Other Plant Sciences Commons^™

Transient Heat Stress During Early Seed Development Primes Germination And Seedling Establishment In Rice, Kevin Begcy, Jaspreet Sandhu, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Rice yield is highly sensitive to increased temperature. Given the trend of increasing global temperatures, this sensitivity to higher temperatures poses a challenge for achieving global food security. Early seed development in rice is highly sensitive to unfavorable environmental conditions. Heat stress (HS) during this stage decreases seed size and fertility, thus reducing yield. Here, we explore the transgenerational phenotypic consequences of HS during early seed development on seed viability, germination, and establishment. To elucidate the impact of HS on the developmental events in postzygotic rice seeds, we imposed moderate (35°C) and severe (39°C) HS treatments initiated 1 day after …

A New Anatomically-Preserved Plant From The Lower Devonian Of Quebec (Canada): Implications For Euphyllophyte Phylogeny And Early Evolution Of Structural Complexity, Selin Toledo

Cal Poly Humboldt theses and projects

An abrupt transition in the fossil record between Early Devonian plants with simple structure and structurally-complex later Devonian plants, has frustrated efforts to understand patterns of phylogeny across the Early/Middle Devonian boundary and the evolution of complex forms. Both these aspects have important implications for lignophyte and seed plant evolution. In the first chapter, I evaluate phylogenetic relationships between the earliest seed plants, Aneurophytales, and Stenokoleales, using comprehensive taxon sampling (28 species, including all relevant permineralized species) and a set of 40 discrete and nine continuous morpho-anatomical characters. Analysis of this dataset supports the three traditional taxonomic groups (seed plants, …

Tomato Spotted Wilt Virus Nss Protein Supports Infection And Systemic Movement Of A Potyvirus And Is A Symptom Determinant, Hernan Garcia-Ruiz, Sergio M. Gabriel Peralta, Patricia A. Harte-Maxwell

Department of Plant Pathology: Faculty Publications

Plant viruses are inducers and targets of antiviral RNA silencing. To condition susceptibility, most plant viruses encode silencing suppressor proteins that interfere with antiviral RNA silencing. The NSs protein is an RNA silencing suppressor in orthotospoviruses, such as the tomato spotted wilt virus (TSWV). The mechanism of RNA silencing suppression by NSs and its role in virus infection and movement are poorly understood. Here, we cloned and tagged TSWV NSs and expressed it from a GFP-tagged turnip mosaic virus (TuMV-GFP) carrying either a wild-type or suppressor-deficient (AS9) helper component proteinase (HC-Pro). When expressed in cis, NSs restored pathogenicity and promoted …

Intermolecular Rna Recombination Occurs At Different Frequencies In Alternate Forms Of Brome Mosaic Virus Rna Replication Compartments, Hernan Garcia-Ruiz, Arturo Diaz, Paul Ahlquist

Department of Plant Pathology: Faculty Publications

Positive-strand RNA viruses replicate their genomes in membrane-bound replication compartments. Brome mosaic virus (BMV) replicates in vesicular invaginations of the endoplasmic reticulum membrane. BMV has served as a productive model system to study processes like virus-host interactions, RNA replication and recombination. Here we present multiple lines of evidence showing that the structure of the viral RNA replication compartments plays a fundamental role and that recruitment of parental RNAs to a common replication compartment is a limiting step in intermolecular RNA recombination. We show that a previously defined requirement for an RNA recruitment element on both parental RNAs is not to …

Metagenomic Analysis Of Viruses Associated With Maize Lethal Necrosis In Kenya, Mwathi Jane Wamaitha, Deepti Nigam, Solomon Maina, Francesca Stomeo, Anne Wangai, Joyce Njoki Njuguna, Timothy A. Holton, Bramwel W. Wanjala, Mark Wamalwa, Tanui Lucas, Appolinaire Djikeng, Hernan Garcia Ruiz

Department of Plant Pathology: Faculty Publications

Background: Maize lethal necrosis is caused by a synergistic co-infection of Maize chlorotic mottle virus (MCMV) and a specific member of the Potyviridae, such as Sugarcane mosaic virus (SCMV), Wheat streak mosaic virus (WSMV) or Johnson grass mosaic virus (JGMV). Typical maize lethal necrosis symptoms include severe yellowing and leaf drying from the edges. In Kenya, we detected plants showing typical and atypical symptoms. Both groups of plants often tested negative for SCMV by ELISA. Methods: We used next-generation sequencing to identify viruses associated to maize lethal necrosis in Kenya through a metagenomics analysis. Symptomatic and asymptomatic leaf samples …

Susceptibility Genes To Plant Viruses, Hernan Garcia Ruiz

Department of Plant Pathology: Faculty Publications

Plant viruses use cellular factors and resources to replicate and move. Plants respond to viral infection by several mechanisms, including innate immunity, autophagy, and gene silencing, that viruses must evade or suppress. Thus, the establishment of infection is genetically determined by the availability of host factors necessary for virus replication and movement and by the balance between plant defense and viral suppression of defense responses. Host factors may have antiviral or proviral activities. Proviral factors condition susceptibility to viruses by participating in processes essential to the virus. Here, we review current advances in the identification and characterization of host factors …

Profile Of Genetically Modified Plants Authorized In Mexico, Mayra Teresa Garcia Ruiz, Aaron N. Knapp, Hernan Garcia Ruiz

Department of Plant Pathology: Faculty Publications

Mexico is a center of origin for several economically important plants including maize, cotton, and cocoa. Maize represents more than a food crop, has been declared a biological, cultural, agricultural and economic patrimony, and is linked to the national identity of Mexicans. In this review, we describe the historic and current use of genetically modified plants in Mexico and factors that contributed to the development of the biosafety regulation. We developed a database containing all permit applications received by the government to release genetically modified plants. A temporal and geographical analysis identified the plant species that have been authorized for …

Genomic-Enabled Prediction Models Using Multi-Environment Trials To Estimate The Effect Of Genotype × Environment Interaction On Prediction Accuracy In Chickpea, Manish Roorkiwal, Diego Jarquin, Muneendra K. Singh, Pooran M. Gaur, Chellapilla Bharadwaj, Abhishek Rathore, Reka Howard, Samineni Srinivasan, Ankit Jain, Vanika Garg, Sandip Kale, Annapurna Chitikineni, Shailesh Tripathi, Elizabeth Jones, Kelly R. Robbins, José Crossa, Rajeev K. Varshney

Department of Agronomy and Horticulture: Faculty Publications

Genomic selection (GS) by selecting lines prior to field phenotyping using genotyping data has the potential to enhance the rate of genetic gains. Genotype × environment (G × E) interaction inclusion in GS models can improve prediction accuracy hence aid in selection of lines across target environments. Phenotypic data on 320 chickpea breeding lines for eight traits for three seasons at two locations were recorded. These lines were genotyped using DArTseq (1.6 K SNPs) and Genotyping-by-Sequencing (GBS; 89 K SNPs). Thirteen models were fitted including main effects of environment and lines, markers, and/or naïve and informed interactions to estimate prediction …

Gene Expression Profiling Of Iron Deficiency Chlorosis Sensitive And Tolerant Soybean Indicates Key Roles For Phenylpropanoids Under Alkalinity Stress, Brian M. Waters, Keenan Amundsen, George L. Graef

Department of Agronomy and Horticulture: Faculty Publications

Alkaline soils comprise 30% of the earth and have low plant-available iron (Fe) concentration, and can cause iron deficiency chlorosis (IDC). IDC causes soybean yield losses of $260 million annually. However, it is not known whether molecular responses to IDC are equivalent to responses to low iron supply. IDC tolerant and sensitive soybean lines provide a contrast to identify specific factors associated with IDC.We used RNA-seq to compare gene expression under combinations of normal pH (5.7) or alkaline pH (7.7, imposed by 2.5mM bicarbonate, or pH 8.2 imposed by 5mM bicarbonate) and normal (25μM) or low (1μM) iron conditions from …

Managing Grazing Lands To Improve Soils And Promote Climate Change Adaptation And Mitigation: A Global Synthesis, Marcia Delonge, Andrea D. Basche

Department of Agronomy and Horticulture: Faculty Publications

The potential to improve soils to help farmers and ranchers adapt to and mitigate climate change has generated significant enthusiasm. Within this discussion, grasslands have surfaced as being particularly important, due to their geographic range, their capacity to store substantial quantities of carbon relative to cultivated croplands and their potential role in mitigating droughts and floods. However, leveraging grasslands for climate change mitigation and adaptation will require a better understanding of how farmers and ranchers who rely on them for their livelihoods can improve management and related outcomes. To investigate opportunities for such improvements, we conducted a meta-analysis of field …

Reactive Oxygen Species Metabolism And Plant-Fungal Interactions, Lauren M. Segal, Richard A. Wilson

Department of Plant Pathology: Faculty Publications

Fungal interactions with plants can involve specific morphogenetic developments to access host cells, the suppression of plant defenses, and the establishment of a feeding lifestyle that nourishes the colonizer often—but not always—at the expense of the host. Reactive oxygen species (ROS) metabolism is central to the infection process, and the stage-specific production and/or neutralization of ROS is critical to the success of the colonization process. ROS metabolism during infection is dynamic—sometimes seemingly contradictory—and involves endogenous and exogenous sources. Yet, intriguingly, molecular decision-making involved in the spatio-temporal control of ROS metabolism is largely unknown. When also considering that ROS demands are …

Pushing The Resolution Limit By Correcting The Ewald Sphere Effect In Single-Particle Cryo-Em Reconstructions, Dongjie Zhu, Xiangxi Wang, Qianglin Fang, James L. Van Etten, Michael G. Rossmann, Zihe Rao, Xinzheng Zhang

Department of Plant Pathology: Faculty Publications

The Ewald sphere effect is generally neglected when using the Central Projection Theorem for cryo electron microscopy single-particle reconstructions. This can reduce the resolution of a reconstruction. Here we estimate the attainable resolution and report a “block-based” reconstruction method for extending the resolution limit. We find the Ewald sphere effect limits the resolution of large objects, especially large viruses. After processing two real datasets of large viruses, we show that our procedure can extend the resolution for both datasets and can accommodate the flexibility associated with large protein complexes.

Clean Low-Biomass Procedures And Their Application To Ancient Ice Core Microorganisms, Zhi-Ping Zhong, Natalie E. Solonenko, Maria C. Gazitua, Donald V. Kenny, Ellen Mosley-Thompson, Virginia I. Rich, James L. Van Etten, Lonnie G. Thompson, Matthew B. Sullivan

Department of Plant Pathology: Faculty Publications

Microorganisms in glacier ice provide tens to hundreds of thousands of years archive for a changing climate and microbial responses to it. Analyzing ancient ice is impeded by technical issues, including limited ice, low biomass, and contamination. While many approaches have been evaluated and advanced to remove contaminants on ice core surfaces, few studies leverage modern sequencing to establish in silico decontamination protocols for glacier ice. Here we sought to apply such “clean” sampling techniques with in silico decontamination approaches used elsewhere to investigate microorganisms archived in ice at ~41 (D41, ~20,000 years) and ~49 m (D49, ~30,000 years) depth …

Genome-Wide Analysis Of Genes Encoding Core Components Of The Ubiquitin System In Soybean (Glycine Max) Reveals A Potential Role For Ubiquitination In Host Immunity Against Soybean Cyst Nematode, Chunyu Zhang, Li Song, Mani Kant Choudhary, Bangjun Zhou, Guangchao Sun, Kyle C. Broderick, Loren Giesler, Lirong Zeng

Department of Plant Pathology: Faculty Publications

Background: Ubiquitination is a major post-translational protein modification that regulates essentially all cellular and physiological pathways in eukaryotes. The ubiquitination process typically involves three distinct classes of enzymes, ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2) and ubiquitin ligase (E3). To date, a comprehensive identification and analysis of core components comprising of the whole soybean (Glycine max) ubiquitin system (UBS) has not been reported.

Results: We performed a systematic, genome-wide analysis of genes that encode core members of the soybean UBS in this study. A total of 1431 genes were identified with high confidence to encode putative soybean UBS components, …

Tor-Autophagy Branch Signaling Via Imp1 Dictates Plant-Microbe Biotrophic Interface Longevity, Guangchao Sun, Christian Elowsky, Gang Li, Richard Wilson

Department of Plant Pathology: Faculty Publications

Like other intracellular eukaryotic phytopathogens, the devastating rice blast fungus Magnaporthe (Pyricularia) oryzae first infects living host cells by elaborating invasive hyphae (IH) surrounded by a plant-derived membrane. This forms an extended biotrophic interface enclosing an apoplastic compartment into which fungal effectors can be deployed to evade host detection. M. oryzae also forms a focal, plant membrane-rich structure, the biotrophic interfacial complex (BIC), that accumulates cytoplasmic effectors for translocation into host cells. Molecular decision-making processes integrating fungal growth and metabolism in host cells with interface function and dynamics are unknown. Here, we report unanticipated roles for the M. …

Wheat Streak Mosaic Virus: A Century Old Virus With Rising Importance Worldwide, Khushwant Singh, Stephen N. Wegulo, Anna Skoracka, Jiban Kumar Kundu

Department of Plant Pathology: Faculty Publications

Wheat streak mosaic virus (WSMV) causes wheat streak mosaic, a disease of cereals and grasses that threatens wheat production worldwide. It is a monopartite, positive-sense, single-stranded RNA virus and the type member of the genus Tritimovirus in the family Potyviridae. The only known vector is the wheat curl mite (WCM, Aceria tosichella), recently identified as a species complex of biotypes differing in virus transmission. Low rates of seed transmission have been reported. Infected plants are stunted and have a yellow mosaic of parallel discontinuous streaks on the leaves. In the autumn, WCMs move from WSMV-infected volunteer wheat and other grass …

Determination Of Vegetative Development And Flower Effect Of Transgenic Nicotiana Tabacum, Hasan Pinar, Aydin Uyun, Semih Yilmaz, Nedim Mutlu, Amitava Mitra

Department of Plant Pathology: Faculty Publications

Species and varieties in the Nicotiana genus may respond differently to photoperiodism in terms of flowering time control. These are classified as short day, neutral day and long day plants. One of these, Nicotiana tabacum cv. The Xanthi nc is a genotype which can flowering on a long day. But the genotype Kanamycin resistance can open its flowers in January when the resistance gene is transferred to the plant. On the other hand, the effect of rootstock to scion in plant species is very important. One of the issues raised is whether the transgenic plant in the rootstock is effect …

Biomass Production Of Herbaceous Energy Crops In The United States: Field Trial Results And Yield Potential Maps From The Multiyear Regional Feedstock Partnership, Dokyoung Lee, Ezra Aberle, Eric K. Anderson, William Anderson, Brian S. Baldwin, David D. Baltensperger, Michael Barrett, Jurg Blumenthal, Stacy Bonos, Joe Bouton, David I. Bransby, Charlie Brummer, Pane S. Burks, Chengci Chen, Christopher Daly, Jose Egenolf, Rodney L. Farris, John H. Fike, Roch E. Gaussoin, John R. Gill, Kenneth Gravois, Michael D. Halbleib, Anna Hale, Wayne Hanna, Keith Harmoney, Emily A. Heaton, Ron W. Heiniger, Lindsey Hoffman, Chang O. Hong, Gopal Kakani, Robert Kallenbach, Bisoondat Macoon, James C. Medley, Ali Missaoui, Robert B. Mitchell, Ken J. Moore, Jesse I. Morrison, Gary N. Odvody, Jonathan D. Richwine, Richard Ogoshi, Jimmy Ray Parrish, Lauren Quinn, Ed Richard, William L. Rooney, J. Brett Rushing, Ronnie Schnell, Matt Sousek, Scott A. Staggenborg, Thomas Tew, Goro Uehara, Donald R. Viands, Thomas Voigt, David Williams, Linda Williams, Lloyd Ted Wilson, Andrew Wycislo, Yubin Yang, Vance Owens

Department of Agronomy and Horticulture: Faculty Publications

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small-scale and short-term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock …

A Transcriptome‑Snp‑Derived Linkage Map Of Apios Americana (Potato Bean) Provides Insights About Genome Re‑Organization And Synteny Conservation In The Phaseoloid Legumes, Jugpreet Singh, Scott R. Kalberer, Vikas Belamkar, Teshale Assefa, Matthew N. Nelson, Andrew D. Farmer, William J. Blackmon, Steven B. Cannon

Department of Agronomy and Horticulture: Faculty Publications

Apios (Apios americana; “apios”), a tuberous perennial legume in the Phaseoleae tribe, was widely used as a food by Native Americans. Work in the last 40 years has led to several improved breeding lines. Aspects of the pollination biology (complex floral structure and tripping mechanism) have made controlled crosses difficult, and the previous reports indicated that the plant is likely primarily an outcrosser. We used a pseudo-testcross strategy to construct a genetic map specific to the maternal parent. The map was built using single-nucleotide polymorphism markers identified by comparing the expressed sequences of individuals in the mapping population …

Enhancing Resolution Of Natural Methylome Reprogramming Behavior In Plants, Robersy Sanchez, Xiaodong Yang, Hardik Kundariya, Jose R. Barreras, Yashitola Wamboldt, Sally A. Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

We have developed a novel methylome analysis procedure, Methyl-IT, based on information thermodynamics and signal detection. Methylation analysis involves a signal detection problem, and the method was designed to discriminate methylation regulatory signal from background noise induced by thermal fluctuations. Comparison with three commonly used programs and various available datasets to furnish a comparative measure of resolution by each method is included. To confirm results, methylation analysis was integrated with RNAseq and network enrichment analyses. Methyl-IT enhances resolution of genome methylation behavior to reveal network-associated responses, offering resolution of gene pathway influences not attainable with previous methods.