Plant Biology Commons^™

High-Resolution Mapping Of Open Chromatin In The Rice Genome, Wenli Zhang, Yufeng Wu, James C. Schnable, Zixian Zeng, Michael Freeling, Gregory E. Crawford, Jiming Jiang

Department of Agronomy and Horticulture: Faculty Publications

Gene expression is controlled by the complex interaction of transcription factors binding to promoters and other regulatory DNA elements. One common characteristic of the genomic regions associated with regulatory proteins is a pronounced sensitivity to DNase I digestion. We generated genome-wide high-resolution maps of DNase I hypersensitive (DH) sites from both seedling and callus tissues of rice (Oryza sativa). Approximately 25% of the DH sites from both tissues were found in putative promoters, indicating that the vast majority of the gene regulatory elements in rice are not located in promoter regions. We found 58% more DH sites in …

Msh1 Influence On Plant Mitochondrial Genome Recombination And Phenotype In Tobacco, Peibei Sun

School of Biological Sciences: Dissertations, Theses, and Student Research

Plant mitochondrial genomes are composed of unusually complex structures, due to active recombination at numerous repeated sequences in the genome. The maintenance of mitochondrial genome stability is under the control of identifiable nuclear genes. In plants, three nuclear genes (MSH1, RECA3 and OSB1) have been shown to participate in recombination surveillance and the suppression of illegitimate recombination in mitochondria. Disruption of these loci in Arabidopsis results in reproducible mitochondrial genome rearrangements. We demonstrated that repeat-mediated de novo recombination was also enhanced in both Arabidopsis and tobacco during passage through in vitro culture. Furthermore, in vitro conditions led …

Heritable Epigenetic Variation Among Maize Inbreds, Steve R. Eichten, Ruth A. Swanson, James C. Schnable, Amanda J. Waters, Peter J. Hermanson, Sanzhen Liu, Cheng-Ting Yeh, Yi Jia, Karla Gendler, Michael Freeling, Patrick S. Schnable, Matthew W. Vaughn, Nathan M. Springer

Department of Agronomy and Horticulture: Faculty Publications

Epigenetic variation describes heritable differences that are not attributable to changes in DNA sequence. There is the potential for pure epigenetic variation that occurs in the absence of any genetic change or for more complex situations that involve both genetic and epigenetic differences. Methylation of cytosine residues provides one mechanism for the inheritance of epigenetic information. A genome-wide profiling of DNA methylation in two different genotypes of Zea mays (ssp. mays), an organism with a complex genome of interspersed genes and repetitive elements, allowed the identification and characterization of examples of natural epigenetic variation. The distribution of DNA methylation …

Transcriptomic Characterization Of A Synergistic Genetic Interaction During Carpel Margin Meristem Development In Arabidopsis Thaliana, April N. Wynn, Elizabeth E. Rueschhoff, Robert G. Franks

Biological Sciences Research

In flowering plants the gynoecium is the female reproductive structure. In Arabidopsis thalianaovules initiate within the developing gynoecium from meristematic tissue located along the margins of the floral carpels. When fertilized the ovules will develop into seeds. SEUSS (SEU) and AINTEGUMENTA (ANT) encode transcriptional regulators that are critical for the proper formation of ovules from the carpel margin meristem (CMM). The synergistic loss of ovule initiation observed in the seu ant double mutant suggests that SEU and ANT share overlapping functions during CMM development. However the molecular mechanism underlying this synergistic interaction is unknown. Using …

Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe

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

The filamentous fungus, Magnaporthe oryzae, responsible for blast rice disease, destroys around 10-30% of the rice crop annually. Infection begins when the specialized infection structure, the appressorium, generates enormous internal turgor pressure through the accumulation of glycerol. This turgor acts on a penetration peg emerging at the base of the cell, causing it to breach the leaf surface allowing its infection.

The enzyme trehalose-6- phosphate synthase (Tps1) is a central regulator of the transition from appressorium development to infectious hyphal growth. In the first chapter we show that initiation of rice blast disease requires a regulatory mechanism involving an …

Herbicide-Resistant Risk Assessment: Response Of Common Nebraska Weeds To Dicamba Dose, Roberto J. Crespo

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

Dicamba-resistant soybeans are being developed to provide an additional herbicide mechanism of action that can be used in soybean, and to provide a tool to help manage or mitigate the evolution of other herbicide-resistant weed populations. The objectives of this thesis were to assess the risk of common Nebraska weeds developing resistance to dicamba, quantify baseline dose-response to dicamba of high-risk weed species, and survey the variability in dicamba dose-response among populations of those species. Twenty-five weed scientists were asked to estimate the risk likelihood of ten weed species evolving resistance to dicamba following the commercialization of dicamba-resistant soybean. Palmer …

Screening Synteny Blocks In Pairwise Genome Comparisons Through Integer Programming, Haibao Tang, Eric Lyons, Brent S. Pedersen, James C. Schnable, Andrew H. Paterson, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Background:

It is difficult to accurately interpret chromosomal correspondences such as true orthology and paralogy due to significant divergence of genomes from a common ancestor. Analyses are particularly problematic among lineages that have repeatedly experienced whole genome duplication (WGD) events. To compare multiple “subgenomes” derived from genome duplications, we need to relax the traditional requirements of “one-to-one” syntenic matchings of genomic regions in order to reflect “one-to-many” or more generally “many-to-many” matchings. However this relaxation may result in the identification of synteny blocks that are derived from ancient shared WGDs that are not of interest. For many downstream analyses, we …

Genes Identified By Visible Mutant Phenotypes Show Increased Bias Toward One Of Two Subgenomes Of Maize, James C. Schnable, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Not all genes are created equal. Despite being supported by sequence conservation and expression data, knockout homozygotes of many genes show no visible effects, at least under laboratory conditions. We have identified a set of maize (Zea mays L.) genes which have been the subject of a disproportionate share of publications recorded at MaizeGDB. We manually anchored these ‘‘classical’’ maize genes to gene models in the B73 reference genome, and identified syntenic orthologs in other grass genomes. In addition to proofing the most recent version 2 maize gene models, we show that a subset of these genes, those that …

Dose–Sensitivity, Conserved Non-Coding Sequences, And Duplicate Gene Retention Through Multiple Tetraploidies In The Grasses, James C. Schnable, Brent S. Pedersen, Sabarinath Subramaniam, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Whole genome duplications, or tetraploidies, are an important source of increased gene content. Following whole genome duplication, duplicate copies of many genes are lost from the genome. This loss of genes is biased both in the classes of genes deleted and the subgenome from which they are lost. Many or all classes are genes preferentially retained as duplicate copies are engaged in dose sensitive protein–protein interactions, such that deletion of any one duplicate upsets the status quo of subunit concentrations, and presumably lowers fitness as a result. Transcription factors are also preferentially retained following every whole genome duplications studied. This …

Phenotypic And Genetic Characterization Of Wildland Collections Of Western And Searls Prairie Clovers For Rangeland Revegetation In The Western Usa, Kishor Bhattarai

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Western prairie clover [Dalea ornata (Douglas ex Hook.) Eaton & J. Wright] is a perennial legume that occurs in the northern Great Basin, Snake River Basin, and southern Columbia Plateau, whereas Searls prairie clover [Dalea searlsiae (A. Gray) Barneby], also a perennial legume, occurs in the southern Great Basin and surrounding areas. Understanding the genetic and ecotypic variation of these prairie clovers is a prerequisite for developing populations suitable for rangeland revegetation in the western USA. DNA sequences of internal transcribed spacer (ITS/5.8S) and trnK/matK were used to study the phylogeny of these species. The species were distinguished …

Following Tetraploidy In Maize, A Short Deletion Mechanism Removed Genes Preferentially From One Of The Two Homeologs, Margaret R. Woodhouse, James C. Schnable, Brent S. Pedersen, Eric Lyons, Damon Lisch, Shabarinath Subramaniam, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Previous work in Arabidopsis showed that after an ancient tetraploidy event, genes were preferentially removed from one of the two homeologs, a process known as fractionation. The mechanism of fractionation is unknown. We sought to determine whether such preferential, or biased, fractionation exists in maize and, if so, whether a specific mechanism could be implicated in this process. We studied the process of fractionation using two recently sequenced grass species: sorghum and maize. The maize lineage has experienced a tetraploidy since its divergence from sorghum approximately 12 million years ago, and fragments of many knocked-out genes retain enough sequence similarity …

Development Of Protocols For Tissue Culture And Mutagenesis In Two Variegated Sansevieria Sp., Irmawati Akma Abdul Hapiz

Student Works (2010-2019)

Studies were conducted to develop the tissue culture protocol and mutagenesis through Gamma ray irradiation for two variegated Sansevieria species known as Sansevieria trifasciata var. Laurentii (goldband Sansevieria) and Sansevieria trifasciata var. Hahnii (birdnest Sansevieria). Seven combinations of BAP and NAA were chosen which are represented by letter A= 1.00 mg/I BAP, B = 1.00 mg/I BAP + 0.25 mg/I NAA, C = 2.00 mg/I BAP + 0.50 mg/I NAA, D = 2.00 mg/I BAP + 1.00 mg/I NAA, E = 3.00 mg/I BAP + 1.00 mg/I NAA, F = 4.00 mg/I BAP + 1.00 mg/I NAA and G = …

Functional Analysis Of B And C Class Floral Organ Genes In Spinach Demonstrates Their Role In Sexual Dimorphism, D Noah Sather, Maja Jovanovic, Edward M. Golenberg

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Evolution of unisexual flowers entails one of the most extreme changes in plant development. Cultivated spinach, Spinacia oleracea L., is uniquely suited for the study of unisexual flower development as it is dioecious and it achieves unisexually by the absence of organ development, rather than by organ abortion or suppression. Male staminate flowers lack fourth whorl primordia and female pistillate flowers lack third whorl primordia. Based on theoretical considerations, early inflorescence or floral organ identity genes would likely be directly involved in sex-determination in those species in which organ initiation rather than organ maturation is regulated. In this …

Molecular Characterization And Expression Analysis Of Putative Rpk1 And Putative Clv1 In Malaysian Indica Rice (Oryza Sativa L.) Cv.Mr219 And Malaysian Wild Rice (Oryza Rufipogon) Irgc105491., Law Yee Song

Student Works (2010-2019)

Two candidate yield-related genes, putative Receptor-like Protein Kinase 1 (putative RPK1) and putative CLAVATA1 Receptor Kinase (putative CLV1), were selected for molecular characterization and expression analysis. This was carried out using in four rice lines comprising the parents and two BC₂F₇ lines from a local rice breeding program, with Malaysian rice variety, Oryza sativa ssp. indica cv. MR219 as recurrent parent, and Oryza rufipogon (IRGC105491) as donor parent. Approximately 2.8 kb and 2.6 kb putative RPK1 cDNA nucleotide sequences were obtained from Oryza rufipogon and Oryza sativa ssp. indica cv. MR219 respectively. However, only 402 …

Characterization Of Microrna172 And Its Potential Target In Oil Palm (Elaeis Guineensis Jaq.), Fatemeh Mehrpooyan

Student Works (2010-2019)

Oil palm (Elaeis guineensis) is the world’s major perennial monocot crop and contributes highly to the economies of South East Asia. As the oil palm fruit is the source of the main economic output for this crop, floral development is a critical process related to oil palm productivity. miR172 has been shown to be an important regulator of the AP2 family transcription factors involved in floral timing in a number of plants and belongs to a group of highly conserved miRNA that can be identified based on sequence homology. Six oil palm miR172 paralogs, representing two distinct mature miR172 sequences, …

Phylogeographical Patterns Of Neobalanocarpus Heimii (Dipterocarpaceae) For The Evolutionary History And Chain Of Custody Certification., Tnah Lee Hong

Student Works (2010-2019)

Tectonic movement and climatic oscillations during the Cenozoic have had dramatic effect on the biota of the tropical rain forest. This study aims to reveal the phylogeography and evolutionary history of a Peninsular Malaysian endemic tropical timber, Neobalanocarpus heimii (Dipterocarpaceae), based on chloroplast DNA (cpDNA) variation. Fifteen haplotypes were identified from 10 intraspecific variable sites of five non-coding cpDNA regions: trnL intron, trnS-trnG spacer, trnG intron, trnK intron and psbK-trnS spacer. Two major genealogical cpDNA lineages of N. heimii were elucidated: a widespread southern and a northern region. The species is predicted to survive in multiple refugia during climatic oscillation: …

A Systematic Study Of Fagraea Sensu Lato And A Revision Of The Peninsular Malaysian Taxa., Sugumaran Manickam

Student Works (2010-2019)

systematic study of the Peninsular Malaysian species of Fagraea sensu lato was undertaken. This was done in the light of recent revisionary work done for Borneo that documented 20 new species and demonstrated that previous species concepts for Fagraea were too broad. Parallel to this the distinction of the subgeneric groups recognised as sections, i.e., Cyrtophyllum, Fagraea and Racemosae, were investigated with molecular phylogenetic methods. Representative taxa from the Malay Peninsula and Borneo augmented by sequences from other taxa in the same subtribe and tribe were used in the molecular analysis. Gene sequences from ITS, trnL–F (trnL intron + trnL–F …

Temperature Compensation Of Auxin Dependent Developmental Patterning, Nicholas J. Kaplinsky

Biology Faculty Works

The establishment of localized auxin gradients plays a central role in developmental patterning in plants. Auxin levels and responses have been shown to increase with temperature although developmental patterning is not affected. This suggests the existence of a homeostatic mechanism that ensures that patterning occurs normally over a range of temperatures. We recently described the cloning and characterization of BOBBER1 (BOB1), an Arabidopsis gene which encodes a small heat shock protein. BOB1 is required for the establishment of auxin gradients and for normal developmental patterning. BOB1 is also required for organismal thermotolerance and localizes to heat shock granules at elevated …

Bobber1 Is A Noncanonical Arabidopsis Small Heat Shock Protein Required For Both Development And Thermotolerance, Dahlia Erin Perez , '08, J. S. Hoyer, Ayanna Iman Johnson , '09, Zachary Ray Moody , '07, J. Lopez, Nicholas J. Kaplinsky

Biology Faculty Works

Plants have evolved a range of cellular responses to maintain developmental homeostasis and to survive over a range of temperatures. Here, we describe the in vivo and in vitro functions of BOBBER1 (BOB1), a NudC domain containing Arabidopsis (Arabidopsis thaliana) small heat shock protein. BOB1 is an essential gene required for the normal partitioning and patterning of the apical domain of the Arabidopsis embryo. Because BOB1 loss-of-function mutants are embryo lethal, we used a partial loss-of-function allele (bob1-3) to demonstrate that BOB1 is required for organismal thermotolerance and postembryonic development. Recombinant BOB1 protein functions as a molecular chaperone and prevents …

Partitioning The Apical Domain Of The Arabidopsis Embryo Requires The Bobber1 Nudc Domain Protein, R. J. Jurkuta, Nicholas J. Kaplinsky, Jennifer Elizabeth Spindel , '10, M. K. Barton

Biology Faculty Works

The apical domain of the embryo is partitioned into distinct regions that will give rise to the cotyledons and the shoot apical meristem. In this article, we describe a novel screen to identify Arabidopsis thaliana embryo arrest mutants that are defective in this partitioning, and we describe the phenotype of one such mutant, bobber1. bobber1 mutants arrest at the globular stage of development, they express the meristem-specific SHOOTMERISTEMLESS gene throughout the top half of the embryo, and they fail to express the AINTEGUMENTA transcript normally found in cotyledons. Thus, BOBBER1 is required to limit the extent of the meristem domain …

Letter From The Dean, Lalit Verma

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

No abstract provided.

Ecotypic Variation In Elymus Elymoides Subspecies Brevifolius Race C In The Northern Intermountain West, Matthew C. Parsons

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Little information is available on the extent of local adaptation for many native grass species. This is the case for squirreltail (Elymus section Sitanion), despite this group's prevalence and importance in rangeland restoration efforts. I evaluated 32 populations of E. elymoides ssp. brevifolius race C, a phylogenetic subdivision of bottlebrush squirreltail (E. elymoides) centered in the northern Intermountain West, for phenotypic variables and neutral genetic markers to measure their association with geographical origin. Phenotypic traits were measured in common field and greenhouse environments, and genetic diversity was assessed using Amplified Fragment Length Polymorphism. Three factors were extracted from the phenotypic …

Decoding The Protein Interaction Network - An Approach Integrating Biology And Math, Ryan Huang, Lingkun Gu, Qingxi J. Shen

Undergraduate Research Opportunities Program (UROP)

The WRKY super family is known to play a major role during the plant stress response and development. My project focuses on the protein-protein interaction of an Oryzasativa (rice) transcription factor, OsWRKY71 which functions as the repressor of gibberellins signaling pathway. Previous literature revealed that OsWRKY71 can interact with itself or OsWRKY51 to form dimmers by using bimolecular fluorescence complementation (BiFC). To confirm this result, we use yeast two-hybrid system. As our data showed, OsWRKY71 seems to suppress the reporter gene expression of the conventional yeast two-hybrid system, so we use a modified yeast two-hybrid, Mating-based Split Ubiquitin System (MbSUS). …

The Complete Plastid Genome Sequence Of Welwitschia Mirabilis: An Unusually Compact Plastome With Accelerated Divergence Rates, Skip R. Mccoy, Jennifer V. Kuehl, Jeffrey L. Boore, Linda A. Raubeson

All Faculty Scholarship for the College of the Sciences

Background

Welwitschia mirabilis is the only extant member of the family Welwitschiaceae, one of three lineages of gnetophytes, an enigmatic group of gymnosperms variously allied with flowering plants or conifers. Limited sequence data and rapid divergence rates have precluded consensus on the evolutionary placement of gnetophytes based on molecular characters. Here we report on the first complete gnetophyte chloroplast genome sequence, from Welwitschia mirabilis, as well as analyses on divergence rates of protein-coding genes, comparisons of gene content and order, and phylogenetic implications.

Results

The chloroplast genome of Welwitschia mirabilis [GenBank: EU342371] is comprised of 119,726 base pairs and exhibits …

2c Dna Content Values In Amaranthus (Amaranthaceae) [Abstract], Donald B. Pratt, Shalini N. Jhangiani, Robert J. Wiggers

Faculty Publications

No abstract provided.

Development And Characterization Of Microsatellite Markers For The Grain Amaranths [Abstract], Melanie A. Mallory, Rozaura V. Hall, Andrea R. Mcnabb, Donald B. Pratt, Eric N. Jellen, Peter J. Maughan

Faculty Publications

No abstract provided.

Whole-Plant Mineral Partitioning Throughout The Life Cycle In Arabidopsis Thaliana Ecotypes Columbia, Landsberg Erecta, Cape Verde Islands, And The Mutant Line Ysl1ysl3, Brian M. Waters, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

Minimal information exists on whole-plant dynamics of mineral flow through Arabidopsis thaliana or on the source tissues responsible for mineral export to developing seeds. Understanding these phenomena in a model plant could help in the development of nutritionally enhanced crop cultivars. A whole-plant partitioning study, using sequential harvests, was conducted to characterize growth and mineral concentrations and contents of rosettes, cauline leaves, stems, immature fruit, mature fruit hulls, and seeds of three WT lines (Col-0, Ler, and Cvi) and one mutant line (Col-0::ysl1ysl3). Shoot mineral content increased throughout the life cycle for all minerals, although tissue-specific …

Australian Temperate Strawberry Breeding Program (Albany Western Australia) Screening Of Advance And New Selections For Albany Western Australia - 2006/2007, Shane Trainer, Dennis Phillips, Hal

Horticulture research reports

Fourteen intermediate day neutral selections from the Australian temperate breeding program were compared in a June trial planting on a commercial property in the Albany region. Intermediate selections were derived from crosses made between 1999 and 2002. Three advanced 'short day' selections were compared for yield, both as trial plots (10 plants) and as large plot demonstrations of up to 500 plants. Accompanying these selections, six named day neutral, three short day and four Queensland cultivars of different runner origins were compared. Camarosa, Selva and Diamante were included as commercial controls.

Day neutral selections 02-083-24 and 02-83-311 were potentially superior …

Comparative Chloroplast Genomics: Analyses Including New Sequences From The Angiosperms Nuphar Advena And Ranunculus Macranthus, Linda A. Raubeson, Rhiannon Peery, Timothy W. Chumley, Chris Dziubek, H. Matthew Fourcade, Jeffrey L. Boore, Robert K. Jansen

All Faculty Scholarship for the College of the Sciences

Background

The number of completely sequenced plastid genomes available is growing rapidly. This array of sequences presents new opportunities to perform comparative analyses. In comparative studies, it is often useful to compare across wide phylogenetic spans and, within angiosperms, to include representatives from basally diverging lineages such as the genomes reported here: Nuphar advena (from a basal-most lineage) and Ranunculus macranthus (a basal eudicot). We report these two new plastid genome sequences and make comparisons (within angiosperms, seed plants, or all photosynthetic lineages) to evaluate features such as the status of ycf15 and ycf68 as protein coding genes, the distribution …

Assessment Of Genetic Diversity In The Usda And Cip-Fao International Nursery Collections Of Quinoa (Chenopodium Quinoa Willd.) Using Microsatellite Markers [Abstract], S. A. Christensen, Donald B. Pratt, C. Pratt, P. T. Nelson, M. R. Stevens, Eric N. Jellen, C. E. Coleman, D. J. Fairbanks, A. Bonifacio, Peter J. Maughan

Faculty Publications

No abstract provided.