Progress 08/01/07 to 07/31/09
OUTPUTS: The three primary categories of outputs from this completed project are 1) a new scientific collaboration, 2) new methods/skills in plant eco-physiology, for the PD (Dr. Cessna), and 3) undergraduate student learning in plant biology and agricultural science. 1) Because of the funding, Dr. Cessna was able to establish a scientific relationship with collaborators in Colorado. Drs. Barbara Demmig-Adams and Williams Adams of the University of Colorado at Boulder are some of the leading experts in the area of photosynthetic responses to stress. Dr. Cessna is now in almost monthly contact with the Adams lab, and one co-authored manuscript has so far been submitted to a peer-reviewed journal, with a few more co-authored manuscripts in their earliest stages. Dr. Cessna hopes that this collaboration will lead to greater opportunity to pursue interesting and fruitful agriculture and ecology-related research projects in the Shenandoah Valley and surrounding mountains. 2) Through the sabbatical appointment in Boulder, Dr. Cessna was able to significantly re-tool and develop several new skills in plant eco-physiology, and to develop teaching skills appropriate to research-based science classrooms. Dr. Cessna audited a course at the U. of Colorado in chromotography and mass spectroscopy, and also worked side-by-side with an analytical chemist, to develop methods for the analysis of plant compounds. Gas chromotography/Mass spectrometry methods for the analysis of free fatty acids and oxylipins from leaf tissues were compared and tested for their suitability in pine needle and arabidopsis research. HPLC-based methods for assessing pigments and antioxidants from leaf tissues were also skills that Dr. Cessna learned. Also, Dr. Cessna learned careful methods of field sampling, chlorophyll fluorescence analysis, and photosynthesis measurements. Finally, during the sabbatical year, Dr. Cessna was able to audit a graduate-level education course, and through that course and associated readings, develop his teaching skills in the botany, plant physiology, and biochemistry classroom and laboratory. 3) The sabbatical training has clearly translated into learning for EMU undergraduate students, who now get hands on training in plant compound analysis, chlorophyll fluorescence, and photosynthesis measurements. It is my hope that my students are now better prepared for careers in the plant/ag. sciences. PARTICIPANTS: Stephen Cessna (PD) was the sole individual on this project, which funded a year-long sabbatical at the University of Colorado at Boulder. Partner organizations, collaborators: The Department of Ecology and Evolutionary Biology at the University of Colorado graciously provided facilities and access to some analytical instrumentation for this research. Training and professional development: the project provided significant training for the PD, both in research methods and in teaching and learning. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Changes in knowledge: Because of this sabbatical funding, Dr. Cessna has learned several new scientific skills and methods, and new skills in teaching (see 'outcomes'). Also, new fundamental knowledge has been gained in basic plant biology: 1) There is significantly more polyunsaturated free fatty acid in leaf tissues subjected to high-light stress than leaves grown under low-light. This increase is greater in mutant Arabidopsis plants that are deficient in photoprotective measures. These findings are interesting in that they link fatty acid signaling/metabolism to photo-protection, a connection that has not previously been made in the research literature. Yet, further repetitions of these experiments are required to verify the findings, generate a working model to explain the data, and to prepare a well-reasoned manuscript. 2) Tobacco plants transformed with anti-apoptotic genes (e.g. CED-9) produce less hydrogen peroxide in their stomata in response to abscisic acid treatments than to control plants. Because hydrogen peroxide is a signaling intermediate in abscisic acid signaling, we think that this difference in peroxide synthesis may explain those plants sensitivity to drought. These findings are in a manuscript that is in preparation. These findings are important because it provides a mechanism by which plant apoptotic regulatory proteins might also affect stomatal signaling, and thereby coordinate water loss/hydration with senescence. 3) Chlorophyll fluorescence measurements of photosynthetic light use efficiency vary depending of whether red or blue light is used for excitation, in a manner depending on the amount of phenolic compounds present. The PD compared the use of a blue exciting light source to a red source in a Walz PAM fluorometer for the measurement of Fv/Fm in several leaves of several species in several environmental conditions. Overall, measurements taken with the two sources largely agree, except in the sun-exposed leaves of plants that accumulate high-levels of phenolic compounds that absorb blue light. A clear linear relationship was seen between a degree to which red vs. blue Fv/Fm measurements agree and the presence of blue-light absorbing phenolics. These data will contribute to a manuscript for a photosynthesis research journal. 4) Chlorophyll fluorescence measurements can be reliably made with relatively inexpensive fluorometers (e.g. Fluorpen and Optisci instruments). A manuscript has been submitted, which is directed towards the agriculture educator audience, advocating the use of inexpensive fluorometer measurement with undergraduates.
- No publications reported this period