Molecular Biology Commons^™

Increasing The Resilience Of Plant Immunity To A Warming Climate, Jong Hum Kim, Christian Castroverde, Shuai Huang, Chao Li, Richard Hilleary, Adam Seroka, Reza Sohrabi, Diana Medina-Yerena, Bethany Huot, Jie Wang, Sharon Marr, Mary Wildermuth, Tao Chen, John Macmicking, Sheng Yang He

Biology Faculty Publications

Extreme weather conditions associated with climate change affect many aspects of plant and animal life, including the response to infectious diseases. Production of salicylic acid (SA), a central plant defence hormone, is particularly vulnerable to suppression by short periods of hot weather above the normal plant growth temperature range via an unknown mechanism. Here we show that suppression of SA production in Arabidopsis thaliana at 28 °C is independent of PHYTOCHROME B (phyB) and EARLY FLOWERING 3 (ELF3), which regulate thermo-responsive plant growth and development. Instead, we found that formation of GUANYLATE BINDING PROTEIN-LIKE 3 (GBPL3) defence-activated biomolecular condensates (GDACs) …

Salicylic Acid And N-Hydroxypipecolic Acid At The Fulcrum Of The Plant Immunity-Growth Equilibrium, Alyssa Shields, Vanessa Shivnauth, Christian Danve M. Castroverde

Biology Faculty Publications

Salicylic acid (SA) and N-hydroxypipecolic acid (NHP) are two central plant immune signals involved in both resistance at local sites of pathogen infection (basal resistance) and at distal uninfected sites after primary infection (systemic acquired resistance). Major discoveries and advances have led to deeper understanding of their biosynthesis and signaling during plant defense responses. In addition to their well-defined roles in immunity, recent research is emerging on their direct mechanistic impacts on plant growth and development. In this review, we will first provide an overview of how SA and NHP regulate local and systemic immune responses in plants. We …

Plants, Pipettes And Pcr, Elizabeth Vierling

Science and Engineering Saturday Seminars

Plants are amazing organisms that provide us with food, building materials, the pleasure of gardens, as well as providing the foundation of critical world ecosystems. Although they may look like they are just stuck in one place and doing not more than growing, they have many, many complex ways in which they respond to the environment. The goal of this STEM Ed session will be to discuss ways that plants can respond to the environment with hands on exercises and exploration of possible classroom activities. Participants will engage in state-of-the art methods of testing plant DNA composition using the polymerase …

Salicylic Acid: A Key Regulator Of Redox Signalling 1 And Plant Immunity, Mohd Saleem, Qazi Fariddudin, Christian Castroverde

Biology Faculty Publications

In plants, the reactive oxygen species (ROS) formed during normal conditions are essential in regulating several processes, like stomatal physiology, pathogen immunity and developmental signaling. However, biotic and abiotic stresses can cause ROS over-accumulation leading to oxidative stress. Therefore, a suitable equilibrium is vital for redox homeostasis in plants, and there have been major advances in this research arena. Salicylic acid (SA) is known as a chief regulator of ROS; however, the underlying mechanisms remain largely unexplored. SA plays an important role in establishing the hypersensitive response (HR) and systemic acquired resistance (SAR). This is underpinned by a robust and …

Mutations In Several Auxin Biosynthesis Genes And Their Effects On Plant Phenotypes In Arabidopsis, Gabriela Hernandez, Lauren Huebner, Bethany Karlin Zolman

Undergraduate Research Symposium

Auxins are important hormones in plants that regulate growth and development. Disruptions in the auxin biosynthesis pathway result in morphological changes in phenotypes in the model plant Arabidopsis thaliana, including differences in root and leaf formation. Mutations in the Tryptophan Aminotransferase of Arabidopsis (TAA1) and YUCCA (YUC4) genes interfere with the plant's ability to synthesize Indole-3-acetic acid (IAA), the primary auxin involved in plant development. IBR1 and IBR3 act in the multistep conversion of indole-3-butyric acid (IBA) to IAA. ILL2, IAR3, and ILR1 hydrolyze IAA-amino acid conjugates into free IAA. The goal of …

Temperature Regulation Of Plant Hormone Signaling During Stress And Development, Christian Castroverde, Damaris Dina

Biology Faculty Publications

Global climate change has broad-ranging impacts on the natural environment and human civilization. Increasing average temperatures along with more frequent heat waves collectively have negative effects on cultivated crops in agricultural sectors and wild species in natural ecosystems. These aberrantly hot temperatures, together with cold stress, represent major abiotic stresses to plants. Molecular and physiological responses to high and low temperatures are intricately linked to the regulation of important plant hormones. In this review, we shall highlight our current understanding of how changing temperatures regulate plant hormone pathways during immunity, stress responses and development. This article will present an overview …

Lighting The Way: Recent Insights Into The Structure And Regulation Of Phototropin Blue Light Receptors, Jaynee E. Hart, Kevin H. Gardner

Publications and Research

The phototropins (phots) are light-activated kinases that are critical for plant physiology and the many diverse optogenetic tools that they have inspired. Phototropins combine two bluelight- sensing Light–Oxygen–Voltage (LOV) domains (LOV1 and LOV2) and a C-terminal serine/threonine kinase domain, using the LOV domains to control the catalytic activity of the kinase. While much is known about the structure and photochemistry of the light-perceiving LOV domains, particularly in how activation of the LOV2 domain triggers the unfolding of alpha helices that communicate the light signal to the kinase domain, many questions about phot structure and mechanism remain. Recent studies have made …

An Analysis Of Crispr-Cas Gene Editing In Agriculture, Ashley Laliberte

Honors Scholar Theses

The CRISPR-Cas system is a promising form of gene editing, especially for the agriculture industry. The ability to make single-nucleotide edits within a gene of interest, without the need to introduce foreign DNA, is a powerful tool for designing healthier and more efficient crops and food animals. This system provides opportunity for increased nutritional value, decreased food waste, and more economically and environmentally sustainable food production. Though this biotechnology is facing mechanistic limitations due to off-target effects and inefficient homology-directed repair, vast improvements have already been made to improve its efficacy. The CRISPR-Cas system is already the most advanced form …

The Effects Of Gibberellic Acid And Auxin Hormones On Heliotropism In Sunflowers, Brandon Bernardo, Hagop S. Atamian

Student Scholar Symposium Abstracts and Posters

Sunflowers are one of many different plant species that are able to track and face the sun in order to optimize the amount of sunlight they are exposed to. This process of orienting towards the sun is called Heliotropism. Sunflowers are able to effectively orient themselves towards the sun because the growth rate on the East and West side of the stem alternates depending on the time of day. At dawn, the East facing stem will grow at a faster rate than the West facing side, resulting in the flower orienting towards the West. This alternating and uneven growth is …

Gamete Nuclear Migration In Animals And Plants, Umma Fatema, Mohammad F. Ali, Zheng Hu, Anthony J. Clark, Tomokazu Kawashima

Plant and Soil Sciences Faculty Publications

The migration of male and female gamete nuclei to each other in the fertilized egg is a prerequisite for the blending of genetic materials and the initiation of the next generation. Interestingly, many differences have been found in the mechanism of gamete nuclear movement among animals and plants. Female to male gamete nuclear movement in animals and brown algae relies on microtubules. By contrast, in flowering plants, the male gamete nucleus is carried to the female gamete nucleus by the filamentous actin cytoskeleton. As techniques have developed from light, electron, fluorescence, immunofluorescence, and confocal microscopy to live-cell time-lapse imaging using …

Arabinose Substitution Effect On Xylan Rigidity And Self-Aggregation, Utsab Shrestha, Sydney Smith, Sai Venkatesh Pingali, Hui Yang, Mai Zahran, Llyod Breunig, Liza Wilson, Daniel Cosgrove, Hugh O'Neill, Loukas Petridis

Publications and Research

Substituted xylans play an important role in the structure and mechanics of the primary cell wall of plants. Arabinoxylans (AX) consist of a xylose backbone substituted with arabinose, while glucuronoarabinoxylans (GAX) also contain glucuronic acid substitutions and ferulic acid esters on some of the arabinoses. We provide a molecular-level description on the dependence of xylan conformational, selfaggregation properties and binding to cellulose on the degree of arabinose substitution. Molecular dynamics simulations reveal fully solubilized xylans with a low degree of arabinose substitution (lsAX) to be stiffer than their highly substituted (hsAX) counterparts. Small-angle neutron scattering experiments indicate that both wild-type …

Evaluation Of Volatile Metabolites Emitted In-Vivo From Cold-Hardy Grapes During Ripening Using Spme And Gc-Ms: A Proof-Of-Concept, Somchai Rice, Devin L. Maurer, Anne Fennell, Murlidhar Dharmadhikari, Jacek A. Koziel

Agronomy, Horticulture and Plant Science Faculty Publications

In this research, we propose a novel concept for a non-destructive evaluation of volatiles emitted from ripening grapes using solid-phase microextraction (SPME). This concept is novel to both the traditional vinifera grapes and the cold-hardy cultivars. Our sample models are cold-hardy varieties in the upper Midwest for which many of the basic multiyear grape flavor and wine style data is needed. Non-destructive sampling included a use of polyvinyl fluoride (PVF) chambers temporarily enclosing and concentrating volatiles emitted by a whole cluster of grapes on a vine and a modified 2 mL glass vial for a vacuum-assisted sampling of volatiles from …

Agronomic And Chemical Performance Of Field-Grown Tobacco Engineered For Triterpene And Methylated Triterpene Metabolism, Zuodong Jiang, Chase Kempinski, Santosh Kumar, Scott Kinison, Kristin Linscott, Eric Nybo, Sarah Janze, Constance Wood, Joseph Chappell

Pharmaceutical Sciences Faculty Publications

Squalene is a linear intermediate to nearly all classes of triterpenes and sterols and is itself highly valued for its use in wide range of industrial applications. Another unique linear triterpene is botryococcene and its methylated derivatives generated by the alga Botryococcus braunii race B, which are progenitors to fossil fuel deposits. Production of these linear triterpenes was previously engineered into transgenic tobacco by introducing the key steps of triterpene metabolism into the particular subcellular compartments. In this study, the agronomic characteristics (height, biomass accumulation, leaf area), the photosynthetic capacity (photosynthesis rate, conductance, internal CO₂ levels) and triterpene content …

Cloning And Characterization Of A Pyrethroid Pesticide Decomposing Esterase Gene, Est3385, From Rhodopseudomonas Palustris Psb-S, Xiangwen Luo, Deyong Zhang, Xuguo Zhou, Jiao Du, Songbai Zhang, Yong Liu

Entomology Faculty Publications

Full length open reading frame of pyrethroid detoxification gene, Est3385, contains 963 nucleotides. This gene was identified and cloned based on the genome sequence of Rhodopseudomonas palustris PSB-S available at the GneBank. The predicted amino acid sequence of Est3385 shared moderate identities (30–46%) with the known homologous esterases. Phylogenetic analysis revealed that Est3385 was a member in the esterase family I. Recombinant Est3385 was heterologous expressed in E. coli, purified and characterized for its substrate specificity, kinetics and stability under various conditions. The optimal temperature and pH for Est3385 were 35 °C and 6.0, respectively. This enzyme could …

Organ-Specific Transcriptome Profiling Of Metabolic And Pigment Biosynthesis Pathways In The Floral Ornamental Progenitor Species Anthurium Amnicola Dressler, Jon Suzuki, Teresita D. Amore, Bernarda Calla, Nathan A. Palmer, Erin D. Scully, Scott E. Sattler, Gautam Sarath, Joanne S. Lichty, Roxanna Y. Myers, Lisa M. Keith, Tracie K. Matsumoto, Scott M. Geib

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Anthurium amnicola Dressler possesses a number of desirable and novel ornamental traits such as a purple-colored upright spathe, profuse flowering, and floral scent, some of which have been introgressed into modern Anthurium cultivars. As a first step in identifying genes associated with these traits, the transcriptome from root, leaf, spathe, and spadix from an accession of A. amnicola was assembled, resulting in 28,019 putative transcripts representing 19,458 unigenes. Genes involved in pigmentation, including those for the metabolism of chlorophyll and the biosynthesis of carotenoids, phenylpropanoids, and flavonoids were identified. The expression levels of one MYB transcription factor was highly …

The Mirnaome Of Catharanthus Roseus: Identification, Expression Analysis, And Potential Roles Of Micrornas In Regulation Of Terpenoid Indole Alkaloid Biosynthesis, Ethan M. Shen, Sanjay Kumar Singh, Jayadri S. Ghosh, Barunava Patra, Priyanka Paul, Ling Yuan, Sitakanta Pattanaik

Plant and Soil Sciences Faculty Publications

MicroRNAs (miRNAs) regulate numerous crucial biological processes in plants. However, information is limited on their involvement in the biosynthesis of specialized metabolites in plants, including Catharanthus roseus that produces a number of pharmaceutically valuable, bioactive terpenoid indole alkaloids (TIAs). Using small RNA-sequencing, we identified 181 conserved and 173 novel miRNAs (cro-miRNAs) in C. roseus seedlings. Genome-wide expression analysis revealed that a set of cro-miRNAs are differentially regulated in response to methyl jasmonate (MeJA). In silico target prediction identified 519 potential cro-miRNA targets that include several auxin response factors (ARFs). The presence of cleaved transcripts of miRNA-targeted ARFs in C. roseus …

Screening Of Plants For Antibacterial Properties: Growth Inhibition Of Staphylococcus Aureus By Artemisia Tridentata, Steven Ross Eichelbaum

FIU Electronic Theses and Dissertations

Drug-resistant pathogenic and opportunistic bacteria are increasing in occurrence and prevalence, and pose a dangerous threat to human health. In the search for novel antibiotics with which to combat this threat, plants, specifically those used in traditional medicine with ascribed antibacterial properties, offer a promising and potentially vast source of such therapeutic compounds. The purpose of this study was therefore to screen chemical extracts created from various plant species for antibacterial properties versus pathogenic bacterial species. In the course of these antibacterial assays, we successfully identified a methanol extract derived from Artemisia tridentata tridentata plant material as capable of inhibiting …

Countercurrent Chromatography Fractions Of Plant Extracts With Anti-Tuberculosis Activity, Douglas Armstrong, Nathan C. Krause, Drew Frey, J. Brent Friesen, Baojie Wan, Jordan Gunn, Scott Franzblau

Faculty Scholarship – Chemistry

Samples of numerous plant species were received from the southwestern part of the USA, from Richard Spjut, and plant samples were collected here in Illinois. All were extracted with typical solvents, giving crude residues, some of which were subjected to chromatographic methods. Some of the crude residues and some of the fractions were tested for anti-tuberculosis activity and/or antibacterial activity.

In a general way, bioactive natural products are dealt with very well by Liang & Fang. More specifically, the southwestern part of the United States has a large variety of indigenous plants many of which have not been investigated for …

Trimethylated Lysine 4 At Histone 3 Shows The Same Circadian Rhythm At Promoters Of Diversely-Expressed Genes In Chlamydomonas Reinhardtii, Robyn M. Wilson

Masters Theses & Specialist Projects

Circadian clocks are biochemical mechanisms that allow eukaryotic and some prokaryotic organisms to coordinate their physiology with daily environmental changes. It enables organisms to increase their fitness by taking advantage of beneficial environmental conditions while also avoiding or restricting certain sensitive processes during harsh conditions. Similarly, post-translational histone modifications allow eukaryotic organisms to regulate gene expression in response to environmental or developmental factors. Some post-translational modifications of histones are associated with active transcription while others are associated with repressed transcription depending upon the location, type and degree of modification. Trimethylation of lysine 4 on the N-terminal tail of histone H3 …

The Role Of Cellulose Synthase-Like D Genes In Tip Growth Of Physcomitrella Patens, Erin E. Killeavy, Arielle Chaves, Alison Roberts

Senior Honors Projects

Physcomitrella patens is a non-vascular plant with a relatively small genome and is amongst the few eukaryotic organisms that have a high rate of homologous recombination. This is valuable in biological research because it allows for targeted genetic modification of the organism. In vascular plants like Arabidopsis thaliana, a model organism, Cellulose Synthase-like D (CSLD) genes have been discovered to be important in tip growth. This type of growth is observed in the pollen tubes and root hairs of these plant types. The CSLD genes in Arabidopsis were found to play a crucial role in the growth of …

Anti-Tb And Antibacterial Activities Of Natural Products Extracts, Douglas Armstrong, Nathan Krause, Drew Frey

Faculty Scholarship – Chemistry

Samples of numerous plant species were received from the southwestern part of the USA from Richard Spjut, and plant samples were collected here in Illinois. All were extracted with typical solvents, giving crude residues, some of which were subjected to counter-current or flash chromatographic methods. Some of the crude extracts and chromatographic fractions had anti-tuberculosis and/or antibacterial activity.

In a general way, bioactive natural products are dealt with very well by Liang & Fang, 2006. More specifically, the southwestern part of the United States has a large variety of indigenous plants, many of which have not been investigated for their …

Acetobixan, An Inhibitor Of Cellulose Synthesis Identified By Microbial Bioprospecting, Ye Xia, Lei Lei, Chad Brabham, Jozsef Stork, James R. Strickland, Adam Ladak, Ying Gu, Ian Wallace, Seth Debolt

Horticulture Faculty Publications

In plants, cellulose biosynthesis is an essential process for anisotropic growth and therefore is an ideal target for inhibition. Based on the documented utility of small-molecule inhibitors to dissect complex cellular processes we identified a cellulose biosynthesis inhibitor (CBI), named acetobixan, by bio-prospecting among compounds secreted by endophytic microorganisms. Acetobixan was identified using a drug-gene interaction screen to sift through hundreds of endophytic microbial secretions for one that caused synergistic reduction in root expansion of the leaky AtcesA6prc1-1 mutant. We then mined this microbial secretion for compounds that were differentially abundant compared with Bacilli that failed to mimic CBI action …

Reverse Genetic Analysis Of A Cysteine Protease-Encoding Gene (Rd19a) Of Arabidopsis Thaliana In Relation To The Mechanism Of Resistance To The Piercing/Sucking Insect Myzus Persicae, Siobhan A. Cusack

Honors College

A recent study in Solanum bulbocastanum (a wild relative of the cultivated potato) aiming to identify potential genes involved in aphid and pathogen resistance mechanisms found that a homolog of the Arabidopsis thaliana cysteine protease gene RD19a is upregulated during aphid infestation. RD19a is upregulated in response to abiotic stresses such as drought and high salinity, and rd19a mutants show increased susceptibility to bacterial infection. In this study, Arabidopsis rd19a mutants and wild-type plants were subjected to aphid feeding to observe and compare the molecular, physiological and phenotypic responses. The aim was to further establish the proof of concept regarding …

Host Pathogen Interactions: Is Arabidopsis Thaliana Remembered By Its Nemesis Pseudomonas Syringae?, Daniel Z. Kreiser

Lawrence University Honors Projects

Plants contain innate immune systems that deter pathogen infection. Pattern recognition receptors bind microbe-associated molecular patterns (MAMPs), triggering immunity. MAMPs are proteins exclusive to pathogens that are typically indispensable for their survival. For this reason, MAMPs cannot be mutated or removed without causing pathogen death. However, this does not necessitate constitutive expression of MAMPs. In this study, the MAMP response of Arabidopsis thaliana was utilized to determine differential detection of MAMPs expressed by Pseudomonas syringe pv. tomato DC3000 when pretreated with A. thaliana. Results demonstrated that more MAMPs are detected when P. syringae had previously encountered A. thaliana, …

Mutation And Complementation Of A Cellulose Synthase (Cesa) Gene, Ahmed Y. El-Araby

Senior Honors Projects

Cellulose is a carbohydrate polymer that is composed of repeating glucose subunits. Being the most abundant organic compound in the biosphere and comprising a large percentage of all plant biomass, cellulose is extremely plentiful and has a significant role in nature. Cellulose is present in plant cell walls, in commercial products such as those made from wood or cotton, and is of interest to the biofuel industry as a potential alternative fuel source. Although indigestible by humans, cellulose is nutritionally valuable, serving as a dietary fiber. Because of its ubiquity and importance in many areas, studying cellulose will prove to …

Template-Based Structure Prediction And Classification Of Transcription Factors In Arabidopsis Thaliana, Tao Lu, Yuedong Yang, Bo Yao, Song Liu, Yaoqi Zhou, Chi Zhang

School of Biological Sciences: Faculty Publications

Transcription factors (TFs) play important roles in plants. However, there is no systematic study of their structures and functions of most TFs in plants. Here, we performed template-based structure prediction for all TFs in Arabidopsis thaliana, with their full-length sequences as well as C-terminal and N-terminal regions. A total of 2,918 model structures were obtained with a high confidence score. We find that TF families employ only a smaller number of templates for DNA-binding domains (DBD) but a diverse number of templates for transcription regulatory domains (TRD). Although TF families are classified according to DBD, their sizes have a significant …

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 …

Arctic Mustard Flower Color Polymorphism Controlled By Petal-Specific Downregulation At The Threshold Of The Anthocyanin Biosynthetic Pathway, Cynthia A. Dick, Jason Buenrostro, Timothy Butler, Matthew L. Carlson, Daniel J. Kliebenstein, Justen B. Whittall

Biology

Intra- and interspecific variation in flower color is a hallmark of angiosperm diversity. The evolutionary forces underlying the variety of flower colors can be nearly as diverse as the colors themselves. In addition to pollinator preferences, non-pollinator agents of selection can have a major influence on the evolution of flower color polymorphisms, especially when the pigments in question are also expressed in vegetative tissues. In such cases, identifying the target(s) of selection starts with determining the biochemical and molecular basis for the flower color variation and examining any pleiotropic effects manifested in vegetative tissues. Herein, we describe a widespread purple-white …

Ethylene Receptors Function As Components Of High-Molecular-Mass Protein Complexes In Arabidopsis, Yi-Feng Chen, Zhiyong Gao, Robert J. Kerriss Iii, Wuyi Wang, Brad M. Binder, G. Eric Schaller

Faculty Publications and Other Works -- Biochemistry, Cellular and Molecular Biology

The gaseous plant hormone ethylene is perceived in Arabidopsis thaliana by a five-member receptor family composed of ETR1, ERS1, ETR2, ERS2, and EIN4. Methodology/Principal Findings

Gel-filtration analysis of ethylene receptors solubilized from Arabidopsis membranes demonstrates that the receptors exist as components of high-molecular-mass protein complexes. The ERS1 protein complex exhibits an ethylene-induced change in size consistent with ligand-mediated nucleation of protein-protein interactions. Deletion analysis supports the participation of multiple domains from ETR1 in formation of the protein complex, and also demonstrates that targeting to and retention of ETR1 at the endoplasmic reticulum only requires the first 147 amino acids of …

Functional Analysis Of Receptor-Like Kinases In Pollen-Pistil Interactions In Arabidopsis Thaliana, Mini Aggarwal

Masters Theses 1911 - February 2014

Rac/Rop GTPases are molecular switches in plants that control the growth of polarized cells such as pollen tubes and root hairs, differentiation, development, actin dynamics, production of reactive oxygen species (ROS) and disease resistance. These small GTPases are activated by guanine nucleotide exchange factors (GEFs) that replace GDP for GTP and are referred to as RopGEFs in plants. To identify upstream components of the RopGEF regulated signaling pathways, GEF1 from Arabidopsis thaliana was used as a bait to screen a seedling cDNA library in a yeast two-hybrid system. This yielded members of a small family of the Catharanthus roseus Receptor-like …