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Investigation Of Cytochrome P450 Monooxygenases In S. Homoeocarpa For Chlorothalonil Biotransformation, Robert Green

Masters Theses

Sclerotinia homoeocarpa (F.T. Bennett) is one of the most economically important pathogens on high amenity cool-season turfgrasses where it causes dollar spot. Due to decades of over-reliance and repeated chemical treatments, S. homoeocarpa has developed resistance and insensitivity to multiple classes of fungicides. To understand the genetic mechanisms of fungicide resistance, the whole genomes of two strains with varying resistance levels to fungicides, were sequenced. In unpublished data (Sang et al.), a RNA-sequencing analysis revealed three CYP450s that were validated to play a functional role in S. homoeocarpa’s resistance against different fungicide classes. We also identified CYP450 metabolic action …

Investigation Of Fungicide Resistance Mechanisms And Dynamics Of The Multiple Fungicide Resistant Population In Sclerotinia Homoeocarpa, Hyunkyu Sang

Doctoral Dissertations

A filamentous ascomycete fungus Sclerotinia homoeocarpa causes dollar spot, which is the most important disease of turfgrasses in the United States. Despite the increased number of reports of site-specific fungicide resistance and a recent report of multidrug resistance (MDR) in S. homoeocarpa field populations, the genetic mechanisms behind resistance or reduced sensitivity to fungicides remain poorly explained in the fungus. In order to prevent further development of fungicide resistance in the dollar spot pathosystem, a detailed elucidation of mechanisms of site-specific fungicide resistance and MDR is needed. In addition, the previous studies of MDR in fungi mostly focused on efflux …

The Key Question In Symbiotic Nitrogen Fixation: How Does Host Maintain A Bacterial Symbiont?, Onur Oztas

Doctoral Dissertations

The fact that plants cannot use nitrogen in the gaseous form makes them dependent on the levels of usable nitrogen forms in the soil. Legumes overcome nitrogen limitation by entering a symbiotic association with rhizobia, soil bacteria that convert atmospheric nitrogen into usable ammonia. In root nodules, bacteria are internalized by host plant cells inside an intracellular compartment called the symbiosome where they morphologically differentiate into nitrogen-fixing forms by symbiosome-secreted host proteins. In this project, I explained the host proteins required to maintain bacterial symbionts and described their delivery to the symbiosome. I showed that the SYNTAXIN 132 (SYP132) gene …

The Effect Of Management Practices On Bacterial, Fungal, And Nematode Communities On Cool Season Turfgrass, Elisha Allan-Perkins

Doctoral Dissertations

Golf courses comprise 50 million acres in the United States of highly managed turf susceptible to abiotic and biotic stressors. A growing area of interest is utilizing microbes to improve plant growth, increase disease and stress tolerance, and reduce pathogens. In order to develop these new practices, we must gain an understanding of turfgrass microbial communities and how they are affected by management practices. We characterized bacteria, fungi, and nematodes on three golf courses: one organic, one with reduced inputs, and one conventional. We took samples from three management areas on each course representing different management intensities (roughs, fairways, and …

Comparative Transcriptome Analysis Of Wild Tomato Species During Fruit Development, Altynay Zhanayeva

Masters Theses

Fleshy fruits in different species can display large variation in color. A link between fruit color and seed dispersal success is suggested by previous studies showing that high intensity of fruit color increases the visitation rate in seed-dispersing birds. Wild tomato species (Solanum spp.) are excellent model organisms for research on genetic basis of differential fruit color development during the ripening process. Despite polymorphism in fruit color, all tomato species have yellow flowers due to accumulation of carotenoid pigments, which suggests that the carotenoid pathway is intact. Thus, regulatory changes controlling enzymes activity during fruit maturation are likely …

Cranberry Research Report 2017: Defining New Approaches To Weed Management In Cranberry, Hilary A. Sandler, Katherine Ghantous

Cranberry Station Research Reports and Surveys

No abstract provided.

Uncovering The Genetic Basis For Biofuel-Related Traits In Brachypodium Distachyon, Scott J. Lee

Doctoral Dissertations

Biofuels derived from plant biomass present a promising avenue to address the negative aspects of fossil-fuel dependence. The sustainability of biofuel production relies in part on the efficient degradation of lignocellulosic feedstocks. In order to capitalize on the potential of lignocellulosic biofuels, the genes underlying natural genetic variation for conversion efficiency must be determined. We have developed a robust and high-throughput assay to measure feedstock quality using the anaerobic bacterium Clostridium phytofermentans. We have measured biomass accumulation phenotypes and utilized this assay to perform quantitative trait locus (QTL) mapping and a genome-wide association study (GWAS) in the model grass species …

Evaluating The Role Of Glutathione In Detoxification Of Metal-Based Nanoparticles In Plants, Chuanxin Ma

Doctoral Dissertations

The potential risks from metal-based nanoparticles (NPs) in the environment have increased with the rapidly rising demand for and use of nano-enabled consumer products. Plant’s central roles in ecosystem function and food chain integrity ensure intimate contact with water and soil systems, both of which are considered sinks for NPs accumulation. Thus, this dissertation describes three main objectives to comprehensively understand the interactions between plants and NPs and to characterize the role of glutathione (GSH) in detoxification of metal-based NPs in plants at physiological, biochemical, and molecular levels. (1) The effects of cerium oxide (CeO₂) and indium oxide …

Investigate The Interactions Between Silver Nanoparticles And Spinach Leaf By Surface Enhanced Raman Spectroscopic Mapping, Zhiyun Zhang

Masters Theses

Owing to their increasing application and potential toxicity, engineered nanoparticles (ENPs) have been considered as a potential agricultural contaminant that may pose unknown risk to human beings. However, many techniques require invasive and complicated sample preparation procedures to detect and characterize engineered nanomaterials in complex matrices. In the first part of this thesis, we present a non-destructive and label-free approach based on surface enhanced Raman spectroscopic (SERS) mapping technique to qualitatively detect and characterize gold nanoparticles (AuNPs), on and in spinach leaves in situ. We were able to detect the clearly enhanced signals from AuNPs at 15 to 125 nm …

Iron Signaling In Arabidopsis Thaliana, Celina Abundis

Masters Theses

Iron is among the essential micronutrients for all living organisms and is a cofactor for many cellular redox reactions. Although iron is a highly abundant metal element found in the earth’s crust, it is also a limiting factor in plant development when it is present as insoluble ferric oxides. Plants have evolved two strategies to acquire soluble iron referred to as Strategy I and Strategy II. Our lab has focused on the Arabidopsis thaliana double mutant ysl1ysl3. The mutants display a chlorotic phenotype and are unable to correctly respond to iron deficiency.

Grafting is a common method for joining …

Novel Advancements For Improving Sprout Safety, Kyle S. Landry

Doctoral Dissertations

All varieties of bean sprouts (mung bean, alfalfa, broccoli, and radish) are classified as a “super-food” and are common staples for health conscious consumers. Along with the proposed health benefits, there is also an inherent risk of foodborne illness. When sprouts are cooked, there is little risk of illness. The purpose of this dissertation was to explore novel techniques to minimize or prevent the incidence of foodborne illness associated with the consumption of sprouts. Three areas were investigated: 1) the use of a biocontrol organism, 2) the use of a novel spontaneous carvacrol nanoemulsion, and 3) the influence of the …

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 …

Understory Plant Community Structure In Forests Invaded By Garlic Mustard (Alliaria Petiolata), Jason Aylward

Masters Theses

ABSTRACT

UNDERSTORY PLANT COMMUNITY STRUCTURE IN FORESTS INVADED BY GARLIC MUSTARD (ALLIARIA PETIOLATA)

MAY 2016

JASON ALLEN AYLWARD, B.S., PAUL SMITH’S COLLEGE

M.S. UNIVERSITY OF MASSACHUSETTS AMHERST

Directed by: Professor Kristina Stinson

Plant invasions represent a significant threat to the structure and function of natural ecosystems. Garlic mustard (Alliaria petiolata) has been identified as a threat to native communities mostly through small-scale studies and focused experiments. In this in situ observational study I examined the effects of garlic mustard invasion on species composition across multiple sites by comparing plant diversity and composition in invaded and adjacent …

Variations In The Invertebrate Communities Of Wild Cape Cod Cranberry Bogs, Barbara Wagner

Masters Theses

As a species domesticated only in the last century, agricultural cranberry plants (Vaccinium macrocarpon) remain little removed from their wild relatives. Thus, it is a potential model species for studies of the earliest stages of domestication; however, there is little available quantitative information on its wild population biology and ecology. As such information is vital to studies of the ecological changes occurring during domestication, the purpose of this study was to consolidate the relevant knowledge available and conduct a preliminary search for patterns in the invertebrate communities of wild bogs. The alpha diversity was found to be greater …

2016 Chart Book: Warnings, Martha Sylvia

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Measures And Conversions Chart, Hilary Sandler

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Weed Management At-A-Glance, Hilary Sandler, Katherine M. Ghantous

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Pesticide Application Recordkeeping, Martha Sylvia

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Cautions, Martha Sylvia

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Table Of Contents, Carolyn J. Demoranville

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Index, Carolyn J. Demoranville

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Nutrition Management, Carolyn J. Demoranville

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Disease Management, Erika Saalau Rojas, Frank L. Caruso, Martha Sylvia

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Disease Management At-A-Glance, Erika Saalau Rojas, Frank Caruso, Martha Sylvia

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Irrigation Water Managenent, Peter Jeranyama

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Late Water And Cranberry Management, Carolyn J. Demoranville, Anne L. Averill, Hilary A. Sandler, Erika Saalau Rojas

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Winter Management, Carolyn J. Demoranville

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Insect Management At-A-Glance, Anne L. Averill, Martha M. Sylvia

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Pesticide Storage Guidelines, Hilary Sandler

Cranberry Chart Book - Management Guide

No abstract provided.

2016 Chart Book: Resistance Management, Martha Sylvia

Cranberry Chart Book - Management Guide

No abstract provided.