The 6th
Annual
NC
Undergraduate
Summer Research Symposium
Independent Researcher
Abstracts are listed in
alphabetical order by the last name of the corresponding author.
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Abdel-Rahman, Ahmed Fang, Shijing |
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Home Institution: |
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Program: |
Chemical
Engineering and Biotechnology Undergraduate Research |
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College: |
Engineering
and Technology |
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Department(s): |
Molecular
Biomedical Sciences |
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Research |
Kenneth B. Adler/
Molecular Biomedical Sciences |
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Title of Presentation: |
The Identification of a
MARCKS-related Protein in HBE1 Cells |
Recently, myristoylated
alanine-rich C-kinase substrate (MARCKS) protein has been proven to be
unquestionably involved in mucous secretion by human bronchial epithelial
cells. With this knowledge, much research has been directed toward
understanding how MARCKS allows for the organization and fusion of mucin
granules to plasma membranes in these cells. While many MARCKS interactions
have been discovered, few have been fully characterized. In this study, we
determined the possible identity of a 120-125 KD protein band seen on Western
blots generated by probing for MARCKS following immunoprecipitation with MARCKS
antibody in normal human bronchial epithelial cells (NHBE, primary cells) and a
human bronchial epithelial cell line (HBE1) (see figure 1). We are interested
in understanding if this “mystery” band has any relevance to how MARCKS protein
associates with mucin granule membranes, thus facilitating the secretion of
mucous. From previous studies, it is known that MARCKS, after being
phosphorylated by PKC and translocated to the cytoplasm, utilizes the cell’s
cytoskeleton to translocate secretory modules. We hypothesize that since MARCKS
associates with these proteins, the mystery band may be a cytoskeletal protein,
such as a member of the actin family or a protein involved in the secretory
module, such as GOB 5. Following the culture of HBE1 cells, SDS PAGE
electrophoresis, and mass spectroscopy, we identified several possible
identities for this band including the interesting Latent Transforming Growth
Factor beta Binding protein (LTBP-1). We plan to narrow these results with
further Western blot analysis in the future and possibly quantitatively prove
that LTBP-1 may be this “mystery band”. If proven to be true, LTBP-1 may serve
as a connecting protein between MARCKS and mucin granules to the extracellar
matrix during the secretion process.
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Bryant, Bessie Sapp, Tracy |
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Home Institution: |
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Program: |
Independent Researcher |
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College: |
Engineering
and Technology |
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Department(s): |
Chemical
Engineering |
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Research |
Sue Carson/Biotechnology
Program and Plant Biology |
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Title of Presentation: |
Characterization of a Xanthomonas campestris pathovar vesicatoria Putative Siderophore
Receptor Gene |
Xanthomonas campestris pathovar vesicatoria
(Xcv) is gram-negative
plant-pathogenic bacterium. Xcv is the cause of
a disease on pepper plants known as black rot. The genome for the Xcv
strain 85-10 has been sequenced and is publicly available. Iron is
necessary for metabolic functions such as respiration and electron transfer,
but there are difficulties the bacterium must surmount, in acquiring iron.
First iron is commonly found in the environment in an insoluble form. Second,
host plants and animals generally sequester iron on host-specific iron-binding
molecules, rendering the iron unavailable to many would-be pathogens. To
overcome these challenges, many bacteria have evolved to produce and utilize
siderophores, or low-molecular-weight ferric-specific chelators which
solubilize the iron. Bacteria synthesize and secrete the siderophores into the
environment, once the siderophore binds iron, it is transported back into the
cell via a specific outer-membrane, energy-dependent receptor. Relative to the
study of iron-utilization in human pathogens, there is much less known about
iron-utilization in plant pathogens. Using sequence homology we identified a
putative siderophore uptake operon and hypothesized that it contains genes
necessary for ferric- siderophore transport into the cell. Members of the lab
have previously cloned putative outer-membrane receptor from the predicted
operon in Xcv
85-10. The goals of this research were to determine whether this gene is
present in another Xcv
strain ( Xcv 135) and attempt
and to create a gene knockout by methods of electroporation and triparental
mating.
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Buchanan, Cara Bisbee, Diana |
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Home Institution: |
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Program: |
Independent Researcher |
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College: |
Engineering and Technology |
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Department(s): |
Biomedical Engineering
Chemical Engineering |
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Research |
Susan Carson/
Biotechnology Program and Plant Biology Melissa Cox/ Biotechnology
Program and Plant Biology |
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Title of Presentation: |
Siderophore Biosynthesis
in Xanthomonas campestris pathovar vesicatoria |
Xanthonomas
campestris pathovar vesicatoria (Xcv) is a gram-negative plant pathogenic bacterium that causes
bacterial leaf spot disease in pepper plants. The bacterium infects the plant
tissue through the stomata and wounds, resulting in defoliation and severe
spotting. This damage is responsible for substantial yield loss and economic
deficit. Most microorganisms depend on iron for optimal growth and essential
cell processes, and pathogenic bacteria thrive only if they are able to obtain
host-sequestered iron. A vital aspect that facilitates survival of the
pathogenic bacteria in the host plant is its ability to accrue iron via
synthesis and secretion of siderophores. Siderophores are microbally produced
iron chelators that enable solubilization and transport of iron to the cells.
The mechanisms that involve production of siderophores and their receptors are
regulated by the bioavailability of iron. The genome of Xcv strain 85-10 has recently been sequenced and published in GenBank.
Using sequence homology, we identified a putative biosynthesis operon and
hypothesize that it is responsible for the production of a siderophore.
Previously, we cloned the first gene of the putative operon from Xcv 85-10. In this research, we established
that a homolog of this gene is present in another Xcv strain (135) as well as determined that both strains produce an
iron-regulated functional siderophore.
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Going, Ryan W. |
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Home Institution: |
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Program: |
Independent Researcher |
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College: |
Engineering and Technology |
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Department(s): |
Electrical Engineering |
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Research |
Michael J.
Escuti/Electrical Engineering |
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Title of Presentation: |
Fabrication Studies on Alignment Layers for Liquid
Crystal Polarization Gratings |
The liquid crystal polarization grating (LCPG) is an
emerging light modulator technology that offers high optical efficiency, low
power demands, and low production cost. Our LCPGs are made with a reflective
backplane, which offer many advantages over transmissive ones such as decreased
physical thickness for the same effective optical thickness, leading to a
faster switching time. In any LCPG, the alignment layers are the most important
aspect toward insuring efficiency of the grating; and reflective LCPGs are
typically made with a holographically patterned UV photo-alignment layer on top
(glass), and a uniform degenerate alignment layer on bottom (mirror). We
studied the effect of several factors on both layers including exposure dosage
of the UV photo-alignment layer, degradation of all layers over time, exposure
to vacuum, initial cleaning of substrates, degenerate alignment layer thickness,
and thermal processing during curing. We observed optimum optical efficiency
and contrast with a UV photo-alignment layer of LPP and a uniform degenerate
alignment layer of 3-GPS. We also determined that both layers are relatively
stable after curing and do not degrade significantly over time. Future work
will include transferring these results to LCPG on a silicon-transistor
backplane with individually addressable pixels.
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Golick,
Laura A. |
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Home Institution: |
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Program: |
Independent Researcher |
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College: |
PAMS |
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Department(s): |
Physics |
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Research |
Karen Daniels/Physics |
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Title of Presentation: |
Segregation of Granular Materials Under Shear |
Granular materials have long been known to segregate
by size under shear but little is known about how the segregation and mixing
rates change depending on size ratio, pressure, and shear rate. In order to
determine these effects on segregation, we shear two horizontal layers of
particles in an annulus. Initially, the
bottom layer contains only large particles while the top layer contains small
particles. As the bottom plate of the
annulus rotates creating shear, the particles mix and then re-segregate so that
the large particles end up on top with the small particles below. We observe
that the segregation and mixing rates increase as particle ratio increases and
decrease as pressure increases except for intermediate particle ratios.
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Gould, Troy D. |
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Home Institution: |
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Program: |
Independent Researcher |
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College: |
Engineering and Technology |
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Department(s): |
Chemical and Biomolecular
Engineering |
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Research |
George W. Roberts/Chemical
and Biomolecular Engineering Nathaniel A. Cain/Chemical
and Biomolecular Engineering |
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Title of Presentation: |
Measurement and Modeling of Polystyrene in
Supercritical CO2 Expanded Decahydronapthalene |
Heterogeneous catalytic hydrogenation can improve the
chemical, thermal, and oxidative resistance of polystyrene. The hydrogenation
reaction requires the polystyrene molecules to diffuse into microscopic
catalyst pores. When diffusing into the catalyst, the polymer coils experience
mass transfer limitations associated with the high viscosity of the polystyrene
solution. Supercritical fluids have been shown to increase mass transfer rates
by enhancing diffusivity and lowering viscosity. Supercritical CO2 was
investigated as a co-solvent with decahydronapthalene (decalin) to determine
the effect CO2 would have on the polystyrene solution viscosity. Phase behavior
and viscosity measurements were obtained for decalin, supercritical CO2
expanded decalin, polystyrene in decalin, and polystyrene in supercritical CO2
expanded 76/24 wt% t/c-decalin. The effects of the decalin isomers on viscosity
and phase behavior were investigated to obtain binary interaction parameters
for the solvent system. The viscosity data of the solutions compares well to
the Free Volume Model (FVM) for viscosity. Both the model and the experimental
data show a significant decrease in viscosity for the polystyrene in
supercritical CO2 expanded decahydronapthalene. Future work will investigate the
effect of hydrogen on the solution properties and determine the kinetic
properties of the hydrogenation reaction.
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Holcomb, Barton A. |
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Home Institution: |
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Program: |
Independent Researcher |
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College: |
Natural Resources |
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Department(s): |
Natural Resources |
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Research |
Glenn Catts/Natural
Resources |
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Title of Presentation: |
Variation in Fecal Coliform Concentration in |
Fecal coliform bacteria, found in the intestinal
tract of warm blooded animals, can be a useful indicator of animal
concentrations within a given area. Fecal coliform can also trigger shellfish
bed closings and contaminates drinking water, as high numbers are often an
indicator of harmful pathogens.
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Stark, David
A. Bryant, Michael T. |
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Home Institution: |
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Program: |
Marine, Earth, and
Atmospheric Sciences |
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College: |
PAMS |
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Department(s): |
Marine, Earth, and
Atmospheric Sciences |
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Research |
Sandra E. Yuter/Marine,
Earth and Atmospheric Sciences |
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Title of Presentation: |
Storm Structure and
Precipitation Characteristics of Snow Events in the |
The
purpose of this research is to examine the natural variability of the physical
characteristics of precipitation during snow events in the southern
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Sylvan, Candice M. |
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Home Institution: |
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Program: |
Independent Researcher |
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College: |
Natural Resources |
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Department(s): |
Forestry and Environmental
Resources |
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Research |
Glenn Catts/Hofmann |
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Title of Presentation: |
Web-based Sharing of Spatial Measurements of
Hofmann Forest Hydrology |
The 6th
Annual
NC
Undergraduate
Summer Research Symposium
Abstracts are listed in
alphabetical order by the last name of the corresponding author.
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Campbell, Olivia M. |
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Home Institution: |
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Program: |
Kelman Scholars |
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College: |
CALS |
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Department(s): |
Biochemistry |
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Research |
Paola
Veronese/Plant Pathology |
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Title of Presentation: |
Microarray Analysis of
Arabidopsis Genes Induced during
Colonization with the Vascular Fungal Pathogen Verticillium dahliae |
Plant pathology is the
study of the pathogenesis, prevention, and control of agents that cause disease
in plants. These agents are the same or very similar to those causing disease
in humans and animals and include microorganisms such as fungi, bacteria,
viruses, protozoa and nematodes. In 2002, $200 billion in crops were lost to
disease worldwide (Agrios, 2005). Plant disease management relies mainly
on chemical control and use of resistant cultivars. The lack of genetic sources
of disease resistance in the available germplasm and the negative impact of
pesticides on the environment demonstrate the need for new methods to limit
pathogen spread. To be able to develop new strategies of prevention and cure of
plant diseases, we have first to acquire a better knowledge of the biology of
plant-microbe interactions. The scope of this research has been to contribute
to uncover mechanisms governing plant susceptibility/resistance to the
cosmopolitan fungal pathogen Verticillium dahliae, causal agent of
vascular disease of several crop species. To facilitate our studies, we have
been using the model plant Arabidopsis thaliana
to take advantage of all the genetic and molecular tools available for this
system. The specific objective of the work has been the identification of
Arabidopsis genes differentially regulated during the V. dahliae
infection through microarray experiments.
Bioinformatics analysis of V. dahliae-induced
genes has led us to propose that the fungal pathogen successfully invades plant
tissue by producing toxic compounds that prevent the onset of specific defense
mechanisms. These compounds appear to act as inhibitors of protein
biosynthesis. Candidate genes with regulatory activity on plant defense were
also selected for further functional studies.
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Garcia, David Hu, Julia Ivors, Kelly |
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Home Institution: |
Technological
Institute |
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Program: |
Kelman
Scholars |
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College: |
Biotechnolog |
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Department(s): |
Plant
Pathology |
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Research |
Jean
Beagle Ristaino/Plant Pathology |
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Title of Presentation: |
Genetic Analysis of
populations Phytophthora infestans on
Organic and Conventionally Grown Tomatoes in |
Late blight, caused by the
oomycete plant pathogen Phytophthora
infestans, is one of the most devastating diseases of potato and tomato worldwide.
Control of this disease relies extensively on fungicide applications. The main
questions of interest in our study were: 1) to determine whether migration of
the pathogen is occurring between organic and conventionally grown staked
tomato fields; 2) to determine the direction of migration; 3) to determine if
population’s are clonal? Are organic fields the source of inoculum for
epidemics in conventional fields or is the reverse true? DNA was extracted from
dried tomato leaf lesions from 13 different samples collected in 2006 from
conventional and organically grown tomatoes. We amplified 4 gene regions
including 2 nuclear (Ras and Intron ras) and 2 mitochondrial (P3 and P4)
regions by polymerase chain reaction (PCR). DNA was sequenced and aligned to
look for polymorphisms that can be used in future studies to identify
haplotypes.
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Haege, Marion J. |
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Home Institution: |
Fuquay-Varina |
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Program: |
Kelman Scholars |
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College: |
CALS |
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Department(s): |
Plant Pathology |
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Research |
Julia Hu/Plant Pathology Jean B. Ristaino/Plant
Pathology |
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Title of Presentation: |
Development of a Phytophthora Lucid Key |
Species in the genus Phytophthora are responsible for plant disease and destruction of a
wide variety of plants. There are a number of species in the genus and it is
difficult to distinguish between them based only on morphological features and
the hosts that they affect. The purpose of this project was to develop a Lucid key that would provide the means of identifying
different Phytophthora species based
on morphological and molecular characters. The Lucid key was created through
the use of several sources and for each species includes information such as
culture characteristics, optimal growing temperatures, asexual and sexual
reproductive structures, host species, disease symptoms and control methods.
Pictures of each species in culture and its asexual and sexual reproductive
structures will be incorporated in the key. DNA sequence of the internal
transcribed spacer regions and a portion of the cox 1 gene (Bar Code of Life
region) will also be incorporated into the key. The identification of Phytophthora species is a difficult
task, and the Lucid key was created to help provide individuals with a tool to
distinguish species based on a number of characteristics.
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Miller,
Casey G. |
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Home Institution: |
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Program: |
Kelman Scholars |
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College: |
CALS |
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Department(s): |
Plant Pathology |
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Research |
Chunying Li/Plant
Pathology Noureddine Hamamouch/Plant
Pathology Eric Davis/Plant Pathology |
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Title of Presentation: |
Functional Analysis of Two Soybean Cyst Nematode
Parasitism Genes |
The soybean cyst nematode (SCN), Heterodera glycines, is a sedentary endoparasite of soybean roots.
Second-stage juveniles (J2) infect the roots of a host plant and change plant
vascular cells into multinucleate feeding sites (syncytia). These changes occur
when the nematode secretes unique proteins from its feeding spear (stylet) into
the vascular cells. The genes producing these unique proteins are referred to
as parasitism genes and are currently being researched. In this study, the
functions of two SCN parasitism gene products, 29D09 (a novel protein) and 3D11
(a chitinase) were investigated. The 29D09 gene was
constitutively expressed in transformed Arabidopsis
thaliana plants and its potential effect on plant growth was monitored. In
addition, in planta expression of double-stranded RNA of the SCN 3D11 gene was
used as a tool to silence the complementary 3D11 parasitism gene transcripts
within the nematode via RNA interference (RNAi) and subsequently analyze
potential effects of 3D11-RNAi on nematode parasitism of plants. This study is
now providing evidence of the effect of 29D09 gene on
host plant development and the importance of 3D11 for successful parasitism by
cyst nematodes.
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Phelps, Crystal L. |
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Home Institution: |
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Program: |
Kelman Scholars |
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College: |
CALS |
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Department(s): |
Biology |
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Research |
Paola Veronese/Plant
Pathology |
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Title of Presentation: |
Functional Analysis of Gene Network Regulating Arabidopsis
Responses to Colonization with the Vascular Fungal Pathogen Verticillium dahliae |
In response to phytopathogenic microorganism attack,
plants deploy a complex array of defense mechanisms. The model plant Arabidopsis thaliana has been extensively
and successfully employed during the past decade to uncover the genetic control
of plant resistance to foliar pathogens. However, molecular and genetic basis
of plant defense against vascular pathogens are still poorly characterized. To
remedy this lack of knowledge, we are studying the interaction of Arabidopsis with the soil-borne fungal
pathogen Verticillium dahliae, a
causal agent of destructive vascular wilt diseases in a broad range of crop
species worldwide. We performed microarray experiments using the Arabidopsis ATH1 GeneChip array to
identify Arabidopsis genes induced
when V. dahliae is penetrating the
root vascular system. This array contains probe-sets representing the
transcripts of approximately 23, 000 genes, (about 85% of total Arabidopsis genes) allowing the
comparison of global gene expression profiles of infected versus un-infected
plant tissues. Bioinformatic analysis of the upregulated genes during pathogen
challenge revealed the co-regulation of ten genes involved in the tryptophan
(Trp) metabolic pathway. These genes are four biosynthetic genes of Trp, four
biosynthetic genes of Trp-derived secondary metabolites and two transcription
factors, MYB51 and MYB122, known to have regulatory activity (Gigolashvili et
al., 2007). The amino acid Trp is the precursor of the hormone indole-3-acetic
acid (IAA) and the defense-related compounds indole-glucosinolates (IG) and
camalexin (Gashon et al., 2005). In response to V. dahliae, we found induction of the genes corresponding to the enzymes
that catalyze the final committed steps of camalexin but not IAA and IG
production, suggesting that V. dahliae
is capable of reprogramming Trp metabolism. We have undertaken a reverse
genetic approach to investigate the role of MYB51 and MYB122 in regulating the
described V. dahliae–induced
responses.
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Sherrod, Joshua M. |
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Home Institution: |
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Program: |
Kelman Scholars |
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College: |
CALS |
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Department(s): |
Plant Pathology Systematic Botany and
Mycology Laboratory, USDA-ARS, |
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Research |
Julia Hu/Plant Pathology Mary Palm/USDA Jean Beagle Ristaino/Plant
Pathology |
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Title of Presentation: |
Genetic Structure of Populations of Phytophthora ramorum Collected from
National Surveys Conducted in the |
The Sudden Oak Death pathogen, Phytophthora ramorum, causes the sudden death of some oak, tree and
shrub species. The
[ 2007 Undergraduate Summer
Research Symposium Main Page ]
Last modified
June 2007 by Sharon E. Hunt