scholarly journals Role of the Gynoecium in Cytokinin-induced Carnation Petal Senescence

1991 ◽  
Vol 116 (4) ◽  
pp. 676-679 ◽  
Author(s):  
William R. Woodson ◽  
Amanda S. Brandt
Keyword(s):  
Ethylene Production ◽  
Dianthus Caryophyllus ◽  
Petal Senescence

Treatment of cut carnation (Dianthus caryophyllus L. `White Sim') flowers with the synthetic cytokinin benzyladenine (BA) at concentrations >1.0 μm induced premature petal senescence. Flowers treated with 100 μm BA exhibited elevated ethylene production in styles and petals before untreated flowers. The gynoecia of BA-treated flowers accumulated 1-aminocyclopropane-l-carboxyllc acid (ACC) and enlarged before untreated flowers. Removal of the gynoecium (ovary and styles) or styles prevented BA-induced petal senescence and resulted in a substantial delay in petal senescence. In contrast, removal of the gynoecium had no effect on timing of petal senescence in flowers held in water. These results indicate BA stimulates petal senescence by inducing premature ACC accumulation and ethylene production in the gynoecium.

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 Physiological and Molecular Characterization of the Response to Ethylene during Senescence of Carnation Genotypic Variants

1995 ◽  
Author(s):  
William Woodson ◽  
Shimon Mayak ◽  
Haim Rabinowitch
Keyword(s):  
Ethylene Production ◽  
Dianthus Caryophyllus ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Early Response ◽  
Vase Life ◽  
Petal Senescence ◽  
Ethylene Treatment ◽  
Novel Proteins ◽  
Exogenous Ethylene

The senescence of carnation (Dianthus caryophyllus L.) flowers is associated with increased production of the phytohormone ethylene, which in turn serves to initiate and regulate the processes involved in programmed petal death. We investigated the regulation of ethylene production and petal senescence in carnation. Several carnation genotypes were identified that exhibited extended vase-life in comparison to flowers from typical commercial cultivars. The capacity of these genotypes to produce ethylene during postharvest vase-life and to respond to exogenous ethylene was investigated. Several genotypes, represented by 'Sandrosa' and 87-37G produced little ethylene durig their postharvest vase-life and as a result failed to exhibit the symptoms (in-rolling and wilting) typical of flowers producing elevated levels of ethylene. These genotypes were further separated by their capacity to respond to exogenous ethylene by both increased ethylene synthesis and premature petal senescence. In one case a genotype (799) was identified that was not capable of responding to exogenous ethylene by either increased ethylene production or premature petal senescence. The regulation of ethylene production during petal senescence was investigated both at the enzyme and gene levels. A full length cDNA was identified for the petal senescence-related ACC synthase gene. Utilizing this, and other ethylene biosynthetic pathway cDNA probes, an increase in both ACC synthase and ACC oxidase mRNAs were detected following ethylene treatment. An increase in ACC oxidase mRNA and enzyme activity was detected within 2-3 h following ethylene treatment, indicating the expression of this gene is an early response to ethylene. An investigation into the expression of novel proteins during petal senescence revealed a number of polypeptides increased in abundance and possibly play a role in the regulation or biochemical processes of senescence. One polypeptide of 70 kDa was identified as being encoded by the previously characterized gene SR12 and possibly represents a b-galactosidase involved in the remobilization of carbohydrates during senescence.

THE ROLE OF CYTOKININS AND ETHYLENE INHIBITORS ON LENTICEL HYPERTROPHY GENERATION AND ETHYLENE PRODUCTION IN IN VITRO CULTURES OF POPULUS EUPHRATICA OLIVIER

1995 ◽  
Vol 43 (4) ◽  
pp. 339-345 ◽  
Author(s):  
M.D. Lledó ◽  
M.B. Crespo ◽  
J.B. Amo-Marco
Keyword(s):  
Ethylene Production ◽  
Populus Euphratica ◽  
In Vitro Cultures ◽  
Nodal Segments ◽  
Ethylene Inhibitors ◽  
Se Spain ◽  
Ethylene Formation ◽  
Free Media

Populus euphratica Olivier is native to the Irano—Turanian areas (Middle East). Elche (Alicante province, SE Spain) is known to be its only European location. Nodal segments from root shoots were established in vitro in a Murashige and Skoog medium supplemented with several cytokinins. Ethylene inhibitors AgNO3 and CoCl2 were used in combination with kinetin. Hormone-free media supplemented with sucrose (20–60 mg 1−1) was also tested. Ethylene was measured by gas chromatography, and both the percentage of sprouting shoots and lenticel hypertrophy in cultures were recorded. Ethylene production was higher in cultures supplemented with cytokinins (especially with meta-topolin), with high sprouting percentages, and lenticel hypertrophy. In cultures supplemented with 6-benzylaminopurine or 6-(γ,γ,-dimethylallylamino)-purine, ethylene production was lower and explants looked unhealthy. Ethylene formation was inhibited in cultures supplemented with AgNO3 (1 mg 1−1), which also decreased percentage of sprouting buds and lenticel hypertrophy.

Herbicide-Induced Ethylene Production: Role of the Gas in Sublethal Doses of 2,4-D

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 498-500 ◽  
Author(s):  
F. B. Abeles
Keyword(s):  
Carbon Dioxide ◽  
Zea Mays ◽  
Glycine Max ◽  
Ethylene Production ◽  
Competitive Inhibitor ◽  
Inhibitory Effect ◽  
Dichlorophenoxyacetic Acid ◽  
Sublethal Doses ◽  
2,4 Dichlorophenoxyacetic Acid

Ethylene production was stimulated by 2,4-dichlorophenoxyacetic acid (2,4-D) from light-grown corn (Zea mays L., var. XL-15) and soybeans (Glycine max Merr., var. Hawkeye). Ethylene had an inhibitory effect on the growth of corn and soybeans, but a reversal of the ethylene effect could not be clearly demonstrated using the competitive inhibitor, carbon dioxide. Ethylene did not mimic the ability of 2,4-D to cause growth curvatures. It was concluded that ethylene played a role in the activity of sublethal amounts of 2,4-D.

Role of Sucrose in the Metabolism of IAA-Conjugates as Related to Ethylene Production by Tobacco Leaf Discs

Ethylene ◽  
1984 ◽  
pp. 97-98 ◽  
Author(s):  
Shimon Meir ◽  
Sonia Philosoph-Hadas ◽  
Ephraim Epstein ◽  
Nehemia Aharoni
Keyword(s):  
Ethylene Production ◽  
Tobacco Leaf ◽  
Leaf Discs ◽  
Iaa Conjugates

scholarly journals EXPRESSION OF ETHYLENE BIOSYNTHETIC PATHWAY mRNAs DURING CARNATION FLOWER SENESCENCE

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 580b-580
Author(s):  
William R. Woodson ◽  
Ky Young Park ◽  
Paul Larsen ◽  
Hong Wang
Keyword(s):  
Biosynthetic Pathway ◽  
Dianthus Caryophyllus ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Molecular Probes ◽  
Flower Senescence ◽  
Mrna Levels ◽  
Petal Senescence ◽  
Sam Synthetase ◽  
Carnation Flower

The senescence of carnation (Dianthus caryophyllus L.) flower petals is associated with increased synthesis of the phytohormone ethylene. This ethylene serves to initiate and regulate the processes of programmed cell death. We are using molecular approaches to study the regulation of ethylene biosynthesis in various floral organs during development and senescence of flowers. We have isolated and cloned mRNAs which encode the ethylene biosynthetic pathway enzymes s-adenosylmethionine (SAM) synthetase, 1-aminocyclopropane-1-carboxylate (ACC) synthase and the ethylene forming enzyme (EFE) from carnation flower petals. These cDNAs have been used as molecular probes to determine the steady-state mRNA levels of these transcripts in senescing flowers. The increase in ethylene associated with petal senescence is accompanied by a dramatic increase in the abundance of transcripts for both ACC synthase and EFE. In striking contrast, the level of SAM synthetase mRNA decreases significantly with the onset of petal senescence. Genomic DNA Southern blots reveal both ACC synthase and EFE are encoded by multigene families. We have recently isolated several genomic clones from carnation which represent different ACC synthase genes. The structure and organization of these gene will be presented.

scholarly journals Beyond Ethylene: New Insights Regarding the Role of AOX in the Respiratory Climacteric

2019 ◽  
Author(s):  
Seanna Hewitt ◽  
Amit Dhingra
Keyword(s):  
Ethylene Production ◽  
Respiratory Pathway ◽  
Physiological Models ◽  
Atp Production ◽  
Climacteric Fruit ◽  
Transcriptional Regulatory ◽  
System 2 ◽  
Transcriptional Regulatory Mechanisms ◽  
System 1

Climacteric fruits are characterized by a dramatic increase in autocatalytic ethylene production, which is accompanied by a spike in respiration, at the onset of ripening. The change in the mode of ethylene production from autoinhibitory to auto-stimulatory is known as the system 1 (S1) to system 2 (S2) transition. Existing physiological models explain the basic and overarching genetic, hormonal, and transcriptional regulatory mechanisms governing the S1 to S2 transition of climacteric fruit. However, the links between ethylene and respiration, the two main factors that characterize the respiratory climacteric, have been largely understudied at the molecular level. Results of recent studies indicate that the AOX respiratory pathway may play an important role in mediating cross talk between ethylene response, carbon metabolism, ATP production, and ROS signaling during climacteric ripening. New genomic, metabolic, and epigenetic information sheds light on the interconnectedness of ripening-associated metabolic pathways, necessitating expanding the current, ethylene-centric physiological models. Understanding points at which ripening responses can be manipulated may reveal key, speciesand cultivar-specific targets for regulation of ripening enabling superior strategies for reducing postharvest wastage.

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