| gerbera hybrida (asteraceae) imposes regulation at several anatomical levels during inflorescence development on the gene for dihydroflavonol-4-reductase. | in the ornamental cut flower plant gerbera hybrida the spatial distribution of regulatory molecules characteristic of differentiation of the composite inflorescence is visualized as the various patterns of anthocyanin pigmentation of different varieties. in order to identify genes that the plant can regulate according to these anatomical patterns, we have analysed gene expression affecting two enzymatic steps, chalcone synthase (chs) and dihydroflavonol-4-reductase (dfr), in five gerbera varieti ... | 1995 | 7640364 |
| chalcone synthase-like genes active during corolla development are differentially expressed and encode enzymes with different catalytic properties in gerbera hybrida (asteraceae). | recent studies on chalcone synthase (chs) and the related stilbene synthase (sts) suggest that the structure of chs-like genes in plants has evolved into different forms, whose members have both different regulation and capacity to code for different but related enzymatic activities. we have studied the diversity of chs-like genes by analysing the structure, expression patterns and catalytic properties of the corresponding enzymes of three genes that are active during corolla development in gerb ... | 1995 | 7787187 |
| a corolla- and carpel-abundant, non-specific lipid transfer protein gene is expressed in the epidermis and parenchyma of gerbera hybrida var. regina (compositae). | we are examining the floral organ differentiation in compositae by isolating and characterizing corolla abundant genes. differential screening of a cdna library made from the ray floret corolla of gerbera hybrida var. regina revealed an abundant cdna clone which is expressed in the corolla but not in leaves. this cdna (gltp1) codes for a polypeptide similar to non-specific lipid transfer proteins of the plants. the gltp1 gene is expressed only in the corolla and carpels and is developmentally re ... | 1994 | 8000009 |
| cloning of cdna coding for dihydroflavonol-4-reductase (dfr) and characterization of dfr expression in the corollas of gerbera hybrida var. regina (compositae). | we are approaching corolla differentiation in compositae by studying the regulation of flavonoid pathway genes during inflorescence development in gerbera. we have cloned a dfr cdna from a ray floret corolla cdna library of gerbera hybrida var. regina by a pcr technique based on homologies found in genes isolated from other plant species. the functionality of the clone was tested in vivo by complementing the dihydrokaempferol accumulating petunia mutant line rl01. by southern blot analysis, g. h ... | 1993 | 8507822 |
| duplication and functional divergence in the chalcone synthase gene family of asteraceae: evolution with substrate change and catalytic simplification. | plant-specific polyketide synthase genes constitute a gene superfamily, including universal chalcone synthase [chs; malonyl-coa:4-coumaroyl-coa malonyltransferase (cyclizing) (ec 2.3.1.74)] genes, sporadically distributed stilbene synthase (ss) genes, and atypical, as-yet-uncharacterized chs-like genes. we have recently isolated from gerbera hybrida (asteraceae) an unusual chs-like gene, gchs2, which codes for an enzyme with structural and enzymatic properties as well as ontogenetic distribution ... | 1996 | 8799149 |
| a bhlh transcription factor mediates organ, region and flower type specific signals on dihydroflavonol-4-reductase (dfr) gene expression in the inflorescence of gerbera hybrida (asteraceae). | the angiosperm family asteraceae is characterized by composite inflorescences, which are highly organized structures consisting of different types of flowers. in order to approach the control of floral organ differentiation in asteraceae at molecular level, we are studying regulation of flavonoid biosynthesis in gerbera hybrida. dihydroflavonol-4-reductase (dfr) expression is regulated according to anthocyanin pigmentation patterns in all tested gerbera varieties at several anatomical levels. we ... | 1998 | 9807831 |
| organ identity genes and modified patterns of flower development in gerbera hybrida (asteraceae) | we have used gerbera hybrida (the cultivated ornamental, gerera) to investigate the molecular basis of flower development in asteraceae, a family of flowering plants that have heteromorphic flowers and specialized floral organs. flowers of the same genotype may differ in a number of parameters, including sex expression, symmetry, sympetaly and pigmentation. in order to study the role of organ identity determination in these phenomena we isolated and functionally analysed six mads box genes from ... | 1999 | 10069067 |
| geg participates in the regulation of cell and organ shape during corolla and carpel development in gerbera hybrida | the molecular mechanisms that control organ shape during flower development are largely unknown. by using differential hybridization techniques, a cdna designated geg (for gerbera hybrida homolog of the gibberellin [ga]-stimulated transcript 1 [gast1] from tomato) was isolated from a library representing late stages of corolla development in gerbera. geg expression was detected in corollas and carpels, with expression spatiotemporally coinciding with flower opening. in corollas and styles, geg e ... | 1999 | 10368180 |
| a deficiens homologue is down-regulated during apomictic initiation in ovules of hieracium. | hieracium is a member of the asteraceae family, and contains sexual species in addition to apomictic species that reproduce by apospory and produce seed without fertilization. a homologue of the floral organ-identity gene deficiens (def) was isolated from an apomictic line of hieracium piloselloides (vill.) following differential display between mature ovules and those initiating autonomous embryogenesis. the gene termed hpdef has 93% amino acid identity with gdef2, a def homologue isolated from ... | 2000 | 10872222 |
| grcd1, an agl2-like mads box gene, participates in the c function during stamen development in gerbera hybrida. | despite the differences in flower form, the underlying mechanism in determining the identity of floral organs is largely conserved among different angiosperms, but the details of how the functions of a, b, and c are specified varies greatly among plant species. here, we report functional analysis of a gerbera mads box gene, grcd1, which is orthologous to agl2-like mads box genes. members of this group of genes are being reported in various species in growing numbers, but their functions remained ... | 2000 | 11041884 |
| an orchid (oncidium gower ramsey) ap3-like mads gene regulates floral formation and initiation. | cdna for a b group mads box gene omads3 was isolated and characterized from oncidium gower ramsey, an important species of orchid. omads3 encoding a 204 amino acid protein showed high sequence homology to both paleoap3 and tm6 lineage of b group mads box gene such as monocots ap3 homologue lmads1 in lily and gdef1 in gerbera hybrida. despite the sequence homology, consensus motifs identified in the c-terminal region of b group genes were absent in omads3. southern analysis indicated that omads3 ... | 2002 | 12407200 |
| application of centrifugal force to the extraction and separation of parasorboside and gerberin from gerbera hybrida. | a method for the separation of parasorboside and gerberin from the ornamental plant gerbera hybrida (asteraceae) has been developed. the two closely related glucosides were extracted using an extrachrom instrument, a prototype multi-functional separation tool equipped with an extraction chamber. the rotation planar extraction procedure was compared with that of a medium pressure solid-liquid extraction system. the resulting extracts were pre-purified using rotation planar chromatography and the ... | 2002 | 12494754 |
| activation of anthocyanin biosynthesis in gerbera hybrida (asteraceae) suggests conserved protein-protein and protein-promoter interactions between the anciently diverged monocots and eudicots. | we have identified an r2r3-type myb factor, gmyb10, from gerbera hybrida (asteraceae) that shares high sequence homology to and is phylogenetically grouped together with the previously characterized regulators of anthocyanin pigmentation in petunia (petunia hybrida) and arabidopsis. gmyb10 is able to induce anthocyanin pigmentation in transgenic tobacco (nicotiana tabacum), especially in vegetative parts and anthers. in g. hybrida, gmyb10 is involved in activation of anthocyanin biosynthesis in ... | 2003 | 14605235 |
| analysis of the floral transcriptome uncovers new regulators of organ determination and gene families related to flower organ differentiation in gerbera hybrida (asteraceae). | development of composite inflorescences in the plant family asteraceae has features that cannot be studied in the traditional model plants for flower development. in gerbera hybrida, inflorescences are composed of morphologically different types of flowers tightly packed into a flower head (capitulum). individual floral organs such as pappus bristles (sepals) are developmentally specialized, stamens are aborted in marginal flowers, petals and anthers are fused structures, and ovaries are located ... | 2005 | 15781570 |
| microbial synthesis of triacetic acid lactone. | native g2ps1-encoded 2-pyrone synthase (2-ps) from gerbera hybrida, a mutant brevibacterium ammoniagenes fatty acid synthase b (fas-b) and two different mutants of penicillium patulum 6-methylsalycilic acid synthase (6-msas) are examined to identify the best enzyme to recruit for the microbial synthesis of triacetic acid lactone (tal). to identify the best microbial host for these evaluations, the native tal-synthesizing activity of g2ps1-encoded 2-ps is expressed in recombinant escherichia coli ... | 2006 | 16245348 |
| anthocyanidin synthase from gerbera hybrida catalyzes the conversion of (+)-catechin to cyanidin and a novel procyanidin. | anthocyanidins were proposed to derive from (+)-naringenin via (2r,3r)-dihydroflavonol(s) and (2r,3s,4s)-leucocyanidin(s) which are eventually oxidized by anthocyanidin synthase (ans). recently, the role of ans has been put into question, because the recombinant enzyme from arabidopsis exhibited primarily flavonol synthase (fls) activity with negligible ans activity. this and other studies led to the proposal that ans as well as fls may select for dihydroflavonoid substrates carrying a "beta-fac ... | 2006 | 16494872 |
| patterns of mads-box gene expression mark flower-type development in gerbera hybrida (asteraceae). | the inflorescence of the cut-flower crop gerbera hybrida (asteraceae) consists of two principal flower types, ray and disc, which form a tightly packed head, or capitulum. despite great interest in plant morphological evolution and the tractability of the gerbera system, very little is known regarding genetic mechanisms involved in flower type specification. here, we provide comparative staging of ray and disc flower development and microarray screening for differentially expressed genes, accomp ... | 2006 | 16762082 |
| mining plant diversity: gerbera as a model system for plant developmental and biosynthetic research. | gerbera hybrida is a member of the large sunflower family (asteraceae). typical of asteraceae, gerbera bears different types of flowers in its inflorescence. the showy marginal flowers comprise elongate, ligulate corollas that are female, whereas the central and inconspicuous disc flowers are complete, with both male and female organs. as such, gerbera offers great potential for comparative developmental research within a single genotype. moreover, different gerbera varieties show an impressive ... | 2006 | 16850408 |
| reproductive meristem fates in gerbera. | flowering plants go through several phases between regular stem growth and the actual production of flower parts. the stepwise conversion of vegetative into inflorescence and floral meristems is usually unidirectional, but under certain environmental or genetic conditions, meristems can revert to an earlier developmental identity. vegetative meristems are typically indeterminate, producing organs continuously, whereas flower meristems are determinate, shutting down their growth after reproductiv ... | 2006 | 17023564 |
| redirection of anthocyanin synthesis in osteospermum hybrida by a two-enzyme manipulation strategy. | modern biotechnology has developed powerful tools for genetic engineering and flower colours are an excellent object to study possibilities and limitations of engineering strategies. osteospermum hybrida became a popular ornamental plant within the last 20 years. many cultivars display rose to lilac flower colours mainly based on delphinidin-derived anthocyanins. the predominant synthesis of delphinidin derivatives is referred to a strong endogenous flavonoid 3',5'-hydroxylase (f3'5'h) activity. ... | 2007 | 17286993 |
| transcriptional analysis of petal organogenesis in gerbera hybrida. | understanding of the molecular interplay, which determines early steps of flower formation has grown considerably during last years. in contrast, genetic actions responsible for how flower organs acquire their size and shape at later phases of organogenesis are still poorly understood. we have exploited the large and anatomically simple gerbera (gerbera hybrida var. terra regina) ray flower petals to describe transcriptional changes during organogenesis. gerbera 9 k cdna microarray was utilized ... | 2007 | 17334783 |
| flavone synthases from medicago truncatula are flavanone-2-hydroxylases and are important for nodulation. | flavones are important copigments found in the flowers of many higher plants and play a variety of roles in plant adaptation to stress. in medicago species, flavones also act as signal molecules during symbiotic interaction with the diazotropic bacterium sinorhizobium meliloti. they are the most potent nod gene inducers found in root exudates. however, flavone synthase ii (fns ii), the key enzyme responsible for flavone biosynthesis, has not been characterized in medicago species. we cloned two ... | 2007 | 17434990 |
| expression of xyloglucan endotransglycosylases of gerbera hybrida and betula pendula in pichia pastoris. | the plant enzyme xyloglucan endotransglycosylase (xet; ec 2.4.1.207, xyloglucan:xyloglucosyl transferase) participates in selective modification of plant cell walls during cell growth. xets are potential catalysts in various applications. here, sequences encoding two xets from gerbera hybrida and betula pendula are reported. the encoded proteins, which are 51% identical at the amino acid level, were expressed in the yeast pichia pastoris in secreted form with the aid of mating factor alpha signa ... | 2007 | 17462775 |
| identification of the molecular basis for the functional difference between flavonoid 3'-hydroxylase and flavonoid 3',5'-hydroxylase. | flavonoid 3'-hydroxylase (f3'h) and flavonoid 3',5'-hydroxylase (f3'5'h) are cytochrome p450 enzymes and determine the b-ring hydroxylation pattern of flavonoids by introducing hydroxyl groups at the 3'- or the 3'- and 5'-position, respectively. sequence identity between f3'h and f3'5'h is generally low since their divergence took place early in the evolution of higher plants. however, in the asteraceae the family-specific evolution of an f3'5'h from an f3'h precursor occurred, and consequently ... | 2007 | 17612530 |
| comparison of transgenic gerbera hybrida lines and traditional varieties shows no differences in cytotoxicity or metabolic fingerprints. | genetic modification using gene transfer (gm) is still controversial when applied to plant breeding at least in europe. one major concern is how gm affects other genes and thus the metabolism of the plant. in this study, 225 genetically modified lines of the ornamental plant gerbera hybrida and 42 non-gm gerbera varieties were used to investigate changes in secondary metabolism. the cytotoxicity of gm and non-gm gerbera extracts was evaluated on human cell lines derived from lung, liver, and int ... | 2008 | 18231872 |
| exogenous ammonium inhibits petal pigmentation and expansion in gerbera hybrida. | petal pigmentation is the most important aspect in natural flower coloration. in the present study, the inhibition of petal pigmentation by exogenous ammonium was investigated. ray floret petals detached from inflorescences of gerbera hybrida (shenzhen no. 5) were cultured in vitro on media supplied with different forms of nitrogen and its assimilated compounds. the expression of a set of genes involved in anthocyanin biosynthesis and regulation was determined by northern blotting assay. it was ... | 2008 | 18346082 |
| prgl: a cell wall proline-rich protein containning gasa domain in gerbera hybrida. | prps (proline-rich proteins) are a group of cell wall proteins characterized by their proline and hydroproline-rich repetitive peptides. the expression of prps in plants is stimulated by wounding and environmental stress. gasa (gibberellic acid stimulated in arabidopsis) proteins are small peptides sharing a 60 amino acid conserved c-terminal domain containing twelve invariant cysteine residues. most of gasas reported are localized to apoplasm or cell wall and their expression was regulated by g ... | 2008 | 18488172 |
| a tcp domain transcription factor controls flower type specification along the radial axis of the gerbera (asteraceae) inflorescence. | several key processes in plant development are regulated by tcp transcription factors. cycloidea-like (cyc-like) tcp domain proteins have been shown to control flower symmetry in distantly related plant lineages. gerbera hybrida, a member of one of the largest clades of angiosperms, the sunflower family (asteraceae), is an interesting model for developmental studies because its elaborate inflorescence comprises different types of flowers that have specialized structures and functions. the morpho ... | 2008 | 18574149 |
| identification of target genes for a myb-type anthocyanin regulator in gerbera hybrida. | genetic modification of the flavonoid pathway has been used to produce novel colours and colour patterns in ornamental plants as well as to modify the nutritional and pharmaceutical properties of food crops. it has been suggested that co-ordinate control of multiple steps of the pathway with the help of regulatory genes would lead to a more predictable control of metabolic flux. regulation of anthocyanin biosynthesis has been studied in a common ornamental plant, gerbera hybrida (asteraceae). an ... | 2008 | 18725377 |
| gt1-7 cell-based cytoxicity screening assay on 96-well microplates as a platform for the safety assessment of genetically modified gerbera hybrida extracts. | in this investigation, a gt1-7 cell-based cytotoxicity screening assay in 96-well microplates was set up. the assay, using propidium iodide fluorescence, was proven to be reliable, with good quality (z' = 0.51) and low plate-to-plate and day-to-day variations. further on, a library containing extracts from 227 genetic modification (gm) gerbera hybrida and 42 gerbera varieties was screened; however, no differences between them were found. based on these findings, we propose the use of the current ... | 2009 | 19514948 |
| functional characterization of b class mads-box transcription factors in gerbera hybrida. | according to the classical abc model, b-function genes are involved in determining petal and stamen development. most core eudicot species have b class genes belonging to three different lineages: the pi, euap3, and tm6 lineages, although both arabidopsis and antirrhinum appear to have lost their tm6-like gene. functional studies were performed for three gerbera (gerbera hybrida) b class mads-box genes--pi/glo-like gglo1, euap3 class gdef2, and tm6-like gdef1--and data are shown for a second eua ... | 2010 | 19767305 |
| temporal and spatial expression analysis of prgl in gerbera hybrida. | gasa-like genes form multigene families in diverse plant species and encode the proteins with a unique cysteine-rich domain (gasa domain). in our previously work, we cloned a gasa-like gene prgl (proline-rich gasa-like) from gerbera. here we report the expression profiles of prgl and the subcellular localization of prgl protein. multiple sequence alignment of the gasa domains indicates that prgl shows the highest homology to atprgl (73.3% of amino acid identity) from arabidopsis. phylogenic anal ... | 2010 | 19885740 |
| characterization of squamosa-like genes in gerbera hybrida, including one involved in reproductive transition. | the flowering process in plants proceeds through the induction of an inflorescence meristem triggered by several pathways. many of the genes associated with both the flowering process and floral architecture encode transcription factors of the mads domain family. gerbera, a member of the sunflower family, asteraceae, bears compressed inflorescence heads (capitula) with three different flower types characterized by differences in both sexuality and floral symmetry. to understand how such a comple ... | 2010 | 20579337 |
| large scale interaction analysis predicts that the gerbera hybrida floral e function is provided both by general and specialized proteins. | the ornamental plant gerbera hybrida bears complex inflorescences with morphologically distinct floral morphs that are specific to the sunflower family asteraceae. we have previously characterized several mads box genes that regulate floral development in gerbera. to study further their behavior in higher order complex formation according to the quartet model, we performed yeast two- and three-hybrid analysis with fourteen gerbera mads domain proteins to analyze their protein-protein interaction ... | 2010 | 20579338 |
| polyketide derivatives active against botrytis cinerea in gerbera hybrida. | a previously isolated cdna molecule from gerbera hybrida (asteraceae) codes for a new chalcone synthase-like polyketide synthase, 2-pyrone synthase (2ps). 2ps is able to synthesise 4-hydroxy-6-methyl-2-pyrone (triacetolactone), a putative precursor for gerberin and parasorboside, two abundant glucosides in gerbera. in this study, we show that gerbera plants transformed with the gene for 2ps in an antisense orientation and unable to synthesise gerberin and parasorboside are susceptible to botryti ... | 2010 | 20878179 |
| over-expression of the gerbera hybrida at-soc1-like1 gene gh-soc1 leads to floral organ identity deterioration. | background and aims the family of mads box genes is involved in a number of processes besides controlling floral development. in addition to supplying homeotic functions defined by the abc model, they influence flowering time and transformation of vegetative meristem into inflorescence meristem, and have functions in roots and leaves. three gerbera hybrida at-soc1-like genes (gh-soc1-gh-soc3) were identified among gerbera expressed sequence tags. methods evolutionary relationships between soc1-l ... | 2011 | 21572092 |
| [determination of nano-silver spatiotemporal distribution in cut gerbera flowers by icp-aes]. | the spatiotemporal distribution of nano-silver in cut gerbera (gerbera hybrida cv. crossfire) flowers were determined by inductively coupled plasma-atomic emission spectrometry technique (icp-aes). the relative standard deviations of this method were between 0.14% and 2.89%, and the recovery ratio obtained by standard addition method ranged from 93.33% to 106.67%. the method was proved to be simple, rapid, reliable and highly sensitive, which can meet the demands of actual sample analysis. the e ... | 2011 | 22007427 |
| evolution and diversification of the cyc/tb1 gene family in asteraceae - a comparative study in gerbera (mutisieae) and sunflower (heliantheae). | plant-specific tcp domain transcription factors have been shown to regulate morphological novelties during plant evolution, including the complex architecture of the asteraceae inflorescence that involves different types of flowers. we conducted comparative analysis of the cycloidea/teosinte branched1 (cyc/tb1) gene family in gerbera hybrida (gerbera) and helianthus annuus (sunflower), two species that represent distant tribes within asteraceae. our data confirms that the cyc/tb1 gene family has ... | 2011 | 22101417 |
| cell expansion and microtubule behavior in ray floret petals of gerbera hybrida: responses to light and gibberellic acid. | it is still unclear how light and gibberellins are integrated to regulate petal size. here, we report that light improves both the length and the width of the ray floret petals in g. hybrid, but ga(3) promotes only the petal length. it is also revealed that the control of the petal size by light and ga(3) depends on modulating the cell size, which is governed by the behavior of cortical microtubule.light and gibberellins are important regulators of plant organ growth. however, little is known ab ... | 2011 | 22020373 |