Life Sciences Commons^™

Integration Of Developmental And Environmental Signals Via A Polyadenylation Factor In Arabidopsis, Man Liu, Ruqiang Xu, Carrie Merrill, Liwei Hong, Carol Von Lanken, Arthur G. Hunt, Qingshun Q. Li

Plant and Soil Sciences Faculty Publications

The ability to integrate environmental and developmental signals with physiological responses is critical for plant survival. How this integration is done, particularly through posttranscriptional control of gene expression, is poorly understood. Previously, it was found that the 30 kD subunit of Arabidopsis cleavage and polyadenylation specificity factor (AtCPSF30) is a calmodulin-regulated RNA-binding protein. Here we demonstrated that mutant plants (oxt6) deficient in AtCPSF30 possess a novel range of phenotypes--reduced fertility, reduced lateral root formation, and altered sensitivities to oxidative stress and a number of plant hormones (auxin, cytokinin, gibberellic acid, and ACC). While the wild-type AtCPSF30 (C30G) was …

Grazing And No-Till Cropping Impacts On Nitrogen Retention In Dryland Agroecosystems, Megan L. Mobley, Rebecca L. Mcculley, Ingrid C. Burke, Gary Peterson, David S. Schimel, C. Vernon Cole, Edward T. Elliott, Dwayne G. Westfall

Plant and Soil Sciences Faculty Publications

As the world's population increases, marginal lands such as drylands are likely to become more important for food production. One proven strategy for improving crop production in drylands involves shifting from conventional tillage to no-till to increase water use efficiency, especially when this shift is coupled with more intensive crop rotations. Practices such as no-till that reduce soil disturbance and increase crop residues may promote C and N storage in soil organic matter, thus promoting N retention and reducing N losses. By sampling soils 15 yr after a N tracer addition, this study compared long-term soil N retention across several …

Warming Reduces Tall Fescue Abundance But Stimulates Toxic Alkaloid Concentrations In Transition Zone Pastures Of The U.S., Rebecca L. Mcculley, Lowell P. Bush, Anna E. Carlisle, Huihua Ji, Jim A. Nelson

Plant and Soil Sciences Faculty Publications

Tall fescue pastures cover extensive acreage in the eastern half of the United States and contribute to important ecosystem services, including the provisioning of forage for grazing livestock. Yet little is known concerning how these pastures will respond to climate change. Tall fescue's ability to persist and provide forage under a warmer and wetter environment, as is predicted for much of this region as a result of climate change, will likely depend on a symbiotic relationship the plant can form with the fungal endophyte, Epichloë coenophiala. While this symbiosis can confer environmental stress tolerance to the plant, the endophyte …

Ergovaline Stability In Tall Fescue Based On Sample Handling And Storage Methods, Krista La Moen Lea, Lori Smith, Cynthia Gaskill, Robert Coleman, S. Ray Smith

Plant and Soil Sciences Faculty Publications

Ergovaline is an ergot alkaloid produced by the endophyte Neotyphodium coenophialum (Morgan-Jones and Gams) found in tall fescue [Schedonorus arundinacea (Schreb.) Dumort.] and blamed for a multitude of livestock disorders. Ergovaline is known to be unstable and affected by many variables. The objective of this study was to determine the effect of sample handling and storage on the stability of ergovaline in tall fescue samples. Fresh tall fescue was collected from a horse farm in central Kentucky at three harvest dates and transported on ice to the University of Kentucky Veterinary Diagnostic Laboratory. Plant material was frozen in liquid …

Fragipan Horizon Fragmentation In Slaking Experiments With Amendment Materials And Ryegrass Root Tissue Extracts, Anastasios D. Karathanasis, Lloyd W. Murdock, Christopher J. Matocha, John H. Grove, Yvonne L. Thompson

Plant and Soil Sciences Faculty Publications

Slaking experiments were conducted of fragipan clods immersed in solutions of poultry manure, aerobically digested biosolid waste (ADB), fluidized bed combustion byproduct (FBC), D-H₂O, CaCO₃, NaF, Na-hexa-metaphosphate, and ryegrass root biomass. The fragipan clods were sampled from the Btx horizon of an Oxyaquic Fragiudalf in Kentucky. Wet sieving aggregate analysis showed significantly better fragmentation in the NaF, Na-hexa-metaphosphate, and ryegrass root solutions with a mean weight diameter range of 15.5-18.8 mm compared to the 44.2-47.9 mm of the poultry manure, ADB, and FBC treatments. Dissolved Si, Al, Fe, and Mn levels released in solution were ambiguous. …

Genome-Wide Determination Of Poly(A) Sites In Medicago Truncatula: Evolutionary Conservation Of Alternative Poly(A) Site Choice, Xiaohui Wu, Bobby Gaffney, Arthur G. Hunt, Qingshun Q. Li

Plant and Soil Sciences Faculty Publications

BACKGROUND: Alternative polyadenylation (APA) plays an important role in the post-transcriptional regulation of gene expression. Little is known about how APA sites may evolve in homologous genes in different plant species. To this end, comparative studies of APA sites in different organisms are needed. In this study, a collection of poly(A) sites in Medicago truncatula, a model system for legume plants, has been generated and compared with APA sites in Arabidopsis thaliana.

RESULTS: The poly(A) tags from a deep-sequencing protocol were mapped to the annotated M. truncatula genome, and the identified poly(A) sites used to update the annotations of 14,203 …

Analyses Of Catharanthus Roseus And Arabidopsis Thaliana Wrky Transcription Factors Reveal Involvement In Jasmonate Signaling, Craig Schluttenhofer, Sitakanta Pattanaik, Barunava Patra, Ling Yuan

Plant and Soil Sciences Faculty Publications

BACKGROUND: To combat infection to biotic stress plants elicit the biosynthesis of numerous natural products, many of which are valuable pharmaceutical compounds. Jasmonate is a central regulator of defense response to pathogens and accumulation of specialized metabolites. Catharanthus roseus produces a large number of terpenoid indole alkaloids (TIAs) and is an excellent model for understanding the regulation of this class of valuable compounds. Recent work illustrates a possible role for the Catharanthus WRKY transcription factors (TFs) in regulating TIA biosynthesis. In Arabidopsis and other plants, the WRKY TF family is also shown to play important role in controlling tolerance to …

Identification Of A Dominant Gene In Medicago Truncatula That Restricts Nodulation By Sinorhizobium Meliloti Strain Rm41, Jinge Liu, Shengming Yang, Qiaolin Zheng, Hongyan Zhu

Plant and Soil Sciences Faculty Publications

BACKGROUND: Leguminous plants are able to form a root nodule symbiosis with nitrogen-fixing soil bacteria called rhizobia. This symbiotic association shows a high level of specificity. Beyond the specificity for the legume family, individual legume species/genotypes can only interact with certain restricted group of bacterial species or strains. Specificity in this system is regulated by complex signal exchange between the two symbiotic partners and thus multiple genetic mechanisms could be involved in the recognition process. Knowledge of the molecular mechanisms controlling symbiotic specificity could enable genetic improvement of legume nitrogen fixation, and may also reveal the possible mechanisms that restrict …

Alternative Splicing In Plant Immunity, Shengming Yang, Fang Tang, Hongyan Zhu

Plant and Soil Sciences Faculty Publications

Alternative splicing (AS) occurs widely in plants and can provide the main source of transcriptome and proteome diversity in an organism. AS functions in a range of physiological processes, including plant disease resistance, but its biological roles and functional mechanisms remain poorly understood. Many plant disease resistance (R) genes undergo AS, and several R genes require alternatively spliced transcripts to produce R proteins that can specifically recognize pathogen invasion. In the finely-tuned process of R protein activation, the truncated isoforms generated by AS may participate in plant disease resistance either by suppressing the negative regulation of initiation of …

Amino Acid Racemase Enzyme Assays, Atanas D. Radkov, Luke A. Moe

Plant and Soil Sciences Faculty Publications

Amino acid racemases are enzymes that invert the α-carbon stereochemistry of amino acids (AAs), interconverting amino acids between their L- and D-enantiomers in a reversible reaction. In bacteria, they are known to have catabolic physiological functions but are also involved in the synthesis of many D-AAs, including D-glutamate and D-alanine, which are necessary components of the peptidoglycan layer of the bacterial cell wall. As such, amino acid racemases represent significant targets for the development of bactericidal compounds. Amino acid racemases are also regarded by the biotechnological industry as important catalysts for the production of economically relevant D-AAs. Here, we provide …

Variation In Vegetation And Microbial Linkages With Slope Aspect In A Montane Temperate Hardwood Forest, Frank S. Gilliam, Radim Hédl, Markéta Chudomelová, Rebecca L. Mcculley, Jim A. Nelson

Plant and Soil Sciences Faculty Publications

Plant ecologists have long been interested in aspect-related contrasts of montane forests. Few studies have assessed correlation (linkage) among vegetation strata; fewer have included soil microbial communities. This study assessed contrasts in overstory, spring herbaceous, and soil microbial communities between northeast (NE) - and southwest (SW) -facing slopes in a second-growth West Virginia hardwood forest. We addressed three questions: (1) how do soil microbial, herbaceous layer, and overstory communities vary with slope aspect? (2) do forest vegetation strata and soil microbial communities exhibit linkage? (3) do biotic relationships and linkage vary with slope aspect? Moisture, organic matter, pH, soil NO …

Vision And Change Through The Genome Consortium For Active Teaching Using Next-Generation Sequencing (Gcat-Seek), Vincent Buonaccorsi, Mark Peterson, Gina Lamendella, Jeff Newman, Nancy Trun, Tammy Tobin, Andres Aguilar, Arthur G. Hunt, Craig Praul, Deborah Grove, Jim Roney, Wade Roberts

Plant and Soil Sciences Faculty Publications

No abstract provided.

Induced Transcriptional Profiling Of Phenylpropanoid Pathway Genes Increased Flavonoid And Lignin Content In Arabidopsis Leaves In Response To Microbial Products, Mohammad Babar Ali, David H. Mcnear

Plant and Soil Sciences Faculty Publications

BACKGROUND: The production and use of biologically derived soil additives is one of the fastest growing sectors of the fertilizer industry. These products have been shown to improve crop yields while at the same time reducing fertilizer inputs to and nutrient loss from cropland. The mechanisms driving the changes in primary productivity and soil processes are poorly understood and little is known about changes in secondary productivity associated with the use of microbial products. Here we investigate secondary metabolic responses to a biologically derived soil additive by monitoring changes in the phenlypropanoid (PP) pathway in Arabidopsis thaliana.

RESULTS: This study …

Does Fungal Endophyte Infection Improve Tall Fescue’S Growth Response To Fire And Water Limitation?, Sarah L. Hall, Rebecca L. Mcculley, Robert J. Barney, Timothy D. Phillips

Plant and Soil Sciences Faculty Publications

Invasive species may owe some of their success in competing and co-existing with native species to microbial symbioses they are capable of forming. Tall fescue is a cool-season, non-native, invasive grass capable of co-existing with native warm-season grasses in North American grasslands that frequently experience fire, drought, and cold winters, conditions to which the native species should be better-adapted than tall fescue. We hypothesized that tall fescue’s ability to form a symbiosis with Neotyphodium coenophialum, an aboveground fungal endophyte, may enhance its environmental stress tolerance and persistence in these environments. We used a greenhouse experiment to examine the effects …

Ectopic Expression Of The Phosphomimic Mutant Version Of Arabidopsis Response Regulator 1 Promotes A Constitutive Cytokinin Response Phenotype, Jasmina Kurepa, Yan Li, Sharyn E. Perry, Jan A. Smalle

Plant and Soil Sciences Faculty Publications

Background

Cytokinins control numerous plant developmental processes, including meristem formation and activity, nutrient distribution, senescence timing and responses to both the abiotic and biotic environments. Cytokinin signaling leads to the activation of type-B response regulators (RRBs), Myb-like transcription factors that are activated by the phosphorylation of a conserved aspartate residue in their response receiver domain. Consistent with this, overexpression of RRBs does not substantially alter plant development, but instead leads to cytokinin hypersensitivity.

Results

Here we present comparative analysis of plants overexpressing Arabidopsis RRB 1 (ARR1) or a phosphomimic ARR1^D94E mutant in which the conserved aspartate-94 (D94) is replaced …

Using Microbial Community Interactions Within Plant Microbiomes To Advance An Evergreen Agricultural Revolution, M. E. Lucero, Seth Debolt, A. Unc, A. Ruiz-Font, L. V. Reyes, Rebecca L. Mcculley, S. C. Alderman, R. D. Dinkins, J. R. Barrow, D. A. Samac

Plant and Soil Sciences Faculty Publications

Innovative plant breeding and technology transfer fostered the Green Revolution (GR), which transformed agriculture worldwide by increasing grain yields in developing countries. The GR temporarily alleviated world hunger, but also reduced biodiversity, nutrient cycling, and carbon (C) sequestration that agricultural lands can provide. Meanwhile, economic disparity and food insecurity within and among countries continues. Subsequent agricultural advances, focused on objectives such as increasing crop yields or reducing the risk of a specific pest, have failed to meet food demands at the local scale or to restore lost ecosystem services. An increasing human population, climate change, growing per capita food and …