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 Variation in Flower Senescence and Ethylene Biosynthesis among Carnations

HortScience ◽  
1992 ◽  
Vol 27 (10) ◽  
pp. 1100-1102 ◽  
Author(s):  
Amanda S. Brandt ◽  
William R. Woodson
Keyword(s):  
Dianthus Caryophyllus ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Enzyme Treatment ◽  
Flower Senescence ◽  
Vase Life ◽  
Petal Senescence ◽  
Ethylene Treatment ◽  
Initial Symptoms ◽  
Visible Symptom

We have investigated the patterns of ethylene biosynthesis in carnation (Dianthus caryophyllus L.) genotypes that exhibit extended vase life in comparison to flowers of White Sim'. `White Sim' flowers exhibited typical symptoms of senescence, including petal in-rolling and rapid wilting, beginning 5 days after harvest. In contrast, the other genotypes studied did not show petal in-rolling or rapid wilting associated with petal senescence. The first visible symptom of senescence in these flowers was necrosis of the petal tips, and it occurred from 3 to 7 days after the initial symptoms of senescence were seen in `White Sim' flowers. In all cases, the extended-vase-life genotypes did not exhibit the dramatic increase in ethylene production that typically accompanies petal senescence in carnation. This appeared to be the result of limited accumulation of ACC. In addition, flowers of these genotypes had limited capacity to convert ACC to ethylene. Therefore, we conclude that the low level of ethylene produced by these flowers during postharvest aging is the result of low activities of both ACC synthase and the ethylene-forming enzyme. Treatment of `White Sim' flowers at anthesis with 1.0 μl ethylene/liter resulted in the induction of increased ethylene biosynthesis and premature petal senescence. The extended-vase-life genotypes exhibited varying responses to ethylene treatment. One genotype (87-37G-2) produced elevated ethylene and senesced prematurely, as did flowers of `White Sim'. A second genotype (82-1) was induced to senesce by ethylene treatment but did not produce increased ethylene. A third genotype (799) was unaffected by ethylene treatment. The results of this study suggest these extended-vase-life genotypes are representative of genetic differences in the capacity to synthesize and respond to ethylene. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).

scholarly journals Post-pollination Signaling in Carnation Flowers

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 680c-680
Author(s):  
Michelle L. Jones ◽  
William R. Woodson
Keyword(s):  
Enzyme Activity ◽  
Ethylene Production ◽  
Dianthus Caryophyllus ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Sequential Pattern ◽  
Carnation Flower

In Dianthus caryophyllus flowers the pollinated stigma gives rise to signals that are translocated throughout the flower and ultimately result in corolla senescence. Pollination leads to a rapid increase in ethylene production by the pollinated styles followed by ethylene biosynthesis from the ovaries, the receptacle tissue, and lastly the petals. The accumulation of ACC in these floral tissues also correlates with the sequential pattern of ethylene production. Ethylene production by the pollinated style can be defined temporally by three distinct peaks, with the first peak detected as early as 1 hour after pollination. In a carnation flower with multiple styles it is also possible to detect ethylene production from an unpollinated style on a pollinated gynoecium by 1 hour after pollination. This finding provides evidence for very rapid post-pollination signaling between styles. ACC synthase expression is induced in pollinated styles as early as 1 hour after pollination, but no message is detected in pollinated ovaries. ACC synthase enzyme activity is also absent in the pollinated ovaries despite the accumulation of large amounts of ACC in the ovary after pollination. This indicates that ACC must be translocated between organs after pollination. When a pollinated styles is removed from the flower at least 12 hours after pollination the corolla will still senesce. This indicates that the pollination signal has exited the style by this time. Evidence in carnations suggests that ACC and ethylene may both be involved in aspects of post-pollination signaling.

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.

scholarly journals Inhibition of Ethylene Biosynthesis and Action in Cut Carnations (Dianthus caryophyllus L.) by Aminotriazole

1994 ◽  
Vol 119 (2) ◽  
pp. 282-287 ◽  
Author(s):  
Steven A. Altman ◽  
Theophanes Solomos
Keyword(s):  
Morphological Changes ◽  
Dianthus Caryophyllus ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
Vase Life ◽  
Ethylene Evolution ◽  
Dependent Inhibition ◽  
Ethylene Action ◽  
Exogenous Ethylene ◽  
Acc Content

Treating `Elliott's White' cut carnations with 50 or 100 mm aminotriazole for 4 days inhibits the respiratory climacteric and significantly extends vase life. Aminotriazole induced time- and concentration-dependent inhibition of ethylene evolution and onset of the ethylene climacteric by inhibiting ACC synthase activity. Flowers treated with 50 or 100 mm aminotriazole for 2 days exhibited concentration-dependent increases in ethylene evolution, respiratory activity, ACC synthase activity, and petal ACC content in response to the application of exogenous ethylene at 10 μl·liter-1. Senescence-associated morphological changes, increased ACC synthase activity, ACC content, and ethylene evolution were completely inhibited in flowers treated for 4 days with 100 mm aminotriazole. Although treatment with 50 mm aminotriazole for 4 days did not completely inhibit components of the ethylene biosynthetic pathway, no morphological or respiratory responses to the application of exogenous ethylene at 10 μl·liter-1 were observed, a result indicating that prolonged aminotriazole treatment inhibited ethylene action. Chemical names used: 3-1H-amino-1,2,4-triazole-1-yl (aminotriazole), 1-aminocyclopropane-1-carboxylic acid (ACC).

Mechanisms of ethylene biosynthesis and response in plants

2015 ◽  
Vol 58 ◽  
pp. 61-70 ◽  
Author(s):  
Paul B. Larsen
Keyword(s):  
Plant Growth ◽  
Growth And Development ◽  
Ethylene Biosynthesis ◽  
Unsaturated Hydrocarbon ◽  
Flower Senescence ◽  
Detailed Knowledge ◽  
Plant Growth And Development ◽  
Step Process ◽  
Ethylene Response ◽  
Ethylene Signalling

Ethylene is the simplest unsaturated hydrocarbon, yet it has profound effects on plant growth and development, including many agriculturally important phenomena. Analysis of the mechanisms underlying ethylene biosynthesis and signalling have resulted in the elucidation of multistep mechanisms which at first glance appear simple, but in fact represent several levels of control to tightly regulate the level of production and response. Ethylene biosynthesis represents a two-step process that is regulated at both the transcriptional and post-translational levels, thus enabling plants to control the amount of ethylene produced with regard to promotion of responses such as climacteric flower senescence and fruit ripening. Ethylene production subsequently results in activation of the ethylene response, as ethylene accumulation will trigger the ethylene signalling pathway to activate ethylene-dependent transcription for promotion of the response and for resetting the pathway. A more detailed knowledge of the mechanisms underlying biosynthesis and the ethylene response will ultimately enable new approaches to be developed for control of the initiation and progression of ethylene-dependent developmental processes, many of which are of horticultural significance.

In Silico Study of Ethylene Biosynthesis: Seeking New Effectors of ACC Synthase and ACC Oxidase

2016 ◽  
Vol 11 (3) ◽  
pp. 346-356
Author(s):  
Nada Ayadi ◽  
Sarra Aloui ◽  
Rabeb Shaiek ◽  
Oussama Rokbani ◽  
Faten Raboud ◽  
...  
Keyword(s):  
In Silico ◽  
Acc Oxidase ◽  
Acc Synthase ◽  
Ethylene Biosynthesis ◽  
In Silico Study

The THI5 gene family of Saccharomyces cerevisiae: distribution of homologues among the hemiascomycetes and functional redundancy in the aerobic biosynthesis of thiamin from pyridoxine

Microbiology ◽  
2003 ◽  
Vol 149 (6) ◽  
pp. 1447-1460 ◽  
Author(s):  
Raymond Wightman ◽  
Peter A. Meacock
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Family ◽  
Biosynthetic Pathway ◽  
Growth Conditions ◽  
Anaerobic Growth ◽  
Gene Copy ◽  
Phylogenetic Study ◽  
Vitamin B ◽  
Mrna Levels ◽  
Quadruple Mutant

The THI5 gene family of Saccharomyces cerevisiae comprises four highly conserved members named THI5 (YFL058w), THI11 (YJR156c), THI12 (YNL332w) and THI13 (YDL244w). Each gene copy is located within the subtelomeric region of a different chromosome and all are homologues of the Schizosaccharomyces pombe nmt1 gene which is thought to function in the biosynthesis of hydroxymethylpyrimidine (HMP), a precursor of vitamin B1, thiamin. A comprehensive phylogenetic study has shown that the existence of THI5 as a gene family is exclusive to those yeasts of the Saccharomyces sensu stricto subgroup. To determine the function and redundancy of each of the S. cerevisiae homologues, all combinations of the single, double, triple and quadruple deletion mutants were constructed using a PCR-mediated gene-disruption strategy. Phenotypic analyses of these mutant strains have shown the four genes to be functionally redundant in terms of HMP formation for thiamin biosynthesis; each promotes synthesis of HMP from the pyridoxine (vitamin B6) biosynthetic pathway. Furthermore, growth studies with the quadruple mutant strain support a previous proposal of an alternative HMP biosynthetic pathway that operates in yeast under anaerobic growth conditions. Comparative analysis of mRNA levels has revealed subtle differences in the regulation of the four genes, suggesting that they respond differently to nutrient limitation.

Sign in / Sign up

Export Citation Format

Share Document