Theses and Dissertations at Montana State University (MSU)
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Item Linking plant and soil nutrient dynamics in temperate and tropical montane forests(Montana State University - Bozeman, College of Letters & Science, 2018) Qubain, Claire Anne; Chairperson, Graduate Committee: David Roberts; Jia Hu (co-chair); Yuriko Yano and Jia Hu were co-authors of the article, 'Linking nitrogen allocation in douglas-fir to soil nitrogen availability in a western montane conifer forest' submitted to the journal 'Oecologia' which is contained within this thesis.; Diego Riveros-Iregui and Jia Hu were co-authors of the article, 'Climate and invasion drive soil nutrient dynamics in tropical montane forests of the Galapagos archipelago' submitted to the journal 'Ecology' which is contained within this thesis.I built on our fundamental understanding of ecosystem function by examining how climate variability influences feedbacks between plant processes and soil nutrient dynamics. At Lubrecht Experimental Forest, I examined how variability in snow depth, precipitation, and soil moisture influenced seasonal nitrogen allocation in Douglas-fir. I then examined if N cycling within Douglas-fir synchronized with patterns of N availability in the soil. In this case, N availability in the soil influenced plant nutrient dynamics. On the other hand, on San Cristobal Island in the Galapagos Archipelago, plants fed back and influenced soil nutrient dynamics. Changes in precipitation, soil moisture, and temperature strongly controlled nutrient concentrations in the soil, and to a lesser degree, plant community type determined nutrient concentrations, especially N concentrations, in the soil.Item Omics approaches identify molecular mechanisms of arsenic-microbial interactions(Montana State University - Bozeman, College of Letters & Science, 2019) Rawle, Rachel Anna; Chairperson, Graduate Committee: Timothy R. McDermott and Brian Bothner (co-chair); Yoon-Suk Kang, Brian Bothner, Gejiao Wang and Timothy R. McDermott were co-authors of the article, 'Transcriptomics analysis defines global cellular response of Agrobacterium tumefaciens 5A to arsenite exposure regulated through the histidine kinases phor and aios' in the journal 'Environmental microbiology' which is contained within this dissertation.; Monika Tokmina-Lukaszewska, Zunji Shi, Brian Tripet, Fang Dang, Timothy R. McDermott, Valerie Copie, Gejiao Wang and Brian Bothner were co-authors of the article, 'Metabolic responses to arsenite exposure regulated through histidine kinases phor and aios in Agrobacterium tumefaciens 5A' submitted to the journal 'Environmental microbiology' which is contained within this dissertation.Arsenic is a class I carcinogen and causes various cancers and diseases. Its toxicity, prevalence, and potential for human exposure has classified arsenic as the number one environmental toxin according to the Environmental Protection Agency. Contamination of groundwater and soil leads to over 200 million human exposures above the health limit. In every environment where arsenic and microbes coexist, microbes are the principal drivers of arsenic speciation, which is directly related to bioavailability, toxicity, and bioaccumulation. These speciation events drive arsenic behavior in the soil, water, and as recent data suggests, human-associated microbiomes. This dissertation details arsenic-microbial interactions through an omics platform, utilizing transcriptomics, metabolomics, and proteomics profiling as a way to globally assess the impacts of arsenic exposure. This work followed two main aims: (1) characterize cell metabolism during arsenic exposure in soil bacterium Agrobacterium tumefaciens 5A, a model organism for arsenite oxidation, and (2) assess the impacts of specific arsenic-processing bacteria within the gut microbiome of mammals. The results of this work provide a foundational understanding for how arsenic speciation events are regulated and how they affect nutrient cycling in environmental systems, which is necessary for bioremediation and health initiatives.Item Zinc efficiency and diversity of Montana wheat and barley(Montana State University - Bozeman, College of Agriculture, 2017) Kaya, Eylul; Chairperson, Graduate Committee: Hikmet Budak; Levent Ozturk and Hikmet Budak were co-authors of the article, 'Micronutrient diversity of Montana wheat and barley' which is contained within this thesis.Zn is essential for all living organisms because of its functional, structural and regulatory roles in more than 300 enzymes found in eukaryotes (McCall, 2000). In plants and humans, trace metal deficiencies cause an altered expression or function of proteins at the metabolic level and may lead to physiological drawbacks in plants and even psychological problems in humans. Plants with improved Zn status may help to alleviate these issues globally. Therefore, it is crucial to understand genes involved in Zn homeostasis. Lack of information on the micronutrient status of Montana wheat and barley was the main reason of this study and most commonly cultivated Montana wheat and barley varieties were included in the study. The aim of this study was; (I) to identify ZIP1 and IRT2 genes in Montana wheat and barley cultivars, (II) to study the physiological response, effectiveness in Zn uptake capacity and Zn translocation to plant edible parts by subjecting these cultivars to Zn deficient and Zn adequate environments and (III) to comprehend the micronutrient diversity and Zn grain localization of local wheat and barley cultivars.Item The Winogradsky test for determining plant food deficiency in Montana soils(Montana State University - Bozeman, College of Agriculture, 1932) Johnson, Charles RobertItem Spotted knapweed (Centaurea maculosa Lam) : water, nutrients, plant competition, bacteria, and the seed head fly (Urophora affinis Frnfd.)(Montana State University - Bozeman, College of Agriculture, 1996) Kearing, Stephen AnthonyItem Relationships between benthic communities, land use, chemical dynamics, and trophic state in Georgetown Lake(Montana State University - Bozeman, College of Agriculture, 1983) Garrett, Paul AllenItem The role of the bottom sediments in the eutrophication of Georgetown Lake, Montana(Montana State University - Bozeman, College of Agriculture, 1976) Garrison, Paul Jackson