This thesis reports on the effects of UVB radiation on charophycean algae and bryophytes. Due to thinning of the ozone layer, more UVB radiation is reaching the earth surface. UVB radiation affects life on earth. Since the discovery of the ozone hole many studies focused on the effects of UV(B) radiation on terrestrial and marine organisms. Studies that focused on the effects on plants showed d...

Approximately 450–500 million years ago, an ancient freshwater green alga successfully colonized land. From this profoundly important event in our planet's natural history, the spectacular diversity of plants that now occupy most of our terrestrial ecosystems arose. Essentially, the planet's atmosphere and biogeochemistry dramatically changed to yield conditions that support our biota. Land pla...

Klebsormidium flaccidum is a charophytic alga living in terrestrial and semiaquatic environments. K. flaccidum grows in various habitats, such as low-temperature areas and under desiccated conditions, because of its ability to tolerate harsh environments. Wax and cuticle polymers that contribute to the cuticle layer of plants are important for the survival of land plants, as they protect agains...

Title of dissertation: PHYLOGENETIC STUDIES OF THE CHARALES: THE CLOSEST LIVING RELATIVES OF LAND PLANTS Kenneth Gregory Karol, Doctor of Philosophy, 2004 Dissertation directed by: Associate Professor Charles F. Delwiche Department of Plant Biology The embryophytes (land plants) consist of organisms such as mosses, ferns, conifers and flowering plants. Although land plants have long been though...

Major differences in primary cell wall (PCW) components between non-vascular plant taxa are reported. (1) Xyloglucan: driselase digestion yielded isoprimeverose (the diagnostic repeat unit of xyloglucan) from PCW-rich material of Anthoceros (a hornwort), mosses and both leafy and thalloid liverworts, as well as numerous vascular plants, showing xyloglucan to be a PCW component in all land plant...

Expansive playa-lake systems situated in high-altitude piggyback basins are important and conspicuous components of both modern and ancient cordilleran orogenic systems. Extant playa lakes provide vital habitat for numerous endemic species, whereas sediments from these deposystems may record signals of climate change or develop natural resources over geological time. Laguna de los Pozuelos (Nor...

A synthesis of recent and previous studies of the Morrison Formation and related beds, in the context of a conceptual climatic/hydrologic framework, permits reconstruction of the Late Jurassic dinosaurian ecosystem throughout the Western Interior of the United States and Canada. Climate models and geologic evidence indicate that a dry climate persisted in the Western Interior during the Late Ju...

In most cases pollutants are unknown, so chemical analysis of the water (and soil as a water extraction) is difficult and expensive. On the other hand biological testing is the only method of integral determination of the water quality, as different environmental factors affect various physiological processes. Thus, the biological testing, as a first stage in ecological monitoring system, enabl...

Auxin is the first identified and essential phytohormone for plant development and survival (Lee and Cho, 2013; Locascio et al., 2014). The synthesis of naturally occurring auxin indole-3-acetic acid (IAA) in plants can be divided into two categories: tryptophan (Trp)-dependent and Trp-independent pathways (Tivendale et al., 2014). Genetic studies have demonstrated the Trp-dependent pathway as ...