Tesis sobre el tema "Plant growth inhibiting substances"

Thesis (Ph. D.)--Illinois State University, 1986.<br>Title from title page screen, viewed July 13, 2005. Dissertation Committee: David P. Brunner (chair), Herman E. Brockman, Arlan G. Richardson, H. Tak Cheung, Lynne Lucher. Includes bibliographical references (leaves 167-183) and abstract. Also available in print.

Thesis (M.S. in Management)--Naval Postgraduate School, June 1990.<br>Thesis Advisor(s): Carrick, Pual M. "June 1990." Description based on signature page. DTIC Identifier(s): Plant growth regulators, growth indicators. Author(s) subject terms: Plant growth regulators, growth indicators. Includes bibliographical references (p. 39-40). Also available online.

Plant growth inhibitors were isolated from Haplopappus acradenius (Green) Blake and Baccharis sarothroides Gray, two desert species, found at the Boyce Thompson Southwestern Arboretum. Leaf and stem tissues of B. sarothroides were extracted with 80% methanol (v/v). This extract was reduced to an aqueous phase in vacuo and partitioned with ethyl acetate at pH 7.3 (NF, neutral fraction), pH 2.8 (AF, acidic fraction), and again at pH 2.8 following hydrolysis at pH 11 (HF, hydrolyzed fraction). Thin layer chromatography (TLC) on silica gel H in chloroform:ethyl acetate:formic acid (CHCl₃:EtOAc:HCOOH) produced a region between R(f)'s 0.5 to 0.6 from AF of B. sarothroides which inhibited wheat seed coleoptile and radicle growth 52.7% and 66.5%, respectively, using 500 ul of a 1.9 mg/ul extract. This section inhibited wheat coleoptile straight growth 38.6% at the same concentration. Additional TLC, UV spectrophotometry, spray reagents, NMR, and GC/MS indicated that the compound was 3,8-dihydroxy-5,6,7-trimethoxy-2-(4-methoxyphenyl)-4H-1-benzopyran-4-one at a concentration of 265 ug/g fresh weight. This compound significantly inhibited the wheat coleoptile straight growth bioassay 18.4% using 2 to 3 ug/ul. An 80% methanol extract of H. acradenius leaves evaporated in vacuo produced an aqueous insoluble brown resin. This resin dissolved in absolute methanol and separated by TLC in CHCl₃:EtOAc:HCOOH contained a region between R(f)'s 0.6 to 0.7 that inhibited wheat seed coleoptile growth 71.8% and radicle growth 90.7% using 200 ul of 1.5 mg/ul solution. Wheat coleoptile straight growth was inhibited 53.7% in this region at the same concentration. Further examination of this region by the same methods as those used for B. sarothroides indicated the presence of a C-12 alkenyl alcohol (2 mg/ml), an aromatic heterocyclic hydrocarbon (4 mg/ml), and an alkyl substituted version of 7-hydroxycoumarin (5 mg/ml) at a concentration of 0.7, 1.4, and 1.8 ug/g fresh weight, respectively. A combination of these compounds inhibited the wheat coleoptile straight growth bioassay 41.1% using 11 ug/ul. A 2 M HCl extract of H. acradenius was partitioned with diethyl ether, which was evaporated and the residue resuspended in 95% methanol. TLC in CHCl₃:EtOAc:HCOOH separated an area between R(f)'s 0.5 to 0.6 where wheat seed coleoptile growth was inhibited 49.7% and radicle growth was inhibited 54.6% using 1000 ul of a 3.3 mg/ul solution. Identified in this region was 7-hydroxycoumarin at a concentration of 150 ug/g fresh weight. The wheat coleoptile straight growth bioassy was inhibited 13.2% using 2 to 3 ug/ul.

Petrol and ethanolic extracts of six asteraceous weeds were added to artificial diet and screened for inhibition of larval growth on variegated cutworm, Peridroma saucia (Hbn.). Petrol and ethanolic extracts of Artemisia tridentata and Chamomilla suaveolens and ethanolic extracts of Chrysothamnus nauseosus and Centaurea diffusa were highly inhibitory at five times the naturally occurring concentrations. The two C. suaveolens extracts and the ethanol extract of A. tridentata were active at the natural concentration (100%) and were further examined at 20, 40, 60, and 80% of this level. Inhibition of larval growth was directly related to concentration for each of the three extracts tested. EC₅₀'S (effective concentration to inhibit growth by 50% relative to controls) for the three extracts were 36-42% of the naturally occurring level in the plants. Nutritional indices were calculated for second instar P. saucia feeding on the active ethanolic A. tridentata extract and the petrol extract from C. suaveolens. The relative growth rate (RGR) of P. saucia larvae fed the ethanolic extract of A. tridentata in artificial diet was significantly lower than that in larvae fed diet with the petrol extract of C. suaveolens and larvae on control diet. Dietary utilization was significantly lower for larvae fed the A. tridentata extract. Results of a field trial indicated that a single treatment of A. tridentata extract at the equivalent of 0.2 g/ml could protect cabbage significantly better than the carrier solvent (30% aq ethanol) or distilled water as measured by a visual damage estimate. An insecticide standard, deltamethrin (17.9 µg/1 with 0.4% Superspred TM ), suppressed pest damage significantly better than the A. tridentata-extract treatment. A residual oviposition deterrency to Pieris rapae was found in the field results. Caged experiments in the laboratory confirmed the contact oviposition deterrency of the A. tridentata extract at 0.2 g/ml. Offspring of field-collected P. saucia larvae grew 2.5-fold heavier than larvae from the laboratory colony. However, diet with the A. tridentata extract inhibited both field-collected and laboratory reared saucia larvae equally when compared to their respective controls fed untreated diet. In summary, these results indicate the potential benefit of using specific unrefined plant extracts for growth inhibitors and oviposition deterrents against insect pests. The contribution of individual phytochemicals in the A. tridentata ethanolic extract to growth inhibition or oviposition deterrency is currently speculative.<br>Land and Food Systems, Faculty of<br>Graduate

Yield fluctuation in <i>Vicia faba</i> is due primarily to reproductive failure, which can occur as a result of bud abortion, flower shedding or pod and ovule abortion (Gates <i>et al</i>., 1983b). Flower drop, which accounts for the major proportion of total reproductive loss, contributes most to the reduction in potential yield. Application of artificial plant growth retardants (EL500, JF 10405 and Alar) were shown to increase the yield of broad beans (<i>Vicia faba</i> L. <i>major</i> cv. Threefold White), by up to 52%, mostly due to increased pod set. Experiments involving the application of plant growth substances directly to the flowers, suggested that increase in pod set was due to changes in intrinsic hormone levels. In particular, high levels of cytokinin are required at the pedicel:peduncle junction pre-pollination, to allow successful initiation of potential sinks, while increased levels of auxin are required after pollination in conjunction with cytokinin to allow cell division, pod expansion and vascular differentiation. Application of anti-gibberellin plant growth retardants appeared to alter internal hormone ratios, affecting the distribution of dry matter production during early flowering, i.e. treated plants had an increased root to stem dry matter growth rate. This suggested an increased cytokinin:gibberellin ratio had been achieved. Although it was shown that pod set could be enhanced by the application of either plant growth retardants and/or plant growth substances, yield was not always as high as anticipated due to increased levels of pod drop. Further applications of cytokinin and auxin to the pods reduced this drop. It followed therefore, that further applications could dramatically increase the yield potential of the plant due to better distribution of assimilates to pods. However, it would appear that the plant also suffers from source limitations and until these are successfully overcome, yield instability in the field environment is still likely.

Thesis (MSc)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: Plant growth promoting substances (PGPS) are emerging as useful tools in the investigation of important plant growth traits. Two PGPS, smoke-water derived from burning plant material and a synthetic strigolactone analogue, GR24, have been reported to regulate a wide variety of developmental and growth processes in plants. These PGPS are beginning to receive considerable attention in the area of improving plant biomass yield and production. Variation in growth between plants is a major impediment towards the complete understanding of the intrinsic processes that control biomass production. Callus cultures of the model plant Arabidopsis thaliana could overcome some of these hindrances. However, the suitability of these callus cultures as a model system for plant biomass production must be established first. This study aimed at using A. thaliana callus cultures as a platform to study the plant growth promoting activities of smoke-water and GR24. The first part of this study was conducted to develop an optimal protocol for inducing A. thaliana callus formation. Wild-type A. thaliana Col-O, as well as strigolactone deficient and insensitive mutants (max1-1, max2-1, max2-2, max3-9 and max4-1) were cultured for callus induction. Hypocotyl and leaf explants were cultured onto MS media supplemented with different hormone concentrations of 2,4-D and kinetin (2:2 mg/L 2,4-D:kinetin and 0.5:0.05 mg/L 2,4-D:kinetin). Both media proved suitable for callus induction of all genotypes, with max1-1 showing the highest efficiency (83.33% and 92.22%) of callus induction. Calli were then used as a platform for future investigations into the effects of smoke-water and GR24. Secondly, this study examined the effects of smoke-water and GR24 on wild-type A. thaliana Col-O callus. Basic physiological studies were conducted to determine if these two compounds would positively affect callus growth, as was shown in previous studies using whole plants. Calli cultivated on MS media containing the two different hormone concentrations were transferred onto the same fresh MS medium, supplemented with either smoke-water or GR24. Growth promotion by smoke-water and GR24 in calli was characterized by a significantly increased mass (biomass). Calli were additionally transferred onto MS medium containing either auxin only or kinetin only and supplemented with GR24 or smoke-water. In the auxin only system, increased mass was recorded for both GR24 and smoke-water treatments, while these two compounds seemed to reduce growth in the kinetin only system. The positive growth stimulatory effect observed for the auxin only system could be attributed to the synergistic relationship between auxin and strigolactones, whilst the reduced mass in the latter system could be due to the antagonistic interaction between strigolactones and cytokinins. Finally, this study has discovered a dual role of strigolactones in biomass accumulation and adventitious root formation for Arabidopsis thaliana callus. On an auxin- and cytokinin-free MS medium supplemented with GR24, calli of Arabidopsis thaliana strigolactone deficient mutants (max1-1 and max4-1) and the wild-type Col- O, but not the strigolactone response mutant (max2-2), showed enhanced biomass accumulation. In addition to this, the max4-1 mutant and wild-type Col-O demonstrated enhanced adventitious rooting, which was not apparent in max2-2. Together these data suggested that the biomass accumulation and the adventitious rooting activities of GR24 in Arabidopsis thaliana calli are controlled in a MAX2- dependent manner. The interaction between strigolactone, auxin and cytokinin signalling pathways in regulating these responses appears to be complex. Gene expression profiling showed regulation of stress-related genes such as B-box transcription factors, CALCINEURIN B-LIKE and RAP4.2 Genes encoding hormones associated with stress (ABA, ethylene) and defence mechanisms (JA) were upregulated. Expression of stress related genes indicated clues on some kind of stress mediation that might be involved during the regulation of the rhizogenic response. Conversely, smoke-water treatment could not enhance the biomass of the calli and nor could it induce adventitious rooting in the absence of auxin and cytokinin. This observation strongly emphasized the distinct roles of these two compounds, as well as the importance of the interaction and ratio of auxin and cytokinin in callus growth. This study has demonstrated a novel role of strigolactones in plant growth and development, i.e. enhancement of biomass production in callus cultures. Secondly the enhanced adventitious rooting ability is in agreement with recently published literature on the role of strigolactones in regulating root architecture. In vitro callus production is advantageous to plant sciences. It creates an opportunity for increasing plant material for cultivation and offers the use of cell cultures that accurately mimic specific growth responses. It could greatly contribute to the study of intricate regulatory and signalling pathways responsible for growth and development in plants. Because the regulation of plant biomass production is very complex and the molecular mechanisms underlying the process remain elusive, it is of paramount importance that further work be done in order to gain more in-depth insights and understanding of this aspect and subsequently improve efficiency and returns when applying biotechnology tools on commercially important crop plants.<br>AFRIKAANSE OPSOMMING: Verbindings wat plantgroei bevorder (PGBV) het as nuttige alternatief ontstaan om plant groei te ondersoek. Rook-water, afkomstig van verbrande plant material, en ‘n sintetiese strigolaktoon analoog, GR24, wat ‘n α, β-onversadigde furanoon funksionele groep in gemeen het, is vir die regulering van ‘n wye verskeidenheid ontwikkelings- en groei prosesse in plante verantwoordelik. Tans ontvang hierdie PGBVs aansienlik aandag in die area van die verbetering van plant biomassa opbrengs en -produksie. Die variasie in groei tussen plante is ‘n groot hindernis om die intrinsieke prosesse wat biomass produksie beheer, volledige te verstaan. Deur gebruik te maak van kallus kulture van die model plant Arabidopsis thaliana kan van hierdie hindernisse oorkom word. Tog moet die geskiktheid van kallus kulture as ‘n model sisteem vir plant groei biomass produksie eers gevestig word. Die doel van hierdie studie was om A. thaliana kallus kulture as ‘n platform vir die studie van die plantgroei bevorderingsaktiwiteite van rook-water en GR24 te gebruik. Die eerste deel van die studie is uitgevoer ten einde ‘n optimale protokol vir die induksie van A. thaliana kallus produksie te ontwikkel. Wilde tipe Col-0, asook strigolaktoon afwesige en onsensitiewe mutante (max1-1, max2-1, max2-2, max3-9 en max4-1) is vir kallus induksie gekultiveer. Hipokotiel en blaar eksplante is op MS medium wat verskillende hormoon konsentrasies van 2,4-D en kinetien (2:2 mg/L 2,4-D:kinetien en 0.5:0.05 mg/L 2,4-D:kinetien) bevat, oorgedra. Beide media was geskik vir kallus induksie van al die genotipes, met max1-1 wat die hoogste effektiwiteit (83.33% en 92.22%) van kallus induksie getoon het. Kalli is daarna as ‘n platform vir toekomstige navorsing i.v.m die effek van rook-water en GR24 gebruik. Tweedens ondersoek die studie die effek van rook-water en GR24 op wilde tipe Col-0 kallus. Basiese fisiologiese studies is uitgevoer om te bepaal of die twee verbindings ‘n positiewe effek op kallus groei toon soos aangedui in vorige studies waar intakte plante gebruik is. Kallus wat op MS medium wat die twee verskillende hormoon konsentrasies bevat gekultiveer was, is op dieselfde vars MS medium, wat addisioneel óf rook-water óf GR24 bevat, oorgedra. Die stimulering van groei van kalli deur rook-water en GR24 is deur ‘n merkwaardige toename in massa (biomassa) gekenmerk. Kallus is additioneel op MS medium wat slegs óf ouksien óf kinetin bevat (gekombineer met GR24 of rook-water behandeling), oorgedra. In die sisteem waar slegs ouksien toegedien is, is ‘n toename in massa waargeneem vir beide GR24 en rook-water behandelinge. In teenstelling hiermee, het die twee verbindings in die sisteem waar slegs kinetin toegedien is, ‘n vermindering in groei meegebring. Die positiewe groei stimulerende effek wat waargeneem is vir die sisteem waar slegs ouksien toegedien is, kan toegedra word aan die sinergistiese verhouding tussen die ouksien en strigolaktone; terwyl die verlaagde massa in die laasgenoemde sisteem aan die antagonistiese interaksie tussen strigolaktone en sitokiniene toegedra kan word. Laastens het hierdie studie het ‘n gelyktydige rol van strigolaktone vir biomassa akkumulasie en bywortelvorming in Arabidopsis thaliana kallus ontdek. Kallus van A. thaliana strigolaktoon afwesige mutante (max1-1 en max4-1) en die wilde tipe Col-0 (maar nie die strigolaktoon reagerende mutant (max2-2) het op ‘n ouksien en sitokinien vrye MS medium wat GR24 bevat ‘n verhoogde biomassa akkumulasie getoon. Die max4-1 mutant en wilde tipe Col-0 het verhoogde bywortelvorming getoon, wat nie so opmerklik by max2-2 was nie. Hierdie data het tesame voorgestel dat die biomassa akkumulasie en die bywortelvormingsaktiwiteite van GR24 in Arabidopsis thaliana kallus op ‘n MAX2-afhanklike wyse beheer word. Die interaksie tussen strigolaktoon, ouksien en sitokinien sein transduksie paaie vir die regulering van hierdie reaksies blyk kompleks te wees. Die geen uitdrukkingsprofiel het die regulering van stres verwante gene soos B-boks transkripsie faktore, CALCINEURIN B-LIKE en RAP4.2, getoon. Gene wat vir hormone wat aan stres (ABA, etileen) en verdedigingsmeganismes (JA) verwant is, is opgereguleer. Die uitdrukking van stress verwante gene dui op tekens van ‘n ander tipe stres bemiddeling wat dalk by die regulering van die risogeniese reaksie betrokke kan wees. In teenstelling, rook water behandeling kon nie die kallus biomassa verhoog nie en dit kon ook nie die bywortelingvorming in die afwesigheid van ouksien en sitokiniene induseer nie. Hierdie waarneming is ‘n sterk bevestiging vir die uitsonderlike rol van die twee verbindings, asook die belang van die interaksie en verhouding van ouksien en sitokinine vir die groei van kallus. Hierdie studie toon op ‘n nuwe rol van strigolaktoon in plant groei en ontwikkeling, d.w.s die verhoogde biomassa produksie in kallus kulture. Tweedens, die verhoogde bywortelvormingsvermoë is in ooreenstemming met literatuur wat onlangs gepubliseer is i.v.m die rol van strigolaktone in die regulering van wortel argitektuur. Die in vitro produksie van kallus is voordelig in plant wetenskappe. Dit skep ‘n geleentheid vir die vermeerdering van plant materiaal vir kultivering en bied die gebruik van selkulture wat spesifieke groei reaksies op ‘n merkwaardige wyse akkuraat namaak. Dit kan grootliks bydra tot die studie van die delikate regulatoriese en sein transduksie paaie wat vir groei en ontwikkeling van plante verantwoordelik is. Aangesien die regulering van plant biomassa produksie baie kompleks is en die molekulêre meganismes vir die proses onbekend bly is dit van grootskaalse belang dat meer werk gedoen word om ‘n meer in diepte insig en kennis van die aspekte en gevolglike verbetering van effektiwiteit en wins te kry deur die toepassing van biotegnologiese metodes op die gewas plante wat van kommersiêle belang is.

Thesis (MSc)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: Almost all processes during the life of a plant are affected by the environment. Changes in phytohormone, metabolite and protein levels follow in response to changes in the environment. Plant growth promoting substances can stimulate changes at these levels to facilitate increased plant growth and yields above what the plant would normally establish. In this study, the effects of two growth promoting substances, smoke water (SW) derived from bubbling smoke from the burning of plant material through water, and a synthetic strigolactone analogue, GR24, on plant growth and architecture, as well as the proteome and metabalome of salt stressed Nicotiana benthamiana seedlings were investigated. Physiological studies were conducted to identify the effects of the growth substances on salt stressed seedlings in a tissue culture system. Under non-stress conditions, SW treatment increased seedling fresh mass, root length and leaf area. Under salt stress conditions (100 mM and 150 mM NaCl), SW increased fresh mass, root length, leaf number and lateral root number significantly. Under non-stress conditions, GR24-treated seedlings showed increased fresh mass, leaf number and area and root length. When GR24-treated seedlings were placed under salt stress, the seedlings showed significant increases in fresh mass, leaf number and lateral root number, but only marginal increases in root length and leaf area. Despite these similarities, slight differences were observed in the metabolomes and proteomes of smoke water and GR24-treated seedlings, both with and without the addition of salt stress. Relatively few of the differentially expressed proteins could be identified with the instruments available. Changes in the metabolome indicated that photoassimilation and photosynthesis could be affected in response to smoke water and GR24 treatment. Our results suggest that smoke water and GR24 both promote growth under salt stress conditions in seedlings and we furthermore conclude that, although there are distinct overlaps between treatments, this is accomplished via slightly different mechanisms.<br>AFRIKAANSE OPSOMMING: Gedurende ‘n plant se lewe word omtrent alle prosesse deur die omgewing geaffekteer. Veranderinge in die omgewing word gevolg deur veranderinge in hormoon, metaboliet en protein vlakke. Plant groei stimulante affekteer hierdie vlakke om plant groei en -opbrengs na bo normalle vlakke te verhoog. In hierdie studie word die effek van twee groei stimulante, rook water verkry deur rook van plant materiaal deur water te borrel en ‘n sintetiese strigolaktoon, GR24, ondersoek op ‘n morfologiese, metaboliese en ‘n proteomiese vlak in Nicotiana benthamiana saailinge. ’n Studie is onderneem om die veranderinge as gevolg van die onderskeie groei stimulante te ondersoek in ‘n weefsel kultuur sisteem. Rook water het onder normale groei omstandighede vars en droeë massa, blaar aantal asook wortel en blaar lengte verhoog. Rook water het na sout behandeling (100 en 150 mM NaCl) steeds vars massa, wortel lengte, blaai aantal en laterale wortel aantal beduidend verhoog in vergelyking met die sout stres kontrole. Behandeling met GR24 het ook vars massa, wortel lengte, blaar aantal en grootte verhoog en onder sout stres met GR24 is ‘n beduidende vergroting opgemerk in vars massa, blaar grootte en laterale wortel aantal. Ongeag van die veranderinge in groei is klein verskille opgemerk in die metaboliet en protein studies. Net ‘n paar proteine kon positief geidentifiseer word met die apparaat beskikbaar. Verandering in die metaboloom wys na veranderinge in fotoassimilasie en fotosintese in reaksie tot rook water en GR24. Hierdie resultate lei tot die gevolgtrekking dat rook water en GR24 beide groei verbeter in saailing behandel met sout en ook dat alhoewel daar sekere ooreenkomste is tussen die reaksies as gevolg van die plant groei stimulante, dit wel geskiet deur geringe verskillende meganismes.

The stringent requirement for hemopoietic growth factors (HGF) in the induction of hemopoiesis in vitro has raised questions as to their possible role(s) in leukemogenesis. Several recent clinical studies have shown aberrant cell growth factor gene activation in patient derived leukemic cells. Assessment of growth factor activity is often based on in vitro bioactivity assays of conditioned media or body fluids. The specificity of this type of endpoint is, however, open to question due to the overlap in biological activities of many HGFs. In assessing the role of growth factor gene expression in a murine myeloid leukemia model I have used a sensitive RNA detection procedure coupled with a vector-probe system that enables the synthesis of uniformly labelled radioactive DNA probes to detect unambiguously the expression of particular growth factor genes. The Abelson murine leukemia virus (A-MuLV) derived myeloid transformants used in this study had previously been shown to produce a multi-lineage colony stimulating activity (CSA). While these A-MuLV transformants were shown to produce GM-CSF, it seemed likely that the multi-lineage CSA was due to another factor. In addition to confirming the expression of GM-CSF mRNA, I was able to show that the cells of all four A-MuLV transformed lines tested also expressed interleukin-3 mRNA. This finding was strongly corroborated by bio-activity data obtained using the CM from the A-MuLV myeloid transformants. Additional preliminary analysis by bioactivity assays have also shown the possible presence of interleukin-6 (IL-6) and a recently described pre-B cell factor suggesting perhaps a common mechanism underlying the activation of these various growth factor genes.<br>Medicine, Faculty of<br>Medical Genetics, Department of<br>Graduate

Auxins are plant hormones involved in virtually all aspects of plant life. Despite long-term commercial and horticultural use of the auxin Indole-3-Butyric Acid (IBA), a full recognition of its natural occurrence in plants was made only recently. I have used multiple approaches to dissect the role of IBA in Arabidopsis thaliana. This thesis includes the first characterization of a mutant with an altered response to IBA that retains wild-type sensitivity to Indole-3-Acetic Acid (IAA), the most studied endogenous auxin. This mutant, named resistant to IBA ( rib1), has modified root architecture and gravitropism and is resistant to auxin transport inhibitors. As these phenotypes are reminiscent of those of characterized auxin transport mutants, movement of IAA and IBA was studied in wild-type and mutant plants. IBA is transported in seedlings in three distinct flows, like IAA, and this transport is saturable, indicating it is carrier mediated. However, unlike IAA, IBA is not polarly transported in inflorescence axes, and IBA transport is not sensitive to IAA transport inhibitors. These results suggest IAA and IBA transport could be mediated or regulated by different mechanisms. In rib1 seedlings, all flows of IBA transport are modified, while IAA transport levels are unchanged. Modifications in IBA transport match phenotypic differences between rib1 and wild-type, and analyses of the physiological effects of IBA also suggest IBA has a role in defining wild-type seedling morphology in Arabidopsis. Though IAA transport levels are not changed in rib1, one flow of IAA transport is rendered insensitive to IAA transport inhibitors, perhaps revealing cross-talk between IAA and IBA transport regulation. Additionally, double mutant analyses reveal that IAA transport and response mutants can suppress some phenotypes of rib1, and some mutant combinations produce novel phenotypes, further suggesting cross-talk between IBA and IAA transport and response p

This thesis concerns a melanoma-derived growth regulatory factor that inhibited proliferation of several malignant human cell lines, and, in particular, a line designated UCT-BR-1, which was derived from a human breast cancer metastasis. The work is presented in four chapters. Chapter 1 provides a review of the relevant literature at the time of writing; Chapters 2 and 3 describe the experimental work that was done; and in Chapter 4 I discuss the implications of my results for current and future work in growth factors. Experimental results are presented as Charts (which may be Figures or Tables) and the methods and experimental protocols that I used are described in the Chart legends and not in the main text of the thesis. The Appendix contains details of the tissue culture techniques and descriptions of the cell lines that were used. Sources of the various laboratory materials as well as the methods that were employed for the more routine procedures are also described in the appendix.

Many of the anabolic effects of growth hormone (GH) are indirect, occurring through GH-stimulated production of insulin-like growth factor-I (IGF-I) by the liver. As well as being GH regulated, plasma IGF-I concentrations have been demonstrated to be dependent upon protein nutrition, with low protein diets being associated with reduced plasma IGF-I concentrations. This effect cannot be reversed by GH, suggesting that liver sensitivity to GH is impaired. To investigate the mechanisms through which protein supply affects GH sensitivity, primary cultures of ovine hepatocytes were grown in defined media. In a first experiment the media contained various fractions (0.2, 1.0, 5.0) of portal vein amino acid concentrations in fed sheep. In the second 24h incubation period, unstimulated IGF-I secretion was highly sensitive the concentration of amino acids in the media, with significantly greater release of basal IGF-I in 5x compared to either 1x (P<0.05) or 0.2x amino acid containing media. In a second series of experiments the effects of specific amino acid depletions was examined. Methionine depletion of 0.2x portal amino acid concentrations ablated the GH response second 24h of culture without affecting basal IGF-I release. By comparison ³H-leucine incorporation into secreted protein, following 20 hours of culture in defined media was significantly reduced in 0.2x aa (P<0.01) and 1.0x aa (P<0.05) media compared with 5.0x aa media, however secretory protein synthesis was unaffected by methionine depletion to 0.2x portal concentrations. The results suggest that amino acid availability regulates both basal and GH stimulated IGF-I release in ovine hepatocytes. Furthermore reducing methionine concentrations in the culture media to 0.2x portal concentrations diminishes GH response without compromising protein secretion.

Made available in DSpace on 2014-06-11T19:26:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-10-06Bitstream added on 2014-06-13T19:34:19Z : No. of bitstreams: 1 fraguas_cb_dr_botfca.pdf: 1400606 bytes, checksum: e3a3b343e1fdf633f6e3bb2a35833a4e (MD5)<br>Este trabalho teve como objetivo avaliar os efeitos da aplicacao exogena de poliaminas e TIBA (antiauxina) na micropropagacao e anatomia foliar de plantulas de abacaxizeiro eIAC Gomo-de-mel f e analisar os teores de poliaminas endogenas, atividade de peroxidase, proteina, IAA-oxidase e a provavel relacao com as diferentes fases da micropropagacao. Inicialmente, retiraram-se as gemas da coroa de frutos sadios e a assepsia foi realizada com hipoclorito de sodio comercial (2 a 2,5% de cloro ativo) a 30% por 20 minutos e lavadas por 3 vezes em agua destilada e autoclavada. Em seguida, inocularam-se as gemas em meio MS solido contendo diferentes combinacoes de BAP (0; 0,5; 1,0 e 1,5 mg L-1) e NAA (0; 0,5 e 1,0 mg L-1). Apos 60 dias, foram selecionados os melhores tratamentos para proliferacao das brotacoes, que foram individualizadas e transferidas para estes meios por mais trinta dias, em meio MS liquido. Plantas oriundas do experimento anterior tiveram as folhas cortadas e apenas segmentos de 1 cm foram inoculados em meio MS liquido contendo os diferentes tratamentos: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPD, T4-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPM, T5-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM PUT, T6-MS + 10 mM SPD, T7-MS + 10 mM SPM e T8-MS + 10 mM PUT. Na ultima fase, segmentos foram inoculados em meio MS liquido contendo os tratamentos: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 0,5 ÊM TIBA, T4-MS + 1,0 ÊM TIBA, T5-MS + 2,0 ÊM TIBA, T6-MS + 4,0 ÊM TIBA, T7-MS + 8,0 ÊM TIBA e T8-MS + 16,0 ÊM TIBA. Apos, as plantas foram aclimatizadas em substrato Plantmax e houve 100% de sobrevivencia, independente do tratamento. Foram realizados cortes histologicos foliares para estudar a influencia das poliaminas e TIBA na anatomia foliar...<br>The effects of exogenous polyamines and TIBA (antiauxin) application in the micropropagation, leaf anatomy of pineapple plants IAC Gomo-de-mel and the contents of endogenous polyamines, peroxidase activity, protein, IAA-oxidase and probable relationship with the different micropropagation phases were studied. Initially, the axillary bud explants were excised from the crown of healthy fruits and the asepsis was accomplished with sodium hypochloride (2 to 2,5% of active chlorine) 30% for 20 minutes and washed 3 times in distilled and autoclaveted water. After, the axillary buds were inoculated in MS solid medium containing the different BAP (0; 0,5; 1,0 and 1,5 mg L-1) and NAA (0; 0,5 and 1,0 mg L-1) combinations. After 60 days, the best treatments were selected for shoot proliferation that were individualized and transferred to these media for more 30 days, in MS liquid medium. Plants from the previous experiment had the leaves cut and just 1 cm segments were inoculated in MS liquid medium containing the different treatments: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPD, T4- MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPM, T5-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM PUT, T6-MS + 10 mM SPD, T7-MS + 10 mM SPM and T8-MS + 10 mM PUT. In the last phase, segments were inoculated in MS liquid medium containing the treatments: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 0,5 mM TIBA, T4-MS + 1,0 mM TIBA, T5-MS + 2,0 mM TIBA, T6-MS + 4,0 mM TIBA, T7-MS + 8,0 mM TIBA and T8-MS + 16,0 mM TIBA. After, the plants were acclimatizated in Plantmax substrate and there were 100% survival, independent of the treatment. Leaf cuts were made to study polyamines and TIBA influence in the leaf anatomy. The highest shoot number wasobserved with 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, however with hyperhydricity...(Complete abstract click electronic access below)

Orientador: Giuseppina Pace Pereira Lima<br>Banca: João Domingos Rodrigues<br>Banca: Moacir Pasqual<br>Banca: Antonio Natal Gonçalves<br>Banca: Alessandra Marcondes Feijó Viu<br>Resumo: Este trabalho teve como objetivo avaliar os efeitos da aplicacao exogena de poliaminas e TIBA (antiauxina) na micropropagacao e anatomia foliar de plantulas de abacaxizeiro eIAC Gomo-de-melf e analisar os teores de poliaminas endogenas, atividade de peroxidase, proteina, IAA-oxidase e a provavel relacao com as diferentes fases da micropropagacao. Inicialmente, retiraram-se as gemas da coroa de frutos sadios e a assepsia foi realizada com hipoclorito de sodio comercial (2 a 2,5% de cloro ativo) a 30% por 20 minutos e lavadas por 3 vezes em agua destilada e autoclavada. Em seguida, inocularam-se as gemas em meio MS solido contendo diferentes combinacoes de BAP (0; 0,5; 1,0 e 1,5 mg L-1) e NAA (0; 0,5 e 1,0 mg L-1). Apos 60 dias, foram selecionados os melhores tratamentos para proliferacao das brotacoes, que foram individualizadas e transferidas para estes meios por mais trinta dias, em meio MS liquido. Plantas oriundas do experimento anterior tiveram as folhas cortadas e apenas segmentos de 1 cm foram inoculados em meio MS liquido contendo os diferentes tratamentos: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPD, T4-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPM, T5-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM PUT, T6-MS + 10 mM SPD, T7-MS + 10 mM SPM e T8-MS + 10 mM PUT. Na ultima fase, segmentos foram inoculados em meio MS liquido contendo os tratamentos: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 0,5 ƒÊM TIBA, T4-MS + 1,0 ƒÊM TIBA, T5-MS + 2,0 ƒÊM TIBA, T6-MS + 4,0 ƒÊM TIBA, T7-MS + 8,0 ƒÊM TIBA e T8-MS + 16,0 ƒÊM TIBA. Apos, as plantas foram aclimatizadas em substrato Plantmax e houve 100% de sobrevivencia, independente do tratamento. Foram realizados cortes histologicos foliares para estudar a influencia das poliaminas e TIBA na anatomia foliar...(Resumo completo, clicar acesso eletrônico abaixo)<br>Abstract: The effects of exogenous polyamines and TIBA (antiauxin) application in the micropropagation, leaf anatomy of pineapple plants ‘IAC Gomo-de-mel’ and the contents of endogenous polyamines, peroxidase activity, protein, IAA-oxidase and probable relationship with the different micropropagation phases were studied. Initially, the axillary bud explants were excised from the crown of healthy fruits and the asepsis was accomplished with sodium hypochloride (2 to 2,5% of active chlorine) 30% for 20 minutes and washed 3 times in distilled and autoclaveted water. After, the axillary buds were inoculated in MS solid medium containing the different BAP (0; 0,5; 1,0 and 1,5 mg L-1) and NAA (0; 0,5 and 1,0 mg L-1) combinations. After 60 days, the best treatments were selected for shoot proliferation that were individualized and transferred to these media for more 30 days, in MS liquid medium. Plants from the previous experiment had the leaves cut and just 1 cm segments were inoculated in MS liquid medium containing the different treatments: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPD, T4- MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPM, T5-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM PUT, T6-MS + 10 mM SPD, T7-MS + 10 mM SPM and T8-MS + 10 mM PUT. In the last phase, segments were inoculated in MS liquid medium containing the treatments: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 0,5 mM TIBA, T4-MS + 1,0 mM TIBA, T5-MS + 2,0 mM TIBA, T6-MS + 4,0 mM TIBA, T7-MS + 8,0 mM TIBA and T8-MS + 16,0 mM TIBA. After, the plants were acclimatizated in Plantmax substrate and there were 100% survival, independent of the treatment. Leaf cuts were made to study polyamines and TIBA influence in the leaf anatomy. The highest shoot number wasobserved with 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, however with hyperhydricity...(Complete abstract click electronic access below)<br>Doutor

Influence de la maturité du compost d'écorce de chêne et des extraits d'écorce sur l'aptitude à servir de substrat pour la culture de végétaux supérieurs (tomates). Aspects ultrastructuraux et effets sur la germination et la croissance (inhibition, stimulation)

by Bi Yu Rong.<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 1996.<br>Includes bibliographical references (leaves 188-220).<br>Acknowledgment --- p.i<br>Abstract --- p.ii<br>Table and contents --- p.v<br>List of abbreviation --- p.x<br>List of Tables --- p.xi<br>List of Figures --- p.xiv<br>Chapter Chapter 1 --- Introduction --- p.1<br>Chapter Chapter 2 --- Literature review --- p.5<br>Chapter 2.1 --- General information of plant growth regulators --- p.5<br>Chapter 2.2 --- Natural plant growth inhibitors --- p.14<br>Chapter 2.3 --- Alkaloids and narciclasine --- p.15<br>Chapter 2.4 --- Studies on expansion and greening of cotyledons --- p.22<br>Chapter 2.5 --- Investigation on chlorophyll synthesis --- p.28<br>Chapter Chapter 3 --- Materials and methods --- p.31<br>Chapter 3.1 --- Plant materials --- p.31<br>Chapter 3.2 --- Isolation and purification of inhibitory substance from Narcissus bulbs --- p.31<br>Chapter I. --- Isolation of inhibitory substance from fresh Narcissus bulbs --- p.31<br>Chapter II. --- Partial purification of the inhibitory substance with different organic solvents --- p.32<br>Chapter III. --- Purification and identification --- p.32<br>Chapter A. --- Thin layer chromatography (TLC) --- p.32<br>Chapter B. --- Column chromatography --- p.33<br>Chapter C. --- Spectrometric analyses --- p.33<br>Chapter IV. --- Bioassays --- p.34<br>Chapter 3.3 --- Effect of narciclasine (NCS) on the seeds germination and seedling growth --- p.34<br>Chapter I. --- Germination experiments --- p.35<br>Chapter II. --- Seedlings growth --- p.35<br>Chapter 3.4 --- Interaction of NCS and phytohormones --- p.35<br>Chapter I. --- Interaction with abscisic acid (ABA) --- p.36<br>Chapter A. --- Seed germination --- p.36<br>Chapter B. --- Seedling growth --- p.36<br>Chapter II. --- Interaction with auxin --- p.36<br>Chapter III. --- Interaction with gibberellin --- p.37<br>Chapter VI. --- Interaction with cytokinin --- p.38<br>Chapter 3.5 --- Interaction of NCS and phytohormones to growth and greening of excised radish cotyledons exposing to light --- p.39<br>Chapter I. --- Growth of excised radish cotyledons exposing to light --- p.39<br>Chapter II. --- Chlorophyll content determination --- p.40<br>Chapter III. --- Effects of a pretreatment with BA or NCS on the growth and greening of excised radish cotyledons --- p.40<br>Chapter 3.6 --- Effect of NCS on the growth and greening of excised radish cotyledons and etiolated wheat leaves --- p.41<br>Chapter I. --- Effect of NCS on the growth and greening of excised radish cotyledons --- p.41<br>Chapter II. --- Effect of NCS on the greening of etiolated wheat leaves --- p.41<br>Chapter 3.7 --- Effect of NCS on chlorophyll synthesis and δ-aminolevulinic acid (ALA) accumulation of etiolated wheat leaves in presence of levulinic acid (LA) --- p.42<br>Chapter 3.8 --- Enzymes studies in the excised radish cotyledons --- p.43<br>Chapter I. --- Assay of isocitrate lyase activity --- p.44<br>Chapter II. --- Assay of hydroxypyruvate reductase activity --- p.44<br>Chapter 3.9 --- Ultrastructural studies --- p.45<br>Chapter Chapter 4. --- Results --- p.47<br>Chapter 4.1 --- Chemical studies of NCS --- p.47<br>Chapter I. --- Isolation and partial purification of inhibitory substance from Narcissus bulbs --- p.47<br>Chapter A. --- "Effect of lyophilized slimy secretion (LSS) on the germination seeds, the growth of radicle and hypocotyl of seedlings of Brassica" --- p.47<br>Chapter B. --- Effect of different solvent extracts on the germination and the elongation of radicle and hypocotyl of Brassica seedlings --- p.47<br>Chapter C. --- Effect of fraction isolated with n-butanol from dried bulbs or LSS on the germination of Brassica seeds and radicle growth --- p.49<br>Chapter D. --- Purification of inhibitory substance from Narcissus bulbs by chromatography --- p.54<br>Chapter II. --- Identification of the inhibitory substance from Narcissus bulbs .… --- p.62<br>Chapter 4.2 --- Physiological and biochemical studies ofNCS --- p.70<br>Chapter I. --- Effects ofNCS on seed germination and seedlings growth of Brassica --- p.70<br>Chapter II. --- Time course studies ofNCS on germination and growth of radish seeds --- p.70<br>Chapter III. --- Comparative studies ofNCS and ABA on seeds germination and seedlings growth --- p.73<br>Chapter IV. --- Interaction between NCS and phytohormones --- p.79<br>Chapter A. --- Interaction of NCS with ABA --- p.79<br>Chapter B. --- Interaction of NCS with IAA --- p.84<br>Chapter C. --- Interaction of NCS with gibberellin --- p.84<br>Chapter D. --- Interaction of NCS with cytokinin --- p.89<br>Chapter V. --- Effects ofNCS and BA on chlorophyll and carotenoid content of excised cotyledons --- p.89<br>Chapter A. --- "Effects ofNCS and BA on expansion, chlorophyll content and carotenoid content of excised radish cotyledons" --- p.89<br>Chapter B. --- Effects of a pretreatment with BA or NCS on the growth and greening of excised radish cotyledons --- p.97<br>Chapter VI. --- Interaction between NCS and phytohormones in growth and greening of excised radish cotyledons --- p.105<br>Chapter A. --- "Effects of BA,GA3 and ABA on the growth and greening of excised radish cotyledons" --- p.105<br>Chapter B. --- Interaction of NCS with phytohormones on growth and greening of excised radish cotyledons --- p.108<br>Chapter 4.3 --- Investigation of effects of NCS on chlorophyll synthesis --- p.113<br>Chapter I. --- Effect of preincubation in water on growth and greening of excised cotyledons under light --- p.113<br>Chapter II. --- Effect of NCS on the growth and greening of etiolated radish excised cotyledons --- p.116<br>Chapter III. --- Effect of NCS on the greening of etiolated leaves of 7-day-old wheat seedlings under light --- p.116<br>Chapter IV. --- Effect of LA on ALA accumulation in the light --- p.120<br>Chapter V. --- Time course study of NCS on ALA accumulation in the presence of LA --- p.122<br>Chapter 4.4 --- Effect of NCS on the development of enzymes activities in the excised radish cotyledons --- p.122<br>Chapter I. --- Effect of NCS on isocitrate lyase activity of excised radish cotyledons --- p.122<br>Chapter II --- Effect of NCS on hydroxypyruvate reductase activity of excised radish cotyledons --- p.125<br>Chapter 4.5 --- Effect of NCS on ultrastructural changes of excised radish cotyledons --- p.128<br>Chapter I. --- Time course studies --- p.128<br>Chapter II. --- "Effect ofNCS, BA and ABA on the ultrastructural change of excised radish cotyledons in the light" --- p.142<br>Chapter III. --- Effect of a pretreatment with dark on the inhibition ofNCS on ultrastructural change of excised radish cotyledons in light --- p.150<br>Chapter Chapter 5. --- Discussion --- p.160<br>Chapter Chapter 6. --- Conclusions --- p.180<br>References --- p.188

Copies of author's previously published material inserted. Bibliography: leaves 212-227. This thesis describes the research aimed to produce a small flowering pot plant of Acacia less than 35 cm high with more than 50 inflorescenses within twenty four months, a potted foliage plant less than 35 cm high within twelve months or a flowering tub plant less than 1m high with more than 50 inflorescences within thirty six months. This study produces a protocol for production of flowering pot plants of A. acinacea using a comination of pruning and paclobutrazol.

It was found that narciclasine retarded the growth of human cancer cells and plant suspension cells in dose-dependent manner. The inhibitory mechanism of narciclasine was found to be apoptosis for the DNA histogram showed an apoptotic peak in narciclasine-treated A375 cancer cells. The fluorescent signal dUTP fluorescein was found in the narciclasine-treated A735 cancer cell in TUNEL assay. The Annexin-V-FLUOS stained A375 cancer cell at 24-hour treatment with no PI found. These results suggest that narciclasine triggered early apoptosis in A375 cancer cell. Immunoblot analysis of the apoptotic signalling pathway showed that narciclasine induced apoptosis through the intrinsic pathway. Narciclasine induced the cleavage of caspase-9 but not the caspase-8, which was triggered by cytochrome c release from mitochondrial intermembrane space into cytosol. The activated caspase-9 triggered caspase cascade (e.g. cleavage of caspase-3, caspase-6 and caspase-7) which induced the cleavage of PARP.<br>Narciclasine is an isoquinoline alkaloid extracted from the bulb of Narcissus tazetta. It shows a wide range of biological activities such as antitumour, antiviral and plant growth inhibitory activities. However, little information is available regarding such inhibitory activities. The objective of this study is to elucidate the mechanisms of the cytotoxic effects of narciclasine in different cell models.<br>On the other hand, narciclasine triggered programmed cell death (PCD) in plant cells as proved by the increased intensity of Evans blue in narciclasine-treated suspension cells. Fluorescent microscopy showed that narciclasine induced PCD in tobacco BY2 cell with the dUTP fluorescein stained in narciclasine-treated cell. The induction of PCD was in dose-dependent and time-dependent manner.<br>Proteomic studies showed that narciclasine may affect A375 cancer cell and rice meristemic cells in similar manner. Narciclasine may affect the metabolism and defence system of both A375 cancer cell and rice meristemic cells through down-regulating the expression of metabolic enzymes (e.g. triosephosphate isomerase in A375 cancer cell and fructose bisphosphate aldolase in rice root tip) and defensive proteins (e.g. peroxiredoxin in A375 cancer cell and catalase in rice root tip). Narciclasine down-regulated the heat-shock proteins (HSP) which is involved in regulating cellular homeostasis and promoting cell survival. Therefore, narciclasine reduced HSP to lower the cell survival ability and induced the caspase cascade or caspase-like activity in A375 cancer cell and rice respectively.<br>To summarize, narciclasine induced apoptosis in A375 cancer cell and programmed cell death in tobacco BY2 cell.<br>Wong, Chi Fai.<br>"October 2007."<br>Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4576.<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 2007.<br>Includes bibliographical references (p. 230-255).<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Abstracts in English and Chinese.<br>School code: 1307.

Excessive growth by red clover, Trifolium pratense L., grown for seed interferes with maximum seed production and harvest in Oregon's Willamette Valley. This study was conducted during 1986 and 1987 on red clover cv. Kenland to determine if plant height and dry matter production could be inhibited and seed yields improved with the plant growth regulators (PGRs) uniconazol (XE-1019) and paclobutrazol (Parlay). The effects of different soil-applied and foliar-applied PGRs and application rates on plant height, crop biomass, and yield components of red clover were measured at Corvallis, OR on Woodburn silt-loam (fine-silty mixed mesic Aquultic Argixerolls) soil. Soil-applied PGRs were also managed under single and multiple irrigation regimes in 1986. Under a single irrigation regime in 1986, canopy height was reduced by 32% when XE-1019 was applied at 1.12 kg ai/ha and was reduced by 13% when Parlay was applied at 1.68 kg ai/ha. Averaged over the two-year period, straw yield was reduced 40% with XE-1019 (1.12 kg ai/ha) and by 12% with Parlay (1.68 kg ai/ha). Seed yield was increased by 11% with the lower XE-1019 rate (0.14 kg ai/ha) and was increased by 14% with the higher Parlay rate (1.68 kg ai/ha). Soil-applied PGR treatments reduced canopy height by 25% with XE-1019 (1.12 kg ai/ha) and was reduced by 11% with Parlay (1.68 kg ai/ha) under multiple irrigation in 1986. Straw yield was reduced by 30% with XE-1019 (0.84 kg ai/ha), but Parlay had no effect on straw yield. In addition, seed yield was increased by 8% with XE-1019 (0.56 kg ai/ha) and by 18% with Parlay (1.68 kg ai/ha). Foliar-applied XE-1019 (1.12 kg ai/ha) reduced canopy height by 13% in 1986 and by 25% in 1987, whereas foliar-applied Parlay (1.12 kg ai/ha) reduced canopy height by 9% in 1986 and by 19% in 1987. In 1986, seed yield increases averaged 16% across all 3CE-1019 treatments (0.07 to 1.12 kg ai/ha) and was increased an average of 21% across all Parlay treatments (0.28 to 1.68 kg ai/ha). However, 1987 was drier and warmer than 1986, consequently, foliar-applied XE-1019 reduced seed yields by an average of 23% and Parlay reduced seed yields by an average of 21%. Total dry weight and straw weight were unaffected by foliar-applied PGR treatment in both years. Use of XE-1019 and Parlay in field crop production has the potential to reduce dry matter production and improve seed recovery, but results vary from year to year. These PGRs have the potential to improve seed yields and may be effective in improving harvest conditions by reducing vegetative biomass.<br>Graduation date: 1995

Tsang, Kwok On.<br>Thesis (M.Phil.)--Chinese University of Hong Kong, 2011.<br>Includes bibliographical references (leaves 147-165).<br>Abstracts in English and Chinese.<br>ACKNOWLEDGMENTS --- p.i<br>ABSTRACT --- p.ii<br>TABLE OF CONTENTS --- p.vii<br>LIST OF FIGURES --- p.xiv<br>LIST OF TABLES --- p.XX<br>Chapter CHAPTER 1 --- Introduction --- p.1<br>Chapter 1.1 --- "Mikania micrantha, a problematic weed around the world" --- p.1<br>Chapter 1.1.1 --- Current situation --- p.1<br>Chapter 1.1.2 --- Properties of M micrantha --- p.2<br>Chapter 1.1.3 --- Control methods of M. micrantha --- p.6<br>Chapter 1.1.3.1 --- Manual removal --- p.6<br>Chapter 1.1.3.2 --- Chemical control methods --- p.7<br>Chapter 1.1.3.3 --- Biological control methods --- p.7<br>Chapter 1.2 --- Parasitic plants --- p.10<br>Chapter 1.2.1 --- Introduction --- p.10<br>Chapter 1.2.2 --- Modes of parasitism --- p.10<br>Chapter 1.2.3 --- Biology of Cuscula spp. --- p.13<br>Chapter 1.2.3.1 --- Seed germination --- p.15<br>Chapter 1.2.3.2 --- I lost detection and parasitism --- p.17<br>Chapter 1.2.3.3 --- Reproduction --- p.19<br>Chapter 1.2.3.4 --- Impacts on hosts --- p.21<br>Chapter 1.3 --- Previous researches on the control of M. micrantha by cuscuta --- p.23<br>Chapter 1.4 --- Research significance --- p.25<br>Chapter 1.4.1 --- Knowledge gap --- p.25<br>Chapter 1.4.2 --- Experimental objectives and significance --- p.26<br>Chapter 1.4.3 --- Thesis layout --- p.28<br>Chapter CHAPTER 2 --- Germination biology of Cuscuta japonica --- p.29<br>Chapter 2.1 --- Introduction --- p.29<br>Chapter 2.2 --- Materials and Methods --- p.34<br>Chapter 2.2.1 --- "Cuscuta seeds collection, treatment and storage" --- p.34<br>Chapter 2.2.2 --- Imbibition --- p.35<br>Chapter 2.2.3 --- Germination --- p.35<br>Chapter 2.2.4 --- Emergence --- p.36<br>Chapter 2.2.5 --- Germination dynamics --- p.37<br>Chapter 2.2.6 --- Statistical analysis --- p.37<br>Chapter 2.3 --- Results --- p.38<br>Chapter 2.3.1 --- Imbibition test --- p.38<br>Chapter 2.3.2 --- Germination test --- p.40<br>Chapter 2.3.3 --- Emergence test --- p.42<br>Chapter 2.3.4 --- Germination dynamic --- p.43<br>Chapter 2.4 --- Discussion --- p.44<br>Chapter 2.4.1 --- Seed dormancy --- p.44<br>Chapter 2.4.2 --- Germination requirements --- p.48<br>Chapter 2.4.3 --- Emergence ability --- p.51<br>Chapter 2.4.4 --- Germination dynamics --- p.52<br>Chapter 2.5 --- Conclusions --- p.54<br>Chapter CHAPTER 3 --- Life cycle of C. japonica --- p.55<br>Chapter 3.1 --- Introduction --- p.55<br>Chapter 3.2 --- Materials and Methods --- p.57<br>Chapter 3.2.1 --- Site description --- p.57<br>Chapter 3.2.2 --- Data collection --- p.62<br>Chapter 3.3 --- Results --- p.64<br>Chapter 3.4 --- Discussion --- p.71<br>Chapter 3.4.1 --- Life cycle of C. japonica in Dragon's Back and its implication --- p.71<br>Chapter 3.4.2 --- Life cycle of (\ japonica in Shan Tong Road and Yau King Lane --- p.74<br>Chapter 3.5 --- Conclusions --- p.80<br>Chapter CHAPTER 4 --- Effect of infestation by C. japonica and C. campcstris on the growth of M. micrantha --- p.82<br>Chapter 4.1 --- Introduction --- p.82<br>Chapter 4.2 --- Materials and Methods --- p.84<br>Chapter 4.2.1 --- Sites description --- p.84<br>Chapter 4.2.2 --- Plant materials --- p.85<br>Chapter 4.2.3 --- Infestation --- p.86<br>Chapter 4.2.4 --- Harvest of plant materials --- p.87<br>Chapter 4.2.5 --- Chlorophyll extraction and concentration determination --- p.87<br>Chapter 4.2.6 --- Measurements --- p.88<br>Chapter 4.2.7 --- Statistical analysis --- p.89<br>Chapter 4.3 --- Results --- p.89<br>Chapter 4.3.1 --- "Changes in length of stem, leaf size and number of leaves" --- p.89<br>Chapter 4.3.2 --- Changes in biomass of hosts and parasites --- p.94<br>Chapter 4.3.3 --- Changes in the chlorophyll concentration --- p.97<br>Chapter 4.4 --- Discussion --- p.99<br>Chapter 4.2.1 --- Cuscuta as a strong sink to the host --- p.99<br>Chapter 4.2.2 --- Growth of cuscuta and comparison of its influence on M micrantha --- p.104<br>Chapter 4.5 --- Conclusions --- p.106<br>Chapter CHAPTER 5 --- Effect of C. japonica infestation on the activities of anti-oxidative enzymes of M. micrantha --- p.107<br>Chapter 5.1 --- Introduction --- p.107<br>Chapter 5.2 --- Materials and Methods --- p.110<br>Chapter 5.2.1 --- Plant materials --- p.110<br>Chapter 5.2.2 --- Infestation --- p.111<br>Chapter 5.2.3 --- Harvest of plant materials --- p.111<br>Chapter 5.2.4 --- Measurement of enzyme activity --- p.112<br>Chapter 5.2.4.1 --- Reagent preparation --- p.112<br>Chapter 5.2.4.2 --- Extraction method --- p.112<br>Chapter 5.2.4.3 --- Enzyme activity determination --- p.113<br>Chapter 5.3 --- Results --- p.115<br>Chapter 5.3.1 --- SOD activity --- p.115<br>Chapter 5.3.2 --- CAT activity --- p.116<br>Chapter 5.3.3 --- POD activity --- p.117<br>Chapter 5.4 --- Discussion --- p.1 19<br>Chapter 5.4.1 --- Changes in SOD activity --- p.120<br>Chapter 5.4.2 --- Changes in CAT and POD activity --- p.122<br>Chapter 5.4.3 --- Effects and implications of the changes in the activities of the anti-oxidative enzymes --- p.123<br>Chapter 5.5 --- Conclusions --- p.124<br>Chapter CHAPTER 6 --- Host range of C. japonica --- p.126<br>Chapter 6.1 --- Introduction --- p.126<br>Chapter 6.2 --- Materials and methods --- p.130<br>Chapter 6.2.1 --- Field study --- p.130<br>Chapter 6.2.1.1 --- Site description --- p.130<br>Chapter 6.2.2.2 --- Data collection --- p.130<br>Chapter 6.2.2 --- Greenhouse study --- p.131<br>Chapter 6.2.2.1 --- Site description --- p.131<br>Chapter 6.2.2.2 --- Plants selection --- p.131<br>Chapter 6.2.2.3 --- Experimental setup --- p.132<br>Chapter 6.2.2.4 --- Statistical analysis --- p.133<br>Chapter 6.3 --- Results --- p.133<br>Chapter 6.3.1 --- Field study --- p.133<br>Chapter 6.3.2 --- Greenhouse study --- p.137<br>Chapter 6.4 --- Discussion --- p.138<br>Chapter 6.4.1 --- Field study --- p.138<br>Chapter 6.4.2 --- Greenhouse study --- p.140<br>Chapter 6.4.3 --- Implications on application --- p.141<br>Chapter 6.5 --- Conclusions --- p.143<br>Chapter CHAPTER 7 --- General Summary and Conclusions --- p.144<br>REFERENCES --- p.147<br>APPENDIX A --- p.166<br>APPENDIX B --- p.173<br>APPENDIX C --- p.176

Indiana University-Purdue University Indianapolis (IUPUI)<br>Drought and cold conditions are among the major factors affecting plant growth and crop production globally. Dehydrins are group II late embryogenesis abundant (LEA) proteins characterized by a conserved K-region (EKKGIMDKIKEKLPG consensus sequence) that accumulate in many plants during drought, low temperature, and high salinity to confer stress tolerance. While it has been demonstrated that overexpression of dehydrins improves cold tolerance in various crop plants, the mechanism leading to cold tolerance is still unclear. Previous studies reported phosphorylation of AtERD14 dehydrin by casein kinase II (CKII) led to an increase in calcium binding activity. Mass spectroscopy analysis determined that the phosphorylation was localized to a poly-serine (S) region. To further characterize the S-region, GST fused ERD14 mutants were created via site-directed mutagenesis and deletion of either the amino or carboxyl ends of ERD14 via the QuickChange® Multi Site-Directed Mutagenesis Kit. Phosphorylation of purified mutant proteins by CKII was analyzed via gel shift and direct phosphorylation assays. The effect of phosphorylation on calcium binding activity was also analyzed. Results showed the serine (S) residue at position 83 was crucial to phosphorylation-dependent molecular mass shift and Ca2+-binding activities followed by the serine residue at position 85 in importance. Mutation of serines at positions 83, 84, and 85 completely eliminated the phosphorylation-dependent gel shift and calcium binding. Examination of truncation mutants determined the N-terminal was an important region for protein structure modification and phosphorylation ability leading to Ca2+ activation. Calcium binding activity of the truncated mutants indicated the calcium binding site was localized in the region between the S-region and the K-region near the C-terminal end. To characterize the acidic dehydrins contribution to cold tolerance in vivo, three single (erd10, erd14, cor47) knockouts (KOs) were characterized. Single KOs produced no cold sensitive phenotype indicating the need for multiple dehydrin KOs in Arabidopsis in order to potentially produce a cold sensitive phenotype.

The application of seaweed concentrates to plants has been shown to enhance growth and improve yield parameters. How these natural products elicit their beneficial responses is still unclear. While many of the growth responses have been attributed to cytokinins, it is obvious that this group of plant hormones cannot account for all the beneficial effects incurred from seaweed use. This study was therefore initiated to investigate the effects of a commercial seaweed concentrate (Kelpak) on several aspects of plant growth and development. Tentative determination of plant growth regulators in the seaweed concentrate (SWC) using bioassay systems, indicated the presence of compounds with gibberellin- , abscisic acid- and auxin-like properties. Tentative identification of the auxins present in the SWC and Ecklonia maxima using High Performance Liquid Chromatography revealed the presence of tryptophan, indole-3-acetamide, indole-3- acetic acid, indole-3-carboxylic acid and indole-3-acetaldehyde. The effect of SWC on the growth of nodal potato explants cultured in vitro was examined. 0.2% SWC significantly accelerated shoot growth and development. When applied at a concentration of 0.4% the number of axillary shoots per node increased. This treatment also stimulated the development of potato tubers on the shoots. The SWC was also shown to enhance the growth of tomato (Lycopersicon esculentum Mill.) roots cultured in vitro. Filtration of the SWC indicated a promotory filtrate phase and an inhibitory cell wall phase. ' The application of the SWC to nematode-infested roots, cultured in vitro, reduced the degree of infestation In susceptible roots but induced host/parasite compatibility in a resistant variety. One of the most pronounced effects noted with seaweed application was the promotion of adventitious roots on several species of garden plants. The application of similar dilutions to Eucalyptus cuttings increased the average root mass but had little effect on the number of roots initiated per cutting. The rooting factors, purified by HPLC, were tentatively identified as indole-3-acetamide, indole-3-acetic acid, indole-3-carbo. xylic acid or indole-3-acetaldehyde by co-chromatography with authentic standards. Finally, the effect of seaweed concentrate on the growth of tomato plants grown in nematode-infested soil was investigated. SWC applied as a soil drench, improved plant vigour, significantly increased shoot and root fresh weights and resulted in a marked reduction in the number of nematode galls per unit length and per unit weight of root. Plants treated with a foliar spray of SWC were invariably the first to produce ripe fruit. Total yield was improved by over 10%. Ashing the SWC indicated that the active constituents are possibly of an organic nature. Filtering the SWC confirmed earlier reports that promotory and inhibitory compounds are present in the concentrate. Chromatographic separation of the SWC into 10 Rf zones indicated the presence of several components with growth regulatory properties. It was found that the same fractions that improved plant growth also reduced nematode infestation. The significance of these findings and the possible relationship between the endogenous plant growth regulators in Ecklonia maxima and the effect of the SWC on plant growth is discussed.<br>Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1990.

Plant growth and survival are affected by the nutrients available in the environment. Nitrogen (N) is most often the limiting nutrient in terrestrial ecosystems, particularly in temperate and boreal forests, such as those on Vancouver Island. To overcome the challenge of limited nutrient availability, plants have evolved symbiotic relationships with fungi, called mycorrhizae. While research on the importance of mycorrhizal symbioses for N uptake by plants continues to grow, we have a limited understanding of the mechanisms of N uptake and transfer by mycorrhizae. This knowledge is crucial to fully understand N uptake and assimilation by plants. This study aimed to determine the influence of soil N availability on conifer growth and foliar N content, and on the N form preferences and sporocarp N content of associated mycorrhizae. Inorganic and organic soil N production was determined for two sites, Fairy Lake and San Juan, near Port Renfrew British Columbia, under pure plantations of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco), Sitka spruce (Picea sitchensis [Bong.] Carr.), western redcedar (Thuja plicata Donn ex D. Don in Lamb) and western hemlock (Tsuga heterophylla [Raf.] Sarg.). Ammonium, nitrate and amino acid production contrasted between the sites, with relatively higher N production in San Juan compared to Fairy Lake. This indicated differences in soil N cycling, most likely due to differences in moisture and topography. In general, conifer species did not affect inorganic and organic soil N production. Growth of conifers increased with increasing N availability, and differed between species, with Douglas-fir and Sitka spruce having the greatest growth and western redcedar having the least growth. Foliar %N and 15N were found to differ among the conifer species, and western redcedar had the lowest foliar N concentrations. While site quality was not reflected in foliar %N, foliar 15N was found to increase with increasing 15N of the forest floor. Ectomycorrhizal (ECM) sporocarps reflected site quality, with greater N concentrations but lower 15N values on the higher N site. Sporocarp 15N concentrations were higher than foliar 15N concentrations, suggesting N isotope fractionation by mycorrhizae. Finally, site N availability was not related to the rates of N form uptake by ECM genera. Both ECM and arbuscular mycorrhizae (AM) did not have substantial nitrate uptake, despite a greater supply of nitrate. Ammonium was found to be taken up at higher rates than nitrate in the ECM and AM roots, suggesting a preference for ammonium, possibly due to ammonium being energetically cheaper to metabolize and suppressing nitrate transporters in mycorrhizal fungi. Differences in proportions of N form uptake and sporocarp N content among ECM genera were seen, indicating potential niche formation based on functional traits such as N form uptake and mycelial morphology. Knowing how mycorrhizae respond to different N forms and rates of N supply will not only increase our knowledge of N dynamics in mycorrhizal symbioses, but will help predict the effects environmental changes, such as disturbance and N deposition, may have on these systems.<br>Graduate<br>2018-08-09

碩士<br>國立成功大學<br>生命科學系<br>104<br>Microbes affect plant growth through several mechanisms. One of the mechanisms affected by microbial volatile organic compounds (mVOCs) are gaseous molecules released by microbes. There are lots of reports that focus on the influence by mixing mVOCs. Just a few researches have analyzed the compositions of mVOCs. Here I analyzed two volatile organic compounds, which are released by Enterobacter aerogenes, a plant growth-inhibiting bacteria. I found the major inhibiting compound, C2, the second large compound in E. aerogenes mVOCs. Using next generation sequencing technique, I found that the key genes of autophagy, exocyst and asparagines synthesis were up regulated when tobacco was exposed to mVOCs of E. aerogenes or C2 compound. To further confirm how vesicle trafficking results in tobacco defense mechanism, virus-induced gene silence (VIGS) was performed to silence Exo70, an important gene participates in autophagy process. NbExo70 silenced tobacco was sensitive to mVOCs of E. aerogenes and C2 compound. H2O2 was not accumulated in leaves when NbExo70 silenced tobacco exposed to mVOCs of E. aerogenes and C2 compound. According to the results I can conclude that Exo70 induces the accumulation of H2O2. The accumulation of H2O2 would induce hypersensitive response programmed cell death(HR-PCD). When the level of H2O2 was abnormal accumulation, it would disturbe the HR-PCD of plant. Thus, Exo70 would help the autophagosomal degradation of H2O2 signaling related protein. NbExo70 silenced tobacco has less deposition in callose, but when it is exposed to mVOCs of E. aerogenes and C2 compound the deposition in callose will be higher than wild-type. It seems that Exo70 is involved in callose deposition, but when under the stress tobacco will turn on another mechanism.

An increased understanding in recent years of the biosynthesis and signal transduction pathways for various plant hormones, including gibberellin (GA), is providing an important tool for understanding interactions between these hormones and their role in plant physiology. In this thesis, interactions between auxin and gibberellin in regulating root growth, and between abscisic acid (ABA) and gibberellin in regulating shoot growth, are explored using the model species, pea. The GA signalling pathway, in particular the involvement of “DELLA” proteins, has received much attention in the last decade. The GAs act by destabilising the growth inhibitory DELLAs; essentially, GA acts as an “inhibitor of an inhibitor”. In Arabidopsis, DELLA proteins have been shown to promote the biosynthesis of active GAs, with the DELLA mutant rga displaying elevated expression of the biosynthesis gene GA4. The recently-sequenced pea DELLA genes LA and CRY are used in this thesis to show that in roots also, DELLA proteins effectively promote GA synthesis gene expression, including a new member of the pea GA 3-oxidase family which appears to play a major role in these organs. Furthermore, these DELLA mutants are used to investigate the role of GA signalling in the interactions with auxin and ABA to regulate growth. Auxin has been shown to promote GA biosynthesis in the above-ground parts of pea (Ross et al., 2000). However, it cannot be assumed that the same interaction also occurs in pea roots. Indeed, another study indicates that auxin acts by enhancing the capacity of GA to destabilise DELLAs in roots of Arabidopsis (Fu and Harberd, 2003). According to the Fu and Harberd model, auxin would down-regulate GA synthesis, the opposite of the up-regulation found by Ross et al. (2000) in stems and consequently, the Ross et al. (2000) and Fu and Harberd (2003) models predict opposite effects of auxin on the expression of GA synthesis genes. Here, to understand the interactions between auxin and GAs in pea roots, wild-type pea roots were treated with the inhibitors of auxin action and auxin transport. These compounds generally down-regulated GA synthesis genes and up-regulated GA deactivation genes, and reduced the level of the bioactive GA1, suggesting that in pea roots, auxin at normal endogenous levels stimulates GA biosynthesis, agreeing with the Ross et al. (2000) model. It is also shown that supra-optimal levels of exogenous auxin reduce the endogenous level of bioactive GA in roots, although the effect appears too small to account for the strong growth-inhibitory effect of high auxin levels. ABA is a known inhibitor of plant growth and historically, ABA and GA have generally been shown to act antagonistically. Previous evidence indicates that ABA inhibits GA synthesis while GA inhibits ABA synthesis. However, the evidence presented here suggests otherwise. GA synthesis gene expression and endogenous levels were not altered in ABA-treated shoots, indicating that, at least in pea, ABA does not regulate GA biosynthesis. The effects of GA deficiency on ABA levels were also investigated. Furthermore, ABA has been reported to act via the GA signalling pathway to inhibit root growth. However, there are conflicting reports on whether ABA acts on GA signalling via the DELLA proteins or downstream of these proteins. Here it is shown that ABA inhibits shoot growth in both the WT and pea DELLA mutants to a similar degree, suggesting that the DELLA proteins are not involved in the ABA-induced inhibition of pea shoot growth. The results presented in this thesis clarify a number of conflicting reports on the auxin-GA and the ABA-GA interactions and how they influence the growth of the plant.

碩士<br>國立臺灣大學<br>園藝學研究所<br>93<br>There were two geneus fungi , including Fusarium and Rhizoctonia had been isolated from roots of Phalaenopsis spp. Two species of Phalaenopsis spp., Phalaenopsis amabilis var. formosana and Dtps. Casablanca Joy × Phal. Taida Pinlong, were inoculated with the isolated fungi GP01 (Fusarium sp.)and R02 (Rhizoctonia sp.). Phal. amabilis var. formosana. showed the high bolting rate by inoculating GP01 and R02 respectively, or Dtps. Casablanca Joy × Phal. Taida Pinlong doesn’t. The treatments of R02+GAs increased the bolting rate of two species of Phalaenopsis spp., suggesting that the orchid mycorrhizal fungi may promote effect of gibberellins positively. Treating gibberellins alone may inhibit bolting of Phalaeonpsis spp. Inoculating R02 also decreased leaf dropping of Phalaenopsis spp., suggesting inoculate orchid mycorrhizal fungi may promote vegetative growth of Phalaenopsis spp. or produce cytokinins. According the result, we suggest that the treatments of R02+GA3 150ppm, 100ppm or R02+GA4+7 150ppm could induce inflorescence of Phalaenopsis spp. effectively. Lysine#3(1000ppm), Aminosong(1000ppm), Cholrine Chloride(300ppm) and Inositol(50ppm) could increase vegetative growth but non-effect on reproduction growth of Phalaenopsis spp.

碩士<br>國立臺灣大學<br>園藝學研究所<br>93<br>Abstract After inoculating one of five Rhizoctonia orchid mycorrhizal fungi(OMF) : RO1 R02 R04 R13 R14 with two cultivars of Paphiopedilum seedlings for 4 months ,we investigated the effects of OMF on the growth of were investigated. Resent showed that in Alma Gavaert ''Goto'' x Maudiae ''Silverado'' AM/AOS, inoculation with R02 increased the leaf length, fresh weight, and the survival rate 100% of seedlings. In another cultivar ,Alma Gavaert ''HB'' x Janet Kunkle ''Grace Hsinying, inoculatioin with R13 increased leaf length and inoculation with R02 and R14 increased the fresh weight of seedlings. It showed that inoculatioin with OMF R02、R13、R14 enhanced the growth and survival rate of Paphiopedilum seedlings. The OMFs in this experiment belonged to Rhizoctonia spp.. It was observed that hypha invaded into orchids root mainly throught root hair cell, and then penetrated throught velamen, exodermis, and then cortex region, but would not reach stele。Hypha formed pelotons in cortex cells and infected neighboring cells by single hypha. Confocal microscop could show 3-D image of pelotons. It was concluded that the model of symbiosis between Rhizoctonia and root of Paphiopedilum is tolypophagy. Effect of plant growth substance on Paphiopedilum showed that inoculation of R02 then applied of Aminosong could increase leaf number and fresh weight of Paphiopedilum delenatii. This treatment increased 3.9 g in fresh weight after four months of treatment control. Aminosong treatment could increased CMR and the length of the first and the second leaf of Paphiopedilum delenatii. Inoculation with R04 and then applied Aminosong or choline chloride increased leaf number. In Paphiopedilum hybrida Impulse ''376-1'' x fairrieanum ''Bounds'', inoculation with R02 paired with use of Lysine＃24 significantly increased leaf number, length of the second leaf and fresh weight significantly. Inoculation with R02 paired with Aminosong also significantly increased leaf number, length of the first leaf, CMR, and fresh weight in this cultivar. In another Paphiopedilum hybrida Alma Gavaert ''Goto'' x Maudiae ''Silverado'' AM/AOS, inoculation with R02 alone or inoculation with R01 or R02 plus the application of Lysine＃24 improved fresh weight substantially them the control. Inoculation with R02 and applied with Aminosong increased length of the second leaf and CMR significantly in this cultivar. Spraying GA3 70 ppm or GA3 70 ppm + BA 30 ppm improved flower stalk emergence on Paphiopedilum Maudiae type, but the flowers with GA3 treatment formed abnormal flower, such as rolled in sepal and petal, reduced in width of petal and twisted in stalk, which lead to loss of ornamental value. GA3 and BA co-treatment also lead to the same result. Only when spraying 30 ppm BA on Paphiopedilum Maudiae type, flowers opened naturally and the length and width of flower were both 1cm longer than the control. This suggested that BA significantly increased flower size of Paphiopedilum Maudiae type. Inoculating with OMF could not reduce flower abnormality as caused by GA3 treatment. Spraying GA3 70 ppm + BA 30 ppm on Paphiopedilum hybrida before the appearance of flower bud would not caused flower stalk emergence at all. GA3 can induce 8% of flower stalk emergence, but BA treatment could not induce flower stalk formation of slipper orchids. Therefore it was concluded that the main function of BA possibly was to induce the flower stalk emergence for those plants already had flower buds. Reducing the GA3 concentration to 30 ppm or 10ppm also produced abnormal flowers. Therefore it was suggested that spraying BA on Paphiopedilum Maudiae type is beneficial to flowering and improving flower quality of slipper orchids. In contrast, GA3 was not recommended.

碩士<br>國立臺灣大學<br>園藝學研究所<br>91<br>There were four geneus fungi , including Trichoderma、Fusarium、Rhizoctonia and mycelia sterile had been isolated from the roots of Paphiopedilum spp. and Spiranthes sinensis. The cell nucleus of PaR1、PaR2 and SpR1 is multinucleate、binucleate and mononucleate respectively as observed by fluorescence microscopy. Use morphological characteristics of hyphea、cell nucleus numbers and checking list , this three Rhizoctonia spp. are Rhizoctonia solani、Rhizoctonia repens and uninucleate Rhizoctonia sp. which was difficult to identify. Two species of Paphiopedilum sp. were inoculated with one of the four Rhizoctonia spp., after six months growth, responses of plant to fungi were variable. The highest growth increase of Paphiopedium delenatii was inoculated with Rhizoctonia repens (PaR2) which was isolated from the same species of root. But the best growth of Paph. Maudiae Type was achieved by the inoculation of uninucleate Rhizoctonia sp. (SpR1) which was isolated from Spiranthes sinensis. While Rhizoctonia solani (R04) fungus which was isolated from Anoecochilus formosanus root could enhance the growth of Paphiopedilum spp. Pelotons revealed in the cortex cells of Paph. delenatii after 15 days of inoculation. The velamen of Paph. delenatii was six to seven layers and has the perforation structures. Hyphae penetrated the velamen through root hairs. The infection process of Rhizoctonia sp. showed that by using single hyphae to penetrate cell wall infected adjacent cell, then pelotons formed near nucleus. The infection with Paph. delenatii was tolypophagy mode. Choline chloride could significantly increased the fresh weight of Paph. delenatii. The treatments of Paph. delenatii by the combination of choline chloride and inositol、choline chloride or Aminosong solution could significantly increase leaf length. Treated Paph. Maudiae Type seedling with Aminosong solution significantly increased leaf length. GA3 and GA4+7 could induce the inflorescence of Paphiopedium sp. and the available concentration was 100 ppm. But gibberellins treatment caused deformed flowers, including curved pedicle、flower appearance asymmetry、upper sepal roll and narrow、petal rolls and increase of ovary length. To amend the deformed flower problem , a change of GA concentration or inoculated with orchid mycorrhizal fungi and the application of other plant hormones was suggested.

碩士<br>國立臺灣大學<br>園藝學研究所<br>92<br>Several fungi isolated from various orchid roots, including Dendrobium, were isolated, purified and mass cultured on PDA medium. After pathogenic tests for fungi inoculated on cucumber, rice and radish seedlings, those non-pathogenic fungi including R01, R02, R04, Ac-1, Ac-2 and Cy were used as inocula to inoculate roots of Dendrobium candidum Wall.ex Linkl. and D. moniliforme Linne.. After 120 days of inoculation, those inoculated with R01, R02 and Cy, the growth of Dendrobium plants were highly enhanced. Among them, plant height was the highest for those were inoculated with R02 of orchid mycorrhizal fungi (OMF). While those were inoculated with R01 and Cy, the length and diameter of the pseudobulb were significantly increased. The mycorrhizal plant weight and number of tiller increased 148 % (by Cy) and 55 % (by R02) respectively than the non-mycorrhizal control (NM-control). For D. moniliforme, Cy or R02 inoculated plants produced bigger and longer pseudoblubs, and the plant weight was 1.07 fold of the NM-control. Cy inoculated plants increased 146% of tillers than the NM-control. Results showed that the inoculation of OMF could highly stimulate the growth of medical use of Dendrobiums, and had great potential for shorten growing period of Dendrobium spp. Results showed that R01 and R02, which were Rhizoctonia spp. and Cy (Cylindrocarpon sp.), which was isolated from Dendrobium sp. were three effective fungi for growth enhancement of medical use of Dendrobium spp. The application of Aminosong solution could enhance plant height, pseudobulb length and node number of Dendrobium tosaense Makino. Choline chloride or inositol could improve the width of pseudoblub and leaf length. Leaf width was enhanced by the Lysine#3 treatment. The application of Lysine#3+ Aminosong solution were would highly promote fresh weight, roots, number of axillary buds and leaves. When PGS (plant growth substance) was treated, the average of plant survival percentage is 99.5% which is 19.5% higher than control (80%). It showed that PGS could enhance the plant survival percentage of Dendrobium tosaense tissue culture seedlings after transplanting from bottles. The plant height and pseudoblub length of Dendrobium candidum Wall. ex Lindl. would be highly increased when Choline chloride + Inositol or Lysine#3 (500ppm) were applied. Number of roots, no. of axillary buds and fresh weight were highest when Lysine#3 was applied. Fresh weight (0.44g) is 1.83 folds higher than control (0.24g), and No. of roots (6.16) is 1.63 folds higher than control (3.77). PGS could improve the vegetative growth and plant survival percentage of Dendrobium tosaense and Dendrobium candidum. It was suggested that the use of Aminosong solution (500 ppm) or Lysine#3 (500 ppm) + Aminosong solution (500 ppm), plant fresh weight was increased. For Dendrobium candidum, Choline chloride (300 ppm) + Inositol (50 ppm) would be suggested.

M.Sc.<br>Bananas are climacteric fruit which are characterised by a low rate of ethylene production and respiration during the pre-climacteric phase, followed by a sudden burst in ethylene production and respiration during ripening. Ethylene is a gaseous plant hormone that accelerates the ripening of climacteric fruit. In order to extend the shelf life of bananas the action or synthesis of ethylene must be inhibited or delayed. Examples of such inhibitors are 1- methylcyclopropene (1-MCP) an inhibitor of ethylene action, and aminoethoxyvinylglycine (AVG), an inhibitor of ethylene synthesis. The purpose of this research was to compare the effect of these two inhibitors on ripening of bananas. 1-MCP acts by blocking the ethylene receptors permanently. The results of this study indicated that 500 nL.L-1 1-MCP is more effective in delaying ripening of banana than AVG, although AVG delivered a better quality fruit in terms of colour. To be effective, bananas must be pre-treated with 1-MCP before they exposed to ethylene. The results also indicated that, the effectiveness 1-MCP to delay ripening decreases with storage time. The results show that ethylene binding to its membrane bound receptors is reversible if the exposure time to ethylene is less than 8 hours. Exposure to ethylene for 8 hours or more results in irreversible binding. However, binding only becomes permanent when exposure to ethylene exceeds 16 hours. For this reason treatment with 1-MCP becomes ineffective after exposure to ethylene for 24 hours due to the fact that ethylene has bound irreversibly and permanently to its binding sites and cannot be displaced by 1-MCP.

碩士<br>國立臺灣大學<br>園藝學研究所<br>96<br>The Dendrobium species have been commonly used in traditional Chinese medicine, by fresh or by dried pseudobulb, as a tonic to nourish the stomach, replenish body fluid and reduce fever. However, the wild Dendrobium spp. are endangered for their slow growing and had been extensively taken off from their native land. The orchid mychorrhiza fungi (OMF) belong to endomychorrizal fungi are generally found in the root cells of Orchid family. OMF normally inoculate and become symbiotic with orchid in the root cells by two ways: tolypophagy and ptyophagy. Growth improvement after inoculation of OMF had been found in several Orchid species. Plant growth substances (PGS) are synthetic compounds that have the same physiological effects as plant hormone and can be used to enhance plant growth. Moscatilin, a bibenzyl derivative originally purified from Dendrobium moscatum, is potentially efficacious against some kinds of cancer. An attempt to increase the growth rate of herbal dendrobium and the content of moscatilin was carried out by the inoculation of OMF and application of PGS in this study. Thus the inoculation of OMF and application of PGS in seedlings of Dendrobium candidum and D. moniliforme results were conducted, and showed that amino acid powder (40 μg/ L), Lysine#24 (1000 μL/ L), Chitosan (500 μL/ L), and amino acid/organic fertilizer mixed solution (200 μL/ L) increased plant height, pseudobulb length, width or leaf numbers of both Dendrobium spp. The inoculation of Cylindrocarpon spp.(Cy) together with application of amino acid powder were highly recommended in practical use for enhancing the growth of both Dendrobium seedlings. An analysis of several common herbal and ornamental dendrobiums in Taiwan, the result showed that only two herbal dendrobium, D. tosaense and D. clavatum, contained moscatilin in the pseudobulbs. The amount of moscatilin stored in the pseudobulb of D. clavatum inoculated with Rhizoctonia spp., R01, are higher than those of the non-mycorrhizal ones. Also the inoculation of R04 significantly increased the amount of moscatilin in the pseudobulb of D. tosaense. Inoculation of Cylindrocarpon spp. enhanced the root growth of mature D. clavatum thus higher root dry weight of D. clavatum was found after 200 days. It was observed that the mycorrhizal structure of different dendrobiums by scanning electron microscopy. Results showed that two genera of OMFs, Rhizoctonia spp. and Cylindrocarpon spp., forming peletons in the roots of inoculated dendrobiums. The infection mode of these two OMFs belong to tolypophagy, in which mycorrhizal cortex cells, peletons could be observed.