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The Global ETD Search service is a free service for researchers
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Showing 1 to 9 of 9 (0.018 seconds)Spelling suggestions: "subject:"dragon"" "subject:"aragon""
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GIS-based landscape visualisation for environmental managementAppleton, Katheryn Jennifer January 2003 (has links)
No description available.
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Quantitative analysis of petal morphology in Antirrhinum majus : an interdisciplinary approachRolland-Lagan, Anne-Gaëlle January 2003 (has links)
No description available.
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Rust of antirrhinumDoran, William Leonard 01 January 1917 (has links) (PDF)
The cultivated snapdragon ( Antirrhinum majus 3 .) is a perennial or biennial under culture, it is a member of the family Scrophulariaceae. The plant was introduced here from Europe. As an escape from gardens, it is rare in New England. The snapdragon has been a popular garden flower for two hundred years, but it is only within the last ten years that it has been grown to any extent as a greenhouse crop. There has been an increasing demand for it as a cut flower, and consequently an increasing amount of glass has been devoted to its culture. As a florist's crop, the snapdragon may be classed as about equal in importance to mignonette, schizanthus, stocks, pansies, and primulas (Nehrling, 1914), varying, of course, in different localities.
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Evaluation of High Tunnel and Field Produced Specialty Cut Flowers in the Northern Great PlainsKluza, Jacob January 2019 (has links)
The demand for local sustainably grown produce and flowers has increased (Low et al., 2015), and stimulated a growing interest in high tunnel production. The goal of this research project was to evaluate the production of cut flowers in high tunnel structures and in the field in the Northern Great Plains (NGP) region. The NGP offers unique climatic and environmental challenges based on its continental climate. Specialty cut flower cultivars Karma Irene and Chocolate dahlia (Dahlia x hybrida), Potomac White and Rocket Mix snapdragon (Antirrhinum majus), and Mariachi Misty Blue, Echo Blue and ABC2 lisianthus (Eustoma grandiflorum) were planted in both field and high tunnel environments at two soil temperature setpoints in the NGP to determine which of the selected crops are best suited for cut flower production. Our results indicate higher yields and more consistent quality in the high tunnel; however, the field was suitable for all species investigated.
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Mechanisms of complex programmed patterns of anthocyanin pigment formation in Antirrhinum majus : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philsophy in Plant Molecular Biology at Massey University, Palmerston North New ZealandPathirana, Nilangani Nadyeshda January 2007 (has links)
Antirrhinum majus is a model plant used in flower pigmentation studies. Anthocyanin pigment production is mainly controlled by regulation of transcription of the anthocyanin biosynthetic genes. Two types of transcription factors, M Y B and bHLH, together with a WD40 type co-regulator have been shown to regulate the transcription of the anthocyanin biosynthetic genes. In antirrhinum, in addition to the wild type Rosea 1 phenotype, in which pigmentation occurs throughout the inner and outer epidermis of the petal , other complex pigmentation patterns are observed, such as anthocyanins being produced only in the outer (abaxial) epidermis of both lobes and upper tube region of the dorsal petals (roseadorsea phenotype). The major objective of this research project was to understand the genetic regulatory system leading to the development of the two different floral pigmentation patterns in antirrhinum as a means to understanding differential regulation of gene expression in similar cells. Promoter deletion analysis coupled with linker scanning mutagenesis identified the - 1 62 bp to - 1 20 bp region of the Rosea l promoter as i mportant for the regulation of the Rosea l gene. Four putative transcription factor-binding sites within this region : a Wbox, a pyrimidine box, a DOF and a WRKY transcription factor binding site were shown to be important for Rosea l gene regulation. Promoter deletion analysis carried out on the rosea ldorsea promoter showed that the proximal 1 87 bp deletion was, surprisingly, not responsible for the roseadorsea phenotype. Cloning and characterisation of the Rosea l promoter sequence from various Antirrhinum species and accessions verified this finding. The rosealdorsea promoter analysis also indicated that - 1 5 1 bp of the promoter was sufficient for its expression as well as for the maintenance of petal specific expression. The rosea ldorsea allele was also shown to encode a functional protein . In situ hybridisation analysis showed that Rosea l transcripts were present in the inner and outer epidermis of the petal tissue of both wild type and roseadorsea petal tissue. Vascular expression of the Roseal mRNA is indicative of regulation of this gene through sugar or hormonal cues. However, rosea ldorsea transcript levels (in roseadorsea) were much lower than Roseal (wild type). Lowered expression of rosea ldorsea transcripts may be responsible for the overall weak pigmentation in the roseadorsea flowers. Analysis of the intron sequences of the two alleles revealed that many sequence changes were present in the intron 2 of rosea l dorsea. These changes may lead to instability or the lower expression of the rosea l dorsea mRNA and may be responsible for the roseadorsea phenotype. Another possibility is that a fourth Myb gene may be responsible for the roseadorsea phenotype. The role of the Deficiens gene in direct regulation of Rosea l was analysed by RNAi and bioinformatics-based methods. The presence of potential MADS box binding sites in the intron 2 region of the Roseal allele indicated that Rosea l might be directly regulated by Deficiens. Initial experiments using transient assays did not support this suggestion. However, silencing of Deficiens in wild type antirrhinum buds led to the loss of anthocyanin pigments in the petals. Further analysis of the RNAi tissue using SEM revealed that the proper development of conical shaped epidermal cells was also affected . The RNAi tissue also developed chlorophyll pigments underscoring the plasticity of petal identity. This work demonstrated that proper expression of Deficiens is required throughout flowering for anthocyanin pigment production as well as maintenance of petal cell identity. The current investigation revealed that the higher order regulation of the Rosea l alleles in antirrhinum petals is much more complex than initially postulated.
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Flavanone-7-O-Glucosyltransferase Activity From Petunia hybridaDurren, Randy L., McIntosh, Cecilia A. 01 November 1999 (has links)
Citrus spp. are known for the accumulation of flavanone glycosides (e.g., naringin comprises up to 70% of the dry weight of very young grapefruit). In contrast, petunia utilizes relatively more naringenin for production of flavonol glycosides and anthocyanins. This investigation addressed whether or not petunia is capable of glucosylation of naringenin and if so, what are the characteristics of this flavanone glucosylating enzyme. Petunia leaf tissue contains some flavanone-7-O-glucosyltransferase (E.C. 2.4.1.185) activity, although at 90-fold lower levels than grapefruit leaves. This activity was partially purified 89-fold via ammonium sulfate fractionation followed by FPLC on Superose 12 and Mono Q yielding three chromatographically separate peaks of activity. The enzymes in the peak fractions glucosylated flavanone, flavonol, and flavone substrates. Enzymes in Mono Q peaks I and II were relatively more specific toward flavanone substrates and peak I was significantly more active. Enzyme activity was not effected by Ca2+, Mg2+, AMP, ADP, or ATP. The petunia enzyme was over 10,000 times more sensitive to UDP inhibition (Ki 0.89 μM) than the flavanone-specific 7GT in grapefruit. These and other results suggest that different flavonoid accumulation patterns in these two plants may be partially due to the different relative levels and biochemical properties of their flavanone glucosylating (7GT) enzymes.
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Role of KNOX genes in the evolution and development of floral nectar spursBox, Mathew S. January 2010 (has links)
A key question in biology is how changes in gene function or regulation produce new morphologies during evolution. The nectar spur is an evolutionarily labile structure known to influence speciation in a broad range of angiosperm taxa. Here, the genetic basis of nectar spur development, and the evolution of differences in nectar spur morphology, is investigated in Linaria vulgaris and two closely related species of orchid, the primitively longer-spurred Dactylorhiza fuchsii, and more derived short-spurred D. viridis (Orchidinae, Orchidaceae). Despite considerable morphological and phylogenetic differences, nectar spur ontogeny is fundamentally similar in each of the study species, proceeding from an abaxial bulge formed on the ventral petal relatively late in petal morphogenesis. However, spur development is progenetically curtailed in the short-spurred orchid D. viridis. In each case spur development involves class 1 KNOTTED1-like homeobox (KNOX) proteins. KNOX gene expression is not restricted to the spur-bearing petal, indicating that additional components are required to define nectar spur position, e.g. canonical ABC genes, determinants of floral zygomorphy, and additional (currently unknown) factors. However, constitutive expression of class 1 KNOX proteins in transgenic tobacco produces flowers with ectopic outgrowths on the petals, indicating that KNOX proteins alone are, to some degree, capable of inducing structures similar to nectar spurs in a heterologous host. Interestingly, KNOX gene expression is high in the ovary of all study taxa, suggesting that KNOX proteins may also have been involved in the evolution of this key angiosperm feature. Although principally involved in maintaining indeterminacy in the shoot apical meristem (SAM), members of the KNOX gene family have been co-opted in the evolution and development of compound leaves where they suppress differentiation and extend the morphogenetic potential of the leaf. A similar model is presented here to explain the role of KNOX proteins in nectar spur development. Co-option of KNOX gene expression to the maturing perianth delays cellular differentiation, facilitating the development of the nectar spur but requiring additional, unknown factors, to determine nectar spur fate. As facilitators of nectar spur development, changes in the spatio-temporal patterns of KNOX gene expression may alter the potential for nectar spur development and explain the critical length differences observed between the orchids D. fuchsii and D. viridis (and among other angiosperm taxa). Taken together, the available data indicate that KNOX genes confer a meristematic state upon plant tissues in a variety of morphogenetic contexts, making the gene family a potentially versatile tool to mediate a wide variety of evolutionary transformations.
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Fixation, Partitioning and Export of Carbon in two Species of the PlantaginaceaeSzucs, Ildiko 05 April 2013 (has links)
During photosynthesis Plantaginaceae species can produce glucose derivatives such as iridoid glycosides and alcohol sugars that in addition to sucrose can be exported from leaves. Plantago lanceolata transported sorbitol in addition to sucrose especially at warmer leaf temperatures. However, two iridoids, catalpol and aucubin, found in P. lanceolata were not readily labelled from 14CO2 under any conditions examined. In contrast, in two greenhouse, cut-flower cultivars of Antirrhinum majus the iridoids, antirrhinoside and antirrhide, were readily 14C-labelled along with sucrose but little 14C was recovered in alcohol sugars (e.g., mannitol). The amount of 14C-partitioned into antirrhinoside increased at higher temperatures. Exposing leaves of P. lanceolata and A. majus to reduced-photorespiratory conditions (e.g. short-term CO2 enrichment and/or low O2) increased fixation and export. Under low O2 in P. lanceolata sorbitol 14C-labelling increased relative to sucrose and in A. majus 14C-labelling of sucrose increased relative to antirrhinoside. Also 14C-labelling of antirrhide increased more than antirrhinoside. During both short-term and long-term acclimation to high CO2, whole plant NCER, leaf photosynthesis and export increased in A. majus. Taken together the temperature and CO2 enrichment studies show plasticity in Plantaginaceae species to synthesize and transport sucrose and auxiliary glucose esters and alcohol sugars in a species-specific manner (depending on the rate of carboxylation).
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SCF cdc4 regulates msn2 and msn4 dependent gene expression to counteract hog1 induced lethalityVendrell Arasa, Alexandre 16 January 2009 (has links)
L'activació sostinguda de Hog1 porta a una inhibició del creixement cel·lular. En aquest treball, hem observat que el fenotip de letalitat causat per l'activació sostinguda de Hog1 és parcialment inhibida per la mutació del complexe SCFCDC4. La inhibició de la mort causada per l'activació sostinguda de Hog1 depèn de la via d'extensió de la vida. Quan Hog1 s'activa de manera sostinguda, la mutació al complexe SCFCDC4 fa que augmenti l'expressió gènica depenent de Msn2 i Msn4 que condueix a una sobreexpressió del gen PNC1 i a una hiperactivació de la deacetilassa Sir2. La hiperactivació de Sir2 és capaç d'inhibir la mort causada per l'activació sostinguda de Hog1. També hem observat que la mort cel·lular causada per l'activació sostinguda de Hog1 és deguda a una inducció d'apoptosi. L'apoptosi induïda per Hog1 és inhibida per la mutació al complexe SCFCDC4. Per tant, la via d'extensió de la vida és capaç de prevenir l'apoptosi a través d'un mecanisme desconegut. / Sustained Hog1 activation leads to an inhibition of cell growth. In this work, we have observed that the lethal phenotype caused by sustained Hog1 activation is prevented by SCFCDC4 mutants. The prevention of Hog1-induced cell death by SCFCDC4 mutation depends on the lifespan extension pathway. Upon sustained Hog1 activation, SCFCDC4 mutation increases Msn2 and Msn4 dependent gene expression that leads to a PNC1 overexpression and a Sir2 deacetylase hyperactivation. Then, hyperactivation of Sir2 is able to prevent cell death caused by sustained Hog1 activation. We have also observed that cell death upon sustained Hog1 activation is due to an induction of apoptosis. The apoptosis induced by Hog1 is decreased by SCFCDC4 mutation. Therefore, lifespan extension pathway is able to prevent apoptosis by an unknown mechanism.
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