Changes in Responsiveness to Ethylene at the Molecular Level during Carnation Petal Development

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 519b-519
Author(s):  
Sven Verlinden ◽  
William R. Woodson
Keyword(s):  
Northern Blot Analysis ◽  
Developmental Stages ◽  
Molecular Level ◽  
Acc Synthase ◽  
Transcript Level ◽  
The Other ◽  
Ethylene Concentration ◽  
Petal Development ◽  
Increased Sensitivity ◽  
Carnation Petals

Differences in responsiveness and sensitivity to plant hormones between tissues and in specific tissues during development have been observed. Increased sensitivity to ethylene during development has been demonstrated in fruits and flowers. In order to study the molecular changes in responsiveness to ethylene during flower development carnation petals of three developmental stages were treated with 0.1, 1, 10, 100, pr 1000 ppm of ethylene for 0, 0.5, 1, 3, 6, 9, 15, or 24 h. Northern blot analysis was performed on total RNA extracted from these treatments. Hybridizations were carried out with the senescence related cDNAs SR5, SR8, SR12, DCACO1, DCACS1, and DCCP. The respective transcripts showed distinct patterns of accumulation in response to ethylene. SR5 transcripts, encoding for a putative β-glucosidase, accumulated significantly faster and at lower ethylene concentrations than all the other transcripts. DCACS1, an ACC synthase, on the other hand showed a delay in the accumulation of its mRNA when compared to the other genes. As the petals develop each mRNA also showed a unique pattern of increased responsiveness to ethylene. This increase in responsiveness is expressed as a decrease in the ethylene-time constant. The ethylene-time concept, similar to degree-days, states that it takes a certain time for a given ethylene concentration to induce a response, 50% maximum transcript level in this study. This allows for a quantitative assessment of changes in ethylene responsiveness during petal development.

scholarly journals THE EFFECT OF POLYAMINES ON THE SENESCENCE OF CARNATION PETALS.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 617d-617
Author(s):  
Ki-Cheol Son ◽  
Y. Chae
Keyword(s):  
Ethylene Production ◽  
Dianthus Caryophyllus ◽  
Acc Synthase ◽  
The Other ◽  
Fresh Weight ◽  
Exact Role ◽  
High Concentrations ◽  
Acc Content ◽  
Carnation Petals

The interaction between polyamines and ethylene is still not clear for floral tissues. The aim of the present paper is to examine the senescence on the isolated petals of carnation (Dianthus caryophyllus cv. Desio) but not the whole flower in an attempt to clarify the exact role of polyamines. Petals were treated with putrescine (Put; 0.0, 1.0, 10mM), spermidine (Spd; 0.0, 1.0, 10mM), spermine (Spn; 0.0, 1.0, 10mM), Put+Spd (1.0mM), Put+Spn (1.0mM). The fresh weight of petals in all 10mM treatment was decreased less than those in the other treatments at all times but there were no significant differences. The differences in ethylene production were significant. In petals maintained in 10mM of polyamines, ethylene production was completely inhibited until 13 days and senescence was considerably retarded. However, ethylene productions in 1.0mM polyamines treatments were delayed 2-3 days with reduced amounts. These results suggest that high concentrations of polyamines retard senescence and completely inhibit ethylene production. ACC content, activities of ACC synthase and SAM decarboxylase were analyzed. Finally, the role of SAM in ethylene and polyamines biosynthesis will be discussed.

scholarly journals Changes in the Activity and Expression of 1-Aminocyclopropane-1-Carboxylate (ACC) Synthase, ACC Oxidase, and Phenylalanine Ammonia-lyase in Asparagus Spears in Response to Wound-induced Ethylene Synthesis

HortScience ◽  
2004 ◽  
Vol 39 (5) ◽  
pp. 1074-1078 ◽  
Author(s):  
Pankaj Kumar Bhowmik ◽  
Toshiyuki Matsui
Keyword(s):  
Enzyme Activity ◽  
Ethylene Production ◽  
Phenylalanine Ammonia Lyase ◽  
Northern Blot Analysis ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
The Other ◽  
Mrna Levels ◽  
Ethylene Synthesis ◽  
Enzymatic Changes

The molecular and enzymatic changes that follow harvesting of asparagus are important aspects for postharvest deterioration. To define the factors contributing to postharvest deterioration, the early changes in ethylene production and the activities and expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase, ACC oxidase, and phenylalanine ammonia-lyase (PAL) were studied in whole spears and in excised top and bottom portions. As a result of wounding, ethylene production was found higher in both top and bottom portions compared with whole spears but followed the same trend reaching the peak at 16 hours after harvest. ACC synthase was rapidly induced in excised top portions but no significant ACC synthase activity was observed in excised bottom portions. In top portions, ACC synthase reached a peak 8 hours after harvest and thereafter started to decline. In contrast to ACC synthase, ACC oxidase was induced markedly in both top and bottom portions and remained high until 16 hours after excision. On the other hand, PAL greatly increased in activity in bottom portions but not in excised tops. Northern blot analysis showed that increased mRNA levels coincided well with the excision-promoted increases in enzyme activity and ethylene production.

An ‘Age of Commerce’ in Southeast Asian History

1990 ◽  
Vol 24 (1) ◽  
pp. 1-30 ◽  
Author(s):  
Anthony Reid
Keyword(s):  
World War Ii ◽  
Southeast Asia ◽  
Economic History ◽  
External Factors ◽  
The Other ◽  
Economic Factors ◽  
World War ◽  
The Past ◽  
Increased Sensitivity ◽  
Asian History

Since the end of World War II the study of Southeast Asia has changed unrecognizably. The often bitter end of colonialism caused a sharp break with older scholarly traditions, and their tendency to see Southeast Asia as a receptacle for external influences—first Indian, Persian, Islamic or Chinese, later European. The greatest gain over the past forty years has probably been a much increased sensitivity to the cultural distinctiveness of Southeast Asia both as a whole and in its parts. If there has been a loss, on the other hand, it has been the failure of economic history to advance beyond the work of the generation of Furnivall, van Leur, Schrieke and Boeke. Perhaps because economic factors were difficult to disentangle from external factors they were seen by very few Southeast Asianists as the major challenge.

The extracellular electrical current pattern and its variability in vitellogenic Drosophila follicles

1986 ◽  
Vol 81 (1) ◽  
pp. 189-206 ◽  
Author(s):  
J. Bohrmann ◽  
A. Dorn ◽  
K. Sander ◽  
H. Gutzeit
Keyword(s):  
Juvenile Hormone ◽  
Current Density ◽  
Developmental Stages ◽  
Electrical Current ◽  
Posterior Pole ◽  
The Other ◽  
Follicular Epithelium ◽  
Nurse Cells ◽  
Vibrating Probe ◽  
Current Pattern

We determined the extracellular electrical current pattern around Drosophila follicles at different developmental stages (7–14) with a vibrating probe. At most stages a characteristic pattern can be recognized: current leaves near the oocyte end of the follicle and enters at the nurse cells. Only at late vitellogenic stages was an inward-directed current located at the posterior pole of many follicles. Most striking was the observed heterogeneity both in current pattern and in current density between follicles of the same stage. Different media (changed osmolarity or pH, addition of cytoskeletal inhibitors or juvenile hormone) were tested for their effects on extrafollicular currents. The current density was consistently influenced by the osmolarity of the medium but not by the other parameters tested. Denuded nurse cells (follicular epithelium locally stripped off) show current influx, while an accidentally denuded oocyte produced no current. Our results show that individual follicles may be electrophysiologically different, though their uniform differentiation during vitellogenesis does not reflect such heterogeneity.

scholarly journals cDNA Cloning and Partial Characterization of the DJ-1 Gene from Tribolium castaneum

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1970
Author(s):  
Shunya Sasaki ◽  
Maaya Nishiko ◽  
Takuma Sakamoto ◽  
Michael R. Kanost ◽  
Hiroko Tabunoki
Keyword(s):  
Oxidative Stress ◽  
Amino Acid ◽  
Tribolium Castaneum ◽  
Cdna Sequence ◽  
Developmental Stages ◽  
Red Flour Beetle ◽  
Genome Database ◽  
Antioxidant Function ◽  
Increased Sensitivity

The DJ-1 gene is highly conserved across a wide variety of organisms and it plays a role in anti-oxidative stress mechanisms in cells. The red flour beetle, Tribolium castaneum, is widely used as a model insect species because it is easy to evaluate gene function in this species using RNA interference (RNAi). The T. castaneum DJ-1 (TcDJ-1) sequence is annotated in the T. castaneum genome database; however, the function and characteristics of the TcDJ-1 gene have not been elucidated. Here, we investigated the cDNA sequence of TcDJ-1 and partially characterized its function. First, we examined the TcDJ-1 amino acid sequence and found that it was highly conserved with sequences from other species. TcDJ-1 mRNA expression was higher in the early pupal and adult developmental stages. We evaluated oxidant tolerance in TcDJ-1 knockdown adults using paraquat and found that adults with TcDJ-1 knockdown exhibited increased sensitivity to paraquat. Our findings show that TcDJ-1 has an antioxidant function, as observed for DJ-1 from other insects. Therefore, these results suggest that TcDJ-1 protects against oxidative stress during metamorphosis.

Developmental expression and cellular localization of glucose transporter molecules during mouse preimplantation development

Development ◽  
1992 ◽  
Vol 115 (1) ◽  
pp. 305-312
Author(s):  
M. Aghayan ◽  
L.V. Rao ◽  
R.M. Smith ◽  
L. Jarett ◽  
M.J. Charron ◽  
...  
Keyword(s):  
Western Blot ◽  
Cellular Localization ◽  
Glucose Transporter ◽  
Developmental Stages ◽  
Molecular Level ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Preimplantation Development ◽  
Developmental Expression

Two general mechanisms mediate glucose transport, one is a sodium-coupled glucose transporter found in the apical border of intestinal and kidney epithelia, while the other is a sodium-independent transport system. Of the latter, several facilitated transporters have been identified, including GLUT1 (erythrocyte/brain), GLUT2 (liver) and GLUT4 (adipose/muscle) isoforms. In this study, we used Western-blot analysis and high resolution immunoelectron microscopy (IEM) to investigate the stage-related expression and cellular localization of GLUT1, 2 and 4. The Western blot results demonstrate that GLUT1 is detectable in the oocyte and throughout preimplantation development. GLUT2 isoforms were not detectable until the blastocyst stage, while the GLUT4 isoform was undetectable in the oocyte through blastocyst stages. The present findings confirm previous studies at the molecular level which demonstrated that mRNAs encoding the same GLUT isoforms are detectable at corresponding developmental stages. GLUT1 and GLUT2 display different cellular distributions at the blastocyst stage as shown by IEM studies. GLUT1 has a widespread distribution in both trophectoderm and inner cell mass cells, while GLUT2 is located on trophectoderm membranes facing the blastocyst cavity. This observation suggests a different functional significance for these isoforms during mouse preimplantation development.

Energy in Thermal Physics

2021 ◽  
pp. 1-48
Author(s):  
Daniel V. Schroeder
Keyword(s):  
Low Temperature ◽  
Molecular Level ◽  
The Other ◽  
Thermal Physics ◽  
Other Hand ◽  
Energy Flows ◽  
Basic Concepts ◽  
Simple Models

The behavior of energy in bulk-matter systems is subtle. We observe that energy flows spontaneously from high to low temperature; we refer to this flowing energy as heat; and we distinguish heat from work, the transfer of energy through mechanical or other means unrelated to temperature. On the other hand, simple models of gases and solids strongly suggest that at the molecular level all energy is purely mechanical. This introductory chapter surveys these basic concepts of thermal physics, illustrates them with a wide variety of familiar examples, and sets the stage for developing a deeper understanding.

Hyperinsulinemia in rats with hypothalamic obesity: effects of autonomic drugs and glucose

1983 ◽  
Vol 245 (3) ◽  
pp. R372-R378 ◽  
Author(s):  
S. Inoue ◽  
Y. S. Mullen ◽  
G. A. Bray
Keyword(s):  
Adrenergic Receptors ◽  
Serum Insulin ◽  
The Other ◽  
Glucose Stimulation ◽  
Hypothalamic Obesity ◽  
Insulin Levels ◽  
Alpha Adrenergic Receptors ◽  
Beta Receptors ◽  
Increased Sensitivity ◽  
Stimulation Of

The present study examined the effects of autonomic drugs and glucose on the insulin and glucose concentrations of sham-operated rats and of rats with ventromedial hypothalamic (VMH) lesions and obesity. In the basal condition both epinephrine and atropine significantly decreased serum insulin levels in VMH-lesioned but not sham-operated rats. During glucose stimulation of insulin secretion in VMH-lesioned rats, epinephrine inhibited the increase of insulin by 83% and atropine inhibited it by 42%; whereas in sham-operated rats, epinephrine inhibited it by 70% and atropine inhibited it by 34%. Epinephrine with atropine completely blocked the increase of insulin in response to glucose in both VMH-lesioned and sham-operated rats. In the basal condition, epinephrine together with propranolol significantly decreased serum insulin levels in VMH-lesioned but not sham-operated rats. Epinephrine with phentolamine, on the other hand, markedly increased insulin in the VMH-lesioned rats and to a lesser degree in the sham-operated rats. During glucose stimulation epinephrine with propranolol inhibited the increase of insulin in both groups. Epinephrine with phentolamine or isoproterenol markedly increased serum insulin in VMH-lesioned rats. These results suggest that stimulation of the vagus nerve and increased sensitivity of the beta-receptors on the beta-cells of the islet contribute to the development of hyperinsulinemia. The sympathetic contribution may also be through suppression of alpha-adrenergic receptors.

scholarly journals CCAP regulates feeding behavior via the NPF pathway in Drosophila adults

2020 ◽  
Vol 117 (13) ◽  
pp. 7401-7408 ◽  
Author(s):  
Michael J. Williams ◽  
Mehwish Akram ◽  
Deimante Barkauskaite ◽  
Sourabh Patil ◽  
Eirini Kotsidou ◽  
...  
Keyword(s):  
Feeding Behavior ◽  
The Other ◽  
Regulatory Role ◽  
Food Cues ◽  
Proboscis Extension Reflex ◽  
Increased Sensitivity ◽  
Proboscis Extension ◽  
Necessary And Sufficient ◽  
The Brain ◽  
Starvation Conditions

The intake of macronutrients is crucial for the fitness of any animal and is mainly regulated by peripheral signals to the brain. How the brain receives and translates these peripheral signals or how these interactions lead to changes in feeding behavior is not well-understood. We discovered that 2 crustacean cardioactive peptide (CCAP)-expressing neurons in Drosophila adults regulate feeding behavior and metabolism. Notably, loss of CCAP, or knocking down the CCAP receptor (CCAP-R) in 2 dorsal median neurons, inhibits the release of neuropeptide F (NPF), which regulates feeding behavior. Furthermore, under starvation conditions, flies normally have an increased sensitivity to sugar; however, loss of CCAP, or CCAP-R in 2 dorsal median NPF neurons, inhibited sugar sensitivity in satiated and starved flies. Separate from its regulation of NPF signaling, the CCAP peptide also regulates triglyceride levels. Additionally, genetic and optogenetic studies demonstrate that CCAP signaling is necessary and sufficient to stimulate a reflexive feeding behavior, the proboscis extension reflex (PER), elicited when external food cues are interpreted as palatable. Dopaminergic signaling was also sufficient to induce a PER. On the other hand, although necessary, NPF neurons were not able to induce a PER. These data illustrate that the CCAP peptide is a central regulator of feeding behavior and metabolism in adult flies, and that NPF neurons have an important regulatory role within this system.

scholarly journals TcsL Is an Essential Virulence Factor inClostridium sordelliiATCC 9714

2011 ◽  
Vol 79 (3) ◽  
pp. 1025-1032 ◽  
Author(s):  
Glen P. Carter ◽  
Milena M. Awad ◽  
Yibai Hao ◽  
Tennille Thelen ◽  
Ingrid L. Bergin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factor ◽  
Reference Strain ◽  
Molecular Level ◽  
Mortality Rates ◽  
The Other ◽  
Strain Atcc ◽  
Human Pathogen ◽  
Uterine Infection ◽  
Major Virulence Factor

ABSTRACTClostridium sordelliiis an important pathogen of humans and animals, causing a range of diseases, including myonecrosis, sepsis, and shock. Although relatively rare in humans, the incidence of disease is increasing, and it is associated with high mortality rates, approaching 70%. Currently, very little is known about the pathogenesis ofC. sordelliiinfections or disease. Previous work suggested that the lethal large clostridial glucosylating toxin TcsL is the major virulence factor, but a lack of genetic tools has hindered our ability to conclusively assign a role for TcsL or, indeed, any of the other putative virulence factors produced by this organism. In this study, we have developed methods for the introduction of plasmids intoC. sordelliiusing RP4-mediated conjugation fromEscherichia coliand have successfully used these techniques to insertionally inactivate thetcsLgene in the reference strain ATCC 9714, using targetron technology. Virulence testing revealed that the production of TcsL is essential for the development of lethal infections byC. sordelliiATCC 9714 and also contributes significantly to edema seen during uterine infection. This study represents the first definitive identification of a virulence factor inC. sordelliiand opens the way for in-depth studies of this important human pathogen at the molecular level.

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