Asymmetric localization of PIN proteins controls directionality of auxin transport and many aspects of plant development. The Arabidopsis mutant, unhinged-1 (unh-1), has defects to leaf veins and other root and shoot phenotypes. I identify UNH as the Arabidopsis VPS51 homologue, a member of the Arabidopsis GARP complex, and show that UNH interacts with VPS52, another member of the complex. I also show that UNH co-localizes with SYP61, a trans Golgi network marker. The GARP complex in yeast and metazoans retrieves vacuolar sorting receptors to the TGN and is important in sorting proteins for lysosomal degradation. PIN1 expression in the margin of unh-1 leaves is expanded and the unh leaf phenotype is suppressed by pin1 mutation, supporting the idea that the phenotype results from expanded PIN expression. My results suggest the UNH is important to restrict expression of PIN1 within the margin, likely by targeting PIN1 to the lytic vacuole. / xv, 100 leaves : ill. ; 29 cm

Peroxisomes are organelles originating from the endoplasmic reticulum. Peroxisome biogenesis requires multiple peroxins, including PEX19, a prenylated protein that helps deliver peroxisomal membrane proteins in yeast and mammals. Arabidopsis thaliana PEX19 is encoded by two isogenes, PEX19A and PEX19B. I demonstrate that pex19A and pex19B insertional mutants lack obvious abberant physiological phenotypes. I provide evidence that pex19A pex19B double mutants are inviable, that PEX19B is more abundant than PEX19A in young seedlings, that Arabidopsis PEX19 is farnesylated in vivo, and that YFP-PEX19 predominantly associates with what appears to be a subcellular membrane regardless of its prenylation state. I show that farnesyltransferase mutants apparently contain only non-prenylated PEX19 and lack phenotypes that would indicate inefficient peroxisome activity. My analysis of PEX19 suggests that PEX19 prenylation is dispensable for peroxisome biogenesis, and has generated tools for future studies of the earliest steps in peroxisome biogenesis in plants.

Graduation date: 1992

A cDNA sequence representing a <i> Brassica carinata</i> gene the expression of which is induced by copper chloride treatment, was isolated from a library constructed with mRNA from treated leaves, and designated CIL1 (COPPER CHLORIDE INDUCED in LEAVES). A Basic Local Alignment Search Tool search revealed that CIL1 has similarities to an auxin-induced gene, AIR12 from <i>Arabidopsis thaliana</i>. Southern blot analysis of CIL1 in <i>B. carinata, B. nigra</i> and <i>B. oleracea</i> indicated that it is a member of a small multigene family. Antisense CIL1 transgenic plants were generated to investigate the function of CIL1, and the resulting transformants displayed increased secondary branching suggesting that CIL1 has a role in regulating hormone content or plant architecture. Results of induction studies indicate that the auxin analog a-naphthalene acetic acid, the cytokinin 6-benzylaminopurine, and +/- abscisic acid increase expression of CIL1. Seven CIL1 antisense lines were grown to the T4 generation and were confirmed homozygous. Analysis of CIL1 expression using real-time quantitative RT-PCR showed reduced expression in every examined line. Transgenic plants produced many leaves at the lateral meristems indicating a release of apical dominance. Additionally, the concentrations of auxins, cytokinins, and abscisic acid were altered in the roots and stems of transgenic plants compared to non-transformed plants. Therefore, CIL1 has a role in regulating hormone content that affects lateral meristem activity, apical dominance, and leaf production.

A cDNA sequence representing a <i> Brassica carinata</i> gene the expression of which is induced by copper chloride treatment, was isolated from a library constructed with mRNA from treated leaves, and designated CIL1 (COPPER CHLORIDE INDUCED in LEAVES). A Basic Local Alignment Search Tool search revealed that CIL1 has similarities to an auxin-induced gene, AIR12 from <i>Arabidopsis thaliana</i>. Southern blot analysis of CIL1 in <i>B. carinata, B. nigra</i> and <i>B. oleracea</i> indicated that it is a member of a small multigene family. Antisense CIL1 transgenic plants were generated to investigate the function of CIL1, and the resulting transformants displayed increased secondary branching suggesting that CIL1 has a role in regulating hormone content or plant architecture. Results of induction studies indicate that the auxin analog a-naphthalene acetic acid, the cytokinin 6-benzylaminopurine, and +/- abscisic acid increase expression of CIL1. Seven CIL1 antisense lines were grown to the T4 generation and were confirmed homozygous. Analysis of CIL1 expression using real-time quantitative RT-PCR showed reduced expression in every examined line. Transgenic plants produced many leaves at the lateral meristems indicating a release of apical dominance. Additionally, the concentrations of auxins, cytokinins, and abscisic acid were altered in the roots and stems of transgenic plants compared to non-transformed plants. Therefore, CIL1 has a role in regulating hormone content that affects lateral meristem activity, apical dominance, and leaf production.

Thesis (M.E.) in Forestry--University of Maine, 2002. / Includes vita. Includes bibliographical references (leaves 39-44).

No description available.

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1957. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 139-145).

Thesis (Ph. D.)--University of Notre Dame, 1941. / Bibliography: p. 13-14.