Life Sciences Commons^™

Characterization Of Lignin Structural Variability And The Associated Application In Genome Wide Association Studies, Nathan D. Bryant

Doctoral Dissertations

Poplar (Populus sp.) is a promising biofuel feedstock due to advantageous features such as fast growth, the ability to grow on marginal land, and relatively low lignin content. However, there is tremendous variability associated with the composition of biomass. Understanding this variability, especially in lignin, is crucial to developing and implementing financially viable, integrated biorefineries. Although lignin is typically described as being comprised of three primary monolignols (syringyl, guaiacyl, p-hydroxyphenyl), it is a highly irregular biopolymer that can incorporate non-canonical monolignols. It is also connected by a variety of interunit linkages, adding to its complexity. Secondary cell wall …

Improving Forage Quality Of Tall Fescue (Festuca Arundinacea) By Genetic Manipulation Of Lignin Biosynthesis, Z. -Y. Wang, L. Chen, C. -K. Auh, A. Hopkins, P. Dowling

IGC Proceedings (1997-2023)

Lignification of plant cell walls is a major factor limiting forage digestibility and concomitantly animal productivity. Improvement in forage grass cell wall digestibility has become an important goal of many plant-ruminant animal research programs. Lignins are complex phenolic heteropolymers associated with the polysaccharidic components of the wall in specific plant cells. Lignin in forage grasses comprises guaiacyl (G) units derived from coniferyl alcohol, syringyl (S) units derived from sinapyl alcohol, and p-hydroxyphenyl (H) units derived from p-coumaryl alcohol. Cinnamyl alcohol dehydrogenase (CAD) and caffeic acid O- methyltransferase (COMT) are key enzymes involved in lignin biosynthesis. Tall fescue …

Snp Discovery And Haplotypic Variation In Full-Length Herbage Quality Genes Of Perennial Ryegrass (Lolium Perenne L.), R. C. Ponting, M. C. Drayton, N. O. I. Cogan, G. C. Spangenberg, K. F. Smith, J. W. Forster

IGC Proceedings (1997-2023)

The development of forages with enhanced nutritive value through improvements of herbage quality (digestibility, carbohydrate content) is potentially capable of increasing both meat and milk production by up to 25%. However, the expense and time-consuming nature of the relevant biochemical and biophysical assays has limited breeding improvement for forage quality. The development of accurate high-throughput molecular marker-based selection systems such as single nucleotide polymorphisms (SNPs) permits evaluation of genetic variation and selection of favourable variants to accelerate the production of elite new varieties.

Divergent Breeding For Tiller Digestibility Modified Leaf, Sheath, And Stem Composition Of Switchgrass (Panicum Virgatum L.), K. P. Vogel, G. Sarath, R. Mitchell

IGC Proceedings (1997-2023)

Switchgrass (Panicum virgatum. L.) is a cross-pollinated, C₄ species that is native to the prairies of temperate North America. Breeding to improve its forage quality has been conducted using post-heading, whole-tiller in vitro dry matter digestibility (IVDMD) as the selection criterion. One breeding cycle (C-1) for low IVDMD and three cycles for high IVDMD (C1, C2, C3) were completed in a switchgrass population adapted to the USA mid-latitudes. Sward trials demonstrated that whole plant IVDMD had been improved (Hopkins et al., 1993). The objective of this study was to determine the effect of breeding for tiller …

Screening Of Perennial Grasses And A Mutant Maize Collection By Fourier-Transformed Infrared (Ftir) Spectroscopy For Improved Biofuel Traits, S. C. Thain, P. Morris, S. Hawkins, C. Morris, I. S. Donnison

IGC Proceedings (1997-2023)

Currently the potential of biomass crops, including grasses, is limited because most species have not been bred for this purpose. However traits such as lignification, phenolic cross-linking and carbohydrate accessibility, which are also important for nutritive quality in forage grasses, can affect potential biofuel quality in applications such as combustion, fast-pyrolysis or fermentation. A collection of Lolium and Festuca species known to exhibit a range of lignin, cell wall phenolic and carbohydrate concentrations have been used to test optimum characteristics for biofuel processing. This collection formed a “calibration” set for subsequent high through-put FTIR chemical screening of additional plant lines: …

Cadmium Uptake In Plants As Influenced By Selenium Uptake And Sulphate Availability, Marnie J. Demand

Electronic Thesis and Dissertation Repository

With cadmium uptake by plants posing a risk to plants and consumers alike, strategies to reduce metal uptake are desirable. One strategy may be to apply selenium (as selenate) to the growth medium. I hypothesized selenate would yield greater lignification, with a higher proportion of cadmium bound to root cell walls. Consequently, higher selenium in plants would result in greater tolerance to cadmium. Additionally, since selenate is taken up in place of sulphate, providing the plants with high sulphate would inhibit uptake and translocation of selenium, mitigating selenate’s benefits of reducing cadmium uptake and translocation. Experimental results did not support …

The Impact Of Plant Cell Wall Lignin On Energy Utilization In Lactating Jersey Cows., Jason Stypinski

Department of Animal Science: Dissertations, Theses, and Student Research

Fiber from forages comprises a significant proportion of dairy cattle rations and by extension, it contributes largely to the energy concentration of the diet. While the proportion of fiber in the diet is important, the composition of fiber is probably more important as the different constituents of this fraction vary in their contributions to the nutritive value of the feed. Lignin has been described as an important factor limiting the digestion of NDF, reducing intake, and compromising milk production. Although lignin’s effects on these responses have been well characterized, the literature lacks data on the use of indirect calorimetry to …

Recovering And Upgrading Kraft Lignin For Application In Flexible Polyurethane Foam, Peng Quan

Dissertations, Master's Theses and Master's Reports

Lignin is the second abundant natural polymer and has been highlighted as a potential substitute for fossil-based raw materials. However, the inherent molecular heterogeneity and the complex recovery processes result in the challenge of controlling the molecular properties and value-added applications of lignin in large scale. To address those issues, a novel acid-liquefaction process was developed in this study to recover Kraft lignin with improved molecular homogeneity directly from black liquor.

In the first study, the liquefaction parameters were screened based on yield and molecular weight properties of the recovered lignin. Then, the recovered lignin samples were used to replace …

Application Of Mass Spectrometry For Characterization Of Plant-Based Phenolics And Alkaloids, Masoumeh Dorrani

Theses and Dissertations--Chemistry

Plant-derived compounds have the potential to produce value-added compounds with a variety of applications. For example, the lignin part of the lignocellulosic biomass, produced in large quantities as waste from the paper and pulp industries, is a rich source of phenolics with potential applications in the renewable energy sector, pharmaceutical, and chemical industries. On the other hand, plant alkaloids are the primary source for developing plant-derived therapeutics. Unfortunately, the recalcitrant nature of plant cell walls, low extraction yields of small secondary metabolites, and the lack of effective analytical methods for a rapid and accurate identification of plant-based compounds and plant’s …

Exploration Of Lignin-Based Superabsorbent Polymers (Hydrogels) For Soil Water Management And As A Carrier For Delivering Rhizobium Spp., Toby Adjuik

Theses and Dissertations--Biosystems and Agricultural Engineering

Superabsorbent polymers (hydrogels) as soil amendments may improve soil hydraulic properties and act as carrier materials beneficial to soil microorganisms. Researchers have mostly explored synthetic hydrogels which may not be environmentally sustainable. This dissertation focused on the development and application of lignin-based hydrogels as sustainable soil amendments. This dissertation also explores the development of pedotransfer transfer functions (PTFs) for predicting saturated hydraulic conductivity using statistical and machine learning methods with a publicly available large data set. A lignin-based hydrogel was synthesized, and its impact on soil water retention was determined in silt loam and loamy fine sand soils. Hydrogel treatment …

Improving The Feeding Value Of Cotton Stalk, Wheat Straw And Rice Straw With Ozonation, Meiji Okamoto, Masaaki Hanada, R. Aoyama, R. Kim, N. Kaiga

IGC Proceedings (1997-2023)

The experiment was conducted to study the effect of ozone treatment on the feed value of cotton stalk, wheat straw and rice straw. These feeds were cut into 2 cm and 4 cm lengths, and rolled before ozonizing. The ozonizing periods were 30 min. 60min and. 120 min. The Acid Detergent Lignin (ADL) concentration of the feeds decreased with ozone treatment. Except for rice straw, the short cutting treatment (2cm) decreased the concentration of ADL and Cellulose of the ozonized cotton stalk and wheat straw. Rolling and ozone treatment were effective in decreasing the ADL concentration of cotton stalk. IVDMD …

Corrigendum: Bel1-Like Homeodomain Protein Blh6a Is A Negative Regulator Of Cald5h2 In Sinapyl Alcohol Monolignol Biosynthesis In Poplar (Front. Plant Sci., (2021), 12, (695223), 10.3389/Fpls.2021.695223), Qiao Wang, Xinren Dai, Hongying Pang, Yanxia Cheng, Xiong Huang, Hui Li, Xiaojing Yan, Fachuang Lu, Hairong Wei, Ronald R. Sederoff, Quanzi Li

Michigan Tech Publications

When originally published, the article title contained a typographical error. The correct gene name should be “CAld5H2” instead of “CAl5H2” as originally published. The correct title is “BEL1-like Homeodomain Protein BLH6a is a Negative Regulator of CAld5H2 in Sinapyl Alcohol Monolignol Biosynthesis in Poplar.” The authors state that this does not change the scientific conclusions of the article in any way. The original article has been updated.

Susceptibility Of High-Elevation Forests To Mountain Pine Beetle (Dendroctonus Ponderosae Hopkins) Under Climate Change, David N. Soderberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Across western North America, pine forests are important for timber, wildlife habitat, and at high elevations are important for water retention and yield from rain and snowmelt. The mountain pine beetle (MPB) is one of the most significant disturbance agents shaping pine forests, and like all insects, temperature is a major driver of its population success and the dynamics of the landscapes that they inhabit. Changing temperature regimes can therefore directly influence MPB population persistence at a particular location, in addition to potential shifts in the range boundaries that they inhabit. MPB is currently expanding its range northward in British …

Degumming Of Hemp Fibers Using Combined Microwave Energy And Deep Eutectic Solvent, Bulbul Ahmed

LSU Master's Theses

Hemp is considered as one of the sustainable agricultural fiber materials. Degumming or surface modification of hemp bast is needed to produce single fibers for ensuing textile and industrial applications. The traditional degumming process necessitates a high amount of alkali, which causes detrimental environmental pollution. This study offers a new method to degum hemp fibers with reduced use of harmful alkali and precious water resources. In this work, hemp bast fibers were degummed by using combined microwave energy and deep eutectic solvent (DES). The properties of hemp fibers manufactured by this method were investigated and compared with the traditional alkali …

Bel1-Like Homeodomain Protein Blh6a Is A Negative Regulator Of Cal5h2 In Sinapyl Alcohol Monolignol Biosynthesis In Poplar, Qiao Wang, Xinren Dai, Hongying Pang, Yanxia Cheng, Xiong Huang, Hui Li, Hairong Wei, Et. Al.

Michigan Tech Publications

Lignin is one of the major components of xylem cell walls in tree stems. The lignin in the wood of most flowering plants (dicotyledonous angiosperms) is typically polymerized from three monolignol precursors, coniferyl alcohol, sinapyl alcohol, and p-coumaroyl alcohol, resulting in guaiacyl (G), syringyl (S), and hydroxyphenyl (H) subunits, respectively. In this study, we focus on the transcriptional regulation of a coniferaldehyde 5-hydroxylase (CAld5H2) gene, which encodes a key enzyme for sinapyl alcohol biosynthesis. We carried out a yeast one-hybrid (Y1H) screen to identify candidate upstream transcription factors (TFs) regulating CAld5H2. We obtained 12 upstream TFs …

Date Fruit Fiber Variability In Composition, Tissue Distribution, And Contribution To Hardness Of Date Fruits (Phoenix Dactylifera L.), Navomy George

Dissertations

Date fruit (Phoenix dactylifera L.) is a major desert crop and is an integral part of the United Arab Emirates. This study is on the various aspects of dietary fiber of ten Emirati date varieties. The main objective of this dissertation is to analyze the content and composition of mature date fruits and to study their microstructure. The aspects of biomineralization with particular importance to silica phytoliths and lignification are also studied. Finally, the date fruit dietary composition and microstructure are related to the textural attributes of the fruit. Uppsala method of dietary fiber analysis (AOAC 994.13) is used …

Methods For The Assessment Of Cell Wall Composition In Miscanthus And Other 'Energy Grasses', Mark P. Robbins, G. G. Allison, E. Hodgson, C. Morris, S. Gill, I. S. Donnison

IGC Proceedings (1997-2023)

No abstract provided.

Zein And Lignin-Based Nanoparticles As Delivery Systems: Pesticide Release And Nanoparticle Health Impact On Soybean Plants, Fallon Polette Salinas Gonzalez

LSU Doctoral Dissertations

This research examined the effect of biodegradable, polymeric, lignin-based nanoparticles (LNPs, 113.8±3.4, negatively charged) and zein nanoparticles (ZNP, 141.6±3.9, positively charged) on soybean plant health. The LNPs were synthesized from lignin, covalently linked to poly(lactic-co-glycolic) acid by emulsion evaporation. ZNPs were synthesized by nanoprecipitation. Soybeans grown hydroponically were treated with three concentrations (0.02, 0.2, and 2 mg/ml) of NPs at 28 days after germination. The effect of ZNPs and LNPs on plant health was determined through analysis of root and stem length, chlorophyll concentration, dry biomass of roots and stem, as well as carbon, nitrogen, and micronutrient absorption after 1, …

Investigation Of Salt Tolerance Mechanisms Across A Root Developmental Gradient In Almond Rootstocks, Yuhang Shao, Yukun Cheng, Hongguang Pang, Mingqin Chang, Fang He, Minmin Wang, Destiny J. Davis, Shuxiao Zhang, Oliver Betz, Chuck Fleck, Tingbo Dai, Shahab Madahhosseini, Thomas E. Wilkop, Judy Jernstedt, Georgia Drakakaki

Physiology Faculty Publications

The intensive use of groundwater in agriculture under the current climate conditions leads to acceleration of soil salinization. Given that almond is a salt-sensitive crop, selection of salt-tolerant rootstocks can help maintain productivity under salinity stress. Selection for tolerant rootstocks at an early growth stage can reduce the investment of time and resources. However, salinity-sensitive markers and salinity tolerance mechanisms of almond species to assist this selection process are largely unknown. We established a microscopy-based approach to investigate mechanisms of stress tolerance in and identified cellular, root anatomical, and molecular traits associated with rootstocks exhibiting salt tolerance. We characterized three …

Enhancing The Production And Sustainability Of Pasture-Fed Beef Using Non-Traditional Legume Forages, Andrea I. Bolletta

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Despite the increasing worldwide demand for beef as a protein source, consumers are concerned about the sustainability of ruminant production systems. Their main concerns are animal welfare for feedlot-fed animals, greenhouse gas (GHG) emissions, global warming and worker safety. Traditional feedlot-based beef production systems have been associated with locally greater levels of soil, water and air contamination, as well as the overuse of antibiotics and growth hormones. The use of legume pastures such as cicer milkvetch (CMV) and birdsfoot trefoil (BFT), which fix their own nitrogen (N) and often contain beneficial secondary compounds such as tannins and provide for rapid …

Characterization And Enzyme Engineering Of A Hyperthermophilic Laccase Toward Improving Its Activity In Ionic Liquid, Joseph Craig Stevens, David W. Rodgers, Claire Dumon, Jian Shi

Biosystems and Agricultural Engineering Faculty Publications

Ionic liquids (ILs) are organic salts molten at room temperature that can be used for a wide variety of applications. Many ILs, such as 1-ethyl-3-methylimidazolium acetate ([C₂C₁Im][OAc]), have been shown to remove a significant fraction of the complex biopolymer lignin from biomass during pretreatment. Valorizing lignin via biological pathways (e.g., enzymes) holds promise but is limited by the low biocompatibility of many ILs used for pretreatment. The discovery of thermostable enzymes and the application of enzyme engineering techniques have yielded biocatalysts capable of withstanding high concentrations of ILs. Converting lignin from a waste product to value-added …

Leaf Traits Can Be Used To Predict Rates Of Litter Decomposition, Marc Rosenfield, Jennifer L. Funk, Jason K. Keller, Catrina Clausen, Kimberlee Cyphers

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Strong relationships exist between litter chemistry traits and rates of litter decomposition. However, leaf traits are more commonly found in online trait databases than litter traits and fewer studies have examined how well leaf traits predict litter decomposition rates. Furthermore, while bulk leaf nitrogen (N) content is known to regulate litter decomposition, few studies have explored the importance of N biochemistry fractions, such as protein and amino acid concentration. Here, we decomposed green leaves and naturally senesced leaf litter of nine species representing a wide range of leaf functional traits. We evaluated the ability of traits associated with leaf and …

Investigating The Transcriptional Regulation Of Secondary Cell Wall Synthesis And Thigmomorphogenesis In The Model Grass Brachypodium Distachyon, Joshua Coomey

Doctoral Dissertations

A key aspect of plant growth is the synthesis and deposition of cell walls. In specific tissues and cell types including xylem and fiber, a thick secondary wall composed of cellulose, hemicellulose, and lignin is deposited. Secondary cell walls provide a physical barrier that protects plants from pathogens, promotes tolerance to abiotic stresses, and fortifies cells to withstand the forces associated with water transport and the physical weight of plant structures. Grasses have numerous cell wall features that are distinct from eudicots and other plants. Study of the model species Brachypodium distachyon has helped us begin to understand the internal …

Cattle Fecal Decomposition On Pennisetum Purpureum Schum. Pastures Managed Under Different Post-Grazing Stubble Heights, José C. B. Dubeux Jr., Felipe M. Saraiva, Mércia V. F. Dos Santos, Alexandre C. L. De Mello, Vicente Imbrosi Teixeira, Erinaldo Viana De Freitas

IGC Proceedings (1997-2023)

Pasture management may affect cattle diet. Post-grazing stubble height is a pasture structural characteristic intrinsically linked to forage quantity and quality. Stubble height also indicates forage utilization rate, and as a result, affects nutrient pathway return (excreta or litter) and ultimately, nutrient cycling. Cattle excreta deposition affects soil chemical and physical characteristics (Carran and Theobald 2000). Slow release of nutrients from cattle dung, however, delays nutrient bioavailability for subsequent forage growth (Haynes and Williams 1993). This study evaluated how different post-grazing stubble heights on elephant grass (Pennisetum purpureum Schum.) pastures may affect cattle dung decomposition and nutrient release.

Root Decomposition Of Elephant Grass Pastures Grazed At Different Management Intensities, José C. B. Dubeux Jr., Hiran Marcelo Siqueira Da Silva, Maria Lúcia Silveira, Erinaldo Viana De Freitas, Mércia V. F. Dos Santos, Alexandre C. L. De Mello

IGC Proceedings (1997-2023)

Grazing management may alter chemical composition of plant components affecting nutrient cycling. Among pasture management tools, adjustment of stocking rate (SR) and N fertilization have potential to affect nutrient cycling in the grassland ecosystem (Dubeux et al. 2007). Excreta from grazing animal and litter are the two major pathways of nutrient return on grazed pastures (Thomas 1992). Fertilization and SR may alter these pathways by different forms. Increasing fertilization generally increases pasture net primary productivity. Stocking rate affects different pasture and animal responses. Regarding nutrient cycling, increasing SR will likely increase proportion of nutrient returned through excreta as opposed …

Increasing Rates Of Carbon Burial In Southwest Florida Coastal Wetlands, Joshua L. Breithaupt, Joseph M. Smoak, Thomas S. Bianchi, Derrick R. Vaughn, Christian J. Sanders, Kara R. Radabaugh, Michael J. Osland, Laura C. Feher, James C. Lynch, Donald R. Cahoon, Gordon H. Anderson, Kevin R.T. Whelan, Brad E. Rosenheim, Ryan P. Moyer, Lisa G. Chambers

Marine Science Faculty Publications

Rates of organic carbon (OC) burial in some coastal wetlands appear to be greater in recent years than they were in the past. Possible explanations include ongoing mineralization of older OC or the influence of an unaccounted-for artifact of the methods used to measure burial rates. Alternatively, the trend may represent real acceleration in OC burial. We quantified OC burial rates of mangrove and coastal freshwater marshes in southwest Florida through a comparison of rates derived from ²¹⁰Pb, ¹³⁷Cs, and surface marker horizons. Age/depth profiles of lignin: OC were used to assess whether down-core remineralization had depleted the …

Potential Of Panicum Maximum As A Source Of Energy, Liana Jank, Edson A. De Lima, Rosangela M. Simeão, Ronimar C. Andrade

IGC Proceedings (1997-2023)

The use of plant biomass as a source of energy presents many advantages, mainly that it is a renewable, clean source of energy. Many tropical grasses have excellent po-tential as energy crops. The main one in Brazil is Pennisetum purpureum (elephant grass) owing to its very high yields. However, it is vegetatively propagated, thus more difficult to establish than seed propagated species. The use of Panicum maximum (guinea grass) is a possible alternative for use as a source of energy, due to its high yields as well as seed propagation. The objective of this research was to evaluate the potential …

Compositional Characterization Of Different Industrial White And Red Grape Pomaces In Virginia And The Potential Valorization Of The Major Components, Qing Jin, Joshua O'Hair, Amanda C. Stewart, Sean F. O'Keefe, Andrew P. Neilson, Young-Teck Kim, Megan Mcguire, Andrew Lee, Geoffrey Wilder, Haibo Huang

Biology Faculty Research

To better evaluate potential uses for grape pomace (GP) waste, a comprehensive chemical composition analysis of GP in Virginia was conducted. Eight commercial white and red pomace samples (cv. Viognier, Vidal Blanc, Niagara, Petit Manseng, Petit Verdot, Merlot, Cabernet Franc, and Chambourcin) obtained from different wineries in Virginia, USA were used. For extractives, GPs contained 2.89%–4.66% titratable acids, 4.32%–6.60% ash, 4.62%–12.5% lipids with linoleic acid being the predominant (59.0%–70.9%) fatty acid, 10.4–64.8 g total phenolic content (gallic acid equivalents)/kg GP, 2.09–53.3 g glucose/kg GP, 3.79–52.9 g fructose/kg GP, and trace sucrose. As for non-extractives, GPs contained 25.2%–44.5% lignin, 8.04%–12.7% glucan, …

Overexpression Of Pear (Pyrus Pyrifolia) Cad2 In Tomato Affects Lignin Content, Mingtong Li, Chenxia Cheng, Xinfu Zhang, Suping Zhou, Lixia Li, Shaolan Yang

Agricultural and Environmental Sciences Faculty Research

PpCAD2 was originally isolated from the ‘Wangkumbae’ pear (Pyrus pyrifolia Nakai), and it encodes for cinnamyl alcohol dehydrogenase (CAD), which is a key enzyme in the lignin biosynthesis pathway. In order to verify the function of PpCAD2, transgenic tomato (Solanum lycopersicum) ‘Micro-Tom’ plants were generated using over-expression constructs via the agrobacterium-mediated transformation method. The results showed that the PpCAD2 over-expression transgenic tomato plant had a strong growth vigor. Furthermore, these PpCAD2 over-expression transgenic tomato plants contained a higher lignin content and CAD enzymatic activity in the stem, leaf and fruit pericarp tissues, and formed a greater number of vessel elements …

Lignin Biopolymers In The Age Of Controlled Polymerization, Mitra S. Ganewatta, Hasala N. Lokupitiya, Chuanbing Tang

Faculty Publications

Polymers made from natural biomass are gaining interest due to the rising environmental concerns and depletion of petrochemical resources. Lignin isolated from lignocellulosic biomass is the second most abundant natural polymer next to cellulose. The paper pulp process produces industrial lignin as a byproduct that is mostly used for energy and has less significant utility in materials applications. High abundance, rich chemical functionalities, CO2 neutrality, reinforcing properties, antioxidant and UV blocking abilities, as well as environmental friendliness, make lignin an interesting substrate for materials and chemical development. However, poor processability, low reactivity, and intrinsic structural heterogeneity limit lignins′ polymeric applications …