Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008. / Source: Dissertation Abstracts International, Volume: 69-05, Section: B, page: 2883. Adviser: Steve P. Long. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3231. Adviser: Steven J. Clough. Includes supplementary digital materials. Includes bibliographical references (leaves 121-149) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6236. Adviser: Evan H. DeLucia. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3631. Adviser: Archie R. Portis, Jr. Includes bibliographical references (leaves 82-91). Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 0770. Adviser: Evan DeLucia. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Abstract not available.

Silk tissue is a specialized reproductive tissue of the maize plant, equivalent to the stigma and style portion of the female inflorescence. The moist and nutrient rich properties of maize silk tissue that facilitate pollen reception and the support of pollen tube growth also make maize silk a preferred site of infection by fungal pathogens such as Fusarium graminearum. The cDNA clone zmgrp5 was isolated in a previous study to identify silk tissue-specific genes. ZmGRP5, the encoded protein, was predicted to be a cell wall glycine-rich protein (GRP) and was experimentally characterized in this study. Using polyclonal antiserum, immunoblot analysis confirmed the silk tissue specificity of the protein. Additionally, subcellular fractionation studies confirmed ZmGRP5 localization in the cell wall fraction, and not in any other subcellular fractions. Interaction of ZmGRP5 with the cell wall matrix was observed to be disrupted by the addition of the reducing agent beta-ME. The reversible nature of disulfide bond formation and disruption under different redox conditions suggest that ZmGRP5 could potentially be important in the regulation of cell wall structural properties such as elasticity and rigidity in accordance with environmental and developmental changes. The variable immobilization of ZmGRP5 to the cell wall matrix could also serve as a potential mechanism of activation or inactivation of any non-structural functions. The identification of potential post-translational modifications such as phosphorylation and glycosylation, which are rarely observed in other cell wall GRPs, suggest that the functional significance of these modifications in ZmGRP5 is worthy of further study.

The phylogeny of land plants, especially angiosperms, has been perplexing scientists for more than 125 years. The aim of this study was to help elucidate unanswered phylogenetic issues using rpb1 genes from twenty-six land plant species (8 gymnosperm species, 17 angiosperm species and Psilotum, a fernally, as the outgroup). The sixteen rpb1 genes which were sequenced in this study had very similar lengths and contained no base compositional bias. Synonymous substitutions of rpb1 sequences were saturated when compared to the outgroup. The third codon positions of these genes contained misleading phylogenetic information. The topology of trees based on first and second codon positions were in line with that of protein trees. Both angiosperms and gymnosperms were monophyletic. Amborella was found at the base of the angiosperm tree, followed by Nymphae, then Illicium. These data rejected the anthophyte hypothesis, weakly supported the gnepine hypothesis, but did not resolve the interrelationship among eumagnoliids and eudicots. rpb1 genes were combined with the 18S ribosomal RNA gene and chloroplast atpB and rbcL genes to obtain more robust phylogenies. This combined data set produced a topology similar to that of the first and second positions of rpb1 genes except that they better resolved the interrelationship among eumagnoliids and eudicots. We conclude that our rpb1 sequences evolve too slowly to provide enough phylogenetic information to fully resolve the phylogeny of seed plants and that other gene sequences will need to be added to these data sets to obtain a well-resolved phylogenetic tree of seed plants.

The ethnobotany of East Timor was examined for the first time with emphasis being placed on documenting traditional knowledge of medicinal plants. The medicinal plant traditions of 3 distinct East Timorese cultures were studied and compared using both modern quantitative ethnobotanical methods but also with classical descriptive ethnobotanical techniques. A total of 116 medicinal plant species were identified. The medicinal plant traditions of the Laklei and Idate cultures of East Timor were compared using Trotter and Logan's (1986) quantitative 'informant consensus factor'. On average, informant consensus was greater in Laklei suggesting a medicinal plant tradition that is more well defined than in Idate, where informants are more likely to use the same medicinal plants when treating similar illnesses. Furthermore, only 11 of 86 medicinal plant species documented with these two cultures were used by both cultures of which only 6 had similar uses. The medicinal plant tradition of a third indigenous culture, the Fataluku people, was documented using classical descriptive ethnobotanical techniques. Over 70% of the Fataluku medicinal plants were different from those used by the Laklei or the Idate people. (Abstract shortened by UMI.)

North American ginseng (Panax quinquefolius L.) is a valuable and widely used medicinal plant and Ontario has become the largest grower of ginseng in North America. Ginseng has been grown in Ontario for over 50 years and has reached the land race stage. The phytochemistry of Ontario ginseng land races was characterized using high performance liquid chromatography (HPLC) coupled with a diode array detector (DAD), evaporative light scattering detector (ELSD), or mass spectrometry (MS) to assess ginsenoside and monosaccharide content. Nuclear magnetic resonance (NMR) was used successfully as a metabolomic tool to distinguish Ontario ginseng land races and ginseng species. Ginsenoside variation was high within and among Ontario ginseng land races and variation in ginsenoside content was correlated positively to the level of inhibition of the drug metabolizing cytochrome P450 enzyme, CYP3A4. Along with the assessment of ginsenosides, LC/MS/MS and LC/ELSD methods were developed to characterize malonyl ginsenosides and monosaccharide components respectively in Ontario ginseng. Malonyl ginsenosides accounted for a significant percentage of total ginsenoside content and glucose was found to be the major monosaccharide component. Although chromatographic ginsenoside analysis did not differentiate land races, 1H NMR was successfully applied to distinguish ginseng species and two of five land races. The results from this study contribute to the validation and characterization of Ontario ginseng and add to the value of this important medicinal crop.