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THE HYPERACCUMULATION OF ZINC IN SUNFLOWERS AND ITS EFFECT ON DISEASE RESISTANCE
Title
THE HYPERACCUMULATION OF ZINC IN SUNFLOWERS AND ITS EFFECT ON DISEASE RESISTANCE.
Creator
Seavey, Rayner J, Mason, Chase, University of Central Florida
Abstract / Description
Sunflowers are considered to be a part of a group of plants known as hyperaccumulators that share the ability to accumulate high amounts of heavy metals in the above ground organs, far in excess of the levels found in other species, often without suffering any phytotoxic effects. Quantifying the effects of zinc accumulation through the lens of the elemental defense hypothesis is essential for uncovering if there is a means to increase herbivore resistance in agricultural settings without the...
Show moreSunflowers are considered to be a part of a group of plants known as hyperaccumulators that share the ability to accumulate high amounts of heavy metals in the above ground organs, far in excess of the levels found in other species, often without suffering any phytotoxic effects. Quantifying the effects of zinc accumulation through the lens of the elemental defense hypothesis is essential for uncovering if there is a means to increase herbivore resistance in agricultural settings without the use of external interventions such as pesticides. A greenhouse study was conducted on four widely grown commercial cultivars of sunflower. Each cultivar was grown under multiple soil Zn concentrations ranging from 0 to 200 mg/kg of soil. Growth rate measurements were taken at evenly spaced intervals until maturity. Samples of leaves were taken from plants and tested for Zn concentration. A qualitative study using Vanessa cardui was conducted to observe the effects of zinc in the diet of caterpillars. Significant variation in the level of zinc accumulated in the leaves was observed as well as variation in overall biomass per treatment level. V. cardui experienced high rates of mortality at high zinc concentrations suggesting that further study may lead to significant evidence that Zinc accumulation is a form of herbivore resistance.
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Date Issued
2019
Identifier
CFH2000491, ucf:45835
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH2000491
DEFENSE TRADE-OFFS IN THE EVOLUTION OF THE FRUITS AND FLOWERS OF GENUS CORNUS
Title
DEFENSE TRADE-OFFS IN THE EVOLUTION OF THE FRUITS AND FLOWERS OF GENUS CORNUS.
Creator
De La Pascua, Danielle R, Mason, Chase, University of Central Florida
Abstract / Description
The optimal defense hypothesis predicts that the allocation of plant defenses across plant organs is proportional to the importance of a given organ to plant fitness. Despite this, much less work has been devoted to the study of reproductive defenses in plants relative to vegetative structures like leaves. This study examines the apparancy hypothesis and the resource availability hypothesis using a phylogenetic comparative approach within the genus Cornus. During the 2016 growing season,...
Show moreThe optimal defense hypothesis predicts that the allocation of plant defenses across plant organs is proportional to the importance of a given organ to plant fitness. Despite this, much less work has been devoted to the study of reproductive defenses in plants relative to vegetative structures like leaves. This study examines the apparancy hypothesis and the resource availability hypothesis using a phylogenetic comparative approach within the genus Cornus. During the 2016 growing season, plants of 25 species of Cornus were tracked for flower and fruit phenology as well as sampled for floral and fruit tissue in a common garden experiment at the Arnold Arboretum of Harvard University. This tissue was used to quantify floral and fruit defensive chemistry (e.g. tannin activity, total phenolics, total flavonoids, titratable acidity), and fruit palatability traits (e.g. water, sugar, lipid, and protein content), and the color of reproductive structure using reflectance spectroscopy. Native habitat environmental data was obtained using digitized herbarium records and publicly available environmental data layers. Trait-trait and trait-environment relationships were assessed with phylogenetic generalized least squares regression. The evolution of later flowering phenology was correlated with increased floral phenolics and tannins, and the evolution of increased fruiting duration was correlated with increased fruit tannins, both supporting the apparancy hypothesis. Additionally, the evolution of higher fruit sugar content was correlated with higher fruit tannins, and a strong evolutionary trade-off between the production of tannins and the production of flavonoids was observed. With respect to habitat, floral and fruit flavonoids and tannins were consistently lower in species native to warmer environments, while fruit phenolics and was higher in drier environments, which may support the resource availability hypothesis.
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Date Issued
2019
Identifier
CFH2000508, ucf:45674
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFH2000508
A Multisystem Approach for the Characterization of Bacteria for Sustainable Agriculture
Title
A Multisystem Approach for the Characterization of Bacteria for Sustainable Agriculture.
Creator
Lee, Briana, Tetard, Laurene, Kang, Hyeran, Mason, Chase, University of Central Florida
Abstract / Description
The chemical, physical, and biological properties of bacteria developing resistance have been explored in animal based bacteria while plant bacteria have been largely neglected. Thus, the ability to probe changes in stiffness, adhesion, binding interactions and molecular traits of bacteria causing plant diseases is of great interest to develop a new generation of more potent, yet sustainable, pesticides. Our study aims to investigate the physical and chemical properties of bacterial systems,...
Show moreThe chemical, physical, and biological properties of bacteria developing resistance have been explored in animal based bacteria while plant bacteria have been largely neglected. Thus, the ability to probe changes in stiffness, adhesion, binding interactions and molecular traits of bacteria causing plant diseases is of great interest to develop a new generation of more potent, yet sustainable, pesticides. Our study aims to investigate the physical and chemical properties of bacterial systems, in particular their cell walls. Building upon this fundamental understanding of the cells, we also investigate the physicochemical responses associated to multivalent nanoparticle-based bactericide treatments on bacterial systems identified as pathogens in plant diseases. Here our efforts focus on developing a protocol for the fundamental understanding of Xanthomonas perforans, a strain known for causing bacterial spot in tomatoes and causing close to 50% losses in production. To support the design and accelerate the development of pesticides and treatments against this disease, we evaluate the changes bacteria undergo in the presence of the treatment. Using a silica nanoparticle-based treatment designed with a shell containing multivalent copper and quaternary ammonium, we compare bacteria pre- and post-treatment with infrared spectroscopy, atomic force microscopy (AFM)-based techniques, and TIRF microscopy. Statistical data analysis enables the identification of attributes that can potentially serve as markers to track the bacterial responses to the treatment in the future. Finally, we will discuss the exciting implications of this work, such as potential clues for the development of more potent treatments for resistant bacteria.
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Date Issued
2018
Identifier
CFE0007038, ucf:52005
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0007038