Plant Biology Commons^™

Molecular Regulation Of The Salicylic Acid Hormone Pathway In Plants Under Changing Environmental Conditions, Christina A. M. Rossi, Eric J. R. Marchetta, Jong Hum Kim, Christian Castroverde

Biology Faculty Publications

Salicylic acid (SA) is a central plant hormone mediating immunity, growth, and development. Recently, studies have highlighted the sensitivity of the SA pathway to changing climatic factors and the plant microbiome. Here we summarize organizing principles and themes in the regulation of SA biosynthesis, signaling, and metabolism by changing abiotic/biotic environments, focusing on molecular nodes governing SA pathway vulnerability or resilience. We especially highlight advances in the thermosensitive mechanisms underpinning SA-mediated immunity, including differential regulation of key transcription factors (e.g., CAMTAs, CBP60g, SARD1, bHLH059), selective protein–protein interactions of the SA receptor NPR1, and dynamic phase separation of the recently identified …

Plant Viruses Of Agricultural Importance: Current And Future Perspectives Of Virus Disease Management Strategies, Satyanarayana Tatineni, Gary Hein

Department of Plant Pathology: Faculty Publications

Plant viruses cause significant losses in agricultural crops worldwide, affecting the yield and quality of agricultural products. The emergence of novel viruses or variants through genetic evolution and spillover from reservoir host species, changes in agricultural practices, mixed infections with disease synergism, and impacts from global warming pose continuous challenges for the management of epidemics resulting from emerging plant virus diseases. This review describes some of the most devastating virus diseases plus select virus diseases with regional importance in agriculturally important crops that have caused significant yield losses. The lack of curative measures for plant virus infections prompts the use …

Modelling Pollinator And Nonpollinator Selection On Flower Colour Variation, Brigitte Tenhumberg, Agnes S. Dellinger, Stacey D. Smith

School of Biological Sciences: Faculty Publications

1. Flower colour variation is ubiquitous within and between populations, which is why it has long been a focal point for studies of natural selection. This body of work has uncovered a wide range of selective agents, including pollinators, herbivores, and various abiotic factors. Nevertheless, we lack an integrative framework for predicting the phenotypic outcome in terms of floral pigmentation when these forces act collectively and often in opposition. 2. We here present such a framework through a model that incorporates selection on pigmentation at the vegetative phase (i.e., through survival to reproduction) and at the flowering phase (i.e., on …

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al³⁺ on plants and microbes by binding with Al³⁺, thus preventing Al³⁺ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …

Investigation Of The Function Of Protein Acyl Transferases Using Crispr-Cas9 To Create Null Mutants, Claire E. Christopher

Honors Theses and Capstones

24 Protein Acyl Transferases (PATs) have been identified in the model organism Arabidopsis thaliana. Despite knowing the enzymatic function of these genes (palmitoylation), the specific subcellular pathways, protein targets, and cellular activities of these proteins remain unknown. To investigate the pathways that PAT genes are involved in, deletion mutations were created in several genes and the phenotype of the organisms carrying homozygous mutations was observed. To introduce mutations, the CRISPR/Cas9 system was inserted into the plant’s genome using Agrobacterium tumefaciens to cause deletions in PAT genes of interest. To date, no CRISPR-induced pat mutants have a noticeable phenotype. These …

Revisiting Plant Defense-Fitness Trade-Off Hypotheses Using Solanum As A Model Genus, Sakshi Watts, Satinderpal Kaur, Rupesh Kariyat

Entomology and Plant Pathology Faculty Publications and Presentations

Plants possess physical and chemical defenses which have been found to deter herbivores that feed and oviposit on them. Despite having wide variety of defenses which can be constitutive or induced, plants are attacked and damaged by insects associated with different mouthparts and feeding habits. Since these defenses are costly, trade-offs for growth and defense traits play an important role in warding off the herbivores, with consequences for plant and herbivore growth, development and fitness. Solanum is a diverse and rich genus comprising of over 1,500 species with economic and ecological importance. Although a large number of studies on Solanum …

Natural Variation In Temperature-Modulated Immunity To Pseudomonas Syringae Pv. Tomato (Pst Dc3000) In Arabidopsis Thaliana Plants, Christina A. M. Rossi

Theses and Dissertations (Comprehensive)

Studies conducted on the model plant-pathogen system Arabidopsis thaliana-Pseudomonas syringae pv. tomato (Pst) showed that elevated temperature suppresses the pathogen-induced production of salicylic acid (SA), which is a key plant defence hormone. This increased host vulnerability at higher temperatures is due to downregulated expression of CALMODULIN BINDING PROTEIN 60-LIKE G (CBP60g) and SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1), which encode master regulators of SA production. Collectively, these previous studies only focused on one natural accession of Arabidopsis called Columbia-0 (Col-0). However, the intraspecific variation in Arabidopsis immunity phenotypes under elevated temperature remains unknown. To fill this critical knowledge gap, my …

Propagation, Physiology And Biomass Of Giant Cane (Arundinaria Gigantea) For Conservation And Restoration, Sanjeev Sharm

Graduate Theses/Dissertations

Giant cane (Arundinaria gigantea) is a native species to 22 states in the U.S. The species and its ecosystem are considered critically endangered, and the species has been reduced to 2% of its original extent. The species has a long cultural and conservation history. Large canebrakes were commonly found in Missouri in bottomland forests, stream and riverbanks, and margins of lakes. My research goals were to: 1) examine methods for propagation success from field to greenhouse to field; 2) examine the physiology of cane at one of the few current canebrakes, for greenhouse propagated plants, and field planted …

Effect Of Soil Ph And Indigenous Bacterial Populations In Selecting Rhizobial Endophytes Within Soybean Root Nodules, Brianne Danielle Edwards

Graduate Theses/Dissertations

Soybean plants fulfill most of their nitrogen requirement by developing symbiotic associations with four different rhizobial genera, including Bradyrhizobium, Sinorhizobium, Mesorhizobium, and genus Rhizobium. In general, members of Bradyrhizobium and Sinorhizobium have been reported as dominant root nodule endophytes under acidic soils and alkaline soil conditions, respectively. So far, it is unknown whether the selection of rhizobial endophytes is regulated by their ability to survive under different soil pH or driven by host plants regardless of their relative abundance in soil. This study was focused on the assessment of the potential role of soil pH in …

Heading For A Breakdown: Assessing Evolution Through The Hybridization Of Two Sexual Systems, Diamanda A. Zizis

Honors Theses

Hybridization is an important evolutionary pathway that has contributed to the world’s vast biodiversity. In plants, especially angiosperms, hybridization is known to be an important mechanism for speciation, phenotypic divergence, and changes in reproductive systems. Solanum species present an ideal system to investigate how hybridization between two different sexual systems impacts the reproductive and phenotypic biology of the hybrid progeny. Hybrid seeds were acquired from crosses between Australian Solanum species Solanum dioicum (dioecious) and S. ultraspinosum (andromonoecious) in order to track what happens when you cross two plants with different sexual systems. Vegetative and floral morphological measurements were conducted, and …

Zonal Application Of Plant Growth Regulator In Cotton To Reduce Variability And Increase Yield In A Highly Variable Field, Carlos M.P. Vaz, Júlio C. Franchini, Eduardo A. Speranza, Ricardo Y. Inamasu, Lúcio A. De C. Jorge, Ladislau M. Rabello, Ivani De O.N. Lopes, Sérgio Das Chagas, Jefferson L.R. De Souza, Márcio De Souza, Amandio Pires, James Schepers

Department of Agronomy and Horticulture: Faculty Publications

Variable-rate application has great potential to reduce variability and increase yield by spatially optimizing agricultural inputs. In cotton, plant growth regulators (PGRs) control excessive growth and provide suitable plant height for harvest operations. This study evaluates the effect of variable-rate PGR application compared to constant-rate application to reduce yield spatial variability and increase yield. The variable-rate approach was carried out in 2020 based on zonal applications defined by clustering analysis using soil electrical conductivity, vegetation indexes, and yield maps. Application doses and timings were determined by integrating plant height measurements for the whole field in 2019 and by zone in …

Hybridization And Polyploidy In The Turtleheads, W. John Hayden

Biology Faculty Publications

The VNPS Wildflower of the Year for 2024 is Chelone glabra, White Turtlehead. Altogether, there are four species of Turtlehead native to eastern North America, and three of these are known to occur in Virginia.

Demography And Habitat Associations Of The Basalt Cactus: Pediocactus Nigrispinus, Zarha Dillon-Zuppelli

All Master's Theses

Cacti are iconic, conspicuous, and important contributors to arid ecosystems. They stabilize soil and provide essential food and habitat to wildlife. Pediocactus nigrispinus is a species of cactus endemic to the Pacific Northwest and has been listed as a sensitive species due to its vulnerability to habitat loss. Pediocactus nigrispinus is being threatened by habitat fragmentation, poaching, and a changing climate. Best conservation methods for this species are poorly understood, due in part to a limited understanding of its demography and associations that may help define its occurrence.

A demographic study in Washington State was implemented in 2016 to give …

Sequencing Antisense Transcriptome Of Populus Through Antisense/Sense Transcript Pair Enrichment, Emma V. Burke

Dissertations, Master's Theses and Master's Reports

Past transcriptome research on plants focused primarily on protein coding genes, and only recently researchers began looking into the non-protein coding regions that may play significant roles in gene regulation. Antisense RNA transcripts that are found naturally in the cell share complementary sequence with sense transcripts and have been shown to regulate expression of their sense counterparts. Since antisense RNA has been largely under-studied and difficult to sequence because of their low relative abundance, new methods are needed to target antisense RNA for efficient genome-wide profiling. To address this gap in methods to efficiently and cost effectively enrich antisense RNA …

Changes In Poplar Digestibility Due To Overexpression Of Laccase Genes, Fnu Arunima

Dissertations, Master's Theses and Master's Reports

Woody biomass, particularly poplar, is a sought-after feedstock for lignocellulosic biofuels because of its year-round availability and high productivity. Because of cell wall components like lignin, poplar is inherently resistant to enzymatic saccharification. The experiment aims to determine whether the controlled overexpression of laccase genes alters the biomass composition and whether it can create poplar that is more digestible than the wildtype.

Three sets of transgenic poplar (Populus tremula x alba) samples were evaluated: laccase 18, laccase 27, and STTM. Laccase 18 samples, an target of miRNA397a was overexpressed along with Laccase 27. Short Tandem target Mimic (STTM) technology …

Phosphate2 And Pin-Likes7 Affect Symbiotic Nodule Phenotypes In Soybean, Bhawandeep Kaur

Electronic Theses and Dissertations

Legumes and soil rhizobia share a symbiotic relationship, wherein rhizobia fix atmospheric dinitrogen in exchange for photosynthates from the host plant. This exchange of mutual benefits occurs in a specialized root structure called ‘nodule’. Soybean (Glycine max) nodules arise from root outer cortical cells. De novo cell differentiation of cortical cells during nodule development leads to the formation of two distinct nodule zones in the mature nodule: the central infection zone where nitrogen fixation occurs and the peripheral parenchyma zone that houses vascular bundles. Plant signaling mechanisms that dictate the development of these nodule zones are not known. To address …

Winter Dynamics Of Storm Water Management Ponds And Winter Tolerance In Three Aquatic Plant Species, Patrick Strzalkowski

Theses and Dissertations (Comprehensive)

The vast majority of the research into the performance of stormwater management ponds (SWMPs) has been performed in warm regions or during the warmer seasons in temperate regions. It is presumed that SWMPs are inactive in the winter as any potential stormwater is trapped in snow and ice. The main goal of this thesis was to test this presumption and to study the dynamics and performance of three SWMPs during the winter. Remote water level loggers were installed into the three SWMPs and daily grab samples from the influents and effluents were taken and analyzed for total phosphorus (TP), chloride, …

Csi Botany: Dna Barcode “Fingerprints” Identify Cryptic Urban Flora, Luis R. Vega

Theses and Dissertations

As short genomic markers, DNA barcodes can play a role in conservation by identifying cryptic species and hybrids when morphological approaches fall short. Here we present our application of barcodes to the identities of two wetland taxa as part of an ongoing floristic inventory of Van Cortlandt Park (VCP), Bronx, NY. Previous barcode data by Marriott et al. (2018) identified the VCP lake water lily as the exotic Nymphaea alba, rather than the native N. odorata as historically described. In addition, cattails in the park were historically identified as the native Typha latifolia and the exotic T. angustifolia …

Quantifying The Carbon Stored And Sequestered By The Trees On Pomona College’S Campus, Paola A. Giron-Carson

Scripps Senior Theses

We are experiencing a climate crisis that must be confronted with strategic mitigation. Pomona College contributes to the climate crisis through its emissions for which there is a baseline record. However there is no baseline record of the climate mitigation currently performed by the trees on Pomona’s campus through carbon storage. This study seeks to determine a current baseline quantity of carbon stored and sequestrated by Pomona’s trees as well as possible courses of climate mitigation for Pomona College to take. Initial information gathering was conducted through interviews with several stakeholders. This study was conducted using data collected prior to …

Opportunities And Challenges In Augmenting Honey Bee Forage Resources With Pasture Legumes In Southern Australia, M. Kratz, M. Brown, M. T. Newell, R. C. Hayes

IGC Proceedings (1977-2023)

More than 80% of Australian honey is produced from native tree and shrub species. However, with increasing demands on public lands along with production risks posed by drought, floods and wildfires, there is a need to identify alternative forage resources to augment Australian honey production. With over 30 pasture legumes now available for agriculture in southern Australia, opportunity exists to increase the utilisation of some species with co-benefits to multiple production industries. However, there is little understanding of the potential value of most pasture legumes for honey production, and side by side comparisons are complicated by factors such as differences …

Data Curation For Modeling Tall Fescue Biomass Dynamics With Dssat-Csm, M. B. Hanson, P. D. Alderman, T. J. Butler, A. Caldeira Rocateli

IGC Proceedings (1977-2023)

While models for predicting forage production are available to aid management decisions for some forage crops, there is limited research for a yield model designed specifically for tall fescue (Schedonorus arundinaceus). Therefore, our objective was to adapt an existing perennial forage model, the Decision Support System for Agrotechnology Transfer Cropping Systems Model (DSSAT-CSM) for predicting forage biomass of tall fescue in the southern Great Plains. To evaluate model performance, there must first be a high level of data manipulation and cleaning. In this project, a cohesive dataset combining biomass, weather, soil, and management data were structured into DSSAT …

Can Changing Breeding Structure Serve As A Climate Adaptation Strategy? Evidence From A Comparative Study Of China And Mongolia, Y. Zhang, Z. Huang, J. Wang, Y. Huang, T. Hao, G. Xu

IGC Proceedings (1977-2023)

Under the influence of climate change, the vulnerability of grassland ecosystems in the Mongolian Plateau has increased. Correspondingly, herdsmen need to adopt more livelihood adaptation strategies to cope with changes in climate and grassland environment. The purpose of this study is to analyze the impact of breeding structure on grassland quality in Mongolian plateau. We select 20 border provinces/banners of Mongolia and Inner Mongolia Autonomous Region for research, and combined statistical data with remote sensing data of 2007-2016. The Normalized Difference Vegetation Index (NDVI) is used to quantify the grassland vegetation quality. Results show that there are differences in livestock …

Mapping Genetic Variation In Arabidopsis In Response To Plant Growth-Promoting Bacterium Azoarcus Olearius Dqs-4t, Fernanda Plucani Do Amaral, Juexin Wang, Jacob Williams, Thalita R. Tuleski, Trupti Joshi, Marco A. R. Ferreira, Gary Stacey

Biomedical Sciences

Plant growth-promoting bacteria (PGPB) can enhance plant health by facilitating nutrient uptake, nitrogen fixation, protection from pathogens, stress tolerance and/or boosting plant productivity. The genetic determinants that drive the plant–bacteria association remain understudied. To identify genetic loci highly correlated with traits responsive to PGPB, we performed a genome-wide association study (GWAS) using an Arabidopsis thaliana population treated with Azoarcus olearius DQS-4^T. Phenotypically, the 305 Arabidopsis accessions tested responded differently to bacterial treatment by improving, inhibiting, or not affecting root system or shoot traits. GWA mapping analysis identified several predicted loci associated with primary root length or root fresh …

Competition And Herbivory Influence The Survival, Growth, And Physiology Of Native Tree Seedlings In The Kentucky Inner Bluegrass Savanna-Woodland, James D. Shaffer

Theses and Dissertations--Biology

Terrestrial plant communities are shaped by competition for resources, herbivory, and abiotic processes. Savanna systems represent a dynamic coexistence of contrasting life forms (grasses and trees) shaped by competition and disturbance. The Kentucky Inner Bluegrass Savanna-Woodland (KIBSW) is described as an open woodland of shade intolerant species; however, climatic, and edaphic conditions can support closed-canopy forest. After European pioneer settlement (c1750-1800), over 99% of “savanna-woodlands” have been lost. KIBSW remnants are experiencing a recruitment failure, leading to a dominance shift in tree communities. I researched how tree-grass competition and mammalian herbivory influence KIBSW regeneration and maintenance. The KIBSW does not …

Attack Of The Clones: Elucidating The Role Of Clonality In The Invasion Success Of Carpobrotus Edulis, Eduardo Luis Cruz

Electronic Theses, Projects, and Dissertations

Transcriptomics is a modern technique in genomics that utilizes RNA sequences to get a snapshot of genetic expression. This is a powerful tool in non-model species lacking a reference genome. Thus, the application of comparative transcriptomics has the potential to help us elucidate the evolutionary mechanisms that facilitate species invasion. Carpobrotus edulis is a prolific and widespread invasive succulent plant belonging to the Aizoaceae family. A native to South Africa, this species has become a dominant invader of many Mediterranean coastal areas. In this study, we leveraged the use of RNAseq to investigate evolutionary changes among invasive populations. RNA-seq data …

Correction To: Genetic Characterization And Expression Analysis Of Wheat (Triticum Aestivum) Line 07or1074 Exhibiting Very Low Polyphenol Oxidase (Ppo) Activity, S. M. Hystad, J. M. Martin, R. A. Graybosch, M. J. Giroux

Department of Agronomy and Horticulture: Faculty Publications

The above mentioned article was published in 2015 with an error in the naming of one of the allele sequences for the PPO gene on the D genome. The PPO-D1f allele was incorrectly named as it is identical to the PPO-D1c allele previously published in GenBank by the authors on March 11th, 2014. An alignment between the previously published PPOD1c allele and a resequencing of the parental line 07OR1074 shows that the PPO-D1f allele is identical to the PPO-D1c allele. The allele in the paper referred to as PPO-D1f should be treated as PPO-D1c and can be accessed at NCBI …

Estimating The Genetic Parameters Of Yield-Related 1 Traits Under Different Nitrogen Conditions In Maize, Semra Palali Delen, Gen Xu, Jenifer Velazquez-Perfecto, Jinliang Yang

Department of Agronomy and Horticulture: Faculty Publications

Understanding the genetic basis responding to nitrogen (N) fertilization in crop production is a long-standing research topic in plant breeding and genetics. Albeit years of continuous efforts, the genetic architecture parameters, such as heritability, polygenicity, and mode of selection, underlying the N responses in maize remain largely unclear. In this study, about n = 230 maize inbred lines were phenotyped under high N (HN) and low N (LN) conditions for two consecutive years to obtain six yield-related traits. Heritability analyses suggested that traits highly responsive to N treatments were less heritable. Using publicly available SNP genotypes, the genome-wide association study …

Interaction Of Quizalofop-P-Ethyl With 2,4-D Choline And/Or Glufosinate For Control Of Volunteer Corn In Corn Resistant To Aryloxyphenoxypropionates, Mandeep Singh, Vipan Kumar, Stevan Z. Knezevic, Suat Irmak, John L. Lindquist, Santosh Pitla, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Corn resistant to aryloxyphenoxypropionates (FOPs) (Enlist™ corn) enables the use of quizalofop-p-ethyl (QPE) as a selective postemergence (POST) herbicide for control of glufosinate/glyphosate-resistant corn volunteers. Growers usually mix QPE with 2,4-D choline and/or glufosinate to achieve broad-spectrum weed control in Enlist™ corn. The objectives of this study were to (1) evaluate the efficacy of QPE applied alone or mixed with 2,4-D choline and/or glufosinate for control of glufosinate/glyphosate-resistant corn volunteers in Enlist™ corn and (2) determine the impact of application time (V3 or V6 growth stage of volunteer corn) of QPE-based treatments on volunteer corn control as well as Enlist™ …

The Biggest Grower: A Youth Gardening Competition For Growing Specialty Crops And Urban Farmers, Stacy A. Adams, Terri James

Department of Agronomy and Horticulture: Faculty Publications

Youth today have tendencies for unhealthy lifestyles, being sedentary, consuming high fat diets low in fruits and vegetables, all contributing to child obesity, Type 2 diabetes, hypertension, and precedence for life-long health concerns. For rural and economically disadvantaged urban households, poor diet is directly attributed to the inaccessibility of fresh produce, affordability and understanding of preparation of various specialty crops. Through a grant from the NE Specialty Crop Block Funding Program, The Biggest Grower Competition (BGC) was developed as a summer extension education program for youth in 8^th through 12^th grade. Project goals included; provide educational materials on …

Molecular Analysis Of Epigenetic Memory Of Stress Establishment And Long-Term Maintenance In A Perennial Woody Plant, Jia Wen Tan

Theses and Dissertations--Plant and Soil Sciences

Plants adapt to extreme environmental conditions through physiological adaptations, which are usually transient. Recent research has suggested that environmental conditions can activate a memory of stress that can result in a primed response to subsequent stress events. While the effect of priming has been observed in many plants, the underlying mechanisms are puzzling and seldom studied. A large body of research has been developed in the last decade linking response to stress, stress priming, and memory of stress with epigenetic mechanisms. This understanding of plant epigenetics has opened the door to the application of epigenetics to crop improvement, such as …