Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"Land plant"”.
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Meristem regulation in the early divergent land plant Marchantia polymorpha
Meristems are key features of land plant development, enabling post-embryonic organogenesis through precise spatial patterning of cell division and differentiation. Extensive work on flowering plant meristems has revealed gene circuits driving meristem patterning, which are increasingly targeted to …
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Early land plant origins of the MYB-bHLH-WDR complex
… of multiple specialised cell types in the seed plant epidermis. Tripartite transcriptional complexes composed of a MYB transcription factor, a bHLH transcription factor and a WD repeat scaffold (MYB-bHLH-WDR or MBW complexes) regulate patterns of flavonoid pigments, trichomes and root hairs in …
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Quantifying the Biogeochemical Impact of Land Plant Expansion in the Mid Devonian and Implications in Marine Anoxic Events
The evolution of land plant root systems occurred stepwise throughout the Devonian, with the first evidence of complex root systems appearing in the mid-Givetian. This biological innovation provided an enhanced pathway for the transfer of terrestrial phosphorus (P) to the marine system via …
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On the role of pectin methylesterases in the development of the non-vascular land plant model Marchantia polymorpha
… different levels of organisation over time. For plant morphogenesis to be understood, it must therefore be studied at multiple scales, from subcellular elements to entire organisms. In this thesis, we examine how the gene family of pectin methylesterases (PMEs) contributes to the development of …
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Enzyme structure, function, and evolution in flavonoid biosynthesis
Plant specialized metabolism is a key evolutionary adaptation that has enabled plants to migrate from water onto land and subsequently spread throughout terrestrial environments. Flavonoids are one particularly important class of plant specialized metabolites, playing a wide variety of roles in …
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The role of enzyme promiscuity in plant metabolic evolution
… a key event facilitating the transition of early plants from aquatic to terrestrial environments and their subsequent radiation on land. The breadth and diversity of plant specialized metabolism reflects upon the adaptive innovations that took place during plants' colonization of land in the past …
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The largest subunit of RNA polymerase II (rpb1) as a phylogenetic marker of seed plant species
The phylogeny of land plants, especially angiosperms, has been perplexing scientists for more than 125 years. The aim of this study was to help elucidate unanswered phylogenetic issues using rpb1 genes from twenty-six land plant species (8 gymnosperm species, 17 angiosperm species and Psilotum, a …
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Late Silurian and Early Devonian fossil plants of Bathurst Island, arctic Canada
Early land plant fossils were retrieved from Bathurst Island, Arctic Canada. These plants are preserved as compressions, impressions or rarely pyrite permineralizations in rocks of Late Silurian and Early Devonian age. Specimens of some taxa are numerous and, sometimes, almost complete, allowing …
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Improved plastid transformation in Marchantia polymorpha
… organelles which perform photosynthesis in plants and algae. They are descended from free-living photosynthetic bacteria which were engulfed by early eukaryotes ~1.5 billion years ago. Nearly all plastids retain a small genome separate from the nuclear genome of the plants in which they …
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Frameworks for reprogramming early diverging land plants
Plant form is a product of emergent processes of cell division, patterning and morphogenesis. These fundamental processes remain poorly characterised in plants. However, engineering approaches can provide new tools and frameworks for the study and manipulation of plant development. This …
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Evolutionary conservation of host responses to arbuscular mycorrhizal symbiosis in liverworts
Arbuscular mycorrhizal symbiosis (AMS) arose in land plants more than 400 million years ago, perhaps acting as a major contributor to plant terrestrialization. The ability to engage in AMS is evolutionarily conserved across most clades of extant land plants, including early diverging bryophytes. …
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Characterization of metabolomic dynamics in synchronized Chlamydomonas reinhardtii cell cultures and the impact of TOR inhibition on cell cycle, proliferation and growth
… eukaryotes has been hampered by the reported land plant resistance to rapamycin. Thus, the finding that Chlamydomonas reinhardtii is sensitive to rapamycin, establish this unicellular green alga as a useful model system to investigate TOR signaling in photosynthetic eukaryotes. The observation …
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Testing the utility of the consortium for the barcoding of life's two 'agreed upon' plant DNA barcodes, matK and rbcL
… oftentimes complicated evolutionary histories of plants, the plant barcoding community has had a much harder time agreeing on a gene region or regions that should be used to barcode the various land plant lineages. This is in large part due to poor reproductive barriers, which allows for …
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The Spatiotemporal Dynamics of Nutrient Exchange at the Arbuscule
Plants are the major primary producers, source of biomass, and defining feature of ecosystems on Earth. But their ability to fix carbon is only half the story: plant growth also requires a suite of mineral elements that usually exist at limiting-levels in the soil. Most land plant species rely on a …
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The effect of UV-B radiation on flavonoid accumulation and gene expression in Marchantia polymorpha
… closest living representation of the earliest land plants and as such may give insight into the response that allow the first land plants to transition from the aquatic environment onto the terrestrial. One such adaption allowing this transition was to that of UV-B radiation and is the main …
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An Investigation into the Evolution and Function of RNA-Directed DNA Methylation and its Component Proteins
… (RdDM) is a major epigenetic pathway in plants that is required to establish methylation in all contexts and maintain CHH methylation. The function of RdDM is mediated by multiple proteins that are still being characterized in land plants. Pol IV and Pol V form a major part of the RdDM …
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Evolution of stomata in mosses (Bryophyta): From molecules to form and function
As one of the first land plant groups to diversify, mosses are central in understanding the origin, diversification, and early function of stomata. Unlike tracheophytes that have stomata on anatomically complex leaves and stems, mosses bear stomata exclusively on spore-bearing organs (capsules). …
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Ecosystem goods and services in semi-arid lanscape : an examination of the relationship between ecological processes, land-use strategies and biodiversity conservation
… to promote biodiversity conservation on private land, through the adoption of biodiversity-friendly land-use practices. Conservation and ecosystem function are linked to the delivery of ecosystem goods and services, which are processes and conditions of ecosystems that benefit humans and their …