Plant Breeding and Genetics Commons^™

Toward Sustainable Production Of Value-Added Bioenergy And Industrial Oils In Oilseed And Biomass Feedstocks, Kiyoul Park, Sanju A. Sanjaya, Truyen Quach, Edgar B. Cahoon

Center for Plant Science Innovation: Faculty Publications

Plant fatty acids are used forfood, feed, fuel, and industrial materials. Structurally and chemically diverse fatty acids, referred to as unusual or specialized fatty acids, are found in the seed oils of diverse plant species. Many unusual fatty acids have potential use as alternative and renewable sources of biofuels and biobased industrial feedstocks due to their variant structures' physical or functional properties. Oils enriched in these fatty acids can increase the value of oilseed crops and provide co-products that can be readily extracted from lignocellulosic materials in biomass crops. Here, we describe recent progress in strategies for enhancement of oil …

Disruption Of Long-Chain Base Hydroxylation Alters Growth And Impacts Sphingolipid Synthesis In Physcomitrella Patens, Abraham R. Steinberger, William Oscar Merino, Rebecca E. Cahoon, Edgar B. Cahoon, Daniel V. Lynch

Center for Plant Science Innovation: Faculty Publications

Sphingolipids have roles as membrane structural components and as bioactive molecules in plants. In Physcomitrella patens, 4-hydroxysphinganine (phytosphingosine, t18:0) is the predominant sphingolipid long-chain base (LCB). To assess the functional significance of t18:0, CRISPR-Cas9 mutagenesis was used to generate mutant lines lacking the sole SPHINGOID BASE HYDROXYLASE (SBH) gene encoding the hydroxylase responsible for converting sphinganine (d18:0) to t18:0. Total sphingolipid content in sbh protonemata was 2.4-fold higher than in wild-type. Modest changes in glycosyl inositolphosphorylceramide (GIPC) glycosylation patterns occurred. Sphingolipidomic analyses of mutants lacking t18:0 indicated modest alterations in acyl-chain pairing with d18:0 in GIPCs and ceramides, but dramatic …

Next Generation Sequencing Identifies Population Structure And Signatures Of Local Adaptation In Red Alder (Alnus Rubra Bong.), Jacob Brent Loveless

Dissertations and Theses

Red alder (Alnus rubra Bong.) is the dominant hardwood tree species in the Pacific Northwest. Red alders are only found in western North America, generally within 200 km of the coast and below 1000 m in elevation--although there are several disjunct populations in the northern Rocky Mountains in Idaho. Commonly a riparian species, the shade intolerant red alder generates most of the leaf litter in the streams and rivers it occupies which has been shown to greatly influence the decomposer communities. This, in turn, has a cascading effect throughout the entire riparian ecosystem greatly influencing multiple levels of the …

Evaluation Of Masculinization Treatments To Produce Feminized Hemp Seed (Cannabis Sativa L.), Ted Fitzgerald, J. Wyatt Brown

Master's Theses

Cannabis sativa L. (hemp) develops plants with either male or female flowers, and growers of hemp greatly prefer female flowers which bear the glandular trichomes that contain cannabinoids. Feminized (all female) seeds are highly desired, which are produced by crossing a female plant with a masculinized female plant. Masculinization is achieved through the inhibition of ethylene and/or addition of gibberellins before flower initiation in female plants. The hemp industry uses silver thiosulfate (STS) to masculinize hemp, but spraying silver poses environmental concerns. This study compared STS to three other ethylene-inhibiting agents: aminoethoxyvinylglycine (AVG), cobalt nitrate (CBN), and 1-methylcyclopropene (1-MCP). Treatments …

Quantitative Trait Loci Controlling Agronomic And Biochemical Traits In Cannabis Sativa, Patrick Woods, Brian J. Campbell, Timothy J. Nicodemus, Edgar B. Cahoon, Jack L. Mullen, John K. Mckay

Center for Plant Science Innovation: Faculty Publications

Understanding the genetic basis of complex traits is a fundamental goal of evolutionary genetics. Yet, the genetics controlling complex traits in many important species such as hemp (Cannabis sativa) remain poorly investigated. Because hemp’s change in legal status with the 2014 and 2018 U.S. Federal Farm Bills, interest in the genetics controlling its numerous agriculturally important traits has steadily increased. To better understand the genetics of agriculturally important traits in hemp, we developed an F2 population by crossing two phenotypically distinct hemp cultivars (Carmagnola and USO31). Using whole-genome sequencing, we mapped quantitative trait loci (QTL) associated with variation …

The Influence Of Singlet Oxygen And Loss Of Function Of Fatty Acid Desaturase 7 In The Chloroplast On Aphid Resistance In Arabidopsis Thaliana, Hillary Donna Fischer

Graduate Theses and Dissertations

Fatty Acid Desaturase 7 (FAD7) is a chloroplast-localized enzyme that alters the fatty acid content of photosynthetic membranes, and that negatively regulates plant defenses against aphids. Previous studies in the model organism Arabidopsis (Arabidopsis thaliana) have shown that loss-of-function mutations in FAD7 decrease population growth of the green peach aphid (GPA; Myzus persicae Sulzer). This study further characterized the effects of a fad7 null mutant on aphids, and investigated the role of reactive oxygen species (ROS), including singlet oxygen (1O2), in plant responses to aphid resistance in fad7 as well as in wild type plants and a mutant with heightened …

Production, Evaluation, And Selection Of Elite Quality Protein Popcorn (Qpp) Hybrids, Leandra Marshall Parsons

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

In 2017, twelve Quality Protein Popcorn (QPP) inbred lines were developed and selected as premier dent by popcorn crosses fit for hybridization and testing. These QPP inbred lines were derived from specific Quality Protein dent Maize (QPM) by ConAgra Brands® popcorn line crosses to produce high lysine, vitreous popcorn lines capable of near-equal popping characteristics compared to the original popcorn parents. The QPP hybridization project commenced in the summer of 2018 utilizing these 12 inbred QPP lines and crossing them in a full diallel. Since then, the production of QPP hybrids has employed a diverse set of selection factors evaluating …

The Importance Of A Multidisciplinary Approach To Public Health: Addressing Food Insecurity Through A Biological And Sociological Lens, Chloe Grant

Honors Theses

Plants can sense the change of 1 ^oC in their growth environment and thus global climate change has a great impact on plant growth and development. The phenomenon that warm non-stress temperatures promote stem and petiole elongation, as well as leaf hyponastic growth, is collectively known as thermomorphogenesis. While it is known that the basic helix-loop-helix (bHLH) transcription factor PIF4 is highly inducible by temperature elevations and controls thermomorphogenesis in dicots (e.g., Arabidopsis thaliana), the molecular mechanism underlying thermomorphogenetic growth in monocots is not clear. In this study, I identify PIF4 orthologs in several economically important monocotyledonous species and …

Evaluation Of Irrigation And Nutrient Management Strategies In Rice Using Alternative Irrigation Methods, Justin Lee Chlapecka

Graduate Theses and Dissertations

As water resources gain value across the Mid-South, alternative irrigation strategies of rice (Oryza sativa L.) have garnered increasing attention. In 2015, an estimated 1.7% of Arkansas rice hectarage used alternate wetting and drying (AWD) irrigation and 0.9% used furrow irrigation. As of 2020, 2.5% used AWD and 16.9% used furrow irrigation, the latter accounting for near 99,000 ha in Arkansas. Little information exists in the scientific literature in relation to management of rice grown in the Mid-South without a conventional flood. This fact coupled with the rapid adoption rate, especially for furrow-irrigated rice (FIR), during the last five years …

Screening And Breeding Soybean For Flood Tolerance, Maria Roberta De Oliveira

Graduate Theses and Dissertations

Waterlogging can be detrimental to soybean [Glycine max (L.) Merr.] growth and development, with effects ranging from chlorosis and stunting to yield loss and plant death. Soybean responses to, and the effects of, waterlogging are dependent on the growth stage of the plant at the initiation of waterlogging. The objectives of this study were: (1) to assess the effectiveness of Genomic Selection (GS), Marker Assisted Selection (MAS) and Phenotypic Selection for flood tolerance at the progeny row stage as compared to random selection, for the development of high-yielding flood-tolerant lines; and (2) to compare field-screening and hydroponic greenhouse screening methodologies …

Transcriptional Activation Of Phytochrome-Interacting Factor 4 Is A Conserved Mechanism Of Thermomorphogenesis In Dicotyledenous Plants, Caroline Clutton

Honors Theses

In the model dicotyledonous plant Arabidopsis thaliana, the basic helix-loop-helix (bHLH) transcription factor Phytochrome-Interacting Factor 4 (AtPIF4) plays a central role in regulating the ambient temperature-regulated hypocotyl growth response. Warm temperatures induce AtPIF4 transcription and the accumulated AtPIF4 promotes thermomorphogenesis by enhancing the expression of a group of growth-related genes. However, whether this thermo-induced growth response is universal, and more importantly, whether there is a conserved thermomorphogenetic mechanism shared in dicots is largely unknown. Here we show that higher ambient temperatures promote the hypocotyl growth in four other dicotyledonous plants, including Brassica rapa, Camelina sativa, Nicotiana benthamiana …

An Ancient, Light-Dependent Hydrocarbon-Forming Enzyme, Ananya Mukherjee

Center for Plant Science Innovation: Faculty Publications

No abstract provided.

Allelic Diversity At Abiotic Stress Responsive Genes In Relationship To Ecological Drought Indices For Cultivated Tepary Bean, Phaseolus Acutifolius A. Gray, And Its Wild Relatives, María A. Buitrago-Bitar, Andrés J. Cortés, Felipe López-Hernández, Jorge M. Londoño-Caicedo, Jaime E. Muñoz-Florez, L. Carmenza Muñoz, Matthew Wohlgemuth Blair

Agricultural and Environmental Sciences Faculty Research

Some of the major impacts of climate change are expected in regions where drought stress is already an issue. Grain legumes are generally drought susceptible. However, tepary bean and its wild relatives within Phaseolus acutifolius or P. parvifolius are from arid areas between Mexico and the United States. Therefore, we hypothesize that these bean accessions have diversity signals indicative of adaptation to drought at key candidate genes such as: Asr2, Dreb2B, and ERECTA. By sequencing alleles of these genes and comparing to estimates of drought tolerance indices from climate data for the collection site of geo-referenced, tepary bean accessions, we …

Sustainability Of Genetically Modified (Gm) Crops, Abdul Hakeem, Wajid Ali Shah

CBER Conference

This proposal identifies the methods used in the modification of crops, their production, modification, expansion, benefits, and carbon emission. Moreover, the special focus of this proposal is to explain the need for GM crops for developing nations which are witnessing exponential growth of their populations. Additionally, it pursues to determine how in the environmental and economic context, the significance of GM crops is overwhelming and cannot be overlooked. The greenhouse ePect reduction is the other essential output of the GM crops as shown through the illustrations.

Anatomical Analysis Of Somatic Mutation Accumulation In Mimulus Guttatus, Amanda Burrell

University Honors Theses

Plants are seemingly immortal in their abilities to survive long periods of dormancy in different life stages, live for thousands of years, and even grow into whole forests from one clone, all through a series of mitotic and meiotic events, but how many mutations do plants acquire in their lifetime? And just how many of these mutations are heritable? To answer these questions, first we must answer: how many cell divisions are there in the length of a stem? The purpose of this study is to answer just that by establishing a protocol for estimating the number of germ cell …

Seed Rain–Successional Feedbacks In Wet Tropical Forests, Nohemi Huanca Nuñez, Robin L. Chazdon, Sabrina E. Russo

School of Biological Sciences: Faculty Publications

Abstract

Tropical forest regeneration after abandonment of former agricultural land depends critically on the input of tree seeds, yet seed dispersal is increasingly disrupted in contemporary human-modified landscapes. Here, we introduce the concept of seed rain–successional feedbacks as a deterministic process in which seed rain is shaped by successional dynamics internal to a forest site and that acts to reinforce priority effects. We used a combination of time series and chronosequence approaches to investigate how the quantity and taxonomic and functional composition of seed rain change during succession and to evaluate the strength of seed rain–successional feedbacks, relative to other …

Compounds Derived From Bacteria Enhance Marine Diatom Growth, Ananya Mukherjee

Center for Plant Science Innovation: Faculty Publications

No abstract provided.

Predicting Transcriptional Responses To Cold Stress Across Plant Species, Xiaoxi Meng, Zhikai Liang, Xiuru Dai, Yang Zhang, Samira Mahboub, Daniel W. Ngu, Rebecca Roston, James Schnable

Center for Plant Science Innovation: Faculty Publications

Although genome-sequence assemblies are available for a growing number of plant species, gene-expression responses to stimuli have been cataloged for only a subset of these species. Many genes show altered transcription patterns in response to abiotic stresses. However, orthologous genes in related species often exhibit different responses to a given stress. Accordingly, data on the regulation of gene expression in one species are not reliable predictors of orthologous gene responses in a related species. Here, we trained a supervised classification model to identify genes that transcriptionally respond to cold stress. A model trained with only features calculated directly from genome …

Arkansas Cotton Variety Test 2020, F. Bourland, A. Beach, E. Brown, C. Kennedy, L. Martin, B. Robertson

Arkansas Agricultural Experiment Station Research Series

The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed companies establish marketing strategies and assists producers in choosing varieties to plant. These annual evaluations will then facilitate the inclusion of new, improved genetic material in Arkansas cotton production. Adaptation of varieties is determined by evaluating the lines at five University of Arkansas System Division of Agriculture research sites (Manila, Keiser, Judd Hill, Marianna, and Rohwer). Entries in the 2020 Arkansas Cotton Variety Test …

Dissecting The Regulatory Roles Of Orm Proteins In The Sphingolipid Pathway Of Plants, Adil Alsiyabi, Ariadna Gonzalez Solis, Edgar B. Cahoon, Rajib Saha

Center for Plant Science Innovation: Faculty Publications

Sphingolipids are a vital component of plant cellular endomembranes and carry out multiple functional and regulatory roles. Different sphingolipid species confer rigidity to the membrane structure, facilitate trafficking of secretory proteins, and initiate programmed cell death. Although the regulation of the sphingolipid pathway is yet to be uncovered, increasing evidence has pointed to orosomucoid proteins (ORMs) playing a major regulatory role and potentially interacting with a number of components in the pathway, including both enzymes and sphingolipids. However, experimental exploration of new regulatory interactions is time consuming and often infeasible. In this work, a computational approach was taken to address …