George Washington Carver Internship Program

Polysaccharides (pectin, hemicelluloses and cellulose) are the major structural components of cell walls. Therefore, knowledge about synthesis, metabolism and degradation of structural polysaccharides is a fundamental problem in improving of plant development and resistance to the environment and biomass production.
a) By characterization of cell wall composition from maize plants that have differently expressed genes involved in lignification we will reveal the most promising varieties that will be better suited for biorenewable applications.
b) Specific oligosaccharide fragments that can be released during polysaccharide modifications occurred in plants can play important role in plant development and adaptation. To understand how such bioactive oligosaccharides are involved in different aspects of plant life is another interesting project in the lab. Purification of oligosaccharide and assaying it in particular biological tests will help to answer this question.

Substantial differences in genome size (i.e. the total amount of DNA in the nucleus) have been observed between closely related species that have very similar gene content. These size differences appear to be influenced by many factors; however, differences in transposable element content have repeatedly been implicated in large differences in size.
Evaluating these differences in transposable element content between species will lead to a better understanding of their role in generating differences in genome size, as well as the roles they play in their host genome.

Phytophthora root rot of soybean causes substantial yield loss. Soybean varieties with resistance genes are available for growers to plant but sometimes this resistance is overcome by the pathogen and infected plants die. Tolerance is a form of resistance that enables the plant to "tolerate" some level of disease but still produce grain.

Screening for tolerance can be tedious and take up to six weeks to get results. Our lab is developing a new method that can give results in two weeks. This method will save soybean breeders considerable time and expense.

We have previously identified several independent barley mutants that affect the process of programmed cell death in response to inoculation with the biotrophic fungus, Blumeria graminis, the causal agent of powdery mildew disease in grain crops. Microarray analysis has been performed on these mutants and their non-mutant progenitors. Comparisons of mutant versus wildtype expression profiles for 23,000 genes have revealed candidate genes for each of the mutants. The objective of the project will be to perform genetic tests of these candidate genes and to perform more in-depth characterizations of the phenotypic anomalies caused by the mutations.

Environmental temperatures experienced during embryonic development permanently determine offspring sex (known as TSD) in several major groups of vertebrate animals. We investigate significant aspects of this unusual phenomenon in imperiled turtles: (1) the impact of long-term climatic variation on population structure, (2) the consequences of nesting behavior on offspring sex ratio, and (3) the effects of climatic variation on differential predation on nests. Students record nesting date and vegetation cover over nests, evaluate nesting behavior, and monitor nest predation. This research has important implications for the biological impacts of climate change and human habitat use on species with TSD.

Social and environmental conditions that mothers experience during reproduction can affect how they invest energy towards offspring. In addition, the amount of investment has important consequences for the survival of offspring. We will evaluate different conditions that may affect maternal investment towards egg production, and how this may influence the quality and survival of offspring in the brown anole lizard. Students will help with experimental breeding projects, and will be involved with regular feeding, egg incubation studies, and measurements of morphology and behavior of hatchling lizards. This research will provide important insights into the evolution of reproductive strategies.

Feed is the most important variable cost in pork production. To investigate the genetic and physiological aspects of feed efficiency we have on ongoing selection experiment in Yorkshire pigs, in which we select for pigs that require less feed for the same amount of growth and backfat. The selection line is compared to a randomly selected control. We use electronic feeders to record daily feed intake on individual pigs housed in groups. We are currently using pigs from these lines to evaluate the genetic and biological basis of the differences in feed efficiency. Background expectations: Animal Science/biology. Experience working with animals.

Studies with botanical supplements are part of a large center at ISU and UI that aims to develop a scientific basis for herbal medicine. Ongoing studies in the Birt laboratory are aimed at identifying the compounds in the botanical supplements Echinacea, Hypericum and Prunella that contribute to their anti-inflammatory bioactivity and to enhance this activity while reducing toxicity. We use cultured macrophage cell systems to seek to understand the mechanisms of action of bioactive constituents, and the effects of interactions among the various constituents. Current investigations are assessing the cellular signaling pathways and gene expression profiles of key constituents in Echinacea and Hypericum. The hypotheses being tested are that anti-inflammatory constituents of Echinacea and Hypericum interact in increasing anti-inflammatory cytokines and suppressing pro-inflammatory mediators.

One of the following projects, depending on student's interest and available projects in the lab. Investigate function of a recently discovered plant virus gene, and how RNA structure controls gene expression of plant viruses. Seek to discover new viruses of aphids. Engineer RNA viruses to kill aphids.

Head smut of corn is an emerging disease that is caused by the fungus Sphacelotheca reiliana. The fungus infects plants systemically, causing the ear to be completely replaced by a mass of fungal spores. The disease can be seed-transmitted as spores, clinging to seeds, germinate and infect the young seedling shortly after planting. In order to better manage this disease, it would be very helpful to detect infection at the seedling stage, long before the ear shoot develops. So we are working on a system that involves a polymerase chain reaction (PCR) protocol for detecting infection by S. reiliana in corn seedlings.

In order to efficiently grow crops in closed systems, such as those on planned lunar or martian colony outposts, lighting systems that consume as small amounts of energy as possible while maintaining plant productivity are needed. Light emitting diodes (LEDs) are increasingly being used in a variety of energy-efficient lighting systems. Besides their relatively low energy consumption, another benefit of LED lighting is that their small and low-temperature characteristics open up the possibility of using them as within-canopy lighting, rather than limiting lighting to overhead. This may result in improved crop productivity compared to that from only overhead lighting.

Striking sectoring of red stripes on a yellow background of flowers or multi-sectored stripe on ears normally seen in what is commonly called Indian Corn are signs that DNA is "actively jumping" in the genome of these plants. This DNA commonly referred as transposon was discovered by the Noble Prize awarder, Barbara McClintock. This discovery of transposons is the most episodic event in plants in this century. Though discovered in corn, they are present in all organisms. Yet there is reason to believe that they contribute to diversity. And, how do they relate to Humans? They are ever-present and could lead to changes. These transposons have been cloned and there is ample opportunity to do molecular biology with these elements in our laboratory.

Endocrine-disrupting hormones threaten aquatic organisms and may enter the environment via land application of livestock manure and municipal biosolids. Our laboratory studies are focused the accumulation and sorption of estrogens by soil organic matter, soil minerals, and manure organic matter. We would like to understand better how these compounds are transferred from manure or municipal biosolids to the aqueous or solid phases of soil and how they accumulate in soil. Our investigations will involve fractionation of organic colloids and chemical analyses of soil and water using infrared spectroscopy, high-performance liquid chromatography, and x-ray diffraction. This opportunity is well-suited for interns with strong interests in chemistry and environmental issues.

Student will have the opportunity to work on projects in which animal-derived foods such as beef and milk are assayed for contents of a variety of nutriehts such as cholesterol, fatty acids, and minerals. Students will also interact with students working on other topics of nutritional biochemistry.

The terrestrial water cycle is an important component of the
global water cycle. Changes in climate will include changes in how water
moves among the soil, vegetation, and atmosphere. We are working with
NASA to develop a field site at which terrestrial water cycle components
such as soil moisture, precipitation, and evapotranspiration are routinely
measured. The long term goal is to understand how these variables are
related, and how they might change in the future. Our short term goal is
to compare these measurements with measurements made from Earth-orbiting
satellites. A student working with our group would assist in making some
of these measurements during the summer months, and then use the data to
test a hypothesis.

The involvement of Native American students and researchers in plant genome research is minimal. In an effort to increase their representation in the research community, a summer program to mentor Native American/American Indian undergraduates in plant genomics research is being conducted on the Iowa State University campus. Participating students study various plant species, including plants of importance to many Native Tribes. Students work with USDA-ARS North Central Regional Plant Introduction scientists to carry out field-work (to grow and propagate the plants) and to collect and preserve plant material. One student, Nate Etsitty, even studied the update of ursolic acid (which is present in apples, basil bilberries, cranberries, elder flower, peppermint, lavender, thyme, hawthorne, and prunes) in a human intestined cell line during the summer of 2008. This is interesting because ursodic acid is known to inhibit various types of cancer cells. Each year one student works with members of the Maize Genetics and Genomics Database (MaizeGDB) team to create a project website. This work is funded by the National Science Foundation, and all participating students' travel, health care, room and board, and a stipend were arranged by the Iowa State University George Washington Carver Summer Research Internship program, which runs from June 6 to August 2. An advisory council made up of Tribal Elders is involved in this process, and each elder travels to Ames to work with the students. In this manner, the Elders' hopes for the students are conveyed alongside the outcomes anticipated by the researcher mentors.