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Satoh S.,Kyoto Prefectural University | Satoh S.,Kyoto Prefectural Institute of Agricultural Biotechnology | Kosugi Y.,Kagawa University | Sugiyama S.,Kyoto Prefectural University | Ohira I.,Kagawa University
Journal of the Japanese Society for Horticultural Science | Year: 2014

2,4-Pyridinedicarboxylic acid (PDCA) is a structural analog of 2-oxoglutarate and has been shown to inhibit 2-oxoglutarate-dependent dioxygenases by competing with 2-oxoglutarate, and ethylene production in detached carnation flowers by competing with ascorbate on 1-aminocyclopropane-1-carboxylate (ACC) oxidase action. In the present study, the inhibition of ACC oxidase action by PDCA was confirmed with a recombinant enzyme produced in Escherichia coli from carnation DcACO1 cDNA. PDCA had various effects on ethylene production in cut 'Light Pink Barbara (LPB)' carnation flowers; ethylene production was accelerated or delayed in some flowers, whereas it did not change in others as compared to untreated control flowers. This varied action of PDCA may be caused by its possible combined actions; that is, inhibition of ACC oxidase action as well as its action on unidentified biochemical processes which use 2-oxoglutarate as a co-substrate, such as the biosynthesis and inactivation of gibberellins. Meanwhile, PDCA treatment significantly prolonged the vase life of bunches of cut 'LPB' carnation flowers; the magnitude of the extension of vase life was 53, 111, and 135% at 0.3, 1, and 2 mM PDCA, respectively, as compared with the non-treated control. Also, PDCA lengthened the vase life of 'Mule' carnation flowers. The present findings suggest the potential of PDCA as a preservative for cut flowers of spray carnations. © 2014 The Japanese Society for Horticultural Science (JSHS), All right reserved.


Sugiyama S.,Kyoto Prefectural University | Morita S.,Kyoto Prefectural Institute of Agricultural Biotechnology | Satoh S.,Kyoto Prefectural Institute of Agricultural Biotechnology
Journal of Applied Horticulture | Year: 2015

Previously we have developed a method, which uses two criteria, 'time to flower opening∗ and Vase life', for characterizing flower opening profiles in cut spray-type flowers of carnation. These two criteria were used to evaluate the activities of flower preservatives, which accelerate flower bud opening, resulting in shortening the time to flower opening, and delay senescence, resulting in extension of vase life. In the present study, we developed the third criterion 'gross flower opening∗ which characterizes the ability of flower buds to open. Using this criterion the activity of analogs of pyridinedicarboxylic acids was successfully evaluated in addition to the previously-reported evaluation of their activity of acceleration of flower bud opening and extension of vase life.


Satoh S.,Kyoto Prefectural University | Satoh S.,Kyoto Prefectural Institute of Agricultural Biotechnology | Miyai M.,Kyoto Prefectural University | Sugiyama S.,Kyoto Prefectural University | Toyohara N.,Research Institute of Environment
Journal of the Japanese Society for Horticultural Science | Year: 2013

Palatinose (isomaltulose) is an analog of sucrose and was regarded as non-metabolizable in plant tissues until recently. In the present study, we found that crude extracts from carnation petals had activity to hydrolyze palatinose. Preliminary characterization of this activity using a crude enzyme extract from 'Lillian' carnation petals revealed that hydrolyzing activity was exhibited by α-glucosidase, which uses isomaltose and palatinose, both being α-1,6-glucosides, as substrates. Exogenous application of palatinose stimulated flower opening of carnation cultivars (Dianthus caryophyllus 'Lillian', 'Pure Red', and 'Light Pink Barbara'), but suppressed it in D. barbatus 'Shin-higuruma'. Palatinose-hydrolyzing activity was much higher in the extract from carnation than that from D. barbatus. These observations suggested that palatinose stimulated flower opening in carnation by supplying glucose and fructose, but suppressed it in D. barbatus, probably through the inhibition of general metabolism, similar to the action of α-glucosidase, caused by its excess accumulation. © 2013.


Satoh S.,Kyoto Prefectural University | Satoh S.,Kyoto Prefectural Institute of Agricultural Biotechnology | Tateishi A.,Nihon University | Sugiyama S.,Kyoto Prefectural University
Journal of the Japanese Society for Horticultural Science | Year: 2013

A mixture of xyloglucan oligosaccharides (XGO) was prepared from xyloglucan (XG) of tamarind seed gum by digestion with Aspergillus recombinant XG-specific xyloglucanase and subsequent purification by ethanol fractionation. The XGO mixture contained XG7, XG8, and XG9 at the ratio of 1: 4: 5, which was almost identical to the literature value of constituent subunits ratio of 1.2: 3.8: 5. The XGO mixture at 1% promoted flower opening in carnation (Dianthus caryophyllus L.) cultivars, such as 'Pure Red' and 'Lillian'. On the other hand, there was no effect on other cultivars, such as 'Collin', 'Light Pink Barbara', and 'Mule'. Promotion of flower opening by 1% XGO was exhibited earlier than that by glucose or sucrose at 1% in 'Pure Red' carnation. Separate application of XG7 or XG9 stimulated flower opening in 'Pure Red' carnation, suggesting that all the constituents in the XGO mixture were effective in stimulating flower opening. Based on these observations, the mechanism of action of XGO on carnation flower opening and its future practical use as a flower-opening agent are discussed. © 2013.


Harada T.,Kyoto Prefectural University | Torii Y.,Kyoto Prefectural University | Morita S.,Kyoto Prefectural University | Morita S.,Kyoto Prefectural Institute of Agricultural Biotechnology | And 6 more authors.
Journal of Experimental Botany | Year: 2011

Growth of petal cells is a basis for expansion and morphogenesis (outward bending) of petals during opening of carnation flowers (Dianthus caryophyllus L.). Petal growth progressed through elongation in the early stage, expansion with outward bending in the middle stage, and expansion of the whole area in the late stage of flower opening. In the present study, four cDNAs encoding xyloglucan endotransglucosylase/hydrolase (XTH) (DcXTH1-DcXTH4) and three cDNAs encoding expansin (DcEXPA1-DcEXPA3) were cloned from petals of opening carnation flowers and characterized. Real-time reverse transcription-PCR analyses showed that transcript levels of XTH and expansin genes accumulated differently in floral and vegetative tissues of carnation plants with opening flowers, indicating regulated expression of these genes. DcXTH2 and DcXTH3 transcripts were detected in large quantities in petals as compared with other tissues. DcEXPA1 and DcEXPA2 transcripts were markedly accumulated in petals of opening flowers. The action of XTH in growing petal tissues was confirmed by in situ staining of xyloglucan endotransglucosylase (XET) activity using a rhodamine-labelled xyloglucan nonasaccharide as a substrate. Based on the present findings, it is suggested that two XTH genes (DcXTH2 and DcXTH3) and two expansin genes (DcEXPA1 and DcEXPA2) are associated with petal growth and development during carnation flower opening. © 2010 The Author(s).


Satoh S.,Kyoto Prefectural University | Satoh S.,Kyoto Prefectural Institute of Agricultural Biotechnology
Journal of the Japanese Society for Horticultural Science | Year: 2011

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. JSHS © 2011.


Morita S.,Kyoto Prefectural University | Morita S.,Kyoto Prefectural Institute of Agricultural Biotechnology | Torii Y.,Kyoto Prefectural University | Harada T.,Kyoto Prefectural University | And 5 more authors.
Journal of the Japanese Society for Horticultural Science | Year: 2011

Flower opening in carnations (Dianthus caryophyllus L.) is the result of the enlargement of petal cells, which requires sugar metabolism. A cDNA encoding sucrose synthase (DcSUS1) was isolated from carnation petals as a candidate gene acting in the initial step of sugar metabolism in petal cells. DcSUS1 transcripts were detected abundantly in floral tissues of flowering carnation plants; the transcripts accumulated most in the petals and style followed by the ovary, whereas only small accumulation were found in stems, leaves, and calyces. Moreover, nearly constant accumulation of DcSUS1 transcripts was found in the petals during flower opening, fully open, and early senescence periods, whereas decreasing accumulation was detected in petals when senescence progressed. These findings suggested the involvement of DcSUS1 expression in petal cell growth during the opening of carnation flowers. JSHS © 2011.


Sugiyama S.,Kyoto Prefectural University | Satoh S.,Kyoto Prefectural University | Satoh S.,Kyoto Prefectural Institute of Agricultural Biotechnology
Horticulture Journal | Year: 2015

2,4-Pyridinedicarboxylic acid (2,4-PDCA) was shown to prolong the vase life of cut flowers of spray-type ‘Light Pink Barbara’ (LPB) carnation, mainly due to the reduced ethylene production caused by inhibition of 1-aminocyclopropane-1-carboxylate oxidase in the flowers. In addition, 2,4-PDCA has been suggested to accelerate flower opening in the flowers (Satoh et al., 2014). In the present study, we successfully developed a procedure to evaluate the activity of chemicals to accelerate flower (bud) opening by determining the shortened time (in days) to flower opening. Using this procedure, we could show the activities of several PDCA analogs to accelerate flower opening, in addition to their already-known activity to extend the vase life in cut flowers of ‘LPB’ carnation. Judging from their effectiveness in the acceleration of flower opening and extension of vase life, 2,3-PDCA and 2,4-PDCA were thought to be suitable agents for treatment of the flowers. The present study confirmed that PDCAs accelerate flower opening and retard senescence, which increase the number of open flowers, resulting in extension of the vase life of cut flowers of ‘LPB’ carnation. © 2015 The Japanese Society for Horticultural Science (JSHS), All rights reserved.


Harada T.,Kyoto Prefectural University | Torii Y.,Kyoto Prefectural University | Morita S.,Kyoto Prefectural University | Morita S.,Kyoto Prefectural Institute of Agricultural Biotechnology | And 4 more authors.
Journal of Experimental Botany | Year: 2010

Flower opening is an event accompanied by morphological changes in petals which include elongation, expansion, and outward-curving. Petal cell growth is a fundamental process that underlies such phenomena, but its molecular mechanism remains largely unknown. Suppression subtractive hybridization was performed between petals during the early elongation period (stage 1) and during the opening period (stage 5) in carnation flowers and a pair of subtraction libraries abundant in differentially expressed genes was constructed at each stage. 393 cDNA clones picked up by differential screening out of 1728 clones were sequenced and 235 different cDNA fragments were identified, among which 211 did not match any known nucleotide sequence of carnation genes in the databases. BLASTX search of nucleotide sequences revealed that putative functions of the translational products can be classified into several categories including transcription, signalling, cell wall modification, lipid metabolism, and transport. Open reading frames of 15 selected genes were successfully determined by rapid amplification of cDNA ends (RACE). Time-course analysis of these genes by real-time RT-PCR showed that transcript levels of several genes correlatively fluctuate in petals of opening carnation flowers, suggesting an association with the morphological changes by elongation or curving. Based on the results, it is suggested that the growth of carnation petals is controlled by co-ordinated gene expression during the progress of flower opening. In addition, the possible roles of some key genes in the initiation of cell growth, the construction of the cell wall and cuticle, and transport across membranes were discussed. © 2010 The Author(s).


Nomura Y.,Kyoto Prefectural University | Morita S.,Kyoto Prefectural University | Morita S.,Kyoto Prefectural Institute of Agricultural Biotechnology | Harada T.,Kyoto Prefectural University | And 3 more authors.
Journal of the Japanese Society for Horticultural Science | Year: 2012

We cloned seven cDNAs coding for ubiquitin (polyubiquitin) (DcUbq1-7) from carnation petals: DcUbq1, 2, 3 encoded polyubiquitins consisting of five ubiquitin monomers; DcUbq4, three monomers and DcUbq5, 6, 7, a monomer. The 3'-UTR nucleotide sequences were separated into three groups; two were specific to DcUbq1 and DcUbq2, respectively, and the third was almost always common to other genes (DcUbq3-7). The transcript levels of DcUbq1 and DcUbq2 in petals fluctuated during flower opening, whereas those of DcUbq3-7 remained unchanged except for an increase in the last stage. On the other hand, during flower senescence, the transcript levels of DcUbq1 and DcUbq2 increased at later stages, and those of DcUbq3-7 remained almost constant during the process. Based on these findings, we suggest an association of ubiquitin gene expression with petal growth during flower opening and petal wilting during the senescence of carnation flowers through the degradation of specific proteins by the ubiquitin-proteasome system. Furthermore, we showed the successful use of DcUbq3-7 transcripts as a normalizing standard in the determination of transcript levels of a target gene in senescing carnation petals, where massive degradation of RNA, such as actin mRNA and rRNA, usually occurs, causing inaccuracy in the estimation of transcript levels of interest. © 2012.

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