Plant Breeding and Genetics Commons^™

The Role Of Ethylene In Plant Responses To K+ Deficiency, Daniel P. Schachtman

Center for Plant Science Innovation: Faculty Publications

Potassium is an essential macronutrient that is involved in regulating turgor , in driving plant growth, and in modulating enzyme activation. The changes in root morphology, root function, as well as cellular and molecular responses to low potassium conditions have been studied in the model plant Arabidopsis and in other plant species. In Arabidopsis ethylene plays a key role in roots in the transduction of the low potassium signal, which results in altered root function and growth. The first clues regarding the role of ethylene were detected through transcriptional profiling experiments showing changes in the expression of genes related to …

Redirection Of Metabolic Flux For High Levels Of Omega-7 Monounsaturated Fatty Acid Accumulation In Camelina Seeds, Huu Tam Nguyen, Hyunwoo Park, Karen L. Koster, Rebecca E. Cahoon, Hanh Nguyen, John Shanklin, Thomas E. Clemente, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Seed oils enriched in omega-7 monounsaturated fatty acids, including palmitoleic acid (16:1Δ9) and cis-vaccenic acid (18:1Δ11), have nutraceutical and industrial value for polyethylene production and biofuels. Existing oilseed crops accumulate only small amounts (<2%) of these novel fatty acids in their seed oils. We demonstrate a strategy for enhanced production of omega-7 monounsaturated fatty acids in camelina (Camelina sativa) and soybean (Glycine max) that is dependent on redirection of metabolic flux from the typical Δ9 desaturation of stearoyl (18:0)-acyl carrier protein (ACP) to Δ9 desaturation of palmitoyl (16:0)-acyl carrier protein (ACP) and coenzyme A (CoA). This was achieved by seed-specific co-expression of a mutant Δ9-acyl-ACP and an acyl-CoA desaturase with high specificity for 16:0-ACP and CoA substrates, respectively. This strategy was most effective in camelina where seed oils with ~17% omega-7 monounsaturated fatty acids were obtained.

Further increases in omega-7 fatty acid accumulation to 60–65% of the total fatty acids in camelina seeds were achieved by inclusion of seed-specific suppression of 3-keto-acyl-ACP synthase II and the FatB 16:0-ACP thioesterase genes to increase substrate pool sizes of 16:0-ACP for the Δ9-acyl-ACP desaturase and by blocking C18 fatty acid elongation. Seeds from these lines also had total saturated fatty acids reduced to ~5% of …

Production Of High Levels Of Poly-3-Hydroxybutyrate In Plastids Of Camelina Sativa Seeds, Meghna R. Malik, Wenyu Tang, Nii Patterson, Jihong Tang, Rachel L. Wellinghoff, Mary L. Preuss, Claire Burkitt, Nirmala Sharma, Yuanyuan Ji, Joseph M. Jez, Oliver P. Peoples, Jan G. Jaworski, Edgar B. Cahoon, Kristi D. Snell

Center for Plant Science Innovation: Faculty Publications

Poly-3-hydroxybutyrate (PHB) production in plastids of Camelina sativa seeds was investigated by comparing levels of polymer produced upon transformation of plants with five different binary vectors containing combinations of five seed-specific promoters for expression of transgenes. Genes encoding PHB biosynthetic enzymes were modified at the N-terminus to encode a plastid targeting signal. PHB levels of up to 15% of the mature seed weight were measured in single sacrificed T1 seeds with a genetic construct containing the oleosin and glycinin promoters.

A more detailed analysis of the PHB production potential of two of the best performing binary vectors in a Camelina …

Toward Production Of Jet Fuel Functionality In Oilseeds: Identification Of Fatb Acyl-Acyl Carrier Protein Thioesterases And Evaluation Of Combinatorial Expression Strategies In Camelina Seeds, Hae Jin Kim, Jillian E. Silva, Hieu Sy Vu, Keithanne Mockaitis, Jeong-Won Nam, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Seeds of members of the genus Cuphea accumulate medium-chain fatty acids (MCFAs; 8:0–14:0). MCFA- and palmitic acid- (16:0) rich vegetable oils have received attention for jet fuel production, given their similarity in chain length to Jet A fuel hydrocarbons. Studies were conducted to test genes, including those from Cuphea, for their ability to confer jet fuel-type fatty acid accumulation in seed oil of the emerging biofuel crop Camelina sativa. Transcriptomes from Cuphea viscosissima and Cuphea pulcherrima developing seeds that accumulate >90% of C8 and C10 fatty acids revealed three FatB cDNAs (CpuFatB3, CvFatB1, and CpuFatB4) …

Microrna Biogenesis, Degradation And Activity In Plants, Meng Xie, Shuxin Zhang, Bin Yu

Center for Plant Science Innovation: Faculty Publications

microRNAs (miRNAs) are important regulators of gene expression. After excised from primary miRNA transcript by dicer-like1 (DCL1, an RNAse III enzyme), miRNAs bind and guide their effector protein named argonaute 1 (AGO1) to silence the expression of target RNAs containing their complementary sequences in plants. miRNA levels and activities are tightly controlled to ensure their functions in various biological processes such as development, metabolism and responses to abiotic and biotic stresses. Studies have identified many factors that involve in miRNA accumulation and activities. Characterization of these factors in turn greatly improves our understanding of the processes related to miRNAs. Here, …

Modifications Of Membrane Lipids In Response To Wounding Of Arabidopsis Thaliana Leaves, Hieu Sy Vu, Rebecca Roston, Sunitha Shiva, Manhoi Hur, Eve Syrkin Wurtele, Xuemin Wang, Jyoti Shah, Ruth Welti

Center for Plant Science Innovation: Faculty Publications

Mechanical wounding of Arabidopsis thaliana leaves results in modifications of most membrane lipids within 6 hours. Here, we discuss the lipid changes, their underlying biochemistry, and possible relationships among activated pathways. New evidence is presented supporting the role of the processive galactosylating enzyme SENSITIVE TO FREEZING2 in the wounding response.

Germplasm Enhancement For Resistance To Pyrenophora Tritici-Repentis In Wheat, Manisha Shankar, Diane E. Mather, Dorthe Jorgensen, Hossein Golzar, Ken J. Chalmers, Grant J. Hollaway, Mark S. Mclean, Stephen M. Neate, Rob Loughman

Conference papers and presentations

Yellow spot (syn. tan spot), caused by Pyrenophora tritici-repentis, is an important foliar disease of wheat in Australia that causes losses exceeding 50 % when conditions are favourable for disease development. Although good progress has been made internationally to understand yellow spot resistance, relatively few resistance genes have been identified and mapped in Australian germplasm and only one (tsn1 on chromosome 5BL) is in general and known use in Australian breeding programs. Although tsn1 is an important yellow spot resistance gene, it doesn’t explain the full spectrum of resistance and there is a significant opportunity to enhance expression …

The Taurine Biosynthetic Pathway Of Microalgae, Rahul Tevatia, James Allen, Deepak Rudrappa, Derrick White, Thomas E. Clemente, Heriberto Cerutti, Yaşar Demirel, Paul H. Blum

Center for Plant Science Innovation: Faculty Publications

Taurine (2-aminoethanesulfonic acid) is an amino acid–like compound widely distributed in animals and an essential nutrient in some species. Targeted metabolomics of marine and freshwater microalgae combined with medium supplementation identified biosynthetic pathway intermediates and necessary catalytic activities. Genomic analysis was then used to predict the first taurine biosynthetic pathway in these organisms. MRM-based electrospray ionization (ESI) LC–MS/MS analysis demonstrated that taurine is synthesized using a carbon backbone from L-serine combined with sulfur derived from sulfate. Metabolite analysis showed a nonuniform pattern in levels of pathway intermediates that were both species and supplement dependent. While increased culture salinity raised taurine …

Nutrient Competition Between Algae And Juncus Effusus In The Lake Fayetteville Artificial Spiral Wetland, Toryn Jones, Thad Scott

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

There is insufficient research focusing exclusively on how nutrient competition between algae and wetland macrophytes affects the growth of these species. This study examined the relationship between nutrient concentrations (N and P), algal concentrations, and the growth of Juncus effusus. Juncus effusus growth in the Lake Fayetteville artificial spiral wetland was monitored over a four month period during the prime growing season. Eighteen plants were taken from the wetland and replanted in 1 of 6 treatments: plant-only, algae-only, combined, plant-only +supplement, algaeonly +supplement, or combined +supplement. The algae and combined environments received an inoculation of algae, and the +supplement treatments …

Genetic And Functional Analysis Of Host Genes Involved In Pathogenic And Symbiotic Legume-Microbe Interactions, Fang Tang

Theses and Dissertations--Plant and Soil Sciences

Legumes form symbiotic and pathogenic interactions with microbes. Understanding the molecular mechanisms underlying the legume-microbe interactions would help us to improve crop production in a sustainable manner. This thesis covers two independent research projects. The first project was to study the role of alternative splicing in RCT1-mediated disease resistance. RCT1 is a TIR-NBS-LRR-type plant resistance (R) gene in Medicago truncatula that confers broad-spectrum resistance to Colletotrichum trifolii, a fungal pathogen that causes anthracnose disease in Medicago. RCT1 undergoes alternative splicing at both coding and 3'-untranslated regions, thereby producing multiple transcript variants in its expression profile. …

Selection And Basis For 2,4-D (2,4-Dicholorphenoxyacetic Acid) Tolerance In Red Clover (Trifolium Pratense), Tara L. B. Lewis

Theses and Dissertations--Plant and Soil Sciences

A red clover (Trifolium pratense) population (UK), from a cross between the cultivar Kenland and a 2,4-D tolerant population (Florida), was recurrently selected for 2,4-D tolerance with evaluations after the 6^th, 7^th, and 8^th selection cycles. All UK populations were more 2,4-D tolerant than Kenland. The 2,4-D tolerance following the 6^th selection cycle was similar to the Florida population and tolerance was increased following 7 and 8 cycles of selection by removing plants showing 2,4-D injury and doubling the rate of 2,4-D used for selection.

Yield and forage quality were evaluated in …

Supersweet Sweet Corn Cultivar Evaluation For Northern Indiana, 2014, Elizabeth Maynard

Purdue Fruit and Vegetable Research Reports

Indiana sweet corn acreage harvested for fresh market averaged 5,233 acres annually from 2011- 2013, with a yield of 63 hundreweight per acre (149 crates or 3.1 tons per acre) and an annual value of $13.9 million (USDA NASS, 2014). Sweet corn fields for fresh market sales are located throughout the state. In northern Indiana, bicolor corn is most commonly grown.

Varieties with improved eating quality are of interest to both producers and consumers. The term ‘supersweet’ commonly refers to sweet corn with two copies of the shrunken-2 (sh2) gene that have high levels of sugar in the kernels and …

Supersweet Sweet Corn Cultivar Evaluation For Northern Indiana, 2014, Elizabeth Maynard

Midwest Vegetable Trial Reports

Indiana sweet corn acreage harvested for fresh market averaged 5,233 acres annually from 2011- 2013, with a yield of 63 hundreweight per acre (149 crates or 3.1 tons per acre) and an annual value of $13.9 million (USDA NASS, 2014). Sweet corn fields for fresh market sales are located throughout the state. In northern Indiana, bicolor corn is most commonly grown.

Varieties with improved eating quality are of interest to both producers and consumers. The term ‘supersweet’ commonly refers to sweet corn with two copies of the shrunken-2 (sh2) gene that have high levels of sugar in the kernels and …

Sugar-Enhanced And Synergistic Sweet Corn Cultivar Evaluation For Northern Indiana, 2014, Elizabeth Maynard

Purdue Fruit and Vegetable Research Reports

Indiana sweet corn acreage harvested for fresh market averaged 5,233 acres annually from 2011- 2013, with a yield of 63 hundredweight per acre (149 crates or 3.1 tons per acre) and an annual value of $13.9 million (USDA NASS, 2014).

Sweet corn fields for fresh market sales are located throughout the state. In northern Indiana, bicolor corn is most commonly grown. Varieties with improved eating quality are of interest to both producers and consumers. Producers are also interested in yield, ear size, appearance, and agronomic characteristics.

This paper reports on nine bicolor and one yellow sugar-enhanced or synergistic sweet corn …

Midwest Vegetable Trial Report For 2014, Elizabeth Maynard

Purdue Fruit and Vegetable Research Reports

This is a compilation of 30 research trial reports from seven land-grant universities in the midwestern and northeastern United States. Crops covered include Asian vegetables (Napa cabbage, pak choy or bok choi, mizuna, tatsoi, Yukina savoy, komatsuna, senposai, and Tokyo bekana) broccoli, cantaloupe, cucumber, kohlrabi, pepper, potato, pumpkin, radish, sweet corn, tomato, and watermelon. Several crops were evaluated in high tunnels or hoophouses. Most trials compared different cultivars or varieties. Four reports addressed specific growing practices: the use of hairy vetch to supply nitrogen, biochar use in a high tunnel bag culture system, effects of organic soil amendments, and scion-rootstock …

Sugar-Enhanced And Synergistic Sweet Corn Cultivar Evaluation For Northern Indiana, 2014, Elizabeth Maynard

Midwest Vegetable Trial Reports

Indiana sweet corn acreage harvested for fresh market averaged 5,233 acres annually from 2011- 2013, with a yield of 63 hundredweight per acre (149 crates or 3.1 tons per acre) and an annual value of $13.9 million (USDA NASS, 2014).

Sweet corn fields for fresh market sales are located throughout the state. In northern Indiana, bicolor corn is most commonly grown. Varieties with improved eating quality are of interest to both producers and consumers. Producers are also interested in yield, ear size, appearance, and agronomic characteristics.

This paper reports on nine bicolor and one yellow sugar-enhanced or synergistic sweet corn …

Midwest Vegetable Trial Report For 2014, Elizabeth Maynard

Midwest Vegetable Trial Reports

This is a compilation of 30 research trial reports from seven land-grant universities in the midwestern and northeastern United States. Crops covered include Asian vegetables (Napa cabbage, pak choy or bok choi, mizuna, tatsoi, Yukina savoy, komatsuna, senposai, and Tokyo bekana) broccoli, cantaloupe, cucumber, kohlrabi, pepper, potato, pumpkin, radish, sweet corn, tomato, and watermelon. Several crops were evaluated in high tunnels or hoophouses. Most trials compared different cultivars or varieties. Four reports addressed specific growing practices: the use of hairy vetch to supply nitrogen, biochar use in a high tunnel bag culture system, effects of organic soil amendments, and scion-rootstock …

Examining Vegetative Growth Of Cool-Season Forage Grasses For Dairy Cattle Grazing Preference, Eric D. Billman

Theses and Dissertations--Plant and Soil Sciences

The objective of this study was to determine dairy cattle preference amongst four species of cool-season forage grasses: eight orchardgrasses (Dactylis glomerata L.), five tall fescues [Schedonorus arundinaceus (Schreb.) Dumort.], five perennial ryegrasses (Lolium perenne L.), and six festuloliums [xFestulolium braunii (K. Richt.) A. Camus.]; 24 cultivars in total. Each grazing trial utilized four Holstein-Friesian heifers over six hours. Maturity differences were eliminated by having animals graze only vegetative material. After six grazing trials (three each in 2014 and 2015), consistent results in animal preference were not found; three of the six trials did show preference …

Breeding For Nitrogen Use Efficiency In Soft Red Winter Wheat, Katlyn Hitz

Theses and Dissertations--Plant and Soil Sciences

Nitrogen use efficient (NUE) wheat varieties have potential to reduce input costs for growers, limit N runoff into water ways, and increase wheat adaptability to warmer environments. Previous studies have done little to explain the genetic basis for NUE and components, nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE). Four studies were conducted to 1) determine genotypic stability of NUE under high and low N regimes and under warming 2) determine effect of warming on NUE 3) indentify QTL associated with NUE components 4) assess the utility of canopy spectral reflectance (CSR) as a high-throughput phenotyping device for NUE. …

Generation Of An Attenuated, Cross-Protective Pepino Mosaic Virus Variant Through Alignment-Guided Mutagenesis Of The Viral Capsid Protein, Godwill M. Chewachong, Sally A. Miller, Joshua J. Blakeslee, David M. Francis, Thomas Jack Morris, Feng Qu

School of Biological Sciences: Faculty Publications

Mild variants of many viruses are able to protect infected plants from subsequent invasion by more severe variants of the same viruses through a process known as cross-protection. In the past, the cross-protective viral variants were commonly derived from mild field isolates that were sometimes genetically heterogeneous, providing variable levels of crossprotection. Here, we report a novel approach to rapidly generate crossprotective variants of the tomato-infecting Pepino mosaic virus (PepMV) independently of the availability of mild field isolates. Our approach sought to attenuate PepMV by mutating less conserved amino acid residues of the abundantly produced capsid protein (CP). These less-conserved …