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Title: Water content effect on nutrient removal in stormwater bioretention systems
Creator: Bender, Rebecca Marian
Date: 2019
Collection: Electronic Theses & Dissertations
Description: "Bioretention cells and constructed wetlands are both established best management practices (BMPs) for stormwater quality improvement. These systems vary in terms of hydraulic loading where processes such as retention, sedimentation, absorption, infiltration, filtration, phytoremediation, nitrification and denitrification remove waterborne pollutants. However, the boundary between bioretention and wetlands can be blurred when it comes to design and operational parameters, and it is therefore...
Show more"Bioretention cells and constructed wetlands are both established best management practices (BMPs) for stormwater quality improvement. These systems vary in terms of hydraulic loading where processes such as retention, sedimentation, absorption, infiltration, filtration, phytoremediation, nitrification and denitrification remove waterborne pollutants. However, the boundary between bioretention and wetlands can be blurred when it comes to design and operational parameters, and it is therefore important to explore the causes and consequences of performance variability in these systems. In an experiment to observe optimum water content for treatment pathways for ecological pollutants, five bioretention bays (2-22% water content) and fifteen bioretention columns (7-47% water content, as much as complete pore space saturation) were used to run parallel tests. Pollutant concentrations were reduced in field bays for COD, TN, and total solids (TS), although there was no difference between treatment groups in terms of any pollutant concentrations. Asclepias incarnata, Carex vulpinoidea, Scirpus validus, and Juncus effusus grew slightly taller in wetter bays, although survival of Sagittaria latifolia was uniformly poor in all treatment groups. No net pollutant removal occurred in columns, although effluent concentrations and mass export were significantly lower for near-saturation treatment groups for chemical oxygen demand (COD), nitrate, and total nitrogen (TN). There was no soil moisture level in which COD, nitrate, TN, phosphate, and TS were simultaneously improved."--Page ii.
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Title: Identification and functional analysis of proteins involved in auxin regulated plant growth
Creator: Li, Jie
Date: 2016
Collection: Electronic Theses & Dissertations
Description: During growth, plants integrate cell division with cell elongation and cell differentiation. We used proteomics to identify proteins from auxin (indole-3-acetic acid; IAA) -induced rapidly growing corn (Zea mays) coleoptiles to find candidates controlling this growth as well as the underlying cell wall and cuticle biosynthesis. Of 86 proteins identified, 15 showed a predicted association with cell wall/cuticle biosynthesis or trafficking machinery; the analysis also revealed four proteins of...
Show moreDuring growth, plants integrate cell division with cell elongation and cell differentiation. We used proteomics to identify proteins from auxin (indole-3-acetic acid; IAA) -induced rapidly growing corn (Zea mays) coleoptiles to find candidates controlling this growth as well as the underlying cell wall and cuticle biosynthesis. Of 86 proteins identified, 15 showed a predicted association with cell wall/cuticle biosynthesis or trafficking machinery; the analysis also revealed four proteins of unknown function. Parallel real-time PCR indicated that the steady-state mRNA levels of genes with a known or predicted role in cell-wall biosynthesis increase upon auxin-treatment. Importantly, genes encoding two of the hypothetical proteins (ARRP1 and Hypothetical protein 3, a putative endoglucanase) also showed higher levels of mRNA; their gene expression was directly correlated with coleoptile and leaf growth. This suggested a role of these two novel proteins in the regulation of processes related to cell and organ expansion and thus plant growth. These data are described in chapter 2.Chapter 3 focuses on ARRP1 (Auxin rapid response protein 1), one of the proteins of unknown function associated with cell and organ growth. Upon auxin treatment ARRP1 mRNA and protein increased within 30 minutes – prior to measurable growth and increased expression of genes encoding cell wall biosynthetic enzymes, suggesting an intracellular signaling function. This was further supported by the localization of ARRP1 at the cell periphery as well as in the nucleus. Arabidopsis mutants lacking the ARRP1 homologue grew normally under standard conditions, but showed delayed growth and delayed flowering when germinated in the dark and transferred to light. This phenotype that could be reversed by expressing ZmARRP1 in the Arabidopsis mutant. ZmARRP1 expression was also induced by red and blue light, indicating a possible role in phytochrome and cryptochrome signaling at the interface with the auxin response. In situ hybridization demonstrated that ARRP1 mRNA is enriched in the vasculature of growing corn tissues. In addition, the corn ARRP1 interacted with the cytoplasmic domain of both Arabidopsis and Zea mays VH1/BRL2 which plays a role in the signaling of vascular development. Based on the fact that ARRP1 protein is involved in light-induced growth responses as well as with components of auxin signaling, we propose that it may integrate several environmental and hormonal signals affecting plant development.Chapter 4 describes the initiation of a series of experiments investigating addtional proteins that interact with ARRP1 to elucidate other components of the signaling pathway that use ARRP1. Using in vitro pull-down assays and mass spectrometry, I identified 32 putative ARRP1-interacting proteins in the developing corn leaf. Some of these proteins appear to be involved in cell wall biosynthesis, including a beta-glucosidase homologue. Others are predicted to be signal molecules, including a tetratricopeptide repeat domain containing protein and a CobW/P47K family protein. Using semiquantitative RT-PCR, I showed that several of these genes have a similar expression pattern compared to ARRP1, suggesting a function in the same signaling/response path.
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