The Experts below are selected from a list of 32817 Experts worldwide ranked by ideXlab platform
Richard N Knowles - One of the best experts on this subject based on the ideXlab platform.
-
a comparison of preharvest and postharvest Ethylene Production and respiration rates of saskatoon amelanchier alnifolia nutt fruit during development
1999Co-Authors: Suzy Y Rogiers, Richard N KnowlesAbstract:Changes in respiration and Ethylene Production rates of nine maturity classes of saskatoon (Amelanchier alnifolia, Nutt.) fruit after harvest were compared with those of fruit maturing and ripening on the plant. During ripening on the plant, Ethylene Production increased on a whole-fruit and fresh-weight basis, while respiration increased substantially on a whole-fruit basis but remained constant on a fresh-weight basis. Fruit harvested at the greenish yellow to pink stages (maturity classes four and five, respectively) increased their Ethylene Production until 15-20 h after harvest, and this was coincident with ripening to maturity class seven and thus a color change to red. Ethylene Production then declined over the next 15 h. Respiration rates of harvested immature, mature, and ripe fruits declined over 5 days, except for a relatively brief 8-12% rise starting 15-20 h after harvest. This brief increase in respiration was characteristic of fruit of all maturity classes, likely reflecting a wound respons...
-
regulation of Ethylene Production and ripening by saskatoon amelanchier alnifolia nutt fruit
1998Co-Authors: Suzy Y Rogiers, G Mohan N Kumar, Richard N KnowlesAbstract:Changes in respiration and Ethylene Production were characterized during maturation and ripening of saskatoon (Amelanchier alnifolia Nutt.) fruit. On a per fruit basis, respiration and Ethylene Production increased 78 and 400%, respectively, as fruit ripened on the plant and trends were consistent with those for climacteric fruits. When estimated on a fresh and dry weight basis, increased rates of Ethylene Production were still apparent during ripening; however, respiration rate declined. Trends in respiration rates and endogenous Ethylene levels of harvested fruit of nine maturity classes, from immature green (class one) to fully ripe and purple (class nine), were consistent with those of fruit growing on the plant. Tissue prints showed that ACC (1-aminocyclopropane-1-carboxylic acid) oxidase was distributed throughout the pericarp of fruit at all nine maturity stages and that the enzyme was most concentrated in the immature stages on a per fruit basis. On a protein basis, ACC oxidase increased progressi...
-
effects of storage temperature and atmosphere on saskatoon amelanchier alnifolia nutt fruit quality respiration and Ethylene Production
1998Co-Authors: Suzy Y Rogiers, Richard N KnowlesAbstract:Abstract Low temperature and controlled atmospheres (CA) were tested for their effectiveness in extending the storage life of saskatoon fruit. The quality of fully ripe (purple) `Smoky' and `Pembina' fruit was assessed over 40 days of storage at 0.5 or 4.0°C in humidified (95% RH) air. Fungal colonization, fruit softening, fresh-weight loss, and anthocyanin degradation were substantially lower in fruit stored at 0.5°C than in that stored at 4.0°C. `Smoky' fruit maintained higher soluble solids when stored at 0.5°C than at 4.0°C, but that of `Pembina' was not affected by temperature. Decreasing the O2 concentration from 23 to 5.8% had little effect on fruit respiration at 23°C; however, the respiration rate fell about 26% as the O2 concentration was lowered from 5.8 to 1.7%. A 2% O2 atmosphere was above the extinction point for aerobic respiration at 23°C. Fruit (cvs. `Smoky' and `Northline') of maturity classes seven, eight and nine were stored in 2, 10 or 21% O2 (0.035% CO2) at 4.0°C (95% RH), and respiration and Ethylene evolution were monitored over 10 days. The rate of Ethylene Production by fruit of both cultivars decreased linearly with advancing maturity class and with declining O2 concentration. Furthermore, the increase in Ethylene Production rate of maturity class nine (fully ripe) fruit with increasing O2 concentration was less than that from fruit of maturity classes seven and eight. Respiration rates of `Northline' and `Smoky' fruit were equal at 21% O2, but `Northline' fruit had a 15% lower respiration rate than `Smoky' fruit at 2% O2. Collectively, our results show that storage at 0.5°C was more effective than 4.0°C at maintaining fresh quality of saskatoon fruit. Low O2 atmosphere (2%) effectively slowed Ethylene Production and fruit respiration and thus may be a beneficial adjunct to low-temperature storage.
Suzy Y Rogiers - One of the best experts on this subject based on the ideXlab platform.
-
a comparison of preharvest and postharvest Ethylene Production and respiration rates of saskatoon amelanchier alnifolia nutt fruit during development
1999Co-Authors: Suzy Y Rogiers, Richard N KnowlesAbstract:Changes in respiration and Ethylene Production rates of nine maturity classes of saskatoon (Amelanchier alnifolia, Nutt.) fruit after harvest were compared with those of fruit maturing and ripening on the plant. During ripening on the plant, Ethylene Production increased on a whole-fruit and fresh-weight basis, while respiration increased substantially on a whole-fruit basis but remained constant on a fresh-weight basis. Fruit harvested at the greenish yellow to pink stages (maturity classes four and five, respectively) increased their Ethylene Production until 15-20 h after harvest, and this was coincident with ripening to maturity class seven and thus a color change to red. Ethylene Production then declined over the next 15 h. Respiration rates of harvested immature, mature, and ripe fruits declined over 5 days, except for a relatively brief 8-12% rise starting 15-20 h after harvest. This brief increase in respiration was characteristic of fruit of all maturity classes, likely reflecting a wound respons...
-
regulation of Ethylene Production and ripening by saskatoon amelanchier alnifolia nutt fruit
1998Co-Authors: Suzy Y Rogiers, G Mohan N Kumar, Richard N KnowlesAbstract:Changes in respiration and Ethylene Production were characterized during maturation and ripening of saskatoon (Amelanchier alnifolia Nutt.) fruit. On a per fruit basis, respiration and Ethylene Production increased 78 and 400%, respectively, as fruit ripened on the plant and trends were consistent with those for climacteric fruits. When estimated on a fresh and dry weight basis, increased rates of Ethylene Production were still apparent during ripening; however, respiration rate declined. Trends in respiration rates and endogenous Ethylene levels of harvested fruit of nine maturity classes, from immature green (class one) to fully ripe and purple (class nine), were consistent with those of fruit growing on the plant. Tissue prints showed that ACC (1-aminocyclopropane-1-carboxylic acid) oxidase was distributed throughout the pericarp of fruit at all nine maturity stages and that the enzyme was most concentrated in the immature stages on a per fruit basis. On a protein basis, ACC oxidase increased progressi...
-
effects of storage temperature and atmosphere on saskatoon amelanchier alnifolia nutt fruit quality respiration and Ethylene Production
1998Co-Authors: Suzy Y Rogiers, Richard N KnowlesAbstract:Abstract Low temperature and controlled atmospheres (CA) were tested for their effectiveness in extending the storage life of saskatoon fruit. The quality of fully ripe (purple) `Smoky' and `Pembina' fruit was assessed over 40 days of storage at 0.5 or 4.0°C in humidified (95% RH) air. Fungal colonization, fruit softening, fresh-weight loss, and anthocyanin degradation were substantially lower in fruit stored at 0.5°C than in that stored at 4.0°C. `Smoky' fruit maintained higher soluble solids when stored at 0.5°C than at 4.0°C, but that of `Pembina' was not affected by temperature. Decreasing the O2 concentration from 23 to 5.8% had little effect on fruit respiration at 23°C; however, the respiration rate fell about 26% as the O2 concentration was lowered from 5.8 to 1.7%. A 2% O2 atmosphere was above the extinction point for aerobic respiration at 23°C. Fruit (cvs. `Smoky' and `Northline') of maturity classes seven, eight and nine were stored in 2, 10 or 21% O2 (0.035% CO2) at 4.0°C (95% RH), and respiration and Ethylene evolution were monitored over 10 days. The rate of Ethylene Production by fruit of both cultivars decreased linearly with advancing maturity class and with declining O2 concentration. Furthermore, the increase in Ethylene Production rate of maturity class nine (fully ripe) fruit with increasing O2 concentration was less than that from fruit of maturity classes seven and eight. Respiration rates of `Northline' and `Smoky' fruit were equal at 21% O2, but `Northline' fruit had a 15% lower respiration rate than `Smoky' fruit at 2% O2. Collectively, our results show that storage at 0.5°C was more effective than 4.0°C at maintaining fresh quality of saskatoon fruit. Low O2 atmosphere (2%) effectively slowed Ethylene Production and fruit respiration and thus may be a beneficial adjunct to low-temperature storage.
Shigeru Satoh - One of the best experts on this subject based on the ideXlab platform.
-
Ethylene Production and petal wilting during senescence of cut carnation dianthus caryophyllus flowers and prolonging their vase life by genetic transformation
2011Co-Authors: Shigeru SatohAbstract:Senescence of carnation flowers is characterized by autocatalytic Ethylene Production from petals and subsequent wilting of the petals. Recent studies on the regulation of Ethylene Production and wilting in senescing carnation petals revealed that (1) petal senescence is triggered by Ethylene evolved from the gynoecium during natural senescence, (2) Ethylene Production in the gynoecium is induced by a factor(s) other than pollination signals in carnation flowers lacking anthers, (3) there are two subsets of Ethylene responses in the petals, one responsible for autocatalytic Ethylene Production and the other for wilting, (4) expression of genes involved in the execution of petal withering is differently regulated between Ethylene-dependent or -independent senescence. Furthermore, it was revealed that the generation of transgenic carnation without detectable Ethylene Production is useful to prolong the vase life of cut carnation flowers.
-
Repressed Ethylene Production in the gynoecium of long-lasting flowers of the carnation 'White candle': role of the gynoecium in carnation flower senescence
2004Co-Authors: Hideki Nukui, Sakiko Kudo, Atsushi Yamashita, Shigeru SatohAbstract:Ethylene Production and expression of Ethylene biosynthetic genes was investigated in senescing flowers of carnation (Dianthus caryophyllus L.) cultivars 'White Candle (WC)' and 'Light Pink Barbara (LPB)', with long and short vase-lives, respectively. Ethylene Production from the gynoecium and petals of senescing 'WC' flowers was below the limit of detection, in agreement with the repressed Ethylene Production from the whole flowers. However, exogenous Ethylene treatment caused the accumulation of transcripts for DC-ACS1 and DC-ACO1 genes in both the gynoecium and petals, resulting in Ethylene Production from the flowers. Moreover, application of ABA or IAA, which are known to exhibit their action through the induction of Ethylene synthesis in the gynoecium, to 'WC' flowers from their cut stem-end induced Ethylene Production and wilting in the flowers. These findings suggested that, in 'WC' flowers the mechanism of Ethylene biosynthesis, i.e. the induction of expression of genes for Ethylene biosynthesis and the action of resulting enzymes, was not defective, but that its function was repressed during natural senescence. Transcripts of DC-ACO1, DC-ACS3, and DC-ACS1 were present in the gynoecium of senescing 'LPB' flowers. In the gynoecium of senescing 'WC' flowers, however, the DC-ACO1 transcript was present, but the DC-ACS1 transcript was absent and the DC-ACS3 transcript was detected only in a small amount; the latter two were associated with the low rate of Ethylene Production in the gynoecium of 'WC' flowers. These findings indicated that the repressed Ethylene Production in 'WC' flowers during natural senescence is caused by the repressed Ethylene Production in the gynoecium, giving further support for the role of the gynoecium in regulating petal senescence in carnation flowers.
-
expression of genes responsible for Ethylene Production and wilting are differently regulated in carnation dianthus caryophyllus l petals
2000Co-Authors: Yusuke Kosugi, Kenichi Shibuya, Toshihito Yoshioka, Teruyoshi Hashiba, Nanako Tsuruno, Yujiro Iwazaki, Atsushi Mochizuki, Shigeru SatohAbstract:Carnation petals exhibit autocatalytic Ethylene Production and wilting during senescence. The autocatalytic Ethylene Production is caused by the expression of 1-aminocyclopropane-1-carboxylate (ACC) synthase and ACC oxidase genes, whereas the wilting of petals is related to the expression of the cysteine proteinase (CPase) gene. So far, it has been believed that the Ethylene Production and wilting are regulated in concert in senescing carnation petals, since the two events occurred closely in parallel with time. In the present study, we investigated the expression of these genes in petals of a transgenic carnation harboring a sense ACC oxidase transgene and in petals of carnation flowers treated with 1,1-dimethyl-4-(phenylsulfonyl)semicarbazide (DPSS). In petals of the transgenic carnation flowers, treatment with exogenous Ethylene caused accumulation of the transcript for CPase and in-rolling (wilting), whereas it caused no or little accumulation of the transcripts for ACC oxidase and ACC synthase and negligible Ethylene Production. In petals of the flowers treated with DPSS, the transcripts for ACC synthase and ACC oxidase were accumulated, but no significant change in the level of the transcript for CPase was observed. These results suggest that the expression of ACC synthase and ACC oxidase genes, which leads to Ethylene Production, is differentially regulated from the expression of CPase, which leads to wilting, in carnation petals.
Kazuo Ichimura - One of the best experts on this subject based on the ideXlab platform.
-
Ethylene Production associated with petal senescence in carnation flowers is induced irrespective of the gynoecium.
2014Co-Authors: Kazuo Ichimura, Tomoko NikiAbstract:To clarify whether climacteric-like increases in Ethylene Production of senescing petals are also induced in the absence of the gynoecium in cut carnation (Dianthus caryophyllus cv. Barbara) flowers, we compared Ethylene Production and expression of Ethylene-biosynthesis genes in detached petals and in petals, which remained on flowers (attached petals). No significant difference in longevity was observed between the attached and detached petals when held in distilled water, and both showed the inward rolling typical of senescing flowers. Treatment with silver thiosulfate complex (STS), an Ethylene inhibitor, similarly delayed senescence of attached and detached petals. Climacteric-like increases in Ethylene Production of petals and gynoecium started on the same day, with similar bursts in attached and detached petals. Transcript levels of DcACS1 and DcACO1 were very low at harvest and increased similarly during senescence in both petal groups. Removal of the gynoecium did not significantly delay wilting of attached petals. In flowers with the gynoecium removed, the petals produced most of the Ethylene while Production by the other floral organs was very low, suggesting that wound-induced Ethylene is not the reason for the ineffectiveness of gynoecium-removal in inhibiting flower senescence. These results indicate that Ethylene biosynthesis is induced in carnation petals irrespective of the gynoecium.
-
heterologous expression of a mutated carnation Ethylene receptor gene dc etr1nr suppresses petal abscission and autocatalytic Ethylene Production in transgenic torenia fournieri lind
2011Co-Authors: Koji Tanase, R Aida, Natsu Tanikawa, Masayasu Nagata, Hiroyasu Yamaguchi, Kazuo IchimuraAbstract:The mutated carnation Ethylene receptor gene Dc-ETR1nr was introduced into Torenia fournieri Lind. This gene contains a missense mutation causing conversion of a Pro36 residue of the carnation Ethylene receptor protein Dc-ETR1 to Leu36, as occurs with the tomato mutant gene Never-ripe (Nr). Agrobacterium transformation of Torenia was performed, and four putative transgenic plants with Dc-ETR1nr were obtained. Real-time RT-PCR analysis confirmed Dc-ETR1nr mRNA expression in all transgenic plants. Unlike wild-type plants and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) transgenic plants, none of the transgenic plants showed flower abscission in response to Ethylene treatment. Flower life in all Dc-ETR1nr transgenic plants following wounding or Ethylene treatment was longer than that in wild-type plants. Levels of autocatalytic Ethylene Production in all transgenic plants following wounding or pollination treatment were lower than those in wild-type plants. These results indicate that transgenic plants expressing Dc-ETR1nr have reduced Ethylene sensitivity, resulting in inhibition of autocatalytic Ethylene Production and flower senescence.
-
Ethylene sensitivity and changes in Ethylene Production during senescence in long lived delphinium flowers without sepal abscission
2009Co-Authors: Koji Tanase, Koji Tokuhiro, Masayuki Amano, Kazuo IchimuraAbstract:Abstract We investigated changes in Ethylene Production, sensitivity, effects of Ethylene inhibitors and levels of Ethylene receptor genes to determine factors responsible for long-lived flowers in a Delphinium line ‘B-10’. Flower longevity of ‘B-10’ was clearly longer than that of the control cultivar ‘Bellamosum’, and sepals of ‘B-10’ did not abscise. ‘B-10’ did not show the climacteric-like Ethylene Production during flower senescence but constitutively produced Ethylene from days 0 to 9. The Ethylene inhibitors silver thiosulfate (STS) and aminoethoxyvinylglycine (AVG) extended flower longevity in both cultivars. Exogenous Ethylene treatment did not affect flower longevity but did increase Ethylene Production in ‘B-10’. These results suggest that low sensitivity to Ethylene is responsible for long-lived ‘B-10’ flowers, and may suppress climacteric-like Ethylene Production.
-
Ethylene Production by gynoecium and receptacle is associated with sepal abscission in cut Delphinium flowers.
2009Co-Authors: Kazuo Ichimura, Hiroko Shimizu-yumoto, Rie GotoAbstract:Abstract Delphinium flowers are sensitive to Ethylene, and exposure to Ethylene is known to accelerate sepal abscission. The relationship of Ethylene to sepal abscission in cut Delphinium flowers was investigated. The gynoecium and receptacle each contributed to climacteric-like increases in Ethylene Production whereas the sepals, petals and stamens did not. 1-Aminocyclopropane-1-carboxylic acid (ACC) concentration, ACC synthase and ACC oxidase activities in the gynoecium and receptacle increased in the senescing flowers. Wounding of the gynoecium or receptacle accelerated abscission of sepals, which was accompanied by a marked increase in Ethylene Production. Accelerated sepal abscission was counteracted by treatment with silver thiosulphate complex (STS), an inhibitor of Ethylene action. The results of this study show that Ethylene produced by the gynoecium and receptacle is closely associated with sepal abscission in cut Delphinium flowers.
-
effects of the time of sucrose treatment on vase life soluble carbohydrate concentrations and Ethylene Production in cut sweet pea flowers
1999Co-Authors: Kazuo Ichimura, Kenichi SutoAbstract:Cut sweet pea flowers were put in vase water containing 200 mg l−1 8-hydroxyquinoline sulfate (HQS), and 100 g l−1 sucrose was added to the solution during the first 24 h (initial treatment), from the 24th h on (late treatment) or throughout the experimental period (continuous treatment). The vase life of the florets in the control (with no sucrose added), initial-, late-, and continuous-treatment groups were 2.8, 6.0, 5.0 and 8.0 days, respectively. Climacteric Ethylene Production of the florets was the earliest in the control group followed by the late-, initial- and continuous-treatment groups, in this order. The concentrations of glucose, fructose and s ucrose at the 2nd day and later were the highest in the continuous-treatment group followed by the initial-treatment, late-treatment and control group, in this order. Thus, the correlation between sugar concentrations in petals and vase life was positive, whereas that between the sugar concentrations and Ethylene Production was negative. These results suggest that sugar concentration in petals affects the vase life of cut sweet pea flowers through Ethylene Production.
Peter Lindblad - One of the best experts on this subject based on the ideXlab platform.
-
Increased Ethylene Production by overexpressing phosphoenolpyruvate carboxylase in the cyanobacterium Synechocystis PCC 6803.
2020Co-Authors: Claudia Durall, Pia Lindberg, Peter LindbladAbstract:Cyanobacteria can be metabolically engineered to convert CO2 to fuels and chemicals such as Ethylene. A major challenge in such efforts is to optimize carbon fixation and partition towards target molecules. The efe gene encoding an Ethylene-forming enzyme was introduced into a strain of the cyanobacterium Synechocystis PCC 6803 with increased phosphoenolpyruvate carboxylase (PEPc) levels. The resulting engineered strain (CD-P) showed significantly increased Ethylene Production (10.5 ± 3.1 µg mL−1 OD−1 day−1) compared to the control strain (6.4 ± 1.4 µg mL−1 OD−1 day−1). Interestingly, extra copies of the native pepc or the heterologous expression of PEPc from the cyanobacterium Synechococcus PCC 7002 (Synechococcus) in the CD-P, increased Ethylene Production (19.2 ± 1.3 and 18.3 ± 3.3 µg mL−1 OD−1 day−1, respectively) when the cells were treated with the acetyl-CoA carboxylase inhibitor, cycloxydim. A heterologous expression of phosphoenolpyruvate synthase (PPSA) from Synechococcus in the CD-P also increased Ethylene Production (16.77 ± 4.48 µg mL−1 OD−1 day−1) showing differences in the regulation of the native and the PPSA from Synechococcus in Synechocystis. This work demonstrates that genetic rewiring of cyanobacterial central carbon metabolism can enhance carbon supply to the TCA cycle and thereby further increase Ethylene Production.