Plant Biology Commons^™

Leaf Identification Using Image Processing And Automatic Pattern Recognition, Thomas E. Humbert, Joseph E. Niemiec, Joshua M. Kaster

The Research and Scholarship Symposium

No abstract provided.

Response Of Nebraska Horseweed (Conyza Canadensis) Populations To Dicamba, Roberto Crespo, Mark L. Bernards, Greg Kruger, Donald Lee, Robert Wilson Jr.

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism-of-action for postemergence weed control in soybean. Numerous broadleaf species, including horseweed, have evolved resistance to glyphosate. It is anticipated that dicamba will be used by farmers as a primary tool to manage these weeds. Studying and understanding variability in horseweed response to dicamba will aid in developing appropriate risk management strategies to extend the utility of the dicamba-resistance technology. Horseweed plants from ten Nebraska populations were treated with one of nine doses of dicamba in greenhouse experiments. At 28 days after treatment (DAT) visual injury estimations were made and ...

Review Of The Purple Amole Chlorogalum Purpureum (Agavaceae): A Threatened Plant In The Coast Ranges Of Central California, Christopher P. Kofron, Connie Rutherford, Elizabeth R. Clark, Darlene Woodbury, Jody Olson, Robert F. Holland

Bulletin of the Southern California Academy of Sciences

The purple amole Chlorogalum purpureum (Agavaceae) is a bulbous, perennial soap plant endemic to central California and listed as threatened under the U.S. Endangered Species Act since 2000. Chlorogalum p. purpureum occurs in the rain shadow of the Santa Lucia Range on Fort Hunter Liggett, south Monterey Co., and on Camp Roberts, north San Luis Obispo Co. Chlorogalum p. reductum occurs in the rain shadow of the La Panza Range in central San Luis Obispo Co., mostly on Los Padres National Forest and with potential for a substantially larger occupied area on private land. We review and enhance the ...

Epigenetics Of Stress Adaptation In Arabidopsis: The Case Of Histone Modifications, Behnaz Najafi Majdabadi Farahani

University of Western Ontario - Electronic Thesis and Dissertation Repository

Changes in the epigenetic status of plants, which contribute to changes in gene expression, in response to abiotic stress are well documented. However, their stability and transmission to subsequent generations, and their incorporation into plant stress adaptation are still a matter for debate. Using chromatin immuno-precipitation and Next Generation Sequencing (ChIP-seq), we compared genome wide enrichment of two histone marks, H3K9ac and H3K4me2, in the progeny of salt stressed and control Arabidopsis plants. Data showed less enrichment of the H3K9ac in the chromatin of the progeny of salt stressed plants, but no changes were detected in the enrichment of the ...

Phosphorylation Regulates Myosin Driven Organelle Movements, Peter Andrew Duden

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Cytoplasmic streaming in plant cells is the continuous flow of cytoplasm and organelles throughout the cell, with the first observation of cytoplasmic streaming being publicized in 1774. However, the mechanism of cytoplasmic streaming remained unclear until components of the cytoskeleton were researched. Research now supports that the motive force generating cytoplasmic streaming is the interaction of myosin XI motor proteins with organelles while sliding along actin filaments. From this, a key topic of interest is how myosin driven organelle movement is regulated. Our research focuses on whether phosphorylation affects the regulation of myosin XI motor proteins. Specifically, the goal of ...

Interactions Between Floral Mutualists And Antagonists, And Consequences For Plant Reproduction, Nicole Leland Soper Gorden

Open Access Dissertations

While pollinators and leaf herbivores have been a focus of research for decades, floral antagonists have been studied significantly less. Since floral antagonists can be as common as leaf herbivores and have strong impacts on plant reproduction, it is important to understand the role of floral antagonists in the ecology and evolution of flowers. I conducted four experiments to better understand the relationship between plants, floral traits, floral antagonists, and other plant-insect interactions. First, I manipulated resources (light and soil nutrients) that are known to have impacts on plants and floral traits to test how they affect floral antagonists and ...

A Comparative Analysis Of The Relative Water Content Of The Pollen Of Early Diverging Angiosperms, Andrew Robert Moffatt

Ecology and Evolutionary Biology Publications and Other Works

The pollen of most angiosperms goes through a process of dehydration before anthesis, the opening of the flower (Heslop-Harrison 1979a). During dispersal, further dehydration often occurs (Heslop-Harrison 1979b). Dehydrated pollen comes in two degrees: hydrated (also termed desiccation-sensitive or recalcitrant) at greater than 30% water content by mass and dehydrated (also termed desiccation-tolerant or orthodox) at less than 30% water by mass (Franchi et al 2002, 2011). Most species tend to undergo some degree of dehydration, or developmental arrest, before anther opening (Franchi et al 2002). Angiosperms are known to have much faster reproductive processes than other seed plants, which ...

Functional Characterization Of The Hua2 Gene Family In Arabidopsis Thaliana, Preetam Janakirama

University of Western Ontario - Electronic Thesis and Dissertation Repository

HUA2 encodes a key developmental regulatory protein implicated in the coordination of induction and the maintenance of floral state in Arabidopsis. To gain further insight into the function of HUA2, I have conducted a series of studies aimed at elucidating the molecular function(s) of its individual domains. I show that the PWWP, RPR and CT-proline rich domains within HUA2 are required for the proper regulation of the flowering time phenotype. I also establish that HUA2 interacts with characterized splicing factors (FCA, AtPRP40, RBP45 and UBP1) through its CT-proline rich domain. In addition, I examine the overlap in function between ...

Effects Of Excitation Pressure On Variegation And Global Gene Expression In Arabidopsis Thaliana, Rainer Bode

University of Western Ontario - Electronic Thesis and Dissertation Repository

I assessed the effects of photosystem II excitation pressure on chloroplast biogenesis and leaf sectoring in the Arabidopsis thaliana variegated mutants im, spotty, var1, var2, chs5 and atd2. The plants were grown under varying degrees of excitation pressure induced by growth at increasing irradiance at different temperatures and the extent of variegation was quantified throughout the plant’s development. I found that the degree of variegation was positively correlated with excitation pressure, regardless of whether high light or low temperature was used to induce increased excitation pressure in all the mutants tested. This was irrespective of whether the mutation causing ...

Ecology And Invasive Properties Of Musk Thistle (Carduus Nutans) In The Central Prairies Of Nebraska, Chengchou Han

Theses, Dissertations, and Student Research in Agronomy and Horticulture

Musk thistle (Carduus nutans) is an herbaceous monocarpic herb introduced to the U. S. from Eurasia. The invasion of musk thistle can reduce forage area, soil stability, and reduce recreation and open areas for humans and wildlife.

Resistance of warm season and cool season perennial grass communities to musk thistle invasion is important for land managers to consider, especially where disturbance has made an area particularly susceptible. Our results show that disturbances, such as overgrazing can open up niches in canopies of warm season grass communities and facilitate invasion but not in cool season grass communities. The mechanism of invasion ...

The Evolutionary Genetics Of Seed Shattering And Flowering Time, Two Weed Adaptive Traits In Us Weedy Rice, Carrie S. Thurber

Open Access Dissertations

Weedy rice is a persistent weed of cultivated rice (Oryza sativa) fields worldwide, which competes with the crop and drastically reduces yields. Within the US, two main populations of genetically differentiated weedy rice exist, the straw-hulled (SH) group and the black-hulled awned (BHA) group. Current research suggests that both groups are derived from Asian cultivated rice. However, the weeds differ from the cultivated groups in various morphological traits. My research focus is on the genetic basis of two such traits: seed shattering ability and differences in flowering time. The persistence of weedy rice has been partly attributed to its ability ...

High School Horticulture Curriculum, Margaret Maratsos

Horticulture and Crop Science

Horticulture is just one of the many topics covered in a high school agriculture curriculum, and yet, there are very few lesson plans or resources available to teachers for these classes specifically. The objectives of this project were to compile a set of lesson plans, lab plans, and tests that would emphasize interactive and investigative learning. The lesson plans were written in such a way that they reflected a certain set of standards, set down by the state of California, and were meant to serve as a bare outline of topics that would be discussed within a week’s worth ...

East Asian Plants In Eastern Us Forests: Are Invaders Pre-Adapted For More Efficient Resource Use? (Talk), Mason Heberling, Jason Fridley

Mason Heberling

The globalization of human activities has resulted in the widespread movement of plants around the world. Paradoxically, many of these exotic species are out-competing native plants, despite the presumption that native species have locally adapted to their environments. Further, global invasion patterns are frequently asymmetric, with some regions more likely to produce invasive species and others more likely to be invaded. This phenomenon is particularly prominent in eastern North American (ENA) forests, where an unexpected, substantial fraction of woody invaders originated from East Asia (EAS). Although both regions lie primarily in the north temperate mesic forest biome with comparable niches ...

Functional Characterization Of Two Putative Nucleobase Transporters In Arabidopsis Using Heterologous Complementation In Yeast, Sara E. Miller

Master's Theses

To identify the substrate profile function for AtNAT5, one of the twelve members of the NAT/NCS2 gene family putatively identified to transport xanthine and/or uric acid, and to identify other functional aspects of transport for the already characterized AtNCS1 adenine-guanine-uracil transporter (Mourad et al., 2012) we used heterologous complementation techniques in S. cerevisiae mutant strains deficient in nucleobase transport. The ability of transformed yeast cells expressing the AtNAT5 locus to grow in the presence of a panel of nucleobase toxic analogs revealed that the AtNAT5 protein is unable to transport adenine, guanine, cytosine, or uracil as expected by ...

Har1 And Ljamp1 Dependent Regulation Of Root Architecture In Lotus Japonicus, Chong Sung Kim

Electronic Thesis and Dissertation Repository

Here, I characterize a root-branching hypermorph of Lotus japonicus, called cluster root-like1 (crl1), which originated from a har1-1 suppressor screen. I have shown that the crl1 root phenotype is determined by two independently segregating recessive mutations, har1-1 and Ljamp1-1, with corresponding HAR1 and LjAMP1 encoding an LRR‑receptor-like kinase and a predicted homologue of the Arabidopsis ALTERED MERISTEM PROGRAM 1 protein, respectively. Unlike har1-1, the Ljamp1 mutation does not affect the symbiotic properties of L. japonicus Gifu but exerts a pleiotropic effect on shoot development. Root architecture, however, is regulated by a synergistic action of HAR1 and LjAMP1, as the ...

Involvement Of Hexokinase1 In Plant Growth Promotion As Mediated By Burkholderia Phytofimans, Jae Min Park

University of Western Ontario - Electronic Thesis and Dissertation Repository

Burkholderia phytofirmans strain PsJN consistently enhanced the growth of potato plants in vitro. The role of hexokinase1 in glucose phosphorylation was investigated in plants with PsJN. Increased hexokinase1 activity only in roots of PsJN-treated plants cultivar Kennebec suggests that hexokinase1 is associated with plant root and stem growth.

Plant growth with PsJN was determined when plants were grown with different sugars at various concentrations. PsJN-treated plants expressed diverse forms of growth promotion. When growth promotion did occur, hexokinase1 activity also increased. Growth promotion and hexokinase1 activity appear to be correlated to the enzyme to recognize the substrate for catalytic activity ...

Cadmium Accumulation And Distribution In Lettuce And Barley, Fardausi Akhter

University of Western Ontario - Electronic Thesis and Dissertation Repository

Cadmium (Cd) is a non-essential trace element and its environmental concentrations are increasing due to human activities. Edible plants can accumulate high concentrations of Cd, which could be toxic to humans. Understanding how and where Cd is stored in plants is important for ensuring lower concentration of Cd in the food. In this thesis, the accumulation and distribution of Cd in three agricultural plants, namely lettuce (Lactuca sativa L.), barley (Hordeum vulgare L.) and radish (Raphanus sativus L.), were investigated with a focus on the potential mechanisms involved in the localization of Cd in the root. The main objectives of ...

Protein Body Formation In Stable Transgenic Plants Of Nicotiana Tabacum Expressing Elastin-Like Polypeptide And Hydrophobin Fusion Proteins, Sonia P. Gutierrez

Electronic Thesis and Dissertation Repository

Plants are recognized as an efficient and inexpensive system to produce valuable recombinant proteins. However, the use of plants still faces two main limitations: the low accumulation levels of some recombinant proteins and the lack of efficient protein purification methods. Two fusion partners, elastin-like polypeptides (ELP) and hydrophobin I (HFBI) were found to increase the accumulation of recombinant proteins and induce the formation of protein bodies (PBs) when targeted to the ER in transient expression assays. In this study I examined the effect of these tags in stable transgenic plants of two Nicotiana tabacum cultivars when fused to green fluorescent ...

List Of Thylakoid Zinc-Finger Proteins In Arabidopsis, Yan Lu

Yan Lu

No abstract provided.

Identification And Characterization Of The Arabidopsis Homolog Of The Yeast Trex-2 Complex, Gang Tian

Electronic Thesis and Dissertation Repository

Nuclear pore complexes (NPCs) are vital to nuclear-cytoplasmic communication in eukaryotes. The yeast Thp1-Sac3-Cdc31-Sus1 complex, also known as the TREX-2 complex, is anchored to the NPC via the nucleoporin Nup1, and is essential for mRNA export. In this study, the Arabidopsis homolog of the yeast TREX-2 complex was discovered. Physical and functional evidence support the identification of the Arabidopsis orthologs of the yeast Thp1 and Nup1. Of three Sac3 Arabidopsis homologs, two are putative TREX-2 components. Surprisingly, none are required for mRNA export as is the yeast Sac3. Physical association with TREX-2 was observed for the two Cdc31 homologs, but ...