Genetics and Genomics Commons^™

With Love, ; An Interdisciplinary And Intersectional Look At Why Creativity Is Essential, Theo Starr Gardner

Whittier Scholars Program

My Whittier Scholars Program self-designed major, Teaching Creativity, is a mixture of Art, Literature, and Education classes. My research and praxis classes have been focused on the ‘how?’s and 'why?’s of creativity, so it felt only right that my project should be a constructivist, generative project. The project I have been working on throughout my time at Whittier, and that has just fully come to fruition on April 11th, 2024, was a solo art gallery/open mic event entitled ‘With Love,’. With Love, was conceptually inspired by the research I’ve conducted on creativity and creative arts education over the past few …

Oystershell Scale (Hemiptera: Diaspididae) Population Growth, Spread, And Phenology On Aspen In Arizona, Usa, Connor D. Crouch, Richard W. Hofstetter, Amanda M. Grady, Nylah N.S. Edwards, Kristen M. Waring

Aspen Bibliography

Oystershell scale (OSS; Lepidosaphes ulmi L.) is an invasive insect that threatens sustainability of aspen (Populus tremuloides Michx.) in the southwestern United States. OSS invasions have created challenges for land managers tasked with maintaining healthy aspen ecosystems for the ecological, economic, and aesthetic benefits they provide. Active management is required to suppress OSS populations and mitigate damage to aspen ecosystems, but before management strategies can be implemented, critical knowledge gaps about OSS biology and ecology must be filled. This study sought to fill these gaps by addressing 3 questions: (i) What is the short-term rate of aspen mortality in …

Pile Burning After Conifer Removal From Aspen Stands Affects Tree Mortality, Regeneration, And Understory Recovery, John-Pascal Berrill, Christa M. Dagley, Yoon G. Kim, J. Morgan Varner

Aspen Bibliography

Quaking aspen (Populus tremuloides Michx.) stands throughout the western United States provide valuable ecosystem services but can be lost via succession from aspen to conifer. Forest managers are cutting conifers, but disposal of cut wood can be challenging in remote or sensitive areas. Piling and burning is being tested within aspen stands but ecosystem responses to this treatment are understudied. We assessed aspen tree mortality, tree regeneration, and understory vegetation after forest restoration thinning followed by pile burning in seven aspen-conifer stands around Lake Tahoe, California and Nevada, USA. Pile burning was conducted after cut wood had dried (1.5–7.5 …

Aspen And Spruce Densities Affect Tree Size, Future Stand Volume, And Aboveground Carbon Following Precommercial Thinning, Philip G. Comeau, Mike Bokalo

Aspen Bibliography

Data collected over a 30-year period from an experiment replicated across 21 locations in western Canada are used to explore the effects of precommercial thinning of trembling aspen to a range of densities in combination with three initial white spruce densities on tree growth and stand dynamics. Increasing differentiation amongst the 15 treatments was observed with age after thinning for both spruce and aspen responses. Spruce height and diameter declined with increasing aspen density. At age 10 spruce diameter with no aspen was 1.5× that of spruce in unthinned while it was 2.6× that of spruce in unthinned at age …

Tracing The Maternal Line In Glacial-Interglacial Migrations Of Populus Tremuloides: Finding Trees For Future Sustainable Forests By Searching In The Past, Luke R. Tembrock, Frida A. Zink, Guozhe Zhang, Andrea Schuhmann, Cuihua Gu, Zhiqiang Wu

Aspen Bibliography

Maintaining and planting sustainable forests is fundamental in perpetuating the essential functions of these ecosystems. A central aspect of managing forests for future resilience is the consideration of past migration and evolution of trees using genetic and genomic data to ensure that functionally appropriate diversity is conserved and utilized. In our study, we generated and compared genetic and genomic data from the plastome to better understand phylogeography and molecular evolution in the tree species Populus tremuloides (aspen). With these analyses, we found evidence of divergence and migration between northern and southern sites. Additionally, evidence of deep incomplete plastome sorting across …

Soybean Genetics, Genomics, And Breeding For Improving Nutritional Value And Reducing Antinutritional Traits In Food And Feed, William M. Singer, Yi-Chen Lee, Zachary Shea, Caio Canella Vieira, Dongho Lee, Xiaoying Li, Mia Cunicelli, Shaila S. Kadam, Mohammad Amir Waseem Khan, Grover Shannon, M. A. Rouf Mian, Henry T. Nguyen, Bo Zhang

Agriculture Faculty Publications

Soybean [Glycine max(L.) Merr.] is a globally important crop due to its valuable seed composition, versatile feed, food, and industrial end-uses, and consistent genetic gain. Successful genetic gain in soybean has led to widespread adaptation and increased value for producers, processors, and consumers. Specific focus on the nutritional quality of soybean seed composition for food and feed has further elucidated genetic knowledge and bolstered breeding progress. Seed components are historical and current targets for soybean breeders seeking to improve nutritional quality of soybean. This article reviews genetic and genomic foundations for improvement of nutritionally important traits, such as protein and …

Potential Hybridization Among Two Species Of California Salvia, Ellie Morrison, Bryan Drew

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Hybridization among plants is fairly common, particularly in instances where closely related species are sympatric. One example of a group in which hybridization has been detected is the genus Salvia (Lamiaceae; mint family). Salvia is a diverse genus consisting of about 1,000 species and is defined primarily by having only two stamens, each with their anther sacs separated by elongated connective tissue. The genus has diversity centers around the world, including Southwest Asia and the Mediterranean region, Mexico/Central America, northern and central South America, and temperate East Asia. The genus also has a smaller species radiation of 19 species in …

Multiple Light Signaling Pathways Control Solar Tracking In Sunflowers, Christopher J. Brooks, Hagop S. Atamian, Stacey L. Harmer

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Sunflowers are famous for their ability to track the sun throughout the day and then reorient at night to face east the following morning. This occurs by differential growth patterns, with the east sides of stems growing more during the day and the west sides of stems growing more at night. This process, termed heliotropism, is generally believed to be a specialized form of phototropism; however, the underlying mechanism is unknown. To better understand heliotropism, we compared gene expression patterns in plants undergoing phototropism in a controlled environment and in plants initiating and maintaining heliotropic growth in the field. We …

Forest Composition Change And Biophysical Climate Feedbacks Across Boreal North America, Richard Massey, Brendan M. Rogers, Logan T. Berner, Sol Cooperdock, Michelle C. Mack, Xanthe J. Walker, Scott J. Goetz

Aspen Bibliography

Deciduous tree cover is expected to increase in North American boreal forests with climate warming and wildfire. This shift in composition has the potential to generate biophysical cooling via increased land surface albedo. Here we use Landsat-derived maps of continuous tree canopy cover and deciduous fractional composition to assess albedo change over recent decades. We find, on average, a small net decrease in deciduous fraction from 2000 to 2015 across boreal North America and from 1992 to 2015 across Canada, despite extensive fire disturbance that locally increased deciduous vegetation. We further find near-neutral net biophysical change in radiative forcing associated …

Genomic And Transcriptomic Analyses Reveal Polygenic Architecture For Ecologically Important Traits In Aspen (Populus Tremuloides Michx.), Jennifer F. L. Riehl, Christopher T. Cole, Clay J. Marrow, Hilary L. Barker, Carolina Bernhardsson, Kennedy Rubert-Nason, Pär K. Ingvarsson, Richard L. Lindroth

Aspen Bibliography

Intraspecific genetic variations in foundation species such as aspen (Populus tremuloides Michx.) shapes their impact on forest structure and function. Identifying genes underlying ecologically important traits is key to understanding that impact. Previous studies, using single-locus genome-wide association (GWA) analyses to identify candidate genes, have identified fewer genes than anticipated for highly heritable quantitative traits. Mounting evidence suggests that polygenic control of quantitative traits is largely responsible for this "missing heritability" phenomenon. Our research characterized the genetic architecture of 30 ecologically important traits using a common garden of aspect through genomic and transcriptomic analyses. A multilocus association model revealed …

Bison Alter The Northern Yellowstone Ecosystem By Breaking Aspen Saplings, Luke E. Painter, Robert L. Beschta, William J. Ripple

Aspen Bibliography

The American bison (Bison bison) is a species that strongly interacts with its environment, yet the effects of this large herbivore on quaking aspen (Populus tremuloides) have received little study. We documented bison breaking the stems of aspen saplings (young aspen > 2 m tall and ≤ 5 cm in diameter at breast height) and examined the extent of this effect in northern Yellowstone National Park (YNP). Low densities of Rocky Mountain elk (Cervus canadensis) after about 2004 created conditions conducive for new aspen recruitment in YNP's northern ungulate winter range (northern range). We sampled …

Isolation Of Arabidopsis Thaliana Plants Homozygous For An Insertional Inactivation Mutation Within Atprp4., Sydney Raitz, Timothy D. Trott

Research in Biology

The AtPRP4 gene in Arabidopsis thaliana has been shown to function in several specific parts of the plant’s cell wall. It is shown to be expressed in the seeds, radicles, roots, leaves, inflorescences, and embryos of Arabidopsis thaliana. These patterns have suggested unique functions for ATPRP4 in determining cell-type-specific wall structure during the development of a plant as well as contributing to defense reactions against physical damage to the plant and pathogen infection within the plant. In this study, a simple DNA prep was performed on the true leaves of Arabidopsis thaliana. Subsequent PCR reactions were performed using …

The Impact Of Soil Disturbance On Soil Bacterial Community Composition, Marie A. Rodriguez, Mark Peach, Timothy D. Trott

Research in Biology

Soil bacterial communities are an important part of terrestrial ecosystems due to their roles in biogeochemical cycling processes. Consequently, understanding how soil disturbance affects the soil bacterial diversity is vital to understanding the entire ecosystem. In this study we examined the effects of soil disturbance (by mining) on the soil bacterial community composition from three sites on Bauxite Ridge in Southeast Tennessee compared to three undisturbed sites in a nearby location. The soil bacterial community was analyzed by 16S rDNA amplicon sequencing of total DNA extracted from the soil samples collected from each of the six sites. Characterization of the …

Variable Synchrony In Insect Outbreak Cycling Across A Forest Landscape Gradient: Multi-Scale Evidence From Trembling Aspen In Alberta, Barry J. Cooke, Jens Roland

Aspen Bibliography

Using multi-scale trembling aspen tree-ring width data from Alberta, we show that scaling has a profound influence on dendroecological inferencing. At all scales of sampling, there is a significant climatological signal whose strength is nevertheless superseded by the pervasive effect of insect herbivory. At the smallest spatial scale, 20 km x 20 km, we demonstrate a quasi-periodic pattern of sharp growth reductions and the existence of negative spatial correlations among successive outbreaks. At the intermediate spatial scale of 20 km x 80 km, we show that the period 1930-1963 was marked by extremely low correlations in aspen ring widths, with …

A Foundational Population Genetics Investigation Of The Sexual Systems Of Solanum (Solanaceae) In The Australian Monsoon Tropics Suggests Dioecious Taxa May Benefit From Increased Genetic Admixture Via Obligate Outcrossing, Jason T. Cantley, Ingrid E. Jordon-Thaden, Morgan Roche, Daniel S. Hayes, Stephamie Kate, Christopher T. Martine

Faculty Journal Articles

Solanum section Leptostemonum is an ideal lineage to test the theoretical framework regarding proposed evolutionary benefits of outcrossing sexual systems in comparison to cosexuality. Theoretically, non-cosexual taxa should support more genetic diversity within populations, experience less inbreeding, and have less genetic structure due to a restricted ability to self-fertilize. However, many confounding factors present challenges for a confident inference that inherent differences in sexual systems influence observed genetic patterns among populations. This study provides a foundational baseline of the population genetics of several species of different sexual systems with the aim of generating hypotheses of any factor—including sexual system—that influences …

Mechanistic Examination Of Protist-Mediated Plant Growth Through The Comparative Development Of Medicago Truncatula, Shane Connolly

University Scholar Projects

Protists are known to increase plant growth through two main mechanisms: the microbial loop and the alteration of the root microbiome. The microbial loop is a nutrient recycling method in which protists provide inorganic nitrogen ions to the plant. Alteration of root microbiome leads to the removal of plant pathogens and shifting communities towards plant growth-promoting bacteria (PGPB). This study aimed to elicit which mechanism could produce the largest boost in shoot weight for Medicago truncatula. A series of microcosm experiments were explored in which M. truncatula was grown with variable microbiome structures to allow for mechanism differentiation. The …

Gene Expression Changes Linked To Phenylpropanoid-Based Resistance To Fusarium Head Blight Of Wheat, Shiv Singla

Department of Plant Pathology: Dissertations, Theses, and Student Research

Fusarium graminearum is a devastating pathogen of wheat that causes Fusarium head blight (FHB) and contaminates the grain with the mycotoxin deoxynivalenol (DON). Resistance to FHB is quantitative and it is important to identify additional genes conferring resistance against it. The goal of this thesis was to examine if the constitutive expression of two sorghum phenylpropanoid pathway genes, SbCCoAOMT (encoding caffeoyl-CoA O-methyltransferase) and SbC3’H (encoding p-coumarate 3-hydroxylase), in the moderately-susceptible spring wheat CB037 can provide Type-I and Type-II resistance to F. graminearum and determine the underlying mechanisms of the enhanced resistance. The constitutive expression lines (CCoAOMT413, CCoAOMT421, C3H112, …

Soil Microbial Community Composition Of White Oak Mountain, Tennessee, Matthew Gano, Timothy D. Trott

Research in Biology

Abstract - Soil microbial communities are responsible for nutrient cycling in terrestrial ecosystems and have symbiotic and parasitic relationships with the plant community. However, little is known about the factors that determine the soil microbial community composition. In this study we examined how spring wildflower diversity and geographical factors influence the soil microbial community composition of the second growth oak hickory forests of White Oak Mountain in Southeast Tennessee. The characterization of the soil microbial community was completed with 16S/18S/ITS rDNA amplicon sequencing of total DNA extracted from soil samples that were normalized for each sample plot. Here we characterize …

Remote Sensing In Mapping Biodiversity – A Case Study Of Epiphytic Lichen Communities, Ida Palmroos, Veera Norros, Sarita Keski-Saari, Janne Mäyrä, Topi Tanhuanpää, Sonja Kivinen, Juha Pykälä, Peter Kullberg, Timo Kumpula, Petteri Vihervaara

Aspen Bibliography

In boreal forests, European aspen (Populus tremula L.) is a keystone species that hosts a variety of accompanying species including epiphytic lichens. Forest management actions have led to a decrease in aspen abundance and subsequent loss of suitable habitats of epiphytic lichens. In this study, we evaluate the environmental responses of epiphytic lichen species richness and community composition on aspen, focusing on the potential of remote sensing by combined hyperspectral imaging and airborne laser scanning to identify suitable habitats for epiphytic lichens. We measured different substrate and habitat parameters in the field (e.g., aspen diameter and bark pH) …

Genetic Markers And Tree Properties Predicting Wood Biorefining Potential In Aspen (Populus Tremula) Bioenergy Feedstock, Sacha Escamez, Kathryn M. Robinson, Mikko Luomaranta, Madhavi Latha Gandla, Niklas Mähler, Zakiya Yassin, Thomas Grahn, Gerhard Scheepers, Lars-Göran Stener, Stefan Jansson, Leif J. Jönsson, Nathaniel R. Street, Hannele Tuominen

Aspen Bibliography

Background Wood represents the majority of the biomass on land and constitutes a renewable source of biofuels and other bioproducts. However, wood is recalcitrant to bioconversion, raising a need for feedstock improvement in production of, for instance, biofuels. We investigated the properties of wood that affect bioconversion, as well as the underlying genetics, to help identify superior tree feedstocks for biorefining.

Results We recorded 65 wood-related and growth traits in a population of 113 natural aspen genotypes from Sweden (https://doi.org/10.5061/dryad.gtht76hrd). These traits included three growth and field performance traits, 20 traits for wood chemical composition, 17 traits for wood anatomy …

Physiological And Transcriptomic Responses Of Two Artemisia Californica Populations To Drought: Implications For Restoring Drought-Resilient Native Communities, Hagop S. Atamian Dr., Jennifer L. Funk

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As climate change brings drier and more variable rainfall patterns to many arid and semi-arid regions, land managers must re-assemble appropriate plant communities for these conditions. Transcriptome sequencing can elucidate the molecular mechanisms underlying plant responses to changing environmental conditions, potentially enhancing our ability to screen suitable genotypes and species for restoration. We examined physiological and morphological traits and transcriptome sequences of coastal and inland populations of California sagebrush (Artemisia californica), a critical shrub used to restore coastal sage scrub vegetation communities, grown under low and high rainfall environments. The populations are located approximately 36 km apart but …

Less Fuel For The Next Fire? Short-Interval Fire Delays Forest Recovery And Interacting Drivers Amplify Effects, Kristin H. Braziunas, Nathan G. Kiel, Monica G. Turner

Aspen Bibliography

As 21st-century climate and disturbance dynamics depart from historic baselines, ecosystem resilience is uncertain. Multiple drivers are changing simultaneously, and interactions among drivers could amplify ecosystem vulnerability to change. Subalpine forests in Greater Yellowstone (Northern Rocky Mountains, USA) were historically resilient to infrequent (100–300 year), severe fire. We sampled paired short-interval (<30-year) and long-interval (>125-year) post-fire plots most recently burned between 1988 and 2018 to address two questions: (1) How do short-interval fire, climate, topography, and distance to unburned live forest edge interact to affect post-fire forest regeneration? (2) How do forest biomass and fuels vary following short-interval versus long-interval severe fires? …

Regeneration Strategies And Forest Resilience To Changing Fire Regimes: Insights From A Goldilocks Model, Tanjona Ramiadantsoa, Zak Ratajczak, Monica G. Turner

Aspen Bibliography

Disturbances are ubiquitous in ecological systems, and species have evolved a range of strategies to resist or rebound following disturbance. Understanding how the presence and complementarity of regeneration traits will affect community responses to disturbance is increasingly urgent as disturbance regimes shift beyond their historical ranges of variability. We define "disturbance niche" as a species' fitness across a range of disturbance sizes and frequencies that can reflect the fundamental or realized niche, that is, whether the species occurs alone or with other species. We developed a model of intermediate complexity (i.e., a Goldilocks model) to infer the disturbance niche. We …

Revisiting Trophic Cascades And Aspen Recovery In Northern Yellowstone, Robert L. Beschta, Luke E. Painter, William J. Ripple

Aspen Bibliography

We revisit the nature and extent of trophic cascades and quaking aspen (Populus tremuloides) recovery in the northern range of Yellowstone National Park (YNP), where studies have reported on Rocky Mountain elk (Cervus canadensis) browsing and young aspen heights following the St. John, 1995-96 reintroduction of gray wolves (Canis lupus). A recent study by Brice et al. (2021) expressed concerns about methodologies employed in earlier aspen studies and that results from those studies exaggerated the extent to which a trophic cascade has benefitted aspen, concerns such as: (a) the selection of aspen stands, (b) …

Bison Influences On Composition And Diversity Of Riparian Plant Communities In Yellowstone National Park, J. Boone Kauffman, Dian Lyn Cummings, Cimarron Kauffman, Robert L. Beschta, Jeremy Brooks, Keeley Macneill, William J. Ripple

Aspen Bibliography

Riparian zones are among the most biologically diverse ecosystems in the Intermountain West, USA, and provide valuable ecosystem services, including high rates of biotic productivity, nutrient processing, and carbon storage. Thus, their sustainability is a high priority for land managers. Large ungulates affect composition and structure of riparian/stream ecosystems through herbivory and physical effects, via trailing and trampling. Bison (Bison bison) in Yellowstone National Park (YNP) have been characterized as "ecosystem engineers" because of their demonstrated effects on phenology, aboveground productivity of grasses, and woody vegetation structure. Bison have greatly increased in numbers during the last two decades …

Assessment Of Carbon Productivity Dynamics In Aspen Stands Under Climate Change Based On Forest Inventories In Central Siberia, Andrey Andreevich Vais, Valentina Valerievna Popova, Alina Andreevna Andronova, Viktor Nikolaevich Nemich, Artem Gennadievich Nepovinnykh, Pavel Vladimirovich Mikhaylov

Aspen Bibliography

The aim of the present research was to study the dynamics of growth and conditions of aspen stands under climate change, according to different periods of forest inventory. The study was conducted in modal aspen forests growing in the subtaiga/forest steppe region of Central Siberia. Aspen forests grow intensively at young age, which allows them to realize maximum carbon sequestration potential. The research was based on forest inventory data from 1972, 1982, 2002, and 2021 (the study was conducted on a limited territory). There was a steady increase in temperatures in the growing season from 1982 to 2002. The amount …

Nuclear Phylogeny And Insights Into Whole-Genome Duplications And Reproductive Development Of Solanaceae Plants, Jie Wang, Weibin Xu, Junwen Zhai, Yi Hu, Jing Guo, Caifei Zhang, Yiyong Zhao, Lin Zhang, Christopher T. Martine, Hong Ma, Chien-Hsun Huang

Faculty Journal Articles

Solanaceae, the nightshade family, have ∼2700 species, including the important crops potato and tomato, ornamentals, and medicinal plants. Several sequenced Solanaceae genomes show evidence for whole-genome duplication (WGD), providing an excellent opportunity to investigate WGD and its impacts. Here, we generated 93 transcriptomes/genomes and combined them with 87 public datasets, for a total of 180 Solanaceae species representing all four subfamilies and 14 of 15 tribes. Nearly 1700 nuclear genes from these transcriptomic/genomic datasets were used to reconstruct a highly resolved Solanaceae phylogenetic tree with six major clades. The Solanaceae tree supports four previously recognized subfamilies (Goetzeioideae, Cestroideae, Nicotianoideae, …

Enhancement Of Developmental Defects In The Boron-Deficient Maize Mutant Tassel-Less1 By Reduced Auxin Levels, Michaela S. Matthes, Norman B. Best, Janlo M. Robil, Paula Mcsteen

Biology Faculty Publications

Background

Plant responses to deficiencies of the micronutrient boron are diverse and go beyond the well-characterized function of boron in cell wall crosslinking. To explain these phenotypic discrepancies, hypotheses about interactions of boron with various phytohormones have been proposed, particularly auxin. While these hypotheses are intensely tested in the root meristem of the model species, Arabidopsis thaliana, studies in crop species and the shoot are limited.

Aims

To address potential boron–auxin interactions during the vegetative and reproductive development of the crop maize (Zea mays), we utilized the boron-deficient tassel-less1 (tls1) mutant and the auxin-deficient vanishing tassel2 (vt2) mutant. We investigated …

Fine-Scale Genetic Structure In Rhizosphere Microbial Communities Associated With Chamaecrista Fasciculata (Fabaceae), Mahboubeh Hosseinalizadeh Nobarinezhad, Lisa E. Wallace

Biological Sciences Faculty Publications

Soil microbiota of the rhizosphere are an important extension of the plant phenotype because they impact the health and fitness of host plants. The composition of these communities is expected to differ among host plants due to influence by host genotype. Given that many plant populations exhibit fine-scale genetic structure (SGS), associated microbial communities may also exhibit SGS. In this study, we tested this hypothesis using Chamaecrista fasciculata, a legume species that has previously been determined to have significant SGS. We collected genetic data from prokaryotic and fungal rhizosphere communities in association with 70 plants in an area of …

Enhancing Tomato Fruit Quality: Application Of Crispr/Dcas9-Mediated Methylation On The Pg Gene Promoter Region, Irena Komninakas

Holster Scholar Projects

Commercially produced tomatoes are typically harvested well before maturation in order to withstand domestic and international distribution. While this process ensures unspoiled goods, the nutritional value of the fruits have been curtailed as a result of premature harvesting. Previous research has found that the polygalacturonase gene (PG gene) is responsible for cell wall degradation of the tomato. In this study, CRISPR/dCas9 technology was employed to increase methylation levels in the promoter regions of the PG gene. This method is significant in that it epigenetically modifies the tomato genome using a technique that has the potential to develop non-genetically modified progeny …