) on the severity of chilling injury were compared for three cultivars known to differ in their sensitivity to low temperatures. Exposure of detached mature leaves to 7.2 °C for 3 days allowed differentiation of cultivars' chilling sensitivity. Chilling injury appeared as dark necrotic patches at or near leaf tips and along margins, as early as 1 day after chilling. Chilling injury became more widespread over a 13-day period, and the best window for evaluating cultivar differences was 9 to 13 days after chilling. Significant differences in chilling sensitivity existed among 16 cultivars. Three cultivars, `Florida Red Ruffles', `Marie Moir', and `Miss Muffet', were resistant to chilling injury. These cultivars could serve as parents for caladium cold-tolerance breeding, and this breeding effort could result in reduced chilling injury in greenhouse production of potted plants, or in new cultivars for regions where chilling occurs during the growing season.

scholarly journals Mitochondrial responses towards intermittent heat shocks in the Eastern Oyster, Crassostrea virginica

2021 ◽  
Author(s):  
Georges Hraoui ◽  
Sophie Breton ◽  
Gilles Miron ◽  
Luc H. Boudreau ◽  
Florence Hunter-Manseau ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Heat Shock ◽  
Crassostrea Virginica ◽  
Heat Waves ◽  
Physiological Stress ◽  
Eastern Oyster ◽  
Emission Rates ◽  
Mitochondrial Functions ◽  
Heat Shocks ◽  
Single Stress

Frequent heat waves caused by climate change can cause physiological stress in many animals, particularly in sessile ectotherms such as bivalves. Most studies characterizing thermal stress in bivalves focus on evaluating the responses to a single stress event. This does not accurately reflect the reality faced by bivalves which are often subject to intermittent heat waves. Here, we investigated the effect of intermittent heat stress on mitochondrial functions of Eastern oyster Crassostrea virginica which play a key role in setting ectotherms’ thermal tolerance. Specifically, we measured changes in mitochondrial oxygen consumption and H2O2 emission rates before, during and after intermittent 7.5°C heat shocks in oysters acclimated to 15°C and 22.5°C. Our results showed that oxygen consumption was impaired following the first heat shock at both acclimation temperatures. After the second heat shock, results for oysters acclimated to 15°C indicated a return to normal. However, oysters acclimated to 22.5°C struggled more with the compounding effects of intermittent heat shocks as denoted with an increase contribution of FAD-linked substrates to mitochondrial respiration as well as high levels of H2O2 emission rates. However, both acclimated populations showed signs of potential recovery ten days after the second heat shock, reflecting a surprising resilience to heat waves by C. virginica. Thus, this study highlights the important role of acclimation in oyster's capacity to weather intermittent heat shock.

Heat shock-induced alterations in phosphorylation of the largest subunit of RNA polymerase II as revealed by monoclonal antibodies CC-3 and MPM-2

1999 ◽  
Vol 77 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Sébastien B Lavoie ◽  
Alexandra L Albert ◽  
Alain Thibodeau ◽  
Michel Vincent
Keyword(s):  
Heat Shock ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Activity ◽  
Phosphorylation Sites ◽  
Stress Genes ◽  
Terminal Domain ◽  
Carboxy Terminal Domain ◽  
Heat Shocks ◽  
Carboxy Terminal

The phosphorylation of the carboxy-terminal domain of the largest subunit of RNA polymerase II plays an important role in the regulation of transcriptional activity and is also implicated in pre-mRNA processing. Different stresses, such as a heat shock, induce a marked alteration in the phosphorylation of this domain. The expression of stress genes by RNA polymerase II, to the detriment of other genes, could be attributable to such modifications of the phosphorylation sites. Using two phosphodependent antibodies recognizing distinct hyperphosphorylated forms of RNA polymerase II largest subunit, we studied the phosphorylation state of the subunit in different species after heat shocks of varying intensities. One of these antibodies, CC-3, preferentially recognizes the carboxy-terminal domain of the largest subunit under normal conditions, but its reactivity is diminished during stress. In contrast, the other antibody used, MPM-2, demonstrated a strong reactivity after a heat shock in most species studied. Therefore, CC-3 and MPM-2 antibodies discriminate between phosphoisomers that may be functionally different. Our results further indicate that the pattern of phosphorylation of RNA polymerase II in most species varies in response to environmental stress.Key words: RNA polymerase II, heat shock, phosphorylation, CC-3, MPM-2.

On the Effects produced by the Attacks of the Pink Bollworm on the Yield of Cotton Seed and Lint in Egypt

1919 ◽  
Vol 9 (4) ◽  
pp. 279-324 ◽  
Author(s):  
L. H. Gough
Keyword(s):  
Pink Bollworm ◽  
Hibiscus Cannabinus ◽  
Food Plants ◽  
Thespesia Populnea ◽  
History Of ◽  
Major Pest ◽  
Hibiscus Esculentus ◽  
Important Position ◽  
Gipsy Moth ◽  
A Minor

The history of but few insects can be compared with that ofPectinophora(Geleckia)gossypiella, which, having started as a minor pest in its native country and having been transported by human agency to a new country, has there suddenly leapt to the most important position as a major pest of the crop it attacks. In this respect it may be placed with thePhylloxeraand the gipsy moth.Although the chief object of this paper is to consider certain aspects of the damage done by the pink bollworm to the cotton crop, the following short summary of the established facts concerning the life-history of the insect may be useful to readers not familiar with its habits.Food-Plants. The pink bollworm feeds on cotton (Gossypium, various species), okra (Hibiscus esculentus; Arabic :bamia; Hindustani :bhindi), Deccan hemp (Hibiscus cannabinus; Arabic :til), hollyhock (Althaea rosea), mallow (Malvasp., probablysilvestris),Thespesia populnea(fideFullaway ; this record is considered doubtful by Busck), andAbutilonsp. (Arabic :hanbuk;fideKing).It will be noticed that all these plants belong to the Malvaceae. The record for pomegranates given by Dudgeon and Gough is without doubt due to error.Of all these food-plants cotton is preferred. The larvae attack the stems (feeding in the cambium and boring a tunnel which encircles the stem), flowers, flower-buds, bolls and seeds.

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