The aim of this study was to investigate trends in population size and dynamics in two populations of the rare orchid Anacamptis palustris on Gotland. The study also examined if there were any correlations between the climate factors, temperature and precipitation, and the amount of flowering plants of A. palustris on Gotland. I found that low temperature during 16 April- 15 June and abundant precipitation in June results in a higher number of flowering plants the same year. Previous studies shows that A. palustris commutes considerably in number of flowering plants between years. Because of the variety in flowering frequency and lack of regular inventories, it is hard to interpret any trends in population growth. Therefore it requires annual inventories in the future to determine whether the populations are decreasing or increasing.

No description available.

Extensive development has destroyed and fragmented wildlife habitat in the Lower Florida Keys. The Lower Keys marsh rabbit (LKMR; Sylvilagus palustris hefneri) and the silver rice rat (SRR; Oryzomys argentatus) are listed by the United States Fish and Wildlife Service (USFWS) and the Florida Fish and Wildlife Conservation Commission (FFWCC) as endangered species. Both species depend on coastal prairies, freshwater marshes, and intertidal salt-marsh zones. The objective of this study was to meet specific, species-level recovery goals and to add reliable information that may modify or support current recovery plans. Specifically, I (1) evaluated the use of LKMR reintroduction to suitable habitat, (2) examined characteristics of habitat used by LKMR, and (3) surveyed the Lower Florida Keys for SRRs, documenting current range and examining survey results for the past decade. I reintroduced 7 rabbits (3 males, 4 females) to suitable habitat on Water Key, and monitored their survival and release-site fidelity. All reintroduced rabbits survived and some reproduced, suggesting these translocation techniques are a viable tool for recovery. On Boca Chica Key, I radio-collared 13 LKMRs and compared vegetation characteristics between core-use and avoided areas within home ranges. Binary logistic regression associated rabbit use with high vegetation heights (7–8 dm), low canopy coverage (<=10%), high bunchgrass densities (2.5–3.8/sq m), and forb presence (>5%), supporting the hypothesis that LKMRs may be detrimentally impacted by hardwood encroachment into salt-marsh habitats. For LKMR recovery, I recommend management to resist hardwood encroachment, together with active predator control. I surveyed 36 locations on 18 islands for SRRs, capturing rats on 12 islands, including 2 on which SRRs had not previously been found. Comparisons of my data with historic data suggest SRRs either have increased in abundance over the past decade or that previous trapping efforts were not effective. Abundance of SRRs does not appear to be significantly different from that of populations of rice rats on the mainland. The USFWS and FFWCC should consider revising the conservation status of the SRR; however, it still should be regarded as a unique evolutionary unit with a very limited potential range.

Bacteriophytochromes (Bphs) comprise a family of protein photoreceptors that help bacteria sense changes in light. Bphs contain a chromophore that, upon absorption of red or far-red light, undergoes a cis-trans isomerization that leads to a conformational change in the holoprotein (photoconversion). In the active conformation, Bphs act as a kinase and regulate gene expression through phosphorylation of target proteins. Two putative Bph orfs (rpa0122 and rpa0990) in the Rhodopseudomonas palustris genome encode Bph-like proteins that have a conserved chromophore-binding cysteine residue. The hypothesis is that one or both of these unique Bph-like genes encode proteins that are capable of binding a chromophore and functioning to modulate the cell’s phenotype. I expressed and purified His-tagged RPA0990 in R. palustris, because proteolytic degradation was observed during overexpression in an E coli. expression system. The results show that RPA0990 contains a chromophore and is capable of photoconversion. The wavelengths of light absorbed by the Pr/Pfr forms of RPA0990, predicted to be active and inactive forms respectively, were determined to be 695 nm and 755 nm. Investigation into the phenotype of the bph mutants rpa0122 and rpa0990 revealed that both of these Bphs may have a small effect on light-harvesting complexes. Also, it was observed that the absence of O₂ does not inhibit the normal function of Bphs, although O₂ was thought to be needed to make a linear tetrapyrrole cofactor, by cleaving heme using heme oxygenase. I suggest that a linear tetrapyrrole can be made anaerobically, either through anaerobic heme cleavage by a novel enzyme, or directly from the heme precursor hydroxymethylbilane without ring cleavage. The activity of a divergent promoter region between the rpa1490 (bph3) and rpa1491 (pucBe) genes was evaluated by using the E. coli lacZ gene as a reporter. The results indicated that the pucBe promoter has much higher activity than the bph3 promoter. It was also found that double knockout of the regulatory genes ppsR1ˉ2ˉ led to an increase in bph3::lacZ expression and a decrease in pucBe::lacZ expression.

Bacteriophytochromes (Bphs) comprise a family of protein photoreceptors that help bacteria sense changes in light. Bphs contain a chromophore that, upon absorption of red or far-red light, undergoes a cis-trans isomerization that leads to a conformational change in the holoprotein (photoconversion). In the active conformation, Bphs act as a kinase and regulate gene expression through phosphorylation of target proteins. Two putative Bph orfs (rpa0122 and rpa0990) in the Rhodopseudomonas palustris genome encode Bph-like proteins that have a conserved chromophore-binding cysteine residue. The hypothesis is that one or both of these unique Bph-like genes encode proteins that are capable of binding a chromophore and functioning to modulate the cell’s phenotype. I expressed and purified His-tagged RPA0990 in R. palustris, because proteolytic degradation was observed during overexpression in an E coli. expression system. The results show that RPA0990 contains a chromophore and is capable of photoconversion. The wavelengths of light absorbed by the Pr/Pfr forms of RPA0990, predicted to be active and inactive forms respectively, were determined to be 695 nm and 755 nm. Investigation into the phenotype of the bph mutants rpa0122 and rpa0990 revealed that both of these Bphs may have a small effect on light-harvesting complexes. Also, it was observed that the absence of O₂ does not inhibit the normal function of Bphs, although O₂ was thought to be needed to make a linear tetrapyrrole cofactor, by cleaving heme using heme oxygenase. I suggest that a linear tetrapyrrole can be made anaerobically, either through anaerobic heme cleavage by a novel enzyme, or directly from the heme precursor hydroxymethylbilane without ring cleavage. The activity of a divergent promoter region between the rpa1490 (bph3) and rpa1491 (pucBe) genes was evaluated by using the E. coli lacZ gene as a reporter. The results indicated that the pucBe promoter has much higher activity than the bph3 promoter. It was also found that double knockout of the regulatory genes ppsR1ˉ2ˉ led to an increase in bph3::lacZ expression and a decrease in pucBe::lacZ expression.

Environmental contamination with radionuclides is a growing problem in the world. Phytoremediation seems to be a suitable method for the removal of radionuclides from the environment. The aim of this study was to determine the impact of potassium on accumulation of stable isotope 133Cs and evaluate the suitability of plant species Calla palustris for phytoremediation. Plants were grown in a water solution in a greenhouse and after one week of pre-cultivation were exposed to stable isotope 133Cs (0,5 mM CsCl). Potassium was added in five various concentrations in the form of K2SO4. The level of cesium in plants was measured after 8 days of exposition. Plants without added potassium absorbed the most cesium (11,52 %). Plants with the highest concentration of added K2SO4 10 mM (3,45 %), 5 mM (3,62 %), 2 mM (5,57 %) absorbed the least. Higher 133Cs accumulation was measured in the plant roots than in the above- ground plant parts. Total uptake of cesium by Calla palustris suggests the possibility to use Calla palustris for phytoremediation.

This work deals with the evaluation of Calla palustris utilization for phytoremediation and clarifying how nitrogen influences the uptake of cesium from aqueous solution. The plants were subjected to nitrogen exposure, which consisted of five different concentrations of NH4+ and NO3- and 0.5 mM CsCl, for eight days. The greatest amount of cesium (13.5%) accumulated the plants without the addition of nitrogen, the smallest amount accumulated plants with concentrations of 6: 3 (3.9%), 8: 4 (3.6%) and 10: 5 NH4NO3: NH4Cl (3.5%). Calla has proved to be suitable for phytoremediation, however with the need for longer exposure. Besides these main hypotheses it has been moreover shown that the state of plants affected the uptake of cesium and that nitrogen influenced the condition of the plant. Further it has not been observed noticeable difference in uptake of cesium in roots and stems with leaves.

The aim of the thesis was to evaluate the effect of potassium on receiving of stable cesium and evaluate the appropriateness of Marsh Calla (Calla palustris) for phytoremediation. The experiment was conducted in a green-house environment where the plants were grown in an aqueous solution. The plants were exposed then to a stable isotope of cesium (133Cs) at a concentration of 1 mM CsCl. Potassium was added to the plants in the form of potassium sulphate (K2SO4), in five different concentrations (0.5 mM, 1 mM, 2 mM, 5 mM and 10 mM). Plants were exposed for 8 days. The largest average income of cesium (9,37 %) had a plant without added potassium. The root part of the plants showed a greater cesium content than the ground part. Based on the total intake of cesium from an aqueous solution, calla marsh can be estimated as a plant usable for phytoremediation.

Bacteriophytochromes (Bphs) comprise a family of protein photoreceptors that help bacteria sense changes in light. Bphs contain a chromophore that, upon absorption of red or far-red light, undergoes a cis-trans isomerization that leads to a conformational change in the holoprotein (photoconversion). In the active conformation, Bphs act as a kinase and regulate gene expression through phosphorylation of target proteins. Two putative Bph orfs (rpa0122 and rpa0990) in the Rhodopseudomonas palustris genome encode Bph-like proteins that have a conserved chromophore-binding cysteine residue. The hypothesis is that one or both of these unique Bph-like genes encode proteins that are capable of binding a chromophore and functioning to modulate the cell’s phenotype. I expressed and purified His-tagged RPA0990 in R. palustris, because proteolytic degradation was observed during overexpression in an E coli. expression system. The results show that RPA0990 contains a chromophore and is capable of photoconversion. The wavelengths of light absorbed by the Pr/Pfr forms of RPA0990, predicted to be active and inactive forms respectively, were determined to be 695 nm and 755 nm. Investigation into the phenotype of the bph mutants rpa0122 and rpa0990 revealed that both of these Bphs may have a small effect on light-harvesting complexes. Also, it was observed that the absence of O₂ does not inhibit the normal function of Bphs, although O₂ was thought to be needed to make a linear tetrapyrrole cofactor, by cleaving heme using heme oxygenase. I suggest that a linear tetrapyrrole can be made anaerobically, either through anaerobic heme cleavage by a novel enzyme, or directly from the heme precursor hydroxymethylbilane without ring cleavage. The activity of a divergent promoter region between the rpa1490 (bph3) and rpa1491 (pucBe) genes was evaluated by using the E. coli lacZ gene as a reporter. The results indicated that the pucBe promoter has much higher activity than the bph3 promoter. It was also found that double knockout of the regulatory genes ppsR1ˉ2ˉ led to an increase in bph3::lacZ expression and a decrease in pucBe::lacZ expression. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

I studied eight habitat types of south Mississippi from 2009-2010 to examine habitat conditions and faunal communities associated with the presence of gopher tortoise burrows (Gopherus polyphemus). Field methods included burrow surveys, vegetation sampling, mound counts, and point count surveys. Active tortoise burrow presence was influenced by percent coverage of bare ground, native legumes, grass-like plants, basal area, overstory canopy, and woody plants. Fire ant mound densities were influenced by percent coverage of overstory canopy cover, bare ground, grass-like vegetation, and woody plants. Northern bobwhite (Colinus virginianus) and Bachman’s sparrow (Peucaea aestivalis) were detected more frequently in longleaf pine (Pinus palustris) dominated habitats supporting gopher tortoises. My findings will be used to address the paucity of information related to gopher tortoise conservation on private and public lands and identify potential areas for inclusion in conservation initiatives supporting longleaf pine restoration or gopher tortoise conservation in the southeastern lower coastal plain.