Agriculture Commons^™

Metabolic Engineering Of Oilseed Crops To Produce High Levels Of Novel Acetyl Glyceride Oils With Reduced Viscosity, Freezing Point And Calorific Value, Jinjie Liu, Adam Rice, Kathleen Mcglew, Vincent Shaw, Hyunwoo Park, Thomas E. Clemente, Mike Pollard, John Ohlrogge, Timothy P. Durrett

Department of Agronomy and Horticulture: Faculty Publications

Seed oils have proved recalcitrant to modification for the production of industrially useful lipids. Here, we demonstrate the successful metabolic engineering and subsequent field production of an oilseed crop with the highest accumulation of unusual oil achieved so far in transgenic plants. Previously, expression of the Euonymus alatus diacylglycerol acetyltransferase (EaDAcT) gene in wild-type Arabidopsis seeds resulted in the accumulation of 45 mol% of unusual 3-acetyl-1,2- diacyl-sn-glycerols (acetyl-TAGs) in the seed oil (Durrett et al., 2010 PNAS 107:9464). Expression of EaDAcT in dgat1 mutants compromised in their ability to synthesize regular triacylglycerols increased acetyl-TAGs to 65 mol%. Camelina and soybean …

Functional Genomics And Microbiome Profiling Of The Asian Longhorned Beetle (Anoplophora Glabripennis) Reveal Insights Into The Digestive Physiology And Nutritional Ecology Of Wood Feeding Beetles, Erin D. Scully, Scott M. Geib, John E. Carlson, Ming Tien, Duane Mckenna, Kelli Hoover

Department of Agronomy and Horticulture: Faculty Publications

Background: Wood-feeding beetles harbor an ecologically rich and taxonomically diverse assemblage of gut microbes that appear to promote survival in woody tissue, which is devoid of nitrogen and essential nutrients. Nevertheless, the contributions of these apparent symbionts to digestive physiology and nutritional ecology remain uncharacterized in most beetle lineages.

Results: Through parallel transcriptome profiling of beetle- and microbial- derived mRNAs, we demonstrate that the midgut microbiome of the Asian longhorned beetle (Anoplophora glabripennis), a member of the beetle family Cerambycidae, is enriched in biosynthetic pathways for the synthesis of essential amino acids, vitamins, and sterols. Consequently, the midgut …

Comprehensive Characterization And Rna-Seq Profiling Of The Hd-Zip Transcription Factor Family In Soybean (Glycine Max) During Dehydration And Salt Stress, Vikas Belamkar, Nathan T. Weeks, Arvind K. Bharti, Andrew Farmer, Michelle A. Graham, Steven B. Cannon

Department of Agronomy and Horticulture: Faculty Publications

Background:

The homeodomain leucine zipper (HD-Zip) transcription factor family is one of the largest plant specific superfamilies, and includes genes with roles in modulation of plant growth and response to environmental stresses. Many HD-Zip genes are characterized in Arabidopsis (Arabidopsis thaliana), and members of the family are being investigated for abiotic stress responses in rice (Oryza sativa), maize (Zea mays), poplar (Populus trichocarpa) and cucumber (Cucmis sativus). Findings in these species suggest HD-Zip genes as high priority candidates for crop improvement.

Results:

In this study we have identified members of …

Synthesis Of The Effect Of Fire On Lesser Prairie‐Chickens, Eric Thacker, Dirac L. Twidwell Jr

Department of Agronomy and Horticulture: Faculty Publications

In this synthesis, we reviewed the scientific literature pertaining to the effects of fire on lesser prairie‐chickens and their habitat. Overall, research is generally lacking that directly assesses relationships among fire, both as a regime and a discrete event, to its effect on lesser prairie‐chicken behavior and habitat value. Yet, research has quantified the effects of fire on vegetation throughout the distribution of the lesser prairie‐chicken, which has been linked to known metrics of habitat value and broad landscape‐level habitat requirements.

To summarize the literature, lesser prairie‐chickens require broad landscapes of fire‐dependent grass‐shrub vegetation. Changes in the eco‐evolutionary fire regime …

Stacking Of A Stearoyl-Acp Thioesterase With A Dual-Silenced Palmitoyl-Acp Thioesterase And Δ12 Fatty Acid Desaturase In Transgenic Soybean, Hyunwoo Park, George L. Graef, Yixiang Xu, Patrick Tenopir, Thomas E. Clemente

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max (L.) Merr) is valued for both its protein and oil, whose seed is composed of 40% and 20% of each component, respectively. Given its high percentage of polyunsaturated fatty acids, linoleic acid and linolenic acid, soybean oil oxidative stability is relatively poor. Historically food processors have employed a partial hydrogenation process to soybean oil as a means to improve both the oxidative stability and functionality in end-use applications. However, the hydrogenation process leads to the formation of trans-fats, which are associated with negative cardiovascular health. As a means to circumvent the need for the hydrogenation process, genetic …

First Report Of Curvularia Inaequalis And Bipolaris Spicifera Causing Leaf Blight Of Buffalograss In Nebraska, B. S. Amaradasa, K. Amundsen

Department of Agronomy and Horticulture: Faculty Publications

During the summer of 2011, foliar blight was observed on buffalograss (Buchloë dactyloides (Nutt.) Engelm.) lawns in Lincoln and Waverly, Nebraska. Disease symptoms were common when buffalograss was growing above 30°C and in drought conditions. Disease symptoms began as dark brown oblong leaf spots, followed by leaf tip dieback and eventual blighting of entire tillers. Leaf infections would progress into patches of thinning turf. Diseased leaf pieces were rinsed in distilled water and placed on 1.5% water agar. Two mitosporic fungal species having conidial morphology of Curvularia and Bipolaris were isolated. Colonies of Curvularia isolates grown on ¼× PDA …

Evaluation Of Soilless Media Sensors For Managing Winter-Time Greenhouse Strawberry Production Using A Capmat System, George E. Meyer, Ellen T. Paparozzi, Stacy A. Adams, Diego Scacalossi Voltan

Department of Agronomy and Horticulture: Faculty Publications

It is important for a greenhouse strawberry grower to know that their capillary mat (CapMat™) fertigation system is working correctly and that plants are receiving the correct amounts of water and fertilizer. Pots with soilless mix are not expected to hold more than 70% water on a volumetric basis. Pots with less than 40% water content continuously are not supplied enough water and nutrients to the plants. Typically, pots located near the manifold distribution system get a little more water than those at the other locations, but water use will really vary according to the factors listed above as well …

The Carbon-Nitrogen Balance Of The Nodule And Its Regulation Under Elevated Carbon Dioxide Concentration, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN₂). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the …

Comparison Of Winter Strawberry Production In A Commercial Heated High Tunnel Versus A University Greenhouse, Ellen T. Paparozzi, Ryan Pekarek, George E. Meyer, Stacy A. Adams, M. Elizabeth Conley, David P. Lambe, Paul Read, Erin E. Blankenship

Department of Agronomy and Horticulture: Faculty Publications

For the past 4 years, the University of Nebraska strawberry team has worked to develop low cost, sustainable methods for farmers and growers to produce strawberries in a double polyethylene greenhouse during the winter. This past year, this growing system was adapted to become a commercial grower’s heated high tunnel for the winter/spring of 2013-14. The idea was to scale up to a farm-size demonstration and compare it to the university greenhouse production system with a goal to expand marketing opportunities for strawberries into the winter season.

Greenhouse Gas Emissions From Soil Treated With Dung Pats, Kenneth Evans, Ana Wingeyer, Martha Mamo, Walter H. Schacht, Pamela Sutton, Kent M. Eskridge

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Grazing Management Effect On Micro- And Macro- Scale Fate Of C And N In Rangelands, Martha Mamo, Jeff Bradshaw, Richard Ferguson, Kent M. Eskridge, John A. Guretzky, Karla Jenkins, Walter H. Schacht, Jerry Volesky, Sean Whipple, Anita Wingeyer, Haishun Yang

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Quantitative Trait Locus Analysis Of Unsaturated Fatty Acids In A Recombinant Inbred Population Of Soybean, Xianzhi Wang, Guo-Liang Jiang, Marci Green, Roy A. Scott, D. L. Hyten, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is an important oilseed crop which produces about 30 %of the world’s edible vegetable oil. The quality of soybean oil is determined by its fatty acid composition. Soybean oil high in oleic and low in linolenic fatty acids is desirable for human consumption and other uses. The objectives of this study were to identify quantitative trait loci (QTLs) for unsaturated fatty acids and to evaluate the genetic effects of single QTL and QTL combinations in soybean. A population of recombinant inbred lines derived from the cross of SD02-4-59 X A02-381100 was evaluated for fatty …

Transcriptomic And Physiological Characterization Of The Fefe Mutant Of Melon (Cucumis Melo) Reveals New Aspects Of Iron-Copper Crosstalk, Brian M. Waters, Samuel A. Mcinturf, Keenan Amundsen

Department of Agronomy and Horticulture: Faculty Publications

Iron (Fe) and copper (Cu) homeostasis are tightly linked across biology. In previous work, Fe deficiency interacted with Cu-regulated genes and stimulated Cu accumulation. The C940-fe (fefe) Fe-uptake mutant of melon (Cucumis melo) was characterized, and the fefe mutant was used to test whether Cu deficiency could stimulate Fe uptake. Wild-type and fefe mutant transcriptomes were determined by RNA-seq under Fe and Cu deficiency. FeFe-regulated genes included core Fe uptake, metal homeostasis, and transcription factor genes. Numerous genes were regulated by both Fe and Cu. The fefe mutant was rescued by high Fe or by …

The Interaction Of Climate Change, Land Cover, And Political Representation In The Usa, Brady W. Allred, Dirac L. Twidwell, Samuel D. Fuhlendorf

Department of Agronomy and Horticulture: Faculty Publications

The difficulties in tackling climate change are inherently complex and primarily centered on political and social values. This is evident in the United States where political divisions and polarizations are fundamental barriers to advancing national policies, which in turn hinder international agreements, mitigation, and adaptation. Within the United States, the vast majority of agricultural and natural resource lands are projected to incur significant climate departures and are represented by the Republican Party. The resources and economic sectors that will be directly affected by climate change are represented by national leadership that is unlikely to accept policies to prevent or adapt …

Drought Effects On Composition And Yield For Corn Stover, Mixed Grasses, And Miscanthus As Bioenergy Feedstocks, Rachel Emerson, Amber Hoover, Allison Ray, Jeffrey Lacey, Marnie Cortez, Courtney Payne, Douglas L. Karlen, Stuart Birrell, David Laird, Robert Kallenbach, Josh Egenolf, Matthew Sousek, Thomas Voigt

Department of Agronomy and Horticulture: Faculty Publications

Drought conditions in 2012 were some of the most severe in recent history. The purpose of this study is to examine the impact of drought on quality, quantity, and theoretical ethanol yield (TEY) of three bioenergy feedstocks, corn stover, mixed grasses from Conservation Reserve Program lands, and Miscanthus × giganteus. To assess drought effects on these feedstocks, samples from 2010 (minimal to no drought) and 2012 (severe drought) were compared from multiple locations in the US. In all feedstocks, drought significantly increased extractives and reduced structural sugars and lignin; subsequently, TEYs were reduced 10–15%. Biomass yields were significantly reduced …

Nonsyntenic Genes Drive Highly Dynamic Complementation Of Gene Expression In Maize Hybrids, Anja Paschold, Nick B. Larson, Caroline Marcon, James C. Schnable, Cheng-Ting Yeh, Christa Lanz, Dan Nettleton, Hans-Peter Piepho, Patrick S. Schnable, Frank Hochholdinger

Department of Agronomy and Horticulture: Faculty Publications

Maize (Zea mays) displays an exceptional level of structural genomic diversity, which is likely unique among higher eukaryotes. In this study, we surveyed how the genetic divergence of two maize inbred lines affects the transcriptomic landscape in four different primary root tissues of their F1-hybrid progeny. An extreme instance of complementation was frequently observed: genes that were expressed in only one parent but in both reciprocal hybrids. This single-parent expression (SPE) pattern was detected for 2341 genes with up to 1287 SPE patterns per tissue. As a consequence, the number of active genes in hybrids exceeded that of …

Identification Of A Sphingolipid Α-Glucuronosyltransferase That Is Essential For Pollen Function In Arabidopsis, Emilie A. Rennie, Berit Ebert, Godfrey P. Miles, Rebecca E. Cahoon, Katy M. Christiansen, Solomon Stonebloom, Hoda Khatab, David Twell, Christopher J. Petzold, Paul D. Adams, Paul Dupree, Joshua L. Heazlewood, Edgar B. Cahoon, Henrik Vibe Scheller

Department of Agronomy and Horticulture: Faculty Publications

Glycosyl inositol phosphorylceramide (GIPC) sphingolipids are a major class of lipids in fungi, protozoans, and plants. GIPCs are abundant in the plasma membrane in plants, comprising around a quarter of the total lipids in these membranes. Plant GIPCs contain unique glycan decorations that include a conserved glucuronic acid (GlcA) residue and various additional sugars; however, no proteins responsible for glycosylating GIPCs have been identified to date. Here, we show that the Arabidopsis thaliana protein INOSITOL PHOSPHORYLCERAMIDE GLUCURONOSYLTRANSFERASE1 (IPUT1) transfers GlcA from UDP-GlcA to GIPCs. To demonstrate IPUT1 activity, we introduced the IPUT1 gene together with genes for a UDP-glucose dehydrogenase …

Quantitative Proteomic Analysis Of The Salmonella-Lettuce Interaction, Yuping Zhang, Renu Nandakumar, Shannon L. Bartelt-Hunt, Daniel D. Snow, Laurie Hodges, Xu Li

Department of Agronomy and Horticulture: Faculty Publications

Human pathogens can internalize food crops through root and surface uptake and persist inside crop plants. The goal of the study was to elucidate the global modulation of bacteria and plant protein expression after Salmonella internalizes lettuce. A quantitative proteomic approach was used to analyse the protein expression of Salmonella enterica serovar Infantis and lettuce cultivar Green Salad Bowl 24 h after infiltrating S. Infantis into lettuce leaves. Among the 50 differentially expressed proteins identified by comparing internalized S. Infantis against S. Infantis grown in Luria Broth, proteins involved in glycolysis were down-regulated, while one protein involved in ascorbate …

Identification And Validation Of Quantitative Trait Loci For Seed Yield, Oil And Protein Contents In Two Recombinant Inbred Line Populations Of Soybean, Xianzhi Wang, Guo‑Liang Jiang, Marci Green, Roy A. Scott, Qijian Song, D. L. Hyten, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

Soybean seeds contain high levels of oil and protein, and are the important sources of vegetable oil and plant protein for human consumption and livestock feed. Increased seed yield, oil and protein contents are the main objectives of soybean breeding. The objectives of this study were to identify and validate quantitative trait loci (QTLs) associated with seed yield, oil and protein contents in two recombinant inbred line populations, and to evaluate the consistency of QTLs across different environments, studies and genetic backgrounds. Both the mapping population (SD02- 4-59 × A02-381100) and validation population (SD02- 911 × SD00-1501) were phenotyped for …

Quantitative Trait Loci (Qtl) That Underlie Scn Resistance In Soybean [Glycine Max (L.) Merr.] Pi438489b By ‘Hamilton’ Recombinant Inbred Line (Ril) Population, Kassem My Abdelmajid, Laura Ramos, D. L. Hyten, Jason Bond, Abdelhafid Bendahmane, Prakash R. Arelli, Victor N. Njiti, Silvia Cianzio, Stella K. Kantartzi, Khalid Meksem

Department of Agronomy and Horticulture: Faculty Publications

Soybean cyst nematode caused by Heterodera glycines Ichinohe is the most devastating pest in soybean [Glycine max (L.) Merr.]. Resistance to SCN is complex, polygenic, race and cultivar specific, and it is controlled by several quantitative trait loci (QTL). Our objective was to identify and map QTL for SCN resistance to races 3 (HG Type 0) and 5 (HG Type 2.5.7) using a high density SNP-based genetic linkage map based on the PI438489B by ‘Hamilton’ (PIxH, n=50) recombinant inbred line population. The PI438489B by Hamilton map contained 648 SNPs distributed on 31 LGs with coverage of 1,524.7 cM and …

Detection And Confirmation Of Quantitative Trait Loci For Soybean Seed Isoflavones, Christopher J. Smallwood, Catherine N. Nyinyi, Dean A. Kopsell, Carl E. Sams, Dennis R. West, Pengyin Chen, Stella K. Kantartzi, P. B. Cregan, D. L. Hyten, Vincent R. Pantalone

Department of Agronomy and Horticulture: Faculty Publications

Interest in soybean [Glycine max (L.) Merr.] isoflavones has increased in recent years owing to numerous reported health benefits. Consequently, quantitative trait loci (QTL) detection for marker-assisted breeding for isoflavones is being examined for genetic gains. This study sought to detect QTL for soybean isoflavones in a population of 274 recombinant inbred lines derived from a cross between ‘Essex’ and ‘Williams 82’ that were subdivided and tested by maturity (early, mid, and late). The field tests were conducted in three environments in 2009 (Knoxville, TN; Harrisburg, IL; and Stuttgart, AR). The population was genotyped with 480 polymorphic single nucleotide …

Phytophthora Root Rot Resistance In Soybean E00003, Zhongnan Zhang, Jianjun Hao, Jiazheng Yuan, Qijian Song, D. L. Hyten, P. B. Cregan, Guorong Zhang, Cuihua Gu, Ming Li, Dechun Wang

Department of Agronomy and Horticulture: Faculty Publications

Phytophthora root rot (PRR) is a devastating disease in soybean [Glycine max (L.) Merr.] production. Michigan elite soybean E00003 is resistant to Phytophthora sojae and has been used as a resistance source in breeding. Genetic control of PRR resistance in this source is unknown. To facilitate marker-assisted selection (MAS), the PRR resistance loci in E00003 and their map locations need to be determined. In this study, a genetic mapping approach was used to identify major PRR -resistant loci in E00003. The mapping population consists of 240 F₄–derived lines developed by crossing E00003 with the P. sojae susceptible …

A Reference Genome For Common Bean And Genome-Wide Analysis Of Dual Domestications, Jeremy Schmutz, Phillip E. Mcclean, Sujan Mamidi, G. Albert Wu, Steven B. Cannon, Jane Grimwood, Jerry Jenkins, Shengqiang Shu, Qijian Song, Carolina Chavarro, Mirayda Torres-Torres, Valerie Geffroy, Samira Mafi Moghaddam, Dongying Gao, Brian Abernathy, Kerrie Barry, Matthew Blair, Mark A. Brick, Mansi Chovatia, Paul Gepts, David M. Goodstein, Michael Gonzales, Uffe Hellsten, D. L. Hyten, Gaofeng Jia, James D. Kelly, Dave Kudrna, Rian Lee, Manon M.S. Richard, Phillip N. Miklas, Juan M. Osorno, Josiane Rodrigues, Vincent Thareau, Carlos A. Urrea Florez, Mei Wang, Yeisoo Yu, Ming Zhang, Rod A. Wing, P. B. Cregan, Daniel S. Rokhsar, Scott A. Jackson

Department of Agronomy and Horticulture: Faculty Publications

Common bean (Phaseolus vulgaris L.) is the most important grain legume for human consumption and has a role in sustainable agriculture owing to its ability to fix atmospheric nitrogen. We assembled 473 Mb of the 587-Mb genome and genetically anchored 98% of this sequence in 11 chromosome-scale pseudomolecules. We compared the genome for the common bean against the soybean genome to find changes in soybean resulting from polyploidy. Using resequencing of 60 wild individuals and 100 landraces from the genetically differentiated Mesoamerican and Andean gene pools, we confirmed 2 independent domestications from genetic pools that diverged before human colonization. …

Mapping The Low Palmitate Fap1 Mutation And Validation Of Its Effects In Soybean Oil And Agronomic Traits In Three Soybean Populations, Andrea J. Cardinal, Rebecca Whetten, Sanbao Wang, Jérôme Auclair, D. L. Hyten, P. B. Cregan, Eleni Bachlava, Jason Gillman, Martha Ramirez, Ralph Dewey, Greg Upchurch, Lilian Miranda, Joesph W. Burton

Department of Agronomy and Horticulture: Faculty Publications

Soybean oil with reduced palmitic acid content is desirable to reduce the health risks associated with consumption of this fatty acid. The objectives of this study were: to identify the genomic location of the reduced palmitate fap1 mutation, determine its molecular basis, estimate the amount of phenotypic variation in fatty acid composition explained by this locus, determine if there are epistatic interactions between the fap1 and fap_nc loci and, determine if the fap1 mutation has pleiotropic effects on seed yield, oil and protein content in three soybean populations. This study detected two major QTL for 16:0 content located in …

Identification Of New Qtls For Seed Mineral, Cysteine, And Methionine Concentrations In Soybean [Glycine Max (L.) Merr.], Raghuprakash Kastoori Ramamurthy, Joseph Jedlicka, George L. Graef, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Increased concentrations of important nutrients in edible parts of plants could result in biofortified foods. Soybean [Glycine max (L.) Merr.] is a major legume crop and an important source of certain nutrients, including protein and minerals, in human and animal diets. Understanding the underlying genetic basis of seed composition is crucial to improving seed nutrient composition. In this study we used three soybean recombinant inbred line mapping populations derived from the crosses Williams 82 × DSR-173, Williams 82 × NKS19-90 and Williams 82 × Vinton 81, and constructed a joint linkage map from these populations. Forty quantitative trait loci (QTLs) …

Development Of Scar Markers And Up-Pcr Cross-Hybridization Method For Specific Detection Of Four Major Subgroups Of Rhizoctonia From Infected Turfgrasses, Bimal S. Amaradasa, Dilip Lakshman, Brandon J. Horvath, Keenan Amundsen

Department of Agronomy and Horticulture: Faculty Publications

A rapid identification assay for Waitea circinata (anamorph: Rhizoctonia spp.) varieties zeae and circinata causing patch diseases on turfgrasses was developed based on the universally primed PCR (UPPCR) products cross-blot hybridization. Tester isolates belonging to the two varieties of W. circinata were amplified with a single UP primer L21, which generated multiple DNA fragments for each variety. Probes were prepared with UP-PCR products of each tester isolate by labeling with digoxigenin. Fieldcollected W. circinata isolates and representative isolates of different R. solani anastomosis groups (AG) and AG subgroups were amplified with L21, immobilized on nylon membrane and cross hybridized with …

Porocercospora Seminalis Gen. Et Comb. Nov., The Causal Organism Of Buffalograss False Smut, Bimal S. Amaradasa, Hugo Madrid, Johannes Z. Groenewald, Pedro W. Crous, Keenan L. Amundsen

Department of Agronomy and Horticulture: Faculty Publications

False smut caused by Cercospora seminalis is an important disease of buffalograss (Buchloe dactyloides) affecting seed production. The pathogen prevents normal caryopsis development and causes considerable yield loss and reduced seed germination. The current taxonomic placement of the false-smut causal pathogen in the genus Cercospora is incorrect based on its morphological characteristics and DNA phylogeny. In the present study the phylogenetic position of C. seminalis is clarified based on DNA sequence analysis of three loci namely the internal transcribed spacer (ITS) region, partial nuclear ribosomal large subunit (LSU) and partial sequences of the RNA polymerase II second largest …

Arabidopsis Lipins, Pdat1 Acyltransferase, And Sdp1 Triacylglycerol Lipase Synergistically Direct Fatty Acids Toward Β-Oxidation, Thereby Maintaining Membrane Lipid Homeostasis, Jilian Fan, Chengshi Yan, Rebecca Roston, John Shanklin, Changcheng Xu

Department of Agronomy and Horticulture: Faculty Publications

Triacylglycerol (TAG) metabolism is a key aspect of intracellular lipid homeostasis in yeast and mammals, but its role in vegetative tissues of plants remains poorly defined. We previously reported that PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE1 (PDAT1) is crucial for diverting fatty acids (FAs) from membrane lipid synthesis to TAG and thereby protecting against FA-induced cell death in leaves. Here, we show that overexpression of PDAT1 enhances the turnover of FAs in leaf lipids. Using the trigalactosyldiacylglycerol1-1 (tgd1-1) mutant, which displays substantially enhanced PDAT1- mediated TAG synthesis, we demonstrate that disruption of SUGAR-DEPENDENT1 (SDP1) TAG lipase or PEROXISOMAL TRANSPORTER1 (PXA1) severely decreases …

Dt2 Is A Gain-Of-Function Mads-Domain Factor Gene That Specifies Semideterminacy In Soybean, Jieqing Ping, Yunfeng Liu, Lianjun Sun, Meixia Zhao, Yinghui Li, Zongxiang Tang, Hanh Nguyen, Zhixi Tian, Lijuan Qiu, Randall L. Nelson, Thomas E. Clemente, James Specht, Jianxin Ma

Department of Agronomy and Horticulture: Faculty Publications

Similar to Arabidopsis thaliana, the wild soybeans (Glycine soja) and many cultivars exhibit indeterminate stem growth specified by the shoot identity gene Dt1, the functional counterpart of Arabidopsis TERMINAL FLOWER1 (TFL1). Mutations in TFL1 and Dt1 both result in the shoot apical meristem (SAM) switching from vegetative to reproductive state to initiate terminal flowering and thus produce determinate stems. A second soybean gene (Dt2) regulating stem growth was identified, which, in the presence of Dt1, produces semideterminate plants with terminal racemes similar to those observed in determinate plants. Here, we report positional …

Nebraska’S Groundwater Legacy: Nitrate Contamination Beneath Irrigated Cropland, Mary E. Exner Spaulding, Aaron J. Hirsh, Roy F. Spalding

Department of Agronomy and Horticulture: Faculty Publications

A 31 year record of ~44,000 nitrate analyses in ~11,500 irrigation wells was utilized to depict the decadal expansion of groundwater nitrate contamination (N>10 mg/L) in the irrigated corn-growing areas of eastern and central Nebraska and analyze long-term nitrate concentration trends in 17 management areas (MAs) subject to N fertilizer and budgeting requirements. The 1.3 M contaminated hectares were characterized by irrigation method, soil drainage, and vadose zone thickness and lithology. The areal extent and growth of contaminated groundwater in two predominately sprinkler-irrigated areas was only ~20% smaller beneath well-drained silt loams with thick clayey-silt unsaturated layers and unsaturated …