Cold Induction Research Articles

Requirement of a CCGAC cis-acting element for cold induction of the BN115 gene from winter Brassica napus

Mutation of the core pentamer, CCGAC, of two putative low temperature responsive elements (LTREs) in the 5'-proximal region for the winter Brassica napus cold-induced gene BN115 was carried out. Analyses of transient expression of the resultant mutated BN115 promoter-GUS fusions revealed the loss of low-temperature regulation by the promoter. This indicates that the CCGAC sequence is critical to the low-temperature response in the BN115 gene. In contrast, mutation of two G-boxes, CACGTG, staggered between the LTREs in the same region of the promoter did not alter cold-inducible gene expression. Replacement of a possible enhancer region of the BN115 promoter with the enhancer from the CaMV 35S promoter resulted in a several-fold increase in low temperature-induced GUS activity.

Effects of acute ethanol administration and cold exposure on the hypothalamic-pituitary-thyroid axis

A single dose of ethanol increases cellular levels of the mRNA encoding thyrotropin-releasing hormone (TRH) in neurons of the paraventricular nucleus (PVN), but blocks the cold-induced increase in the levels of this mRNA. Because the thyrotropic response to cold is dependent upon TRH secretion, we hypothesized that ethanol uncouples the stimulus-induced regulation of TRH secretion from the stimulus-induced regulation of TRH expression. We employed two complementary strategies to test this hypothesis. The first was to determine whether ethanol alters pituitary sensitivity to TRH. Animals given a single intraperitoneal injection of ethanol (3 g/kg) that produced a blood alcohol concentration of nearly 300 mg/100 mL exhibited the same increase in circulating levels of TSH following an intravenous infusion of TRH. Thus, ethanol does not appear to alter pituitary sensitivity to TRH. Second, we tested whether ethanol blocks the cold induction of c-fos expression in TRH neurons of the PVN. Both cold exposure and ethanol induced the expression of c-fos in the PVN and in TRH neurons; the effects of cold and ethanol on c-fos expression were additive. Thus, ethanol clearly does not block the cold activation of TRH neurons.

Regulation of the Arabidopsis Adh Gene by Anaerobic and Other Environmental Stresses

The promoter of the alcohol dehydrogenase (Adh, E.C.1.1.1.1.) gene from Arabidopsis thaliana (L.) Heynh. is inducible by the environmental stresses anaerobiosis, dehydration and low temperature. Analysis of the Adh promoter using 5′-deletion and substitution mutants has allowed the identification of promoter elements which interact differentially under the different stress conditions. One element, located between positions -160 and -140, consists of a GT/GC-rich motif and functions as a general stress responsive element (GSRE). The G-box-1 sequence (-216 to -209) is necessary only for cold and dehydration induction. We have started to dissect the signal transduction pathways involved in the different environmental stress responses.

Microsomal polypeptides in sunflower (Helianthus annum). Comparison between normal type before and after cold‐induction, and a high oleic acid mutant

Differences in high‐resolution two‐dimensional gel electrophoresis patterns of micro‐somal proteins from developing normal sunflower (Helianthus annuus L.) seeds before and after cold‐induction, and also from normal and a high oleic sunflower mutant have been studied in order to detect the polypeptides associated with the microsomal Δl2‐desaturase activity and its regulation by temperature. Proteins were obtained from developing seeds of two isogenic sunflower lines HA‐89 (normal) and HA‐OL9 (high oleic) which greatly differed in linoleic acid content and “in vitro” oleate desaturase activity. In the high oleic mutant, four polypeptides of about 32 kDa and two of 33 kDa were found to change in position, to the same extent, toward a lower isoelectric point in the high oleic mutant. Also, two polypeptides, of 32 and 49 kDa each, appeared in the mutant. Quantitative differences between cold‐induced seeds (10°C, 24 h) and their non‐induced controls were found. One polypeptide of 43 kDa decreased in the cold‐treated seeds and two others, of 30 and 32 kDa each, increased markedly after cold induction. Some of these polypeptides could be related to oleate desatnrase activity or its regulation by temperature.

Cyclomorphosis in Scenedesmus subspicatus R. Chod. Cell Behavior During the Unicell-Colony Transformation of a Phenotypicly Plastic Organism

An ordered sequence of ecomorph development, from a unicellular type to multi-spined colonies to acaudate forms, takes place over time in the spiny forms of Scenedesmus. This is the first report of two steps of such a sequence, the unicell-colony morphogenesis, in one strain of S. subspicatus. A detailed analysis of growth and morphology of UTEX 2532 at 10°C revealed that colonies were formed at that temperature and that cell mortality was occurring during this unicell-colony transformation. As the unicellular stage disappears and colonial ecomorphs develop within the population, a deflection in the growth curve has previously been noted, especially with S. armatus. Such deflections also occurred with S. subspicatus. At various stages of growth the developmental phenomena in these phenotypicly plastic microorganisms were indicative of the occurrence of a cyclomorphosis. Supporting data are derived from experiments conducted at both cold and warm incubation temperatures. Additionally, cold temperature induction of extra spines on individual ecomorphs takes place when the processes of cell adhesion and subsequent spine formation, closely coupled at warm incubation temperatures (standard conditions), become uncoupled at 10°C. These developmental steps take place while progeny are still within the parent wall. With all the morphological changes, organisms are able to adapt to the prevailing environmental conditions.

Reduction of myocardial infarction after emergency coronary artery bypass grafting for failed coronary angioplasty with use of a normothermic reperfusion cardioplegia protocol

Emergency coronary artery bypass grafting is necessary in 2.7% to 13.5% of patients undergoing elective percutaneous transluminal coronary angioplasty. Myocardial infarction develops in 11% to 49% of these patients, with 18% to 46% of infarcts resulting in new Q waves. Since February 1987 a revised protocol for myocardial preservation has been used in 19 patients undergoing emergency bypass grafting for failed angioplasty. Cardioplegia is induced with a normothermic blood cardioplegic solution. Multiple maintenance doses of cold (4 degrees C) blood cardioplegic solution are then delivered through the aortic root and vein grafts. Before the aortic crossclamp is removed, normothermic reperfusion cardioplegic solution is delivered through the aortic root and vein grafts. This group was compared with all patients undergoing emergency bypass grafting for failed angioplasty before February 1987. These 45 patients received cold induction of cardioplegic solution, multiple maintenance doses of cold cardioplegic solution, and no reperfusion cardioplegic solution. The prevalence of myocardial infarction in the group receiving cold cardioplegic solution was 65% versus 26% in the group receiving normothermic cardioplegic solution (p less than 0.007). Multivariate analysis identified the use of the normothermic cardioplegia protocol (p less than 0.005), nontotal occlusion of the angioplasty vessel (p less than 0.03), and presence of collateral flow to the angioplasty vessel (p less than 0.04) as being independently associated with absence of myocardial infarction.

The inheritance of the cold induction response with respect to floral initiation in white clover (Trifolium repens L.)

The inheritance of the cold induction response in the UK cultivar of white clover Menna, was assessed in controlled environments.

Requirements for Floral Induction in Contrasting White Clover (Trifolium repens) Populations

Norm, I. B. 1987. Requirements for floral induction in contrasting white clover (Trifolium repens) populations.—J. exp. Bot. 38: 900–907. Floral initiation and development of four contrasting white clover (Trifolium repens) populations was examined after different induction treatments (16 h, 5 °C and 8 h, 5 °C. The number of reproductive stolons and of reproductive buds per stolon was increased after cold induction. Varietal differences in response to daylength were large; some varieties responding better to a long day cold period, others to a short day cold period while one variety required no induction at all. Whether the daylength effect was due to photoperiod, irradiance or to their interaction was not known. The induction periods had a subsequent effect upon peduncle length, floret and ovule number. Short days and chilling reduced peduncle length but increased ovule number, whereas long days and chilling tended to increase floret number. Nectar concentration was highest after short day induction.

Influence of Light Treatments Before and After Induction Treatment on Flowering of Alstroemeria ‘Regina’

Abstract Early winter flowering of Alstroemeria ‘Regina’ plants was accomplished by a long-day, high-pressure sodium vapor lamp (HPS) treatment before the low 5°C temperature induction treatment. This HPS treatment predisposed the plants to respond to a subsequent long photoperiod treatment during winter. Winter generative shoot yield was increased by 35% through the use of HPS pretreatment. Stem length increased as the duration of the HPS treatment prior to cold induction increased.

On the germination of turions and the life cycle of Potamogeton trichoides Cham. et Schld.

The life cycle of P. trichoides Cham. et Schld. has been studied in a pond near Nijmegen (The Netherlands); the germination of its turions has been studied in relation to temperature, cold induction (stratification) and light dependency. The species shows a summer-green annual life cycle, surviving the winter period by means of turions. Timing of turion germination appears to be well regulated by the water temperature, but light was also effective.

Benefits of normothermic induction of blood cardioplegia in energy-depleted hearts, with maintenance of arrest by multidose cold blood cardioplegic infusions

This study tests the hypothesis that warm induction of cardioplegia prior to prolonged maintenance by multidose infusions of cold blood cardioplegic solution would increase the tolerance of energy-depleted hearts to subsequent aortic clamping. Eighty percent depletion of subendocardial adenosine triphosphate (ATP) was produced in 30 dogs by 45 minutes of normothermic ischemia. This was followed either by unmodified blood reperfusion or 2 additional hours of aortic clamping with multidose cold blood cardioplegia. We compared a brief (5 minute) period of 37 degrees C cardioplegic induction to standard 4 degrees C blood cardioplegic induction to determine if warm induction would enhance metabolic and functional recovery. Warm cardioplegic induction resulted in more oxygen consumption than cold induction (16.9 versus 8.1 cc/100 gm), and lower levels of glucose-6-phosphate (G6P), suggesting better aerobic metabolism (0.97 versus 1.87 microM/gm wet weight). Prompt repletion of creatine phosphate (CP) occurred with warm and cold cardioplegic induction, although ATP levels levels remained low. Hearts undergoing ischemia and unmodified reperfusion consumed insufficient oxygen to meet basal metabolic needs during reperfusion (7 cc/100 gm below requirement) and recovered only 33% +/- 5% of control left ventricular performance. Better function occurred with cold cardioplegic induction (63% +/- 5%), and almost complete recovery (85% +/- 5%) occurred when warm induction of cardioplegia was used. We conclude that warm induction followed by prolonged cold multidose blood cardioplegic arrest enhances aerobic metabolism, results in normal left ventricular performance, and improves tolerance of aortic clamping in energy-depleted hearts.

Regulation of Growth and Flowering in Basket of Gold, Aurinia saxatilis (L.) Desv1

Abstract Cold storage for a minimum of 12 weeks induced flowering of Aurinia saxatilis. Seedlings became receptive to cold induction of flowering only after reaching the stage of 10 crowns/plant, approximately 7 months after sowing. The species is suited to production in 7.5 – 10 cm diameter containers.

Effect of Daminozide and Chlormequat on Bolting Suppression in Carrots1

Abstract Ten compounds applied as foliar spray were screened for reducing and delaying bolting in fall-planted carrots (Daucus carota L.). Only butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide) was effective; seedstalk height was reduced and root size was unaffected. Daminozide effectiveness was greatest in weak-bolting cultivars. Two sprays of 5000 ppm, 2 weeks apart at about 4 and 2 weeks prior to natural bolting were most effective, suggesting that daminozide does not interfere in the cold temperature induction process, but rather has a delaying and inhibitory effect on the initial seedstalk elongation. Two sprays of 500 liters/ha of daminozide solution of 5000 ppm gave promising results. Root quality was improved without influencing carrot yield or dry matter content. Although (2-chloroethyl)trimethymammonium chloride (chlormequat) suppressed bolting in some experiments, it was less effective than daminozide at comparable rates and higher rates decreased yield.

Treatments to shorten the development period of celery(Apium graveolensL.)

SummaryStudies on the vernalization requirement of celery showed that 20–30 days at 4–6°C were sufficient to induce maximum bolting and subsequent flowering in cv. Prazsky obrovsky when harvested at the end of October. For early harvesting at the beginning of September, it was necessary to extend the period of vernalization to 30–40 days. Gibberellic acid did not fully replace cold induction, but it hastened bolting and increased the percentage of bolting plants. Bolting and flowering took place even in short winter days in the glasshouse. Bulb celery can therefore be classified as day-neutral. Treatments leading to substantial shortening of the life-cycle of bulb celery for seed production are recommended.

Enhanced binding of 3,5,3'-L-triiodothyronine by rat kidney microsomes after acclimation to cold.

SummaryWhole-tissue binding of triiodothyronine was augmented in liver, kidney and skeletal muscle following adaptation of the rat to cold. The basis of the increased kidney binding of this hormone was increased binding to microsomes, the putative subcellular locus of hormonal deiodination. Cold induction of deiodinative sites in tissues is the suggested etiology of the increased deiodination of triiodothyronine in vivo after cold acclimation observed in previous studies.

Regulation of perithecium development and maturation in Pleospora herbarum by light and temperature

Exposure of growing colonies of Pleospora herbarum (Pers.) Rabenhorst (Imperfect stage = Stemphylium botryosum ) to UV radiation stimulated the formation of protoperithecia which matured only when subjected to long uninterrupted periods at low temperature (21 days at 5–10 °C). Equivalent periods of intermittent (diurnal) low temperature were not effective. Maturation was influenced by the temperature during near-UV induction, and protoperithecia formed at 24–27° were most likely to mature following cold treatment. The temperature following cold treatment also influenced maturation of protoperithecia: 10–15° was most favourable. Maturation was governed by an inverse relationship between the length of the cold treatment and of the terminal incubation. Light was essential for induction of protoperithecia but not for their subsequent maturation. Maturation once started by cold treatment was negated by relatively high temperatures (30°) Cold induction of protoperithecia in the dark, hitherto unrecorded, was observed when actively growing vegetative colonies were exposed to low temperatures (5–15°) for 1–35 days. An 8-day exposure to cold was necessary for maximum induction, although a few protoperithecia formed after a 24 h exposure. Maturation required another 35 days at low temperature (12–5°). The influence of low temperature on sexual reproduction of fungi is reviewed.

The Influence of Succinic Acid 2,2-Dimethyl-hydrazide (Alar) on Plant Growth, Inflorescence and Seed Development and Chemical Analysis of Barbarea verna, Land Cress1

Abstract Under certain conditions, fall and spring applications of Succinic acid 2,2-dimethylhydrazide (Alar) at 5,000 ppm delayed inflorescence development of land cress plants 12 to 14 days following cold induction of winter. Alar-treated plants were greener, shorter and more compact; pods were smaller in length and diameter. Seeds of Alar-treated plants were delayed in maturity, smaller, and had a much lower per cent of germination. Chemical analysis showed that immature, Alar-treated greenhouse plants were higher in protein and lower in nitrates than untreated plants. Under a favorable, cool, field environment, plants of all treatments were higher in protein and Alar caused no increase.

オーステナイト系不銹鋼の応力腐食割れに関する研究(第7報)

We investigated the effects of cold working on the stress corrosion cracking of austenitic stainless steels in the boiling solution of 42% MgCl2.In the case of an 18-8 stainless steel which is transformed partially into quasi-martensite by cold working, both induction period and crack propagation time are changed by cold working. Especially, the crack propagation time is very much lengthened by heavy cold working.But in the case of other stainless steels, both induction period and crack propagation time are hardly changed by cold working.As a result of the quasi-martensite obstructing the advance of crack, the crack propagation time is lengthened. And this effect is generally called "keying effect".The electro-chemical potential of test piece indicated at the crack-initiation time is a little changed by cold working. When the test piece is cold worked lightly such as 7% or 15%, it indicates a slightly lower potential than the original test piece. But when the test piece is cold worked heavily such as 30% or 45%, it indicates a slightly higher potential than the original one.The slip bands occurring at the time of cold working are never attacked during the stress corrosion test, but the slip bands occurring in the MgCl2 solution by the applied test load are gradually attacked during the stress corrosion test. When a slip band occurs, its fault plane has not any protective film, If this unprotected fault plane appears in the MgCl2 solution, it is attacked. But if it appears in the atmosphere, its area is suddenly oxidized and goes into passive state.The higher the applied stress is, the more of cracks appear on the surface of tested specimen. When the test piece is cold worked, this relation is shifted toward upward stress followed by the rising of yield point.