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1 Iron deficiency chlorosis (IDC) is a disease resulting from lack of useable iron that eventually results in yield loss at the end of the season. This is particularly important in the midwestern part of the United States because soil conditions favor the development of IDC. To control IDC symptoms, farmers rely on chemical treatments that can be hazardous to the environment. Therefore, we’re interested in characterizing soybean’s response to iron stress as little is known about short- and long-term responses to iron stress. Our research will take advantage of two near isogenic lines that are 98% genetically identical but differ in their iron response. Clark plants are iron efficient, while IsoClark plants are iron inefficient and will develop symptoms of IDC under iron stress conditions. We have conducted an experiment comparing short-term and long-term iron stress by using a shocking method. Both Clark and IsoClark plants were grown in hydroponics in a greenhouse for a total of ten days. A subset of plants were iron stressed for the entire ten days whereas another set were iron stressed for two days. We will look at transcriptional responses by quantitative PCR, RNA sequencing, and test candidate genes by viral-induced gene silencing.
BACTERIAL PROSPECTS FOR ALIPHATIC ALKANE DEGRADATION ACROSS TROPICAL ECOSYSTEMSMigel Rosario-Mariani1, Yomarie Bernier2, José R. Pérez-Jiménez1.
Universidad del Turabo, Gurabo, PR, 2Universidad del Turabo, Caguas, PR.
1 Contamination by organic compounds has been a consequence of industrial times. High concentrations can be harmful to all living things especially to ecosystems that thrive with the anthropogenic activities that take place each day. Alkanes are organic compounds derived from petroleum, but some plants produce them naturally. Our objective is to study the aerobic bacterial degradation capabilities of the organic compounds pentane and decane.
Samples were collected from soil minor (mechanic garage) and major (Caño Tiburones) chronic discharges. Alkanedegrading prospects were isolated by aerobic cultivation on mineral salt media supplemented with specific alkane as sole carbon source. A total of 11 prospects have been isolated so far with alkane-degrading capabilities. Bacterial prospects for aliphatic alkane degradation were subjected to 16S rDNA sequencing. We identified species from the genera Citrobacter. Most of the strains prefer decane as a substrate. The prevalence of aliphatic alkane degradation prospects across different ecosystems including the rain forest (El Yunque) has been found for other aliphatic alkanes.
By means of this research, we concluded that pentane- and decane-degrading bacteria can be found in the natural ecosystem regardless of the prevailing level of pollution.
36 UNDERGRADUATE POSTER ABSTRACTS
Biological Sciences SAT-470
CHARACTERIZATION OF EPITHELIAL-TO-MESENCHYMAL TRANSITION AND PROLIFERATION IN LEPTINTREATED RAT MAMMARY TUMOR CELLSDenisse Resendiz, Ignacio Camarillo.
Purdue University, West Lafayette, IN.
Breast cancer is among the most commonly diagnosed cancers among women in the United States and the second leading cause of cancer-related deaths. Hormones play a crucial role in the development and progression of breast cancer. Obese women have an increased risk of developing breast cancer, increasing as adipose tissue increases.
The secretion of hormones from adipose tissue is elevated during obesity; in particular, the peptide hormone leptin increases in correlation with increased adipose tissue mass. Leptin has been shown to stimulate breast cancer cell proliferation progression and recently has been correlated with tumor cell metastasis. It is our objective to elucidate the mechanisms of leptin on proliferation and its role in epithelial-to-mesenchymal transition (EMT) in rat mammary tumor cells by identifying key proteins involved in EMT. We hypothesize that in vitro leptin will increase mammary tumor cell proliferation (CRL 1743 cells) and promote EMT through decreasing expression of E-cadherin and increased expression of N-cadherin. The regulation of these proteins by leptin in CRL 1743 cells will lead to a better understanding of the link between obesity and cancer aggressiveness. Ultimately, these studies may lead to identification of novel molecular targets for development of future treatments for obese patients with breast cancer.
IMPACT OF SOIL TEXTURE ON GRAPES AND WINE: COMPARISON OF CABERNET SAUVIGNON AND SYRAH
IN THE TEXAS HILL COUNTRYAntonio Moreno1, Lisa Morano1, Kenneth Johnson1, Jay Neal2, Aaron Corsi2.
University of Houston-Downtown, Houston, TX, 2University of Houston, Houston, TX.
1 Viticulturists are aware that topography and soil characteristics such as soil texture (percent sand, silt, and clay) can have a profound impact on wine quality. Shallow soils or soils high in sand may be lacking in water and nutrients, but soils that are too deep or with a high clay content may create too much vigor in the vine and also reduce wine quality.
Our goal was to establish if soil texture impacts wine character and vine vigor differently among Cabernet Sauvignon and Syrah varietals in the Texas Hill Country. Soil and fruit samples were gathered from 28 vines and produced a total of 28 wines. By means of a principle components analysis (PCA), soil texture parameters of sand, silt, and clay were compared to viticulture parameters of stem weight (a vigor parameter) and basic juice and wine quality parameters such as pH, Brix (sugar concentration), and yeast available nitrogen (YAN). Our initial PCA showed that soil texture parameters could be linked to viticultural parameters such as stem weight. We are currently analyzing data to determine if soil texture and vine vigor parameters can be linked to specific aroma and taste characteristics for the Texas Hill Country vineyards we evaluated.
TAP WATER QUALITY: SOCIAL IMPLICATIONS AND POSSIBLE EFFECTS ON HEALTHNicolle Lebrón, Javier Arce.
Universidad de Puerto Rico en Cayey, Cayey, PR.
The objective of this study was to analyze how social and environmental variables affect the quality of water in Puerto Rican homes and how water quality affects consumers’ health. More than 250 interviews were conducted in the towns of Cayey, Caguas, and Comerío which addressed self-reported cases of gastrointestinal illness (GI) and consumers’ perceptions of tap water service. We studied communities that receive water from governmentmanaged systems known as PRASA (Puerto Rican Aqueduct and Sewer Authority) and from community-managed water systems known as non-PRASA. After each interview, a water sample was collected from the tap and from any household water treatment system. We measured total coliforms (TC), fecal coliforms (FC), and free chlorine for each water sample. The non-PRASA systems showed a presence of TC in 74% of the houses, while the PRASA systems showed a presence of TC in 17% of the houses. The presence of TC was related to the level of free chlorine in the water. Every house from the PRASA system had free chlorine in the water with the exception of houses with water treatment systems. Almost half (49%) of the water samples collected from household water treatment systems (n =
45) had presence of TC. These results demonstrate that a considerable number of people are affected by improper maintenance of their domestic and community-level water systems, which is an important public health concern.
However, GI cases were not correlated to coliform presence, highlighting a need for better water quality indicators in Puerto Rico.
37 UNDERGRADUATE POSTER ABSTRACTS
VICTORIA VICTOR SUMMER RESEARCH ABSTRACTVictoria Victor, Henry Trapido-Rosenthal.
Chaminade University, Honolulu, HI.
Dinoflagellates of the genus Gambierdiscus produce ciguatoxin, a polyether molecule that is the causative agent of ciguatera fish poisoning. These single-celled algae reside epiphytically on macroalgae in tropical coastal environments. The toxin is bioaccumulated up the food web in coral reef ecosystems, as herbivorous fish consume the dinoflagellates, carnivorous fish consume the herbivores, and humans catch and eat these reef fish. In order to better understand the ecology of ciguatoxin production, we am attempting to generate uni-algal cultures of Gambierdiscus found in Hawaiian waters. The hypotheses being tested in this project include, but are not limited to: 1) Viability of cultures will vary as a function of the species of macroalgae from which the dinoflagellates were isolated;
2) Viability of cultures will vary as a function of the temperature at which the cells are maintained; and 3) Viability of cultures will vary as a function of the light regime under which the cells are maintained. Methods for establishing cultures include the following: 1) Collection of macroalgae from inshore Hawaiian waters; 2) Mechanical removal of dinoflagellates from macroalgae by mechanical agitation followed by sequential rounds of filtration; 3) Visual identification of dinoflagellate cells under the microscope; 4) Collection of individual cells by pipette; 5) Placement of cells into defined sterile media; and 6) Incubation of cells under defined conditions of irradiation, temperature, and time. Microscopic observation of cell number and growth rate will then be used to determine the viability of cultures.
SCREENING FOR XYLAN DEGRADATION FUNGICaroline Delgado, Sharon A Cantrell, Yentel Rodriguez.
Universidad del Turabo-Gurabo, Gurabo, PR.
Leaf litter is the main component of biomass. The specific objectives are to isolate fungi from leaf litter using general and specific culture media and to conduct cellulose lignin and xylan degradation assays. The methodology consisted of taking leaf litter from four forest types at El Yunque National Forest, Tabonuco Palm, Palo Colorado, and Elfin.
Particle filtration technique was used to isolate fungi using different general growth media: 50% PDA, 50% MEA, and 50% MEA + 5% NaCl. Fungal isolates were purified and screened for potential cellulase, xylanase, peroxidase, and phenol activity using cellulose agar, remezol blue agar, and xylan agar. Isolates were identified using morphological and molecular characters. A total of 127 isolates were obtained. Of the 127 isolates collected, only 10 were positive for the enzymatic degradation of cellulose and xylan. The 10 fungal isolates belonged to several of the forests’ types except for Elfin forest. The isolates were identified by sequencing the fungal ITS region of the rDNA. The following species were identified: Candida micetangii, Glionectria tenuis, Mucor nidicola, Mucor fragilis, Purpureocillium lilacinum, Rhizomucor variabilis, and Trichoderma koningiopsis. A degradation test was conducted at variable temperatures. The temperatures were 25 oC and 37 oC. Three of the ten isolates that were successful prospects were analyzed in this test. At both temperature variables, degradation was observed, concluding that the degradation of these fungi can take place in a range of temperatures, but degradation was better at 25 oC. Future plans are to conduct quantitative assays for the degradation of xylan.
VALIDATING GENETIC TOOLS FOR SUPPRESSING MAJOR OXIDATIVE DNA DAMAGE-REPAIRING PROTEINSJosephine Gonzales1, Priyamvada Rai2.
California State University San Marcos, San Marcos, CA, 2Leonard M. Miller School of Medicine, University of Miami, 1 Miami, FL.
Reactive oxygen species (ROS) are produced as inevitable byproducts of aerobic mitochondrial respiration. ROS can damage DNA by causing base alterations, mutations, and DNA strand breakage. Unless such damage is repaired, the cell will die or enter proliferation arrest. Cancer cells produce higher levels of metabolic ROS relative to normal cells and possess elevated levels of DNA repair proteins to protect themselves. Thus, targeting such proteins in cancer cells is likely to induce cell death or proliferation arrest. Accordingly, loss of function methods such as small hairpin RNAs (shRNA), capable of suppressing major oxidative DNA damage repair proteins, will allow investigation of how a specific DNA repair protein affects cell survival. A commercial shRNA bacterial library was obtained expressing shRNA constructs against the following major oxidative damage repair proteins: OGG1, NTH1, MYH1, APE1, FEN1, and APEX. Individual bacterial colonies were grown overnight in LB broth with ampicillin to ensure only shRNA plasmidexpressing clone survival. Plasmid DNA was then isolated from the bacterial cultures, concentrated using a Qiagen
RED-LIGHT PHOTORECEPTORS IN MYXOBACTERIA: IMPLICATIONS FOR LIGHT-STIMULATED
MULTICELLULAR ASSEMBLIESDorina Bizhga, Kevin D. Gallagher, Emina A. Stojkovic.
Northeastern Illinois University, Chicago, IL.
Myxobacteria are Gram-negative, non-photosynthetic bacteria known for the multicellular stage in their life cycles.