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Visual Attention In Jumping Spiders, Margaret Bruce Mar 2019

Visual Attention In Jumping Spiders, Margaret Bruce

Masters Theses

The different ways that animals extract and analyze visual information from their environment is of interest to sensory ecologists. Jumping spiders, well-known for visually guided mating and hunting behavior, are an interesting model for the study of visual attention because they quickly and efficiently integrate information from eight eyes with a small brain. Stimuli in front of the spider are examined by two functionally and morphologically distinct pairs of forward-facing eyes. The principal eyes discern fine details and have small retinas and thus a small visual field. However, their position at the back of moveable tubes within the cephalothorax expands ...


Cardiovascular Disease Risk And Menopause: Effects Of Cardiorespiratory Fitness, Exercise, And Follicle Stimulating Hormone, Corinna Serviente Nov 2018

Cardiovascular Disease Risk And Menopause: Effects Of Cardiorespiratory Fitness, Exercise, And Follicle Stimulating Hormone, Corinna Serviente

Doctoral Dissertations

Menopause is associated with adverse changes in cardiovascular disease risk factors. A reduction in estrogens is most commonly associated with changing cardiovascular disease risk; however, recent observations suggest that the increase in follicle stimulating hormone that accompanies menopause may also influence risk, potentially through its influence on lipid levels. The changes in cardiovascular disease risk factors may adversely affect endothelial cell function, a pre-clinical marker for cardiovascular disease. Whether cardiorespiratory fitness is protective of endothelial health in this population, thereby mitigating the changes in risk that accompany menopause, is unclear. This dissertation evaluated differences in endothelial health and endothelial responses ...


An Integrative Approach To Understanding Morphological Novelties: Anatomy, Development, Genetics, And Evolution Of An Extreme Craniofacial Trait In East African Cichlids, Moira R. Conith Nov 2018

An Integrative Approach To Understanding Morphological Novelties: Anatomy, Development, Genetics, And Evolution Of An Extreme Craniofacial Trait In East African Cichlids, Moira R. Conith

Doctoral Dissertations

Phenotypic novelties are an important but poorly understood category of morphological diversity that are often associated with elevated rates of diversification and/or ecological success. The aim of this dissertation is to explore a phenotypic novelty at many levels to contribute to our understanding of how these unique traits can arise (e.g., genetically, developmentally, and evolutionarily) as well as their ecological consequences (e.g., trait function). The extreme snout of the Lake Malawi cichlid fish Labeotropheus is used as a case study. The first chapter establishes the Labeotropheus snout as a model of phenotypic novelty by characterizing the gross ...


Plants, Parasites, And Pollinators: The Effects Of Medicinal Pollens On A Common Gut Parasite In Bumble Bees, George Locascio Oct 2018

Plants, Parasites, And Pollinators: The Effects Of Medicinal Pollens On A Common Gut Parasite In Bumble Bees, George Locascio

Masters Theses

Declines in several pollinator species are due to a variety of factors, including pathogens. Incorporating pollinator-friendly plant species into wild and agricultural habitats could reduce the stress of pathogens if food sources act medicinally against pathogens. Previous research demonstrated one domesticated sunflower cultivar (Helianthus annuus) can dramatically reduce a gut pathogen (Crithidia bombi) of the common eastern bumble bee, Bombus impatiens. To ascertain the breadth of this medicinal trait, we tested whether pollen from several H. annuus cultivars and four relatives could also reduce C. bombi infections in B. impatiens. We also investigated whether timing of exposure to sunflower pollen ...


Transposable Elements In Fusarium Oxysporum & Growth Inhibition Of Fusarium Oxysporum Using Pepper Extracts, Taylor Aguiar Jul 2018

Transposable Elements In Fusarium Oxysporum & Growth Inhibition Of Fusarium Oxysporum Using Pepper Extracts, Taylor Aguiar

Masters Theses

The following contains two projects focused on the fungal pathogen, Fusarium oxysporum. The first project was purely computational in the examination of transposable elements (TEs), which are mobile sequences with the ability to multiply and move in their host genome. In F. oxysporum, TEs such as miniature impala elements are associated with the secreted in xylem gene that are related to its virulence over its host. The F. oxysporum species complex can be utilized as a model system for the examination of TE content and TE expression during the infection cycle. To find whether TEs play a role in the ...


Effects Of Floral Phytochemicals On Growth And Evolution Of A Parasite Of Bumble Bees, Evan Palmer-Young Mar 2018

Effects Of Floral Phytochemicals On Growth And Evolution Of A Parasite Of Bumble Bees, Evan Palmer-Young

Doctoral Dissertations

Background: Nectar and pollen are rich in phytochemicals, some of which can reduce disease in pollinators, including agriculturally important honey and bumble bees. Floral phytochemicals could influence the ecological and evolutionary relationships between plants, their pollinators, and parasites that cause pollinator disease. Antiparasitic effects of phytochemicals could be exploited to ameliorate pollinator disease and decline, and thereby sustain pollinator-dependent agricultural production. However, prior studies showed variable effects of phytochemicals on infection in live bees, where differences in bee genotype, abiotic conditions, and parasite strain could influence results.

Approach: I used cell cultures of the intestinal trypanosome parasite of bumble bees ...


Characterization Of Calcium Homeostasis Parameters In Trpv3 And Cav3.2 Double Null Mice, Aujan Mehregan Dec 2017

Characterization Of Calcium Homeostasis Parameters In Trpv3 And Cav3.2 Double Null Mice, Aujan Mehregan

Masters Theses

In mammals, calcium influx is required for oocyte maturation and egg activation, as it supports the persistent calcium oscillations induced by fertilization. These oscillations are required for the initiation of embryo development. The molecular identities of the plasma membrane calcium-permeant channels that underlie calcium influx are not established. Among these channels, Transient Receptor Potential Vanilloid, member 3 (TRPV3) allows divalent cations, namely strontium (Sr2+) and calcium (Ca2+) with high permeability, into cells, and its expression pattern seems to predict an essential role in the initiation of development. Another channel that was identified to be expressed in oocytes/eggs ...


Uncovering Tasselsheath3. A Genomic And Phenotypic Analysis Of A Maize Floral Mutant., Thompson Zhang Oct 2017

Uncovering Tasselsheath3. A Genomic And Phenotypic Analysis Of A Maize Floral Mutant., Thompson Zhang

Masters Theses

In the modern era, maize has become the most successful crop grown in the United States. According to the USDA over 90 million acres of land are planted to corn and 96.2% of the U.S feed grain production is made up of the cereal. Part of the success of maize is due to its floral architecture, and its pollination technique in which the flower opens, exposing stamens containing pollen into the air. A unique organ called the lodicule functions as a release mechanism, forcing the flower to open. Lodicules from grasses and eudicot petals are homologous, yet there ...


The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr. Jul 2017

The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr.

Doctoral Dissertations

In this dissertation several research studies are discussed that characterize the effects of anthropogenic, or human-induced, stress on both ammonia-oxidizing and total bacterial soil microbial communities. The disturbances of land-use change in tropical, South American rainforests and artificial warming and nitrogen (N) fertilization in temperate, North American forests were investigated as these disturbances represent past and current disturbances caused by human landscape alteration and climate change. Initially, the response of soil ammonia-oxidizing microbial communities to land-use change from primary rainforest to pasture and, finally, back to secondary forest was determined. Next, these analyses of land-use change effects were expanded to ...


Potential Enhancement Of Dietary Isothiocyanates Combination On Biological Activities, Kanyasiri Rakariyatham Jul 2017

Potential Enhancement Of Dietary Isothiocyanates Combination On Biological Activities, Kanyasiri Rakariyatham

Doctoral Dissertations

Isothiocyanates (ITCs) such as allyl isothiocyanate (AIT) and sulforaphane (SFN) are well-known bioactives with wide range of beneficial properties, which may be consumed simultaneously through diets containing cruciferous vegetables. However, biological activities of ITCs in combinations had not been well defined. The present study evaluated the potential efficacy of AIT, SFN and their combinations on three important biological properties: anticancer, anti-inflammation and antioxidant.

Our results showed that the combination between AIT and SFN led to a stronger growth inhibition on A549 non-small cell lung cancer cells than treatments with the individual compounds. The enhanced effect was proved to be synergistic ...


The Role Of Phenotypic Integration In Mammalian Tooth Function And Jaw Morphological Diversity, Andrew Conith Jul 2017

The Role Of Phenotypic Integration In Mammalian Tooth Function And Jaw Morphological Diversity, Andrew Conith

Doctoral Dissertations

Here I investigate how two major components of the mammalian feeding system, teeth and jaws, are influenced by functional, environment, and developmental factors. First, I build physical models of the molars from two early mammals, Morganucodon and Kuehneotherium, and compare their ability to process a proxy food item. Early mammals were under strong selection to reduce metabolic costs, so any savings in energy during feeding would be advantageous. I tested the ability of both mammals to process a hard and soft food item with material properties similar to that of the insects they would have likely consumed. Morganucodon was better ...


Burrowing And Walking Mechanisms Of North American Moles, Yi-Fen Lin Jul 2017

Burrowing And Walking Mechanisms Of North American Moles, Yi-Fen Lin

Doctoral Dissertations

Moles (Family Talpidae) are a classic example of extreme specialization, in their case highly derived forelimb morphologies associated with burrowing. Despite many observations of mole burrows and behaviors gathered in the field, we know very little about how and how well moles use their forelimbs to dig tunnels and to walk within the built tunnels to collect and transport food. The first chapter investigates the effect of soil compactness on two sympatric mole species under controlled laboratory conditions. My results demonstrate that increasing soil compactness impedes tunneling performance as evidenced by reduced burrowing speed, increased soil transport, shorter tunnels, shorter ...


Factors Influencing Impact Of Biological Control Agents Of The Emerald Ash Borer, Theresa Murphy Mar 2017

Factors Influencing Impact Of Biological Control Agents Of The Emerald Ash Borer, Theresa Murphy

Masters Theses

Agrilus planipennis, the emerald ash borer (EAB), is a destructive invasive forest pest decimating North American ash trees. Population-wide management of EAB focuses on biological control, with the introduction of four parasitic wasps; one egg parasitoid, Oobius agrili and three larval parasitoids- Spathius galinae, Spathius agrili and Tetrastichus planipennisi. This thesis examines some of the factors influencing the establishment of these larval biocontrol agents. Chapter 1 examines the relationship between woodpeckers and the parasitoids S. agrili and T. planipennisi. Both woodpeckers and these parasitoids attack the larval stage of EAB, which means their impacts overlap and potentially interact. To examine ...


An Adult Zebrafish Brain Atlas To Investigate Shh Mediated Cell-Cell Signaling In Neurogenic Zones, Alyssa P. Lutservitz Mar 2017

An Adult Zebrafish Brain Atlas To Investigate Shh Mediated Cell-Cell Signaling In Neurogenic Zones, Alyssa P. Lutservitz

Masters Theses

Adult neurogenesis occurs in proliferative zones of the brain that contain neural progenitor cell populations capable of differentiating into specific cell types. However, we remain limited in our understanding of the signals that regulate neural progenitor cell proliferation and differentiation in adults. Recently zebrafish (Danio rerio) have emerged as an excellent model for studying the molecular mechanisms behind adult neurogenesis, because sixteen proliferative zones remain active in the adult brains. Thousands of fluorescent transgenic reporter lines have been generated in zebrafish that reveal gene expression patterns of cell-cell signaling systems, some of which may regulate neurogenesis in these brain regions ...


The Consequences Of Speed: Studies Of Cavitation During The Mantis Shrimp Strike And The Control Of Rapid Deceleration During Toad Landing, Suzanne M. Cox Nov 2016

The Consequences Of Speed: Studies Of Cavitation During The Mantis Shrimp Strike And The Control Of Rapid Deceleration During Toad Landing, Suzanne M. Cox

Doctoral Dissertations

There are consequences of moving quickly in this world. Here we investigate how two very different species, mantis shrimp (Odontodactylus scyllarus) and cane toads (Bufo marinus), negotiate forces that result from moving rapidly in different environments. To study the mechanical principles and fluid dynamics of ultrafast power-amplified systems, we built Ninjabot, a physical model of the extremely fast mantis shrimp. While mantis shrimp produce damaging cavitation upon impact with their prey, they do not cavitate during the forward portion of their strike despite extreme speeds. In order to study cavitation onset in non-linear flows common during the mantis shrimp strike ...


Spider Brain Morphology & Behavior, Skye M. Long Jul 2016

Spider Brain Morphology & Behavior, Skye M. Long

Doctoral Dissertations

Spiders are ideal model animals for experimental and comparative studies of behavior, learning and perception. They display many complex behaviors, such as the multimodal mating dances of lycosid spiders, the stealthy hunting strategies of the jumping spider Portia sp., to the labile sociality of theridiids. Spiders also demonstrate a wide range of cognitive capabilities. Spiders perceive their environment using multiple sensory modalities including: chemosensory organs; lyriform and slit-sense organs and specialized hairs that detect vibration and air movement; and up to eight eyes that vary in function, some able to detect polarization and a broad spectrum of light, including ultraviolet ...


Chemically Mediated Interactions Between Hosts, Parasitic Plants And Insect Herbivores, Muvari C. Tjiurutue Jul 2016

Chemically Mediated Interactions Between Hosts, Parasitic Plants And Insect Herbivores, Muvari C. Tjiurutue

Doctoral Dissertations

Species interactions, by changing phenotypic traits, can alter the outcome of subsequent interactions. Plant-mediated responses to herbivores have been extensively studied, but little is known about plant-mediated responses involving parasitic plants within a broader community context that also includes herbivores. Because parasitic plants are important components of many ecosystems and can shape community structure, it is important to understand how host-mediated interactions influence parasite preference and success. The goal of this thesis is to examine interactions between hosts, parasitic plants and herbivores mediated by chemical traits. We first examined the effects of dodder (Cuscuta sp.) parasitism on induced defenses in ...


Curcumin And Its Oxidative Degradation Products: Their Comparative Effects On Inflammation, Julia Zhu Jul 2016

Curcumin And Its Oxidative Degradation Products: Their Comparative Effects On Inflammation, Julia Zhu

Masters Theses

The anti-inflammatory agent curcumin degrades rapidly, leading to speculations that curcumin’s reported effects stem from its degradation products. Curcumin can degrade via hydrolysis, and more recently it was discovered that curcumin can degrade via oxidation at physiological pH. Additionally, bicyclopentadione is the major degradation product from this oxidation reaction. Evidence from the literature suggests that curcumin degrades primarily through oxidation. However, the biology of the oxidation products is not well characterized, and there is debate on whether oxidation intermediates or curcumin itself is more biologically active. To further elucidate the biology of the oxidation products, their effects on inflammation ...


Evaluating A Novel Photochemical Tool For Labeling And Tracking Live, Endogenous Calcium-Permeable Ampars, Rosamund Elizabeth Combs-Bachmann Jul 2016

Evaluating A Novel Photochemical Tool For Labeling And Tracking Live, Endogenous Calcium-Permeable Ampars, Rosamund Elizabeth Combs-Bachmann

Masters Theses

The purpose of this research is to advance development of a photochemical tool designed to probe the role of ionotropic glutamate receptor signaling in neurodegenerative processes, and to delve more deeply into the biological processes underlying the role of these receptors in signaling and memory formation. This ligand-targeted nanoprobe was designed and developed in our lab to label endogenous calcium-permeable AMPARs (CP-AMPARs) in live cells with minimal disruption to native receptor activity. Nanoprobe is designed to use naphthyl acetyl spermine (NASPM) as a photocleavable ligand to target and covalently label native CP-AMPARs with a non-perturbing, fluorescent marker that then allows ...


Evolvability Of The Skull: A Study Of Genetic Basis And Integration In The Teleost Craniofacial Skeleton, Yinan Hu Mar 2016

Evolvability Of The Skull: A Study Of Genetic Basis And Integration In The Teleost Craniofacial Skeleton, Yinan Hu

Doctoral Dissertations

As the field of evolutionary biology pivots away from a gene-centric view of how adaptive evolution proceeds, renewed emphasis is placed on the origin of phenotypic variation. Understanding the developmental processes that underlie the production of novel traits, and how they might influence evolvability, is considered a primary goal in the on-going “extended evolutionary synthesis”. The following dissertation explores these questions in the context of adaptive radiations in fish, with a focus on morphological variation in the craniofacial skeleton. Specifically, the first chapter investigates the genetic and developmental basis of shape (co-)variation in the feeding apparatus of African cichlid ...


Promoting Extracellular Matrix Crosslinking In Synthetic Hydrogels, Marcos M. Manganare Nov 2015

Promoting Extracellular Matrix Crosslinking In Synthetic Hydrogels, Marcos M. Manganare

Masters Theses

The extracellular matrix (ECM) provides mechanical and biochemical support to tissues and cells. It is crucial for cell attachment, differentiation, and migration, as well as for ailment-associated processes such as angiogenesis, metastases and cancer development. An approach to study these phenomena is through emulation of the ECM by synthetic gels constructed of natural polymers, such as collagen and fibronectin, or simple but tunable materials such as poly(ethylene glycol) (PEG) crosslinked with short peptide sequences susceptible to digestion by metalloproteases and cell-binding domains. Our lab uses PEG gels to study cell behavior in three dimensions (3D). Although this system fosters ...


Estimation Problems In Complex Field Studies With Deep Interactions: Time-To-Event And Local Regression Models For Environmental Effects On Vital Rates, Krzysztof M. Sakrejda Nov 2015

Estimation Problems In Complex Field Studies With Deep Interactions: Time-To-Event And Local Regression Models For Environmental Effects On Vital Rates, Krzysztof M. Sakrejda

Doctoral Dissertations

Field studies that measure vital rates in context over extended time periods are a cornerstone of our understanding of population processes. These studies inform us about the relationship between biological process and environmental noise in an irreplaceable way. These data sets bring ``big data'' and ``big model'' challenges, which limit the application of standard software (e.g., \textbf{BUGS}). The environmental sensitivity of vital rates is also expected to exhibit interactions and non-linearity, which typically result in difficult model selection questions in large data sets. Finally, long-term ecological data sets often contain complex temporal structure. In commonly applied discrete-time models ...


An Integrative, Cost-Benefit Analysis On Animal Perturbations: Autotomy And Life-History Related Weight Gain, Chi-Yun Kuo Nov 2015

An Integrative, Cost-Benefit Analysis On Animal Perturbations: Autotomy And Life-History Related Weight Gain, Chi-Yun Kuo

Doctoral Dissertations

The variation in behavioral traits and the adaptive significance behind such variation has been a classic question in behavioral ecology. Traits that enhance while simultaneously impose high fitness costs are particularly suitable for addressing this fundamental question, as their expressions are likely under strong selection. In this dissertation, I investigate the variation in a costly antipredator behavior and the underlying cost-benefit mechanisms. The trait of interest is the voluntary shedding of the tail, or tail autotomy, in lizards. Tail autotomy allows lizards to survive close-range encounters with predators but also has severe fitness consequences, including increased energetic demand for regeneration ...


Engineering Novel Detection And Treatment Strategies For Bacterial Therapy Of Cancer, Jan T. Panteli Aug 2015

Engineering Novel Detection And Treatment Strategies For Bacterial Therapy Of Cancer, Jan T. Panteli

Doctoral Dissertations

Finding and treating cancer is difficult due to limited sensitivity and specificity of current detection and treatment strategies. Many chemotherapeutic drugs are small molecules that are limited by diffusion, making it difficult to reach cancer sites requiring high doses that lead to systemic toxicity and off-target effects. Tomographic detection techniques, like PET, MRI and CT, are good at identifying macroscopic lesions in the body but are limited in their ability to detect microscopic lesions. Biomarker detection strategies are extremely sensitive and able to identify ng/ml concentrations of protein, but are poor at discriminating between healthy and disease state levels ...


The Effects Of Ovarian Hormones And Exercise On Gene Markers Of Cardiac Dysfunction, Anisha S. Patel Jul 2015

The Effects Of Ovarian Hormones And Exercise On Gene Markers Of Cardiac Dysfunction, Anisha S. Patel

Masters Theses

Heart disease is the leading cause of death in women in the United States. Premenopausal women appear to have better cardiac function and lower risk of heart disease compared to male postmenopausal female counterparts. Ovarian hormone loss influences blood pressure homeostasis and causes systemic inflammation, which may result in chronic stress on the heart. Two key physiological changes in cardiac dysfunction are reemergence of the fetal gene pattern and myocardial remodeling. Physical activity has been linked to improved cardiac function. The purpose of this study was to investigate the effects of ovariectomy on early markers of cardiac dysfunction and fibrosis ...


Rnai Mediated Silencing Of Cell Wall Invertase Inhibitors To Increase Sucrose Allocation To Sink Tissues In Transgenic Camelina Sativa Engineered With A Carbon Concentrating Mechanism, Joshua Zuber Jul 2015

Rnai Mediated Silencing Of Cell Wall Invertase Inhibitors To Increase Sucrose Allocation To Sink Tissues In Transgenic Camelina Sativa Engineered With A Carbon Concentrating Mechanism, Joshua Zuber

Masters Theses

Plant invertases are a class of proteins that have enzymatic function in cleaving sucrose to fructose and glucose. Cell wall invertase, located on the exterior of the cell wall of plant cells, plays a key role in the unloading of sucrose from the apoplast to the sink tissues. Cell wall invertase interacts with an inhibitor, cell wall invertase inhibitor, post-transcriptionally to regulate its activity. The inhibitor is constitutively expressed in pollen development, early developing seeds, and senescing leaves: indicative of sucrose allocation being a limiting factor at these stages of development. We introduced algal bicarbonate transporters LCIA/CCP1 to Camelina ...


Thermocycle-Regulated Wall Regulator Interacting Bhlh Encodes A Protein That Interacts With Secondary-Cell-Wall-Associated Transcription Factors, Ian P. Whitney Mar 2015

Thermocycle-Regulated Wall Regulator Interacting Bhlh Encodes A Protein That Interacts With Secondary-Cell-Wall-Associated Transcription Factors, Ian P. Whitney

Masters Theses

Lignocellulosic biomass is one of the most abundant raw materials on earth that can be utilized to created carbon-neutral biofuels as a replacement for conventional fossil fuels. In order to create ideal energy crops, the regulation and deposition of cell wall polysaccharides must first be fully understood. Improved understanding of cell wall regulation will enable selection of traits that can optimize biofuel feedstocks. Herein, I utilize the grass model system Brachypodium distachyon in order to understand the transcriptional regulation of secondary cell wall deposition. Gene expression profiling was used to elucidate transcription factors that regulate secondary cell wall biosynthesis. Through ...


Efficient Irrigation For Recreational Turfgrass In New England: Evapotranspiration And Crop Coefficients, James W. Poro Mar 2015

Efficient Irrigation For Recreational Turfgrass In New England: Evapotranspiration And Crop Coefficients, James W. Poro

Masters Theses

ABSTRACT

EFFICIENT IRRIGATION FOR RECREATIONAL TURFGRASS IN NEW ENGLAND: EVAPOTRANSPIRATION AND CROP COEFFICIENTS

AUGUST 2014

JAMES PORO, B.S., UNIVERSITY OF MASSACHUSETTS AMHERST

M.S., UNIVERSITY OF MASSACHUSETTS AMHERST

Directed by: Dr. J. Scott Ebdon

As water demand increases it will become more imperative for golf course superintendents, landscape managers, and other industry professionals to improve water use efficiency in the management of recreational turfgrass. Scheduling irrigation according to actual turfgrass evapotranspiration rates (ETT) is an integral component of efficient irrigation practices. Impracticality of field derived ETT for industry use, however, directs the need of weather station derived ...


A Novel Population Of Natural Killer Cells Plays A Critical Role In The Depletion Of Splenic B2 B Cells During Experimental African Trypanosomiasis, Deborah Frenkel Mar 2015

A Novel Population Of Natural Killer Cells Plays A Critical Role In The Depletion Of Splenic B2 B Cells During Experimental African Trypanosomiasis, Deborah Frenkel

Doctoral Dissertations

Loss of humoral immune competence in T. brucei-infected mice is associated with the apoptotic depletion of splenic transitional, marginal zone and follicular B cells as well as a depletion of CD8+ T cells. This occurs rapidly after infection and impairs responses to vaccine antigens in addition to responses to newly arising VSG antigenic variants, leading to uncontrolled parasite growth and death of the infected mice. Infection-induced B2 B cell and CD8+ T cell loss requires the presence of a novel population of natural killer (NK) cells and is mediated by a perforin-dependent process consistent with perforin- and granzyme-mediated cytotoxicity ...


Understanding The Transcriptional Regulation Of Secondary Cell Wall Biosynthesis In The Model Grass Brachypodium Distachyon, Pubudu Handakumbura Nov 2014

Understanding The Transcriptional Regulation Of Secondary Cell Wall Biosynthesis In The Model Grass Brachypodium Distachyon, Pubudu Handakumbura

Doctoral Dissertations

Secondary cell wall synthesis occurs in specialized cell types following completion of cell enlargement. By virtue of mechanical strength provided by a wall thickened with cellulose, hemicelluloses, and lignin, these cells can function as water-conducting vessels and provide structural support. Several transcription factor families regulate genes encoding wall synthesis enzymes. Certain NAC and MYB proteins directly bind upstream of structural genes and other transcription factors. The most detailed model of this regulatory network is established predominantly for a eudicot, Arabidopsis thaliana. In grasses, both the patterning and the composition of secondary cell walls are distinct from that of eudicots. These ...