Progress 10/01/12 to 04/30/14
Outputs
Target Audience: Target audiences include educators, commercial crop producers, the scientific community, The Environmental Protection Agency, and the Pennsylvania Department of Environmental Protection. Efforts were made to deliver science-based knowledge by making oral presentations at formal and non-formal educational and scientific conferences and meetings. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? John Carlson collaborated with minority faculty member Ketia Shumaker from the University of West Alabama, a predominantly minority-serving undergraduate institution. Dr. Shumaker and a team of 8 undergraduate students from the University of West Alabama visited Penn State University for two months each summer from 2011 to 2013. The students assessed the effects of ozone stress treatments in various hardwood tree species. The students were introduced to all aspects of the research including growing seedlings in the greenhouse, ozone treatments, RNA extraction, RNA sequencing and gene expression analysis. The students received hands-on training in the Schatz Center for Tree Molecular Genetics and CSTR ozone exposure chambers at FRL. The genetics research was supported by The Schatz Center for Tree Molecular Genetics at Penn State, by a grant from the USDA NIFA Plant Genome Program (#2008-35300-19234), and by grant # TRPGR IOS-1025974 from the National Science Foundation’s Plant Genome Research Program. How have the results been disseminated to communities of interest? The Air Quality Learning and Demonstration Center provided hands on learning experiences for classes at Penn State and the general public around Centre County in Pennsylvania. During 2012-2014 approximately 400 individuals attended course lectures or public presentations on air pollution effects on terrestrial plants at the Learning Center. Dr. Decoteau also presented a summary of the outreach efforts of the Learning center at the Air Pollution Global Change Symposium in Monterrey CA in June, 2014. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Ambient air quality was continuously monitored using EPA-approved equivalent method analyzers year-round from 2012-2014 at four Pennsylvania monitoring sites: Gleason (Tioga Co.), Elliott State Park (Clearfield Co.), State College (Centre Co.), and Towanda area (Bradford Co.). Overall operation, data collection, and reporting of air quality and meteorological data including ground level ozone, sulfur dioxide, nitrogen oxide, particulate matter (PM10, PM2.5), wind speed, wind direction, temperature, relative humidity, rainfall, and solar radiation data was relayed to the Pennsylvania Department of Environmental Protection, Bureau of Air Quality. Greenhouse and field studies evaluated the usefulness of Ailanthus altissima as a bioindicator plant species for detecting phytotoxic levels of ambient ground-level ozone in rural areas. Ailanthus seedlings that originated from seed collected near Corvallis, Oregon (OR) were significantly more susceptible to ozone than seedlings from other seed sources, and symptom severity was directly related to concentration and duration of ozone exposure. In the field, Ailanthus seedlings from the OR seed source were out-planted in central Pennsylvania where they developed ozone-induced foliar symptoms from low levels of ambient ozone. Results of this study should help clarify exposure/response relationships between ambient ozone levels and foliar symptoms on Ailanthus, as well as provide useful data for setting the National Ambient Air Quality Standard (NAAQS) for ozone. Various milkweed (Asclepias) species were evaluated for their sensitivity to ozone. Asclepias syriaca, Asclepias incarnata, Asclepias exaltata, Asclepias specisa, Asclepias sullivantii, Asclepias curassavica, Asclepias ovalifolia, Asclepias viridis were germinated, and grown and fumigated in continuous stir tank reactors in a carbon-filtered greenhouse at 0, 40, 75, and 120 ppb ozone. Asclepias syriaca, Asclepias incarnata, Asclepias specisa, Asclepias sullivantii, Asclepias curassavica, Asclepias viridis, and Ocimum basilicum did exhibit foliar damage, namely adaxial stippling to ozone. Asclepias curassavica was determined to be extremely sensitive to ozone. The characterization of molecular basis of oxidative-stress tolerance/-sensitivity in forest trees was evaluated. Leaf tissue of control and ozone-treated seedlings of black walnut (Juglans nigra), green ash (Fraxinus pennsylvanica), Tulip poplar (Liriodendron tulipifera) and Black gum (Nyssa sylvatica) was collected for RNA extraction and cDNA library preparation and sequencing. Black walnut and Green Ash underwent ozone treatment in greenhouse-controlled environment in June 2012, while Black gum and tulip poplar in June of 2013. Genome assembly and annotation revealed that expression of stress-response, senescence and programmed cell death genes was generally up-regulated, while genes involved in the photosynthetic apparatus were highly down regulated in all 4 species. Genes encoding for heat shock proteins were mostly up-regulated; these genes are also known to be involved in drought and cold tolerance. A unique observation of this study is that, even though only a few genes were found to be similarly regulated in all 4 species, there were many gene families that were co-regulated in all 4 species. It appears that each species responded to ozone stress by regulating different genes from within gene families, by either up-regulation or down-regulation, resulting in similar overall responses among the four species. The comparative hardwoods transcriptome analysis indicates that ozone stress triggers pathways that are similar to those triggered by other known abiotic stressors.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2014
Citation:
Seiler, L.K., D.R. Decoteau, and D.D. Davis 2014. Evaluation of Ailanthus altissima as a bioindicator to detect phytotoxic levels of ozone. Northeastern Naturalist 21:541-553.
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Progress 10/01/12 to 09/30/13
Outputs
Target Audience: Target audiences include educators, commercial crop producers, the scientific community, The Environmental Protection Agency, and the Pennsylvania Department of Environmental Protection. Efforts were made to deliver science-based knowledge by making oral presentations at formal and non-formal educational and scientific conferences and meetings. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? John Carlson collaborated with minority faculty member Ketia Shumaker from the University of West Alabama, a predominantly minority-serving undergraduate institution. Dr. Shumaker and a team of 8 undergraduate students from the University of West Alabama visited Penn State University for two months each summer from 2011 to 2013. The students assessed the effects of ozone stress treatments in various hardwood tree species. The students were introduced to all aspects of the research including growing seedlings in the greenhouse, ozone treatments, RNA extraction, RNA sequencing and gene expression analysis. The students received hands-on training in the Schatz Center for Tree Molecular Genetics and CSTR ozone exposure chambers at FRL. The genetics research was supported by The Schatz Center for Tree Molecular Genetics at Penn State, by a grant from the USDA NIFA Plant Genome Program (#2008-35300-19234), and by grant # TRPGR IOS-1025974 from the National Science Foundation’s Plant Genome Research Program. How have the results been disseminated to communities of interest? The Air Quality Learning and Demonstration center provided hands learning experiences for classes at Penn State and the general public around Centre County in Pennsylvania. During 2013 approximately 200 individuals attended course lectures or public presentations on air pollution effects on terrestrial plants at the Learning Center. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
A series of greenhouse exposures and field studies were conducted to evaluate the usefulness of Ailanthus altissima to function as a bioindicator plant species for detecting phytotoxic levels of ambient ground-level ozone in rural areas. Ailanthus seedlings that originated from seed collected near Corvallis, Oregon (OR) were significantly more susceptible to ozone than seedlings from other seed sources, and symptom severity was directly related to concentration and duration of ozone exposure. In the field, Ailanthus seedlings from the OR seed source were out-planted in central Pennsylvania where they developed ozone-induced foliar symptoms from low levels of ambient ozone. Results of this study should help clarify exposure/response relationships between ambient ozone levels and foliar symptoms on Ailanthus, as well as provide useful data for setting the National Ambient Air Quality Standard (NAAQS) for ozone. The characterization of molecular basis of O3-tolerance/-sensitivity in forest tree species included two more north-eastern species. For the past 4 years, leaf tissue of control and ozone-treated seedlings of black cherry (Prunus Serotina), northern red oak (Quercus rubra L.), black walnut (Juglans nigra), green ash (Fraxinus pennsylvanica), Tulip poplar (Liriodendron tulipifera L. ), and Black gum (Nyssa sylvatica) was collected for RNA extraction and cDNA library preparation and sequencing. After genome assembly and annotation we found that 12-13% of the EST sequences were from genes known to be involved in response to biotic and abiotic stresses (with almost no difference among species). Expression of stress-response genes was generally up-regulated, while more genes in the mitochondria were down-regulated than up-regulated. Genes encoding for heat shock proteins were mostly up-regulated; these genes are also known to be involved in drought and cold tolerance. Expression of salt-responsive genes was found to be up-regulated while regulatory factors involved in stomatal closure were down-regulated. Transcription factors involved in leaf senescence were up-regulated in more sensitive species (black cherry, black walnut, green ash, and tulip poplar) and down-regulated in Northern red oak and Black gum which were more tolerant species (e.g. at the end of treatment did not show visible injury). The comparative hardwoods transcriptome analysis indicates that ozone stress triggers pathways that are similar to those triggered by other known abiotic stressors.
Publications
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