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Phosphorus uptake rates of a Ceratophyllum/periphyton community in a southern Florida freshwater marsh
Title
Phosphorus uptake rates of a Ceratophyllum/periphyton community in a southern Florida freshwater marsh.
Creator
Pietro, Kathleen C., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Net uptake rates of soluble reactive phosphate (SRP) of Ceratophyllum demersum and the dense periphyton mat associated with the macrophyte were calculated by measuring the disappearance of stable phosphorus (30, 50, 100, or 200 μg P/L) from the water column over a one-hour period each month for one year. Two seasonal periods were established based on average photosynthetically active radiation (PAR) and length of daylight through the year. ANOVA showed that the uptake rates were significantly...
Show moreNet uptake rates of soluble reactive phosphate (SRP) of Ceratophyllum demersum and the dense periphyton mat associated with the macrophyte were calculated by measuring the disappearance of stable phosphorus (30, 50, 100, or 200 μg P/L) from the water column over a one-hour period each month for one year. Two seasonal periods were established based on average photosynthetically active radiation (PAR) and length of daylight through the year. ANOVA showed that the uptake rates were significantly affected (P < 0.05) by the amount of SRP added and were greater during the period of increased irradiance. Uptake rates continued to increase, even at spike concentrations equal to 10,000 μg P/L, indicating that maximum uptake was not achieved and that this plant complex is able to sequester even greater amounts of SRP. Estimates of the yearly uptake capabilities of the plant complex for a 525 ha wetland for the 30, 50, 100, 200 μg P/L spike treatments were 27, 55, 103, and 182 kg P/yr, respectively.
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Date Issued
1998
PURL
http://purl.flvc.org/fcla/dt/15601
Subject Headings
Biology, Ecology, Biogeochemistry, Biology, Plant Physiology
Format
Document (PDF)
Effects of Hydrology and Applied Gibberellic Acid and Paclobutrazol on the Growth of the Invasive Exotic Lygodium Microphyllum (Old World Climbing Fern)
Title
Effects of Hydrology and Applied Gibberellic Acid and Paclobutrazol on the Growth of the Invasive Exotic Lygodium Microphyllum (Old World Climbing Fern).
Creator
Gandiaga, Sonia, Volin, John C., Florida Atlantic University
Abstract/Description
I conducted a greenhouse study in order to examine the effects of hydrology and its interaction with gibberellic acid (GA3) on the invasive exotic Lygodium microphyllum (Old World climbing fern) growth and physiology. Three hydrological (flood, drought and field capacity) and three hormonal (gibberellic acid, paclobutrazol and water) treatments were studied using a 3x3 factorial experimental design. Plants under flooded conditions had a significantly lower relative growth rate compared to...
Show moreI conducted a greenhouse study in order to examine the effects of hydrology and its interaction with gibberellic acid (GA3) on the invasive exotic Lygodium microphyllum (Old World climbing fern) growth and physiology. Three hydrological (flood, drought and field capacity) and three hormonal (gibberellic acid, paclobutrazol and water) treatments were studied using a 3x3 factorial experimental design. Plants under flooded conditions had a significantly lower relative growth rate compared to plants under field capacity or drought. Plants under flooded conditions showed a significantly lower specific leaf area and area-based photosynthetic rate than plants under field capacity and drought treatments, resulting in significantly lower massbased photosynthesis. Overall, the variation in growth response to treatments was most explained by mass-based photosynthesis (r^2=0.66). Treatments with gibberellic acid or paclobutrazol (GA inhibitor) resulted in no differences in growth as compared to untreated plants.
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Date Issued
2007
PURL
http://purl.flvc.org/fau/fd/FA00000771
Subject Headings
Plants--Effect of gibberellic acid on, Plants, Flowering of, Ferns--Physiology, Growth (Plants)
Format
Document (PDF)
Biomonitoring of hypoxia and sulfide stress in three sub-tropical seagrasses
Title
Biomonitoring of hypoxia and sulfide stress in three sub-tropical seagrasses.
Creator
Irwin, Connor., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Hypoxia and sulfide exposure, increased using glucose, are considered major environmental stressors in seagrass communities. Quantum efficiency, total soluble protein and catalase activity were quantified to evaluate the applicability of each of these bioindicators to detect environmental stress in three tropical seagrass species, Thalassia testudinum (Banks ex Kèoenig), Halodule wrightii (Ascherson) and Syringodium filiforme (Kuetz). Hypoxia + sulfide treatments significantly decreased the...
Show moreHypoxia and sulfide exposure, increased using glucose, are considered major environmental stressors in seagrass communities. Quantum efficiency, total soluble protein and catalase activity were quantified to evaluate the applicability of each of these bioindicators to detect environmental stress in three tropical seagrass species, Thalassia testudinum (Banks ex Kèoenig), Halodule wrightii (Ascherson) and Syringodium filiforme (Kuetz). Hypoxia + sulfide treatments significantly decreased the quantum efficiency of all three species, but showed no response in protein and catalase activity. Although no treatment effect was found, catalase activity was enhanced in T. testudinum leaves and H. wrightii roots relative to other tissues, while S. filiforme showed no location-specific catalase activity. These results indicate that quantum efficiency is a more sensitive indicator than protein and catalase activity to hypoxia and sulfide stress in seagrasses.
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Date Issued
2010
PURL
http://purl.flvc.org/FAU/2976445
Subject Headings
Plant physiology, Environmental management, Seagrasses, Habitat, Environmental aspects, Sulfites, Physiological effect, Marine ecology
Format
Document (PDF)
Studies of specific gene expression of phosphate transporters in sawgrass (Cladium jamaicense crantz) and cattail (Typha domingensis pers.)
Title
Studies of specific gene expression of phosphate transporters in sawgrass (Cladium jamaicense crantz) and cattail (Typha domingensis pers.).
Creator
Lin, Li, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
In the Florida Everglades, sawgrass has been displaced by cattail, predominantly resulting from phosphate enrichment. It has been found that phosphate transporters and arbuscular mycorrhizal (AM) fungi play an important role in phosphate uptake in the plants. This study aimed to reveal the symbiosis between AM fungi and sawgrass and cattail and identify the phosphate transporters, especially AM-specific phosphate transporters in these two species. AM colonization was only found in sawgrass...
Show moreIn the Florida Everglades, sawgrass has been displaced by cattail, predominantly resulting from phosphate enrichment. It has been found that phosphate transporters and arbuscular mycorrhizal (AM) fungi play an important role in phosphate uptake in the plants. This study aimed to reveal the symbiosis between AM fungi and sawgrass and cattail and identify the phosphate transporters, especially AM-specific phosphate transporters in these two species. AM colonization was only found in sawgrass roots, not cattail, at low phosphate concentrations in lab and field samples by trypan blue staining. AM fungi could increase sawgrass growth and had little effect on cattail growth. Four phosphate transporters were identified in sawgrass. CjPT1, CjPT2 and CjPT3 were expressed in roots and shoots independent of AM fungi and phosphate availability, while CjPT4 appeared to be an AM regulated phosphate transporter gene and its expression was induced by AM fungi.
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Date Issued
2010
PURL
http://purl.flvc.org/FAU/1930493
Subject Headings
Phosphorus, Physiological transport, Soil stabilization, Vegetation dynamics, Ecosystem management, Soil mineralogy, Plant physiology
Format
Document (PDF)
Elevated pCO2 effects on the macroalgal genus Halimeda: Potential roles of photophysiology and morphology
Title
Elevated pCO2 effects on the macroalgal genus Halimeda: Potential roles of photophysiology and morphology.
Creator
Peach, Katherine, Koch, Marguerite, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
While ocean acidification (OA) is predicted to inhibit calcification in marine macroalgae, species whose photosynthesis is limited by current dissolved inorganic carbon (DIC) levels may benefit. Furthermore, variations in macroalgal morphology will likely give rise to a range of OA tolerance in calcifying macroalgae. One genus of calcifying macroalgae that has shown varying species’ tolerance to OA is Halimeda, a major carbonate sediment producer on tropical reefs. Species within this genus...
Show moreWhile ocean acidification (OA) is predicted to inhibit calcification in marine macroalgae, species whose photosynthesis is limited by current dissolved inorganic carbon (DIC) levels may benefit. Furthermore, variations in macroalgal morphology will likely give rise to a range of OA tolerance in calcifying macroalgae. One genus of calcifying macroalgae that has shown varying species’ tolerance to OA is Halimeda, a major carbonate sediment producer on tropical reefs. Species within this genus occupy a range of habitats within tropical environments (reefs and lagoons), illustrating their ability to adapt to diverse environmental conditions (e.g. carbonate chemistry, irradiance). To date it is not clear if morphological and photophysiological diversity in Halimeda will translate to different tolerances to OA conditions (elevated pCO2 and lower pH).
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Date Issued
2016
PURL
http://purl.flvc.org/fau/fd/FA00004621
Subject Headings
Coral reef ecology., Chemical oceanography., Halimeda., Environmental mapping., Plants--Effect of light on., Plant physiology., Photobiology., Carbon cycle (Biogeochemistry)
Format
Document (PDF)
Sulfur-35 incorporation in the seagrass Thalassia testudinum under oxic and anoxic conditions
Title
Sulfur-35 incorporation in the seagrass Thalassia testudinum under oxic and anoxic conditions.
Creator
Peters, Jasmine Star., Florida Atlantic University, Koch, Marguerite
Abstract/Description
Currently, there is a great deal of interest in the role of sulfur in the seagrass ecosystems and for sulfide, a known phytotoxin, in particular. This research used a 35S tracer technique to examine sulfur metabolism in the seagrass Thalassia testudinum. The uptake of the 35S radiotracer was documented at similar rates under both oxic and anoxic treatments. The highest total radioactivity was in root and rhizome tissue, as compared to the leaves. 35S translocation from roots to leaves was...
Show moreCurrently, there is a great deal of interest in the role of sulfur in the seagrass ecosystems and for sulfide, a known phytotoxin, in particular. This research used a 35S tracer technique to examine sulfur metabolism in the seagrass Thalassia testudinum. The uptake of the 35S radiotracer was documented at similar rates under both oxic and anoxic treatments. The highest total radioactivity was in root and rhizome tissue, as compared to the leaves. 35S translocation from roots to leaves was found to be more efficient in young versus mature leaves. Total sulfur uptake was estimated and found to be significantly different between root and rhizome tissue under oxic conditions. In the anoxic treatment, 1 mM sulfide may have been a threshold, at which the seagrass showed reduced uptake of 35S into the below-ground tissue. While the plants assisted in the production of sulfide in this experiment, sulfide accumulation may inhibit 35S uptake. This is counter to the idea of increased sulfide intrusion under sediment hypoxia. This study represents the first attempt to use 35S to trace sulfur incorporation into seagrass; further research will be required to understand the complex sulfur biochemistry of these important marine plants using this method.
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Date Issued
2006
PURL
http://purl.flvc.org/fcla/dt/13385
Subject Headings
Seagrasses--Ecology, Sulfates--Physiological effect, Plant morphology, Marine sediments
Format
Document (PDF)
The expression and analysis of a lysine-rich wound-response protein in tomato plants.
Title
The expression and analysis of a lysine-rich wound-response protein in tomato plants.
Creator
Kaplan, Noah, Zhang, Xing-Hai, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Understanding the genetic regulation of the response to wounding and wound healing in fruiting plants is imperative to maintaining agricultural sustainability, preserving the quality of food supplies, and ensuring the economic viability of agriculture. Many genes are known to be induced by wounding, providing both structural repair and defense. The KED gene in tobacco (Nicotiana tabacum) has been shown to be induced by wounding. We have identified its homologue gene in tomato (Solanum...
Show moreUnderstanding the genetic regulation of the response to wounding and wound healing in fruiting plants is imperative to maintaining agricultural sustainability, preserving the quality of food supplies, and ensuring the economic viability of agriculture. Many genes are known to be induced by wounding, providing both structural repair and defense. The KED gene in tobacco (Nicotiana tabacum) has been shown to be induced by wounding. We have identified its homologue gene in tomato (Solanum lycopersicum) that we named SlKED. We have analyzed gene expression pattern of SlKED through tomato growth and development and in response to wounding as well as hormonal and inhibitor treatments. We found that the plant hormone ethylene played a major role in the expression of SlKED. To further identify evidence for physiological and transductional functions of KED and SlKED, the tobacco KED gene was introduced to tomato and overexpressed by the fruit tissue-active PUN1 promoter from pepper (Capsicum annuum,). The expression of this gene was compared to the expression of the native SlKED gene and other known wound response genes in both the wild-type and transgenic tomato plants. The upregulation of the native SlKED gene by wounding was significantly muted in the tobacco KED-expressing transgenic plants. The expression of other genes known to be associated with wound response transduction pathways was also altered. Our studies implicate the KED gene in defense mechanisms for mechanical stress in tomato plants.
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Date Issued
2016
PURL
http://purl.flvc.org/fau/fd/FA00004773, http://purl.flvc.org/fau/fd/FA00004773
Subject Headings
Wound healing., Wounds and injuries--Genetic aspects., Plant gene expression., Plant genetic regulation., Nanostructured materials--Physiological effect., Biomedical engineering.
Format
Document (PDF)