Thesis--Bonn University.

Inaug.-Diss.--Leipzig. / Lebenslauf. Includes bibliographical references.

Plant growth, development, and environmental responsiveness are dependent on hormone-induced gene expression. This dissertation reports multiple interactions between the plant hormones auxin and ethylene and investigates their contribution to the gravitropic response, elongation growth, adventitious root formation, callus and tracheary element initiation and growth, and flower development. Four mutants of tomato (Lycopersicon esculentum, Mill.) altered in either hormone production or hormone response were used to test the involvement of ethylene and auxin. These mutants included diageotropica (dgt) which is auxin-resistant, Never-ripe (Nr), which is ethylene-resistant, epinastic (epi), which overproduces ethylene and lazy-2 (lz-2), which exhibits a phytochrome-dependent reversed-gravitropic response. Additionally, a double mutant between Nr and dgt was constructed and tested. Gravitropism was studied as an exemplary process involving both auxin and ethylene. Mutant analysis demonstrated that ethylene does not play a primary role in the gravitropic response via the currently known ethylene response pathways. However, ethylene can modify the gravitropic response, e.g. the delayed gravitropic response of the dgt mutant can be restored with exceedingly low concentrations of ethylene and ethylene synthesis- and ethylene-action inhibitors can partially inhibit the graviresponse. The role of gravity in tracheary element (TE) production was tested in microgravity (during a space shuttle flight) and in hypergravity (centrifugation). A correlation was found between gravitational force and the production of TEs, with decreased numbers of TEs produced in microgravity and increased numbers produced in response to hypergravity. Increased production of TEs by dgt in both increased and reduced gravity indicates that gravity regulates vascular development via a DGT-dependent pathway involving auxin. Combination of both the Nr and dgt mutations in a double mutant leads to plants which exhibit the reduction of auxin-sensitivity typical of dgt as well as a delay in fruit ripening typical of Nr. The reduced gravitropic response of the dgt mutant was restored to wild-type levels in the double mutant confirming a complex role for ethylene in the gravitropic response. Abnormal floral organ development was observed in a subset of double mutant flowers.These data demonstrate multiple connections between auxin and ethylene during development and provide further insight into their cellular interactions. / Graduation date: 2001

Thesis (M.S.)--Oregon State University, 1989. / Typescript (photocopy). Mounted photographs. Includes bibliographical references. Also available on the World Wide Web.

La poésie de Lorand Gaspar, par la constance de sa variété même et sa réticence à cultiver une forme fixe, semble autoriser l’hypothèse d’une "poétique du mouvement", qui se découvre en résonance avec toute une conception immanentiste du monde, advenue dès l’enfance du poète et cultivée au fil de l’expérience. Fortement indicative d’une relation analogique avec le système neuronal ― d’où la lecture que nous proposons d’une "neuropoétique" ―, cette poétique cinétique, tissée dans la tension stylistique d’une "continuité discontinue", serait pénétrée d’une poétique adverse, à la fois contraire et complémentaire, qui semble incliner vers les formes spécifiques d’une géographie élective. Fondée par une puissante thématique du relief et par l’expérience, fondamentale dans la vie de Gaspar, de la nature, cette théorie "géotropique" entend déployer la construction esthétique, dans l’œuvre, d’un "relief poétique", ou encore, pour dire en un mot l’instillation de la géologie dans la forme du poème, d’une géopoétique. La poétique de Lorand Gaspar, essentiellement contrastive, serait la conjugaison de ces deux mouvements linguistiques, de cette tension entre finitude et infini, qui montre que le poème de Gaspar n’est pas un élan simple dans le monde, mais un monde où le sujet, à travers l’invention poétique, tend, aussi bien, à se dégager de l’infini "mouvement" où il est engagé. / Lorand Gaspar’s poetry bears a constant variety that resists the development of a fixed form. It thereby seems to allow for the hypothesis of a "poetics of motion" which echoes the poet’s immanence-based conception of the world, occurred to him since his childhood and fostered over the years of experience. Strongly pointing at an analogical relationship with the neuronal system, which accounts for our reading of a "neuropoetics", this kinetic poetics, woven in the intricate stylistics of a "discontinuous continuity", is likely infused with an adverse poetics, both contradicting and complementing it, which seems to tend towards the specific forms of a peculiarly chosen geography. Informed by a forceful theme of the relief and the fundamental experience of nature in Gaspar’s life, this "geotropic" theory means to display the aesthetic making up of a "poetic relief", or, of a geopoetics, a word that conveys the ingraining of geology into the form of the poem. Lorand Gaspar’s poetics, which is essentially contrastive, would bring together those two linguistic movements, this tense interplay between the finite and the infinite, which shows that Gaspar’s poem does not merely spring up to the world, but is, in itself, a world where the subject, through the poetic invention, also tends to break free from the infinite "movement" in which he is involved.

Thesis (Ph. D.)--Miami University, Dept. of Botany, 2008. / Title from second page of PDF document. Includes bibliographical references.