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  • Botany & Mycology 2009 - Abstract Search
    Locations or Search Botany Mycology 2009 Home Login Unable to connect to database 13 12 48 Unable to connect to database 13 12 48 SQL Statement is null or not a SELECT 13 12 48 Abstract Detail The Power of Movement in Plants Whippo Craig W 1 Hangarter Roger 2 Chloroplast Movements in Plants Chloroplast relocation in response to changing light environments is common in plants Under low light conditions chloroplast aggregate along the cell walls perpendicular to the light and under bight light chloroplast move adjacent to the cell wall perpendicular to the incoming light Several Arabidopsis mutants with altered chloroplast movement have been identified Three mutants display impaired but not abolished chloroplast movements under both dim and bright light conditions plastid movement impaired 1 pmi1 pmi3 and pmi13 PMI1 is a unique plant specific protein whereas the PMI3 and PMI13 proteins contain conserved domains also found in animal proteins that are known to associate with the plasma membrane or cytoskeleton components The intercellular localization of these PMI mutants will be discussed as well as how these proteins affect the cytoskeleton during chloroplast movements Log in to add this item to your schedule 1 Indiana University Biology 915 E

    Original URL path: http://2009.botanyconference.org/engine/search/index.php?func=detail&aid=151 (2016-02-01)
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  • Botany & Mycology 2009 - Abstract Search
    53 Abstract Detail The Power of Movement in Plants Hangarter Roger 1 Gravitropism and the development of plant form Darwin pointed out that Under the influence of gravitation certain plant parts are excited to place themselves more or less transversely to the line of its action However because of the ease of working with young seedlings and their vertical gravity responses most research on gravitropism has focused on primary roots and shoots This research has provided tremendous insight into the molecular components controlling tropistic responses of primary roots and shoots Yet the bulk of a plant consists of lateral organs that do not grow parallel to the gravity vector Using Arabidopsis as a model we found that lateral organs are capable of both positive and negative gravitropism consistent with the notion that organ orientation is determined by the developmentally contingent gravitropic set point angle GSA Arabidopsis mutants were identified that have altered orientations of lateral organs while maintaining the normal gravitropic vertical orientation of the primary organs These mutants have been tentatively named mgsa mutants for their modified gravitropic set point angle Our analyses of the mgsa mutants show that many aspects of plant architecture are strongly influenced by developmentally

    Original URL path: http://2009.botanyconference.org/engine/search/index.php?func=detail&aid=1170 (2016-02-01)
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  • Botany & Mycology 2009 - Abstract Search
    need to be able to take several different points of view Sitting on the apex we can look back at the developmental pattern that exists along the plant root or shoot axis This perspective allows us to determine the stages that are competent to move in response to environmental stimuli It is essential to understand the physiology of tropisms Also from the plant apex we can look out to see a microenvironment created by the interaction between the root or shoot and the surrounding soil water or atmosphere A second perspective is evident when we hop off the apex onto a stationary soil or air particle see the parade of developing plant cells and experience the exchange of material with the developing cells This point of view is needed to understand how the moving plant affects its environment A third perspective is that of a particle attached to the plant tip With time the particle accelerates to a constant velocity of displacement from the plant apex and simultaneously decelerates to a fixed position relative to the environment This perspective allows us to understand temporal spatial relationships inherent in plant form Keeping in mind these different perspectives will help integrate the

    Original URL path: http://2009.botanyconference.org/engine/search/index.php?func=detail&aid=1053 (2016-02-01)
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  • Botany & Mycology 2009 - Abstract Search
    Detail The Power of Movement in Plants Drenovsky Rebecca E 1 James Jeremy J 2 Plant invasions in rangelands physiological traits underlying success Humans have deliberately or accidentally moved plant species around the globe drastically altering plant communities However not all non native species become invasive Thus understanding the traits that make some non native species more competitive than others is an important first step in determining which species may become invasive Our objective was to compare a suite of native and non native perennial forbs with respect to their relative growth rates and physiological traits related to nutrient uptake and use We predicted specific leaf area would be the key trait underlying faster relative growth rates in non native species Additionally we hypothesized that non native species would have a greater ability to exploit soil nutrient resources and have higher photosynthetic rates biomass accumulation and nutrient use efficiency compared to native species As predicted high relative growth rate in non native species was due to primarily higher specific leaf area and leaf area ratio than to other factors This result indicates faster growth was related to plants creating more leaf area per unit biomass allocated to leaves rather than differences in biomass partitioning between shoots and roots or differences in net assimilation rate Non native species also were able to more effectively exploit soil resources having higher leaf nitrogen than native species Additionally non native species had higher photosynthetic rates higher photosynthetic nutrient use efficiencies and biomass accumulation than native species However native species differed greatly in their relative growth rates physiological traits and biomass accumulation These results suggest that 1 multiple traits contribute to the success of non native species and 2 that native species within a functional group showed large trait variation Thus managing these communities should

    Original URL path: http://2009.botanyconference.org/engine/search/index.php?func=detail&aid=172 (2016-02-01)
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  • Botany & Mycology 2009 - Abstract Search
    orchids Orchids possess an exquisite suite of characters to support pollination Among the most remarkable of these characters is the forcible pollinarium discharge of the genus Catasetum When ejected from a male flower the pollinarium attaches precisely to the dorsum of a bee which will upon visiting a female flower deposit the pollen bearing pollinia into the stigmatic cavity thus achieving pollination The fast release of the pollinarium and precise targeting to the bee s dorsum are critical for successful pollination in the genus yet these features have received only limited attention in the literature In this talk we show that the impulse that propels the pollinarium comes from the elastic energy stored in the stipe and that subsequent interaction with the flower column guides the pollinarium toward the bee This active pollination mechanism stands in sharp contrast with pollination in the majority of orchid genera where floral architecture must ensure that the pollinator comes in direct contact with the static pollinarium In Catasetum the pollinarium guidance mechanism and remote triggering via the action of the antennae have relaxed this structural constraint in the design of flowers This innovation we propose has enabled the exceptional diversification of male flower morphology

    Original URL path: http://2009.botanyconference.org/engine/search/index.php?func=detail&aid=62 (2016-02-01)
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  • Botany & Mycology 2009 - Abstract Search
    Plants Mocko Kerri 1 Jones Cynthia S 1 Nicotra Adrienne B 2 Service to the plant Solar tracking and leaf shape in Pelargonium Solar tracking in plants describes the temporary and reversible movement of leaves in response to light Darwin recognized that this phenomenon provided a service to the plant that has since been studied by ecophysiologists most extensively in arid environments Under cool temperatures and non water stressed conditions plants display diaheliotropic movements that maintain leaves perpendicular to incident light maximizing photon flux density to achieve high photosynthetic rates throughout the day Under hot dry conditions paraheliotropic movements parallel to solar incidence reduce photon flux density to prevent thermal damage and enhance water use efficiency Examined mostly in species with pulvini and pinnate leaves there has been little direct attention to the effect of leaf shape on the extent of solar tracking Leaf energy exchange with the environment depends on the physical properties of a given leaf shape such that an entire leaf has a thicker boundary layer and less heat transfer with the environment than a highly dissected leaf Therefore dissected leaves are predicted to maintain temperatures closer to ambient However energy budgets for any shape of leaf can be influenced by changes in leaf angle We measured diurnal changes in leaf inclination and azimuth of two closely related co occurring geophytic Pelargonium species of contrasting leaf shape While both species tracked the sun during the course of the day there was more movement in highly dissected leaves Under winter growing conditions leaves of the dissected species moved to intercept more solar radiation and heat up more quickly than the non dissected species Between species differences in leaf shape and solar tracking combined to result in similar maximum leaf temperatures Thus the full extent of Darwin s service

    Original URL path: http://2009.botanyconference.org/engine/search/index.php?func=detail&aid=1236 (2016-02-01)
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  • Botany & Mycology 2009 - Abstract Search
    13 14 Abstract Detail The Greatest Opportunists of all Celebrating 40 years of Job Kuijt s Randle Christopher P 1 Keith Couch Sarah 2 Tarson Victor G 1 Characterization of rbcS in Orobanchaceae Plants that are no longer dependent on endogenous photosynthesis often experience rapid evolution at loci responsible for photosynthesis Common results include gene deletion and the evolution of non functional sequences through insertions deletions and premature stop codons Much has been documented about the evolution of the chloroplast gene encoding the large subunit of Rubisco rbcL in Orobanchaceae with many holoparasitic plants experiencing loss of function mutations However some of these holoparasites retain functional copies of this gene through purifying selection or in other cases stochastically On the other hand little is known regarding the structure and evolution of the nuclear gene family encoding the small subunit of Rubisco rbcS in these plants In this study rbcS will be characterized in hemiparasitic and holoparasitic members of Orobanchaceae Characterization includes ascertaining the number of copies the number of introns of each copy inferred amino acid sequence The presence or absence of functional rbcS sequences may be especially important in determining the role of selection in maintaining rbcL in that

    Original URL path: http://2009.botanyconference.org/engine/search/index.php?func=detail&aid=294 (2016-02-01)
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  • Botany & Mycology 2009 - Abstract Search
    coupled to the origin of haustorium development indeed it is the organ which embodies the very idea of parasitism Kuijt 1969 We are interested in identifying the genetic events that resulted over evolutionary time in the ability to initiate and develop haustoria The Orobanchaceae is a fantastic family for parasite evolution studies because multiple stages in the evolution of parasitic plants are represented by extant species We are part of a multi investigator Parasitic Plant Genome Project whose goal is to sequence transcripts from several Orobanchaceae species and use comparative approaches to identify genes associated with plant parasitism at many levels In my lab we are using a facultative parasite as a model because its genome is presumably less divergent than obligate or holoparasites from their common autotrophic ancestor Triphysaria previously Orthocarpus is small genus of five cross hybridizing species that grow as annual root parasites throughout the Pacific Coast We are taking transcriptional approaches to identify parasitic plant genes associated with haustorium development cDNAs were prepared from mRNA extracted from Triphysaria roots before and after exposure to host roots Over one hundred thousand cDNAs were sequenced by the Department of Energy Joint Genome Institute as part of their Community

    Original URL path: http://2009.botanyconference.org/engine/search/index.php?func=detail&aid=738 (2016-02-01)
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