Progress 02/29/16 to 01/31/21
Outputs
Target Audience:The project goal is to improve our fundamental understanding of tree-environment interactions, which has as its target audience the scientific community, especially in forestry and plant sciences, and natural resource managers. The scientific advances of this project will ultimately contribute knowledge to improve tree germplasm and forest management approaches, which will impact forest land owners and foresters, as well as environmental quality for the broader community, particularly as relates to conservation of water resources and forest species (e.g., flood-adapted oaks). Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?STEM work-force development • Issue: There is a need for college graduates trained to enter science, technology, engineering and math (STEM) jobs. • Activity: I contributed to STEM work-force education through hands-on training of three UAM undergraduate students this year, and 4 Master's students, 1 of whom is now employed while finishing his thesis, and another graduated this year and is now employed in forest management. In addition to hands-on training, I seek opportunities for students to attend scientific meetings to expand their knowledge and connectedness to the relevant scientific communities, although this year we had to settle for webinars and virtual meetings due to COVID-19. In addition to my direct advisees, I served on committees for three M.S. students working on the NRCS WRE project under Objective 2. One of these M.S. students graduated in August 2020 and is currently employed. A second M.S. student is planning to graduate in summer 2021. A third M.S. student left the program, but was replaced this fall. • Impact: Two of my Master's students are now enrolled in STEM doctoral programs, and two others are employed in STEM careers, which provides evidence that my students are prepared to enter STEM careers and/or to pursue post-graduate education upon graduation, helping to meet the national need for STEM work-force development. How have the results been disseminated to communities of interest?This year our results have been disseminated primarily via publications (listed in "Products" section). I and my students have given no seminars or lectures this year due to travel restrictions associated with the COVID-19 pandemic. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact: Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. • Issue: Flood management practices in Green Tree Reservoirs (GTRs) may be causing damage to bottomland hardwood forests. It is thought that flooding early in the fall may harm desired species, such as willow oak. GTR managers need to know if or when root activity declines relative to shoot dormancy. • Activity: We tested for changes in root growth, root respiration and root nitrate uptake during the transition from fall to winter under several controlled soil temperature regimes, and tested the hypothesis that flooding during the winter dormancy period would have minimal impact on spring growth and result in little root mortality. At least one manuscript for publication is in progress. • Impacts: Decreasing soil temperatures in late fall resulted in reduced, and root respiration, which encompasses all energy-requiring activities. There was also a decrease in root respiration and nitrate uptake that was independent of soil temperature, perhaps due to dormancy-related processes triggered by decreasing air temperature. Furthermore, flooding during winter appeared to have little impact on willow oak seedling performance when soil temperatures were low, but resulted in a small amount of fine root mortality where soil temperatures were warm (15°C). Taken together with my previous experiment that showed stress due to early fall flooding, my results suggest that seasonal flooding of GTRs should be delayed until soil and/or air temperatures have decreased enough to slow root activity. This adaptive management type of approach may reduce mortality of moderately flood tolerant oak trees and enhance the sustainability of GTRs. Flood stress effects tree cellulose quality for cellulosic nanoparticle yields • Issue: There is an overabundance of trees in parts of the southeast U.S. Novel markets are needed for various types of wood in order to finance management operations to keep these forests healthy. Novel products made from cellulosic nanoparticles (CNPs) could represent one such opportunity, with the additional environmental benefits of bio-based products. It is unclear what tree species and grown under what conditions would provide appropriate feedstocks for producing CNPs. • Activity: CNPs were extracted from wood of several species to compare CNP yields. Additionally, we tested the hypothesis that growth of trees in stressful conditions would affect the yields of cellulosic nanoparticles (CNPs) that could be extracted from those trees. CNPs were extracted from willow oak trees grown either where annual flooding was deeper and longer duration or where annual flooding was shallow and shorter duration. • Impacts: Initial results suggest that tree species may affect CNP yields, although substantial CNPs were produced from all of the tested species. The yields of CNPs from the more flood-stressed trees were about twice as high as CNP yields from trees that were grown with shallower, shorter-duration annual flooding. Our effort to link plant genetics and environment with nanocellulose quality is cutting-edge in the field of study straddling plant biology and lignocellulosic materials. Use of this information to develop and expand a CNP industry could have positive economic and ecological impacts in these important ecosystems. Accomplishments Objective 1. Mechanisms governing nutrient allocation and nutrient use efficiency. I coauthored a paper showing that storage protein in bark tissues can affect nitrogen resorption from leaves, which was submitted last year and now has been accepted and published. The paper also shows that the plant hormone auxin plays an important role in regulating the release of nitrogen from storage tissues for use in spring stem and leaf growth. Previously, I used publicly available poplar gene expression data to identify an ammonium transporter (AMT) that has high expression in stems during seasonal recycling of N in poplars, and produced a transgenic poplar designed to knockdown expression of the AMT gene. This year, experiments were conducted to characterize the impact of reduced AMT expression on seasonal nitrogen cycling in trees. Amino acid profiling has been completed, and gene expression analysis is ongoing. Additional studies are on hold due to a lack of funding. Objective 2. Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. It is surmised that moderately flood-adapted oak trees, that are important in the LMAV, are least susceptible to flood when root activity is low during the dormant season. We conducted a large-scale greenhouse study of the patterns of willow oak root growth, root respiration, and nitrate uptake during winter dormancy induction, under controlled soil temperature conditions. Low soil temperatures resulted in reduced overall root activity, but root activity was partially reduced even with constant warm soil temperature, suggesting that both above and below ground temperature changes may be important to root activity. Waterlogging during winter appeared to have little impact on willow oak performance if soil temperatures were low (5° or 10°C), but caused some fine root mortality where soil temperatures were warm (15°C). Building on a previous study, this suggests that limiting flooding of green tree reservoirs to the dormant season would benefit forest health in those systems. In a related study, we are evaluating the conditions of 15-20 year-old NRCS wetland easements in Arkansas to assess whether management interventions are needed. To date, we have measured forest conditions on the ground for 33 easements. Analysis of this massive data set is in progress. We have run forest growth models to predict future conditions of the forests with and without management intervention in comparison with conservation objectives. Tuning of the models is ongoing. We have collected and processed initial drone imagery to determine how remote sensing could aid regular assessments with improved spatial information about forest structure for better management decision making by NRCS. We are currently modifying methodologies to improve the quality of image splicing. Objective 3. Potential resistance mechanisms of trees to insect attack, and the impacts of tree mortality on forest communities. Although our work demonstrating the potential for using an "electronic nose" volatile chemical detection system was published previously, I have no further work to report for this objective due to a lack of specific funding. Objective 4. Effects of stress, management regime, and/or genotype on tree cellulose quality, in relation to nanocellulosic products. The goal for my lab in this collaborative project is to determine whether quality of wood for nanocellulose production depends on the tree species, and whether growth environment affects the quality or abundance of cellulose nanoparticles (CNPs) that can be extracted from wood. This project will result in both scientific outcomes and potential economic development in the southern United States. Our assay indicated that hardwood species may yield more CNPs than pine wood. Tree cores were collected from willow oak trees to determine whether growth under flood-stress conditions the quality of wood for production of CNPs. Use of wood from flood-stressed willow oak trees resulted in yields of CNPs twice as high as from trees that were grown with less flood stress. It is not clear whether this increase in CNP yields is an effect of stress generally, or if this is specific to flood stress. This type of information will be essential for the development of a CNP industry in the lower Mississippi River Valley, which would have both positive economic and ecological outcomes.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Sample R, Babst BA (2020) Autumn flooding disrupts seasonal nitrogen storage and impacts spring growth in Quercus texana seedlings. Trees 34: 813-823
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Li G, Lin R, Egekwu C, Blakeslee J, Lin J, Pettengill E, Murphy AS, Peer WA, Islam N, Babst BA, Gao F, Komarov S, Tai Y-C, Coleman GD (2020) Seasonal nitrogen remobilization and the role of auxin transport in poplar trees. Journal of Experimental Botany 71: 4512-4530
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Progress 10/01/18 to 09/30/19
Outputs
Target Audience:Target audience includes the scientific community, especially in forestry and plant sciences, and natural resource managers to some degree. The project goal is to improve our fundamental understanding of tree-environment interactions, which is important to forestry, as well as to plant biology. The scientific advances of this project will ultimately contribute knowledge to improve tree germplasm and forest management approaches, which will impact forest land owners and foresters, as well as environmental quality for the broader community, particularly as itrelates to conservation of water resources and forest species (e.g., flood-adapted oaks). Changes/Problems:The NSF-EPSCoR funding for Objective 4 will end this year. I will consider funding opportunities to continue this line of research. What opportunities for training and professional development has the project provided?STEM work-force development • Issue: There is a need for college graduates trained to enter science, technology, engineering and math (STEM) jobs. • Activity: I contributed to STEM work-force education through hands-on training of two UAM undergraduate students, one of whom graduated this year and is employed, and 4 currently matriculating Master's students. My grant from Arkansas Game and Fish Commission provides for one additional graduate student. In addition to hands-on training, I seek opportunities for students to attend webinars and scientific meetings to expand their knowledge and connectedness to the relevant scientific communities. • Impact: These students are prepared to enter STEM careers upon graduation, and/or to pursue post-graduate education, helping to meet a national need. One of my undergraduate mentees is enrolled in a post-graduate STEM degree program, and my Master's student who graduated is enrolled in a STEM doctoral program. How have the results been disseminated to communities of interest?Our results have been disseminated via publications (listed above in "Products" section), seminars and poster presentations, as listed below. Seminars/Lectures (4): Research results have been presented via 3 seminars by the PI and 1 seminar by a MS student, including 2 presentations to forestry professionals. • "The threat of flood during dormancy transitions in bottomland hardwood forests." Ouachita Society of American Foresters, Hot Springs, AR. December 2018 • "Sugar Loading Is Not Required For Phloem Sap Flow In Maize Plants." Plant Vascular Biology 2019 Meeting, Asilomar, CA. June 2019 • "A Vision for Developing the Future (Nano-) Cellulosic Economy in Arkansas: Thinking Beyond CASE." Center for Advanced Surface Engineering (CASE) Webinar Series, Webinar, Arkansas. June 2019 • Science Flash Talk: "Autumn flooding disrupts seasonal nitrogen storage and impacts spring growth in Quercus texana seedlings." Society of American Foresters Annual Convention, Louisville, KY. November 2019 Posters (6): • Poster: James Cook (presenter), Jin-Woo Kim, Gurshagan Kandhola, Joseph Batta-Mpouma, Soma Shekar Dachavaram, Peter Crooks, and Benjamin A. Babst. "Investigation of woody feedstocks for cellulosic nanocrystals."Society of American Foresters Annual Convention, Louisville, KY. November 2019 • Poster: Benjamin A. Babst (presenter), Fei Gao, Lucia M. Acosta-Gamboa, Abhijit Karve, Michael J. Schueller, Argelia Lorence. "Three NPF genes in Arabidopsis are necessary for normal nitrogen cycling under low nitrogen stress." Plant Vascular Biology 2019 Meeting, Asilomar, CA. June 2019 • Poster: Richard Sample and Benjamin A. Babst (presenter). "Fall flooding disrupts seasonal nitrogen storage, but not phloem transport in Quercus texana seedlings." Plant Vascular Biology 2019 Meeting, Asilomar, CA. June 2019 • Poster: James Cook (presenter) and Benjamin A. Babst. "An investigation of renewable sources for cellulosic nanocrystals."Arkansas Annual EPSCoR Conference, Little Rock, AR. May 2019 • Poster: James Cook (presenter) and Benjamin A. Babst. "Enhanced diameter growth in Poplar under flooded conditions." Southern Forest Research Group Meeting, Stoneville, MS. April 2019 • Poster: James T. Collins (presenter), Matthew Olson, Doug Osborne, Benjamin A. Babst. "Comparison of a harvested and unharvested stand in a mature bottomland hardwood forest to the desired forest conditions." Biennial Southern Silvicultural Research Conference, Shreveport, LA. March 2019 What do you plan to do during the next reporting period to accomplish the goals?Overall, I will continue my effort to publish high quality publications to disseminate my research results, and I will focus on guiding my current M.S. students in the completion of their research. Objective 1: I will continue studies of the impacts of reduced AMT (ammonium transporter) expression in poplar on nitrogen metabolism of stems during short-day and cold temperature induction of leaf senescence. This work will determine the role of the AMT in seasonal nitrogen recycling within poplar trees, and provide a better understanding of how nitrogen is retained in trees and other perennial plants. Objective 2: I plan to prepare one new manuscript for publication. For the project assessing NRCS easements, in 2019 we plan to complete analysis of our data on current forest conditions for 33 WRP easements in Arkansas; complete initial modeling predictions of future forest conditions on easements; and begin developing management recommendations for NRCS. We will also continue testing remote sensing techniques to determine how drones can complement on-the-ground measurements, and what measurements could be replaced by using drones for assessment of afforestation plantations relative to conservation goals. Additionally, I will make a focused effort to manage the time- and labor-intensive experiment that I have in progress to ensure that we generate high quality data. The tree root dormancy project, funded by AGFC, will need a lot of attention to take all of the technically challenging measurements, and process all of the samples and data. I will make an extra effort to complete the current experiment and evaluate data quickly enough to guide modifications to the next in the series of experiments proposed in the grant. Objective 3: We will explore future directions for e-nose detection of emerald ash borer, if time permits. The technology showed promise to detect infestation from wood volatiles. Future steps could include determining the "smell-profile" of the insects, developing a field-portable approach to emerald ash borer detection, or detection of natural enemies of the emerald ash borer, which are being released as biological control agents. Currently the other objectives are higher priority in order to meet funding obligations. Objective 4: Analysis of the final replicates of our species panel will be completed this year, and being preparing a manuscript to share our results. Also, we will analyze tree cores from willow oak trees to determine whether trees grown under flood-stress conditions are altered such that production of nanoparticles from the wood is affected.
Impacts
What was accomplished under these goals?
Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. • Issue: Flood management practices in Green Tree Reservoirs (GTRs) may be causing damage to bottomland hardwood forests. • Activity: I presented a synthesis of literature research and my own experimental data at the OSAF meeting in Hot Springs in 2018. • Impacts: The presentation provided relevant continuing education for 50 - 60 forestry professionals, which included individuals from private industry, small companies, universities, and state and federal government agencies (e.g., AGFC, NRCS, AFC, and US Forest Service). My synthesis of previous and recent literature suggested that timing floods in GTRs later in the fall would help protect desired oak trees, and planting of oaks where they will encounter frequent early fall flooding should be avoided. Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. • Issue: Flood management practices in Green Tree Reservoirs may be causing damage to bottomland hardwood forests. It is thought that prolonged flooding in the spring may harm desired species, such as Nuttall oak. • Activity: We tested the hypothesis that prolonged flooding during winter that extends into the spring growing season would decrease spring growth and result in root mortality. I am preparing a manuscript to publish these results. • Impacts: There was some mortality of Nuttall oak when flooding lasted 2 months into the growing season, but the less tolerant Shumard oak had high mortality even from shorter duration flooding. Prolonged winter/spring flooding reduced growth of both Nuttall oak and Shumard oak seedlings. By the end of summer Nuttall oaks that had been flooded appeared to recover, with biomass near that of unflooded seedlings. Shumard oaks showed little signs of recovery. Combined with my previous results showing stress due to early fall flooding, my results suggest that early fall flooding may present a bigger problem to moderately flood tolerant oak trees in GTRs than winter flooding that extends into the spring. Adjusting hydroperiods accordingly may reduce oak mortality and increase the sustainability of GTRs. Objective 1. Mechanisms governing nutrient allocation and nutrient use efficiency. An ammonium transporter (AMT) appears to be important for seasonal recycling of N in poplars, based on gene expression data showing high expression of the AMT in stems during winter dormancy induction. Previously, we produced transgenic poplar expressing an RNAi construct designed to knockdown expression of the AMT. This year, we validated that AMT expression is in fact reduced in several of the transgenic lines. Currently, experiments are in progress to characterize the impact of reduced AMT expression and to investigate the role of AMT in seasonal nitrogen cycling in trees. I coauthored a paper showing that storage protein in bark tissues can affect nitrogen resorption from leaves, which has been submitted and is undergoing peer review. The paper also shows that the plant hormone auxin plays an important role in regulating the release of nitrogen from storage tissues for use in spring stem and leaf growth. Related to this objective, I published a paper in Plant Physiology and Biochemistry that identified three NPF genes (Nitrate transporter/Peptide transporter Family) that are necessary for normal cycling of nitrogen within Arabidopsis plants. Our findings were interesting because this family of genes is known for its role in transport of inorganic nitrogen, yet we found effects on organic nitrogen remobilization from leaves. Thus, the two are likely interconnected. Objective 2. Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. Use of oak trees in wetland restoration in the Mississippi River Valley is highly desirable, especially for wildlife and waterfowl, but oak species may be somewhat susceptible to the flooding that typically occurs at these sites. Several experiments studying dormant season flood effects on oak seedlings are completed (1 manuscript submitted and 1 in preparation). We submitted a manuscript for publication in Trees: Structure & Function in which we found that substantial nutrient uptake occurred during dormancy induction, but flooding essentially eliminated this fall nutrient accumulation, in part due to death of 40% of fine roots. This new information provides an important warning to government and private owners of green tree reservoirs that there may be considerable impacts on tree health and survival if these forests are flooded too early in the fall. With new funding from Arkansas Game and Fish Commission, I conducted a pilot project in the field studying patterns of root respiration during seasonal soil temperature changes. Currently, I have an ongoing large-scale experiment studying seasonal changes in root respiration, root growth, and root nitrogen uptake activity. The current experiment will also investigate whether the effects of flood are moderated by cold temperatures during the dormant season. In a related study, we are evaluating the conditions of 15-20 year-old NRCS wetland easements in Arkansas to assess whether management interventions are needed. To date, we have measured forest conditions on the ground for 33 easements. We are running forest growth models to predict future conditions of the forests with and without management intervention in comparison with conservation objectives. Additionally, a new M.S. student started working on the project this year to determine how remote sensing could aid regular assessments with improved spatial information about forest structure for better management decision making by NRCS. Objective 3. Potential resistance mechanisms of trees to insect attack, and the impacts of tree mortality on forest communities. This exploratory project aims to determine whether a novel volatile chemical detection system, the "electronic nose," could be used to detect the presence of emerald ash borer larvae in ash trees. We found distinct volatile chemical signatures (or "smell") of infested bark using electronic aroma detection (i.e., an e-nose), despite the fact that defensive chemistry showed little response to emerald ash borer infestation according to an independt biochemical analysis (LCMS). Our findings were published this year in the journal "Biosensors." There is potential for practical application of this work, developing a technique using a field-portable e-nose device to detect emerald ash borer, which could aid tree improvement research, and revolutionize management of this very destructive exotic pest. Objective 4. Effects of stress, management regime, and/or genotype on tree cellulose quality, in relation to nanocellulosic products. The goal for my lab in this collaborative project is to determine what tree species are best suited for nanocellulose production and whether growth environment affects the quality or abundance of nanocellulose particles that can be extracted from wood. This project will result in both scientific outcomes and potential economic development in the southern United States. A rapid assay is needed since this study will require analysis of many samples at once. We have now completed development of a rapid micro-scale protocol to extract cellulose, hydrolyze cellulose to produce cellulose nanoparticles, purify the nanoparticles, and measure the amount of nanocellulose produced. Analysis of the first set of samples is under way, but preliminary results indicate that hardwood species may yield more cellulosic nanoparticles than pine wood. We are now completing analysis of the final replicates of our species panel. Tree cores have been collected from willow oak trees to determine whether trees grown under flood-stress conditions are altered such that production of nanoparticles from the wood is affected.
Publications
- Type:
Book Chapters
Status:
Published
Year Published:
2019
Citation:
Babst BA, Ferrieri R, Schueller M (2019) Detecting rapid changes in carbon transport and partitioning with carbon-11 (11C). In J Liesche, ed, Phloem: Methods and Protocols. Springer New York, New York, NY, pp 163-176
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Babst BA, Gao F, Acosta-Gamboa LM, Karve A, Schueller MJ, Lorence A (2019) Three NPF genes in Arabidopsis are necessary for normal nitrogen cycling under low nitrogen stress. Plant Physiology and Biochemistry 143: 1-10
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Sample RD and Babst BA (2019) Timing of nitrogen resorption-related processes during fall senescence in southern oak species. Forest Science 65: 245-249.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Wilson AD, Forse LB, Babst BA, and Bataineh MM (2019) Detection of emerald ash borer infestations in living green ash by noninvasive electronic-nose analysis of wood volatiles. Biosensors 9: 123. DOI:10.3390/bios9040123
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Hossain SMY, Stuhlinger HC, Olson M, and Babst BA (2019) A comparison of indirect watering devices for benefiting newly transplanted urban trees. Arboriculture & Urban Forestry 45: 109-119.
|
Progress 10/01/17 to 09/30/18
Outputs
Target Audience:Target audience includes the scientific community, especially in forestry and plant sciences, and natural resource managers to some degree. The project goal is to improve our fundamental understanding of tree-environment interactions, which is important to forestry, as well as to plant biology. The scientific advances of this project will ultimately contribute knowledge to improve tree germplasm and forest management approaches, which will impact forest land owners and foresters, as well as environmental quality for the broader community, particularly asrelates to conservation of water resources and forest species (e.g., flood-adapted oaks). Changes/Problems:A new study was funded by the Arkansas Game and Fish Commission to study the timing and cues for tree root dormancy. This study, which is a direct off-shoot of my recently completed experiment, will provide information that is needed to improve green tree reservoir (GTR) management. It is assumed that tree roots are less susceptible to flooding during dormancy. This study will test whether there is a period of lower susceptibility during winter, and if so, determine when that period begins and ends. This information will aid GTR managers to stabilize these forests by providing a basis for adaptive management of the flood regimes of GTRs to reduce tree mortality. This study is classed under objective 2, and so will shift more effort and emphasis onto objective 2. What opportunities for training and professional development has the project provided?STEM work-force development • Issue: There is a need for college graduates trained to enter science, technology, engineering and math (STEM) jobs. • Activity: In my lab, I contributed to STEM work-force education through hands-on training of three UAM undergraduate students who completed their bachelor's degrees, and 4 additional undergraduate students who are expected to graduate this year, one Master's student, Richard Sample, who graduated in 2018, and two new Master's students, James Cook and Parikrama Sapkota. • Impact: These students are prepared to enter STEM careers upon graduation, and/or to pursue post-graduate education, helping to meet a national need. One of my undergraduate mentees is enrolled in a post-graduate STEM degree program, and my Master's student who graduated is enrolled in a STEM doctoral program. How have the results been disseminated to communities of interest?Our results have been disseminated via publications (listed above in "Products" section), seminars and poster presentations, as listed below. • Seminars/Lectures (3): Research results have been presented via 2 seminars by the PI and 1 seminar by a MS student, including a presentation to forest management professionals. "The threat of flood during dormancy transitions in bottomland hardwood forests." Ouachita Society of American Foresters, Hot Springs, AR. December 2018 "Sugar Loading Is Not Required For Phloem Transport In Plants." Plant Biology 2018 Meeting, American Society of Plant Biologists, Montreal, Canada. July 2018 Richard Sample (presenter) "Nitrogen uptake continues during dormancy induction in poplar, enhances stem diameter growth." Southern Section American Society of Plant Biologists, New Orleans, LA. March 2018 • Posters (4): Benjamin A. Babst (presenter), Abhijit Karve, R. Frank Baker, Thu Tran, Douglas Kenny, Julia Rohlhill, David Braun, Jan Knoblauch, Michael Knoblauch, and Kaare Jensen. "Sugar Loading Is Not Required For Phloem Transport In Plants." Plant Biology 2018 Meeting, American Society of Plant Biologists, Montreal, Canada. July 2018 Benjamin A. Babst (presenter), Fei Gao, Lucia M. Acosta-Gamboa, Argelia Lorence. "Identification and characterization of nitrogen cycling mutants in Arabidopsis using nitrogen-13 radiotracer assays and high throughput phenotyping." Plant Biology 2018 Meeting, American Society of Plant Biologists, Montreal, Canada. July 2018 James Cook and Benjamin A. Babst. "An investigation of renewable sources for cellulosic nanocrystals." Arkansas Annual EPSCoR Conference, Fayetteville, AR. June 2018 Richard Sample and Benjamin A. Babst. "Nitrogen resorption timeline in relation to protein and chlorophyll degradation in southern oaks." Southern Forest Research Group Meeting, Stoneville, MS. March 2018 What do you plan to do during the next reporting period to accomplish the goals?Objective 1: I plan to finish writing 2 articles and submit them for publication in scientific journals. Also, I will complete initial studies of the impacts of reduced AMT expression in poplar on nitrogen metabolism of stems during short-day and cold temperature induction of leaf senescence, and begin preparing a manuscript. This work will determine the role of the AMT in seasonal nitrogen recycling within poplar trees, and provide a better understanding of how nitrogen is retained in trees and other perennial plants. Objective 2: We plan to prepare at least one manuscript for publication. An additional experiment studying the impacts of winter/spring flooding duration on nutrient remobilization and spring growth will be completed. For the project assessing NRCS easements, in 2019 we will measure an additional 20-30 easements, model future conditions of easements, and begin developing management recommendations for NRCS. We will also begin testing remote sensing assessment techniques to determine how drones can complement on-the-ground measurements, and what measurements could be replaced by using drones. Objective 3: I will finish processing LCMS data to measure the phytochemical contents of green ash bark samples from emerald ash borer-infested and -uninfested trees, if time permits. Currently the other objectives are higher priority in order to meet funding obligations. Objective 4: With a graduate student now working on this objective, we will finish optimizing our nanocellulose assay early this year. We will then use the assay to test the suitability of different species for nanocellulose production, and also test whether growth under annually flooded conditions impacts the suitability of wood for producing nanocellulose.
Impacts
What was accomplished under these goals?
Impact: Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. (Preliminary study) • Issue: It is possible that nutrient cycling in southern oak trees is impacted by flooding, but there was very limited background information on nutrient cycling in these species. • Activity: We measured protein, nitrogen and chlorophyll concentrations in leaves of oak trees during the course of dormancy induction for two Fall seasons. • Impact: We found that southern oak leaf senescence was a very slow and protracted process. Slow loss of function might allow continued photosynthesis and high productivity in unusual years when Fall water availability is high. This potential for Fall productivity has implications for the global carbon cycle. Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. • Issue: Oak trees are highly desirable in both natural and human constructed wetlands (green tree reservoirs), especially for wildlife and waterfowl, but oak species may be somewhat susceptible to the flooding that typically occurs at these sites. • Activity: We conducted an experiment to determine whether flooding impacts nutrient resorption, the seasonal transfer of nutrients between leaves to stems during winter dormancy. • Impacts: Although we found no negative impact of flooding on nutrient resorption, flooding caused a substantial reduction in nutrient uptake. Since nutrient uptake during Fall was sizeable, managers of green tree reservoirs should avoid flooding these forests during the fall dormancy induction period, which could weaken trees and lead to tree death. Objective 1. Mechanisms governing nutrient allocation and nutrient use efficiency. An ammonium transporter (AMT) appears to be important for seasonal recycling of N in poplars, based on gene expression data showing high expression of the AMT in stems during winter dormancy induction. Previously, we produced transgenic poplar expressing an RNAi construct designed to knockdown expression of the AMT. This year, we validated that AMT expression is in fact reduced in several of the transgenic lines. Currently, experiments are in progress to characterize the impact of reduced AMT expression and to investigate the role of AMT in seasonal nitrogen cycling in trees. Objective 2. Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. Use of oak trees in wetland restoration in the Mississippi River Valley is highly desirable, especially for wildlife and waterfowl, but oak species may be somewhat susceptible to the flooding that typically occurs at these sites. This year, we published a study that examined the patterns of protein and chlorophyll degradation in relation to nitrogen resorption from leaves. Our results suggest that leaf senescence processes begin early in the fall, but proceed rather slowly. It is possible that this slow senescence is due to a physiological constraint. Alternatively, it may be an adaptation to the unpredictable Fall moisture availability in the southern U.S. Slow senescence might allow continued photosynthesis and high productivity in years when Fall water availability is high, which has implications for the global carbon cycle. Also, we completed an experiment to determine whether flooding impacts seasonal transfers of nutrients between leaves to stems (resorption) during winter dormancy. Soil flooding had a limited impact on nutrient resorption. We also found that substantial nutrient uptake occurred during dormancy induction, but flooding essentially eliminated this fall nutrient accumulation, in part due to death of 40% of fine roots. A manuscript reporting this work is being prepared for publication, and results were reported to Arkansas and Oklahoma forestry professionals at the Ouachita Society of American Foresters annual meeting this year. This new information provides an important warning to government and private owners of green tree reservoirs that there may be considerable impacts on tree health and survival if these forests are flooded during the fall dormancy induction period, and the weakening of the trees continues into the subsequent year. In a related study, we began evaluating the conditions of 15-20 year-old NRCS wetland easements in Arkansas to assess whether management interventions are needed. To date, we have measured forest conditions on the ground for 40 - 50 forest stands within 14 easements. Objective 3. Potential resistance mechanisms of trees to insect attack, and the impacts of tree mortality on forest communities. This exploratory project aims to determine whether a novel volatile chemical detection system, the "electronic nose," could be used to detect the presence of emerald ash borer larvae in ash trees. Dr. Mohammad Bataineh (UAM) and I sent bark samples from emerald ash borer-infested and -uninfested green ash trees to Dr. Dan Wilson. Dr. Wilson found distinct volatile chemical signatures (or "smell") of infested bark using electronic aroma detection (i.e., an e-nose). A duplicate set of samples was used in my lab for LCMS analysis to complement the e-nose measurements by quantifying a broad swath of biochemicals present in the bark of infested and uninfested ash trees. We propagated our best-performing poplar/cottonwood clones in the Pine Tree Station clone-bank last winter. This new clone bed was designing as an experiment itself, and will also cuttings for a rigorous test of cottonwood clone suitability in different site types within Arkansas. Objective 4. Effects of stress, management regime, and/or genotype on tree cellulose quality, in relation to nanocellulosic products. The goal of my lab in this project is to determine what tree species are best suited for nanocellulose production and whether species and growth environment affect the quality or abundance of nanocellulose particles that can be extracted from wood. This project will result in both scientific outcomes and potential economic development in the southern United States. We are developing rapid assays since we will need to analyze many samples at once. We now have a rapid micro-scale protocol to extract cellulose, hydrolyze cellulose to produce cellulose nanoparticles, purify the nanoparticles, and measure the amount of nanocellulose produced. Every aspect of this assay has been a challenge. We are currently optimizing the protocol to improve yields, which we expect to finalize this year and proceed to comparing species and different growth conditions.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Babst BA, Coleman GD (2018) Seasonal nitrogen cycling in temperate trees: Transport and regulatory mechanisms are key missing links. Plant Science 270:268-277.
- Type:
Book Chapters
Status:
Published
Year Published:
2018
Citation:
Ferrieri RA, Herman E, Babst BA, Schueller MJ (2018) Managing the soil nitrogen cycle in agroecosytems. In: Lal R, Stewart BA (eds) Advances in Soil Science: Soil Nitrogen Uses and Environmental Impacts. CRC Press, Boca Raton, FL, pp 343-360.
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2019
Citation:
Sample R, Babst BA (2018) Timing of nitrogen resorption-related processes during fall senescence in southern oak species. Forest Science DOI:10.1093/forsci/fxy062.
- Type:
Journal Articles
Status:
Accepted
Year Published:
2019
Citation:
Hossain SMY, Stuhlinger HC, Olson M, and Babst BA (in press) A comparison of indirect watering devices for benefiting newly transplanted urban trees. Arboriculture & Urban Forestry.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2018
Citation:
Sample RD. 2018. Environmental effects on internal nitrogen cycling during dormancy induction in trees. M.S. Thesis. University of Arkansas at Monticello, Monticello, AR, p 83.
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:Target audience includes the scientific community, especially in forestry and plant sciences. The scientific advances of this project will impact forest land owners and foresters, as well as the broader environmental community. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?STEM work-force development • Issue: There is a need for college graduates trained to enter science, technology, engineering and math (STEM) jobs. • Activity: I contributed to STEM work-force education through hands-on training of three undergraduate students in my lab, one Master's student who is expected to graduate in the Summer of 2018, and I am recruiting a new Master's student. • Impact: These students are prepared to enter STEM careers upon graduation, and/or to pursue post-graduate education, helping to meet a national need. How have the results been disseminated to communities of interest?Our results have been disseminated via publications, seminars and poster presentations. Novel ideas for managing nitrogen cycling have been disseminated to the scientific community via one book chapter, and several journal articles are being prepared. Research results have been presented via 4 seminars and 4 posters,including a research progress report seminar to the Plant Imaging Consortium (PIC) Annual Meeting in St. Louis, MO. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: I plan to finish writing and publish 2 articles in scientific journals. Also, I will analyze the impacts of reduced AMT expression in poplar on nitrogen metabolism of leaves and stems during short-day and cold temperature induction of leaf senescence, nitrogen accumulation in stems, and winter dormancy. This work will determine the role of the AMT in seasonal nitrogen recycling within poplar trees, and provide a better understanding of how nitrogen is retained in trees and other perennial plants. Objective 2: We will be processing samples for biochemical analysis, and then preparing at least one manuscript for publication. An additional experiment studying the impacts of winter/spring flooding duration on nutrient remobilization and spring growth will be conducted. The new project assessing NRCS easements is in the planning stage, and on-the-ground measurements will begin in summer 2018. Objective 3: We are currently designing a new experiment to test for genotype x environment interactions, to provide a more rigorous test of cottonwood clone suitability in different site types within Arkansas. We plan to propagate the best-performing clones in the Pine Tree clone-bank this winter. This will also provide a platform for testing genotype x environment effects on cellulose quality for Obj. 4. Additionally, I will perform LCMS analysis of phytochemical contents of green ash bark samples from emerald ash borer-infested and -uninfested trees. Objective 4: I hope to finalize our nanocellulose assay this year, and begin to use the assay to test the suitability of different species for nanocellulose production. Time permitting, I also hope to start analysis of wood samples that were grown under different environmental conditions to determine whether growth conditions impact the quantity and/or quality of cellulose nanocrystals that can be produced.
Impacts
What was accomplished under these goals?
Impact: Development of Woody Biomass for Nanocellulose Markets • Issue: With an over-abundance of wood in the southern US, there are major risks to forest health due to weak markets for wood. This impacts the economy and forest landowners. • Activity: There is potential to develop new markets for woody biomass using cellulose nanocrystals (CNCs) to make novel products, which could have substantial economic benefits for the nation. I have successfully produced cellulosic nanocrystals at micro-scale from wood of trees native to the southern United States, which can be used to assess CNC quality for medium throughput analysis. • Impact: These methods will be used to determine the best wood sources for producing nanocellulose crystals. Mechanisms of Nitrogen Transport and Nitrogen Stress Tolerance • Issue: Nitrogen availability often limits growth in forests, but we have a poor understanding of how trees cope with low nitrogen by recycling nitrogen internally. • Activity: We adapted methods for measuring nitrogen export from leaves non-invasively in live plants using N-13 radiotracers to identify several genes that are involved in nitrogen transport. Also, we found that sink tissues where nutrients are stored within the tree over winter, such as the stem, act to "pull" nitrogen out of leaves before autumn leaf fall. • Impacts: Identification of genes will aid in improving nitrogen use efficiency in plants. Forest managers should avoid practices that may stress roots and stems in the Fall to maximize nitrogen retention. Objective 1. Mechanisms governing nutrient allocation and nutrient use efficiency. We have completed several experiments, studying Arabidopsis nitrogen transporter mutants at Arkansas State University (ASU) high throughput phenotyping facility, and poplar mutants at the radiotracer imaging lab at Washington University in St. Louis (WUSL), and 2 manuscripts are being written. The phenotyping experiment helped to identify and understand the role of several possible components of the nitrogen transport system in Arabidopsis. In the radiotracer experiment, we found that production of storage form of nitrogen (bark storage protein) is essential for movement of nitrogen out of leaves to stems during the initiation of winter dormancy, and so is crucial not just for storage, but also for retention of nitrogen in overwintering trees. A component of this project, using transgenic poplars that we recently produced is ongoing. An ammonium transporter (AMT) appears to be important for seasonal recycling of N in poplars, based on gene expression data showing high expression of the AMT in stems during winter dormancy induction. We produced transgenic poplar expressing an RNAi construct designed to knockdown expression of the AMT. The transgenic poplars will be characterized and used to study seasonal nitrogen cycling in trees. Objective 2. Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. Use of oak trees in wetland restoration in the Mississippi River Valley is highly desirable, especially for wildlife and waterfowl, but oak species may be somewhat susceptible to the flooding that typically occurs at these sites. We are currently conducting experiments to determine whether flooding impacts seasonal transfers of nutrients between leaves to stems during winter dormancy. Preliminary experiments examined the patterns of protein and chlorophyll degradation in relation to nitrogen resorption from leaves. We are currently collecting data for a second season, and expect to publish the results of this experiment in 2018. We are also collecting data for a study of the effects of flooding on nitrogen resorption in oak seedlings (seedlings donated by AR Forestry Commission). Flooding reduces the ability of tree roots to take up nutrients. If it also reduces the ability of trees to withdraw nutrients from leaves for storage in stems and roots over winter, then flooded trees may be experiencing even more nutrient stress than we realize. Data collection will be completed for this study and a manuscript prepared for publication in 2018. This knowledge will aid in the development of management strategies for bottomland hardwood forest easements and green tree reservoirs, and possibly in tree breeding efforts. In a related, newly funded study we will evaluate the conditions of 15-20 year old NRCS wetland easements in Arkansas, and asses whether management interventions are needed. This study will measure forest conditions on the ground, test potential remote sensing assessment techniques, model future conditions of easements, and develop management recommendations for NRCS. Currently we are gathering information to aid selection of measurement sites. Objective 3. Potential resistance mechanisms of trees to insect attack, and the impacts of tree mortality on forest communities. Cottonwood trees can play an important role in river-side buffer strips to reduce water pollution, and could also produce biomass in a short-rotation coppice system for bioenergy, pulp, or other bioproducts (e.g., nanocellulose). We are currently analyzing tree growth, disease and insect damage data for a large number of cottonwood clones in a preliminary assessment of clonal suitability for growth in Arkansas. Trees were coppiced during winter 2017 to encourage sprouting of shoots suitable for propagating the cottonwood clones, in order to expand the experiment. This exploratory project aims to determine whether a novel volatile chemical detection system, the "electronic nose," could be used to detect the presence of emerald ash borer larvae in ash trees. Dr. Mohammad Bataineh (UAM) and I sent bark samples from emerald ash borer-infested and -uninfested green ash trees to Dr. Dan Wilson for preliminary assessment using his e-nose. We also collected a duplicate set of samples for analysis in my lab by LCMS to complement the e-nose measurements. Objective 4. Effects of stress, management regime, and/or genotype on tree cellulose quality, in relation to nanocellulosic products. The overarching goal of this multidisciplinary project is to develop novel materials and marketable product applications using nanocellulose; refine processing methodologies to produce nanocellulose from wood in an efficient and environmentally friendly manner; and determine what wood sources would be best suited for production of nanocellulosic materials in Arkansas. My responsibility will be to determine what tree species are best suited for nanocellulose production and whether intraspecific genetic variation and environmental effects on wood quality impact the resulting nanocellulose. This project will result in both scientific outcomes and potential economic development in the southern United States. To answer our questions, rapid assays are needed in order to address the need to analyze many samples. Current methodologies process one sample at a time over several days. I am developing medium-throughput assays of nanocellulose using small amounts of wood as starting material. With the assistance of an undergraduate student, I have adapted a rapid micro-scale extraction of cellulose, an assay to measure lignin (to test for cellulose purity), hydrolysis of cellulose to produce cellulose nanocrystals, and an assay for the amount of nanocellulose produced. Every aspect of this assay has been a challenge. We are currently developing the last part, separation of the nanoparticles from the glucose and oligosaccharides released by the hydrolysis. Comparing species and different growth conditions depends on overcoming these final technical challenges.
Publications
- Type:
Book Chapters
Status:
Awaiting Publication
Year Published:
2018
Citation:
Ferrieri RA, Herman E, Babst BA, Schueller MJ. Managing the soil nitrogen cycle in agroecosytems. In L Rattan, ed, Advances in Soil Science. CRC Press. In press
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Progress 02/29/16 to 09/30/16
Outputs
Target Audience:Target audiences will include the scientific community, especially in forestry. The project effort will also likely improve our fundamental understanding of plant-environment interactions, which will be of interest in plant biology and agriculture. The scientific advances of this project will ultimately lead to improvements in germplasm and management approaches that will impact landowners, silviculturalists and industrial foresters, as well as environmental quality for the broader community, particularly as relates to conservation of water resources and forest species (e.g., flood-adapted oaks, and ash). Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A postdoctoral associate was provided with several training and professional development opportunities, including training to do poplar transformation; training in 13N radioisotope PET imaging of N transport at Washington University in St. Louis; training to do high throughput phenotyping and the subsequent data analysis at Arkansas State University; and the opportunity to teach a lab on tree genetics and tree improvement. A graduate student started the masters program and is training in general experimental methodologies, field experiment design, field sampling of tree tissues; physiological skills (e.g., chlorophyll measurement and photosynthesis determination), and biochemical analysis (e.g., protein assay). A local high school biology teacher was provided a summer research experience in my lab, administered via the Arkansas STRIVE program. The teacher contributed to research under my mentorship (e.g., PCR, cloning), shared research experiences with other STRIVE participants, and developed an inquiry-based project to add to her high school biology class curriculum. Training and professional development opportunities were provideed to two undergaduate students this year. One of the students learned plant tissue culture and molecular techniques, while the other learned biochemical assays and aspects of wood processing, including protein content determination, cellulose extraction, and cellulose and lignin content determination. These students also attended a workshop for undergraduates, where they had training in lab skills and research ethics, and had the opportunity to present their research to their peers. How have the results been disseminated to communities of interest?This year, research results have been disseminated to the scientific community via two published articles in scientific journals. Additionally, research results have been presented via 5 invited seminars by the PI (Arkansas State U., Washington State U., University of Arkansas Fayetteville, University of Arkansas at Little Rock, and Arkansas Tech University), a research report to the Plant Imaging Consortium (PIC) Annual Meeting in Fayetteville, and a poster presented at the American Society for Plant Biology annual meeting (presented by postdoc, Dr. Fei Gao). Additionally, I have attended several forest management meetings, and have spoken with numerous forestry professionals about my research, and how we can work together to enhance my research, and to enhance forest management using the knowledge gained through my research. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact: I have made substantial progress in developing efficient assays that will be used to evaluate the wood of different trees for use in the manufacture of novel nano-products derived from sustainable cellulose. I am collaborating with chemists who have developed chemical modifications to cellulose nanocrystal surfaces to provide a very versatile materials for engineering products, including biofilm-resistant packaging, filters, and substrates for medical applications, which promise to enhance quality of life. These technologies will also promote economic development in the southern United States, where wood is an abundant, sustainable source of cellulose. I am developing assays needed to determine the best source trees for commercialization of this technology. Furthermore, by understanding the effects of stress on trees, such as damage by herbivores, nutrient deficiency, and excess or inadequate water, and plant adaptive responses to stress, this project will contribute to the knowledgebase needed to improve tree germplasm and continue to enhance forest management approaches to take full advantage of the natural adaptations of plants to environmental stresses. This will be particularly important in areas where management practices are not yet well established, such as bottomland hardwood forests, which provide multiple societal benefits, including habitat for wildlife conservation, reduced pollution of waterways with fertilizer runoff and leaching, and flood control. Objective 1. Mechanisms governing nutrient allocation and nutrient use efficiency in nutrient deficient plants. Previously we had identified several transporter genes in Arabidopsis and in poplar that appear to be important for nitrogen recycling within the plant. This year we confirmed that the target genes are not expressed in the mutants using RT-PCR, and produced green fluorescent protein (GFP)-tagged constructs to determine the subcellular localization of the expressed proteins. An initial small scale test run was conducted at the Arkansas State University (ASU) high throughput phenotyping facility, to prepare for a full-scale experiment in January 2017. I visited the radiotracer imaging facility in Washington University in St. Louis (WUSL) to help develop a system for delivering nitrogen-13 (13N) to plant leaves as 13NH3. We now have a workable system for dynamic imaging of nitrogen transport in plants, and have confirmed that the 13N is metabolized by the leaf. With this sytem, we will compare wild type poplars with transgenic poplars in which the nitrogen storage compound, bark storage protein, has been manipulated by overexpression or RNA-interference (RNAi), respectively. Nitrogen transport from leaves to stems is a crucial aspect of seasonal nitrogen recycling, which is the basis for efficient use of nitrogen by trees, and forests increasing the abundance of nutrients on a site over time. This experiment will provide crucial information about the rate and timing of leaf nitrogen transport from leaves to stems during autumn senescence, establishing a foundation for understanding the mechanisms underlying nitrogen recycling in plants. Objective 2. Impacts of insufficient and excessive soil moisture regimes in bottomland hardwood trees. In the last century, almost 20 million acres of bottomland hardwood forests were converted for use as farmland in the lower Mississippi Alluvial Valley. For 30 years, federal programs have stimulated restoration of vast portions of these forests that provide multiple societal benefits, including habitat for wildlife conservation and reduced pollution of waterways with fertilizer runoff and leaching. These forests experience periodic flooding, which benefits wildlife, but can harm the trees. We know that flooding impacts plant health, and can result in leaf loss and ultimately plant death if flooding is prolonged. We started an experiment to determine whether site flooding prevalence reduces seasonal recycling of nitrogen, which is often the most limiting nutrient in forests. We are in the process of analyzing leaf nitrogen and protein concentrations before and after leaf senescence to determine whether the stress experienced by trees on flood prone sites reduces their ability to recycle nutrients, which is crucial to their competitive ability, functionality in the ecosystem, and productivity from either an economic or ecological standpoint. We are also planning pilot studies for the 2017 growing season to determine whether nitrogen recycling in tree seedlings is affected by various controlled flooding regimes. This will lay a foundation for discovering adaptations that help bottomland trees survive flooding, and will guide tree improvement and development of management strategies for sustainable forestry in bottomlands. Objective 3. Potential resistance mechanisms of trees to insect attack, and the impacts of tree mortality on forest communities. Cottonwood trees can play an important role in river-side buffer strips to reduce water pollution, and could also rapidly produce biomass in a short-rotation coppice system for bioenergy, pulp, or other bioproducts (e.g., nanocellulose). There is no published assessment of the performance of various "high-performing" cottonwood clones for growth in Arkansas' climate and soils. A clone-bank nursery was started at Pine Tree Station in Arkansas about 10 years ago by Chris Stuhlinger. This summer (2016), I led a team to assess disease and insect damage prevalence in all of those clones for which enough replicate plots existed (21 clones). We plan to assess growth this year, also, before coppicing. Using clones from the Pine Tree clone-bank, we are currently designing a new experiment to test for genotype x environment interactions, which will provide a more rigorous test of cottonwood clone suitability and susceptibility to pests. The experiment will also provide a platform for testing genotype x environment effects on cellulose quality for Obj. 4. Objective 4. Effects of stress, management regime, and/or genotype on tree cellulose quality, in relation to nanocellulosic products. Nanocellulose is a young, rapidly developing technology. Little is known about the impact of the source tree genotype or growth conditions on either the efficiency of nanocellulose extraction or the quality of the resultant nanocellulose (shape, size, other chemical properties). Objective 4 of this project will be important to determine the best sources, and maximize the quality and efficiency of nanocellulose production to make it a viable industry in Arkansas. Our results could be used either (1) to guide growers on the best conditions for producing wood for nanocellulose, or (2) to aid nanocellulose producers in choosing wood that has been grown in appropriate conditions to faciliate nanocellulose production. I am currently conducting an initial experiment in collaboration with Dr. Bill Headlee (UAM) and Dr. Jin Woo Kim's lab group (U. Arkansas Fayetteville) to compare cellulose yields and quality (and resultant nanocellulose yields and quality) between 4 tree species that are abundant in Arkansas and have potential for commercial-scale production. Analysis is underway. I identified a critical need for a cellulose quality assay(s) that can be conducted rapidly for many samples, in order to study the effects of genotype and environmental conditions with appropriate sample sizes. I have extracted cellulose in my lab using a micro-scale protocol, that can potentially be used for many samples at once. This small-scale cellulose extraction is the first step toward developing assays of various aspects of wood quality, e.g., based on microscopy or NMR, but also we will attempt to expand our medium-throughput protocol to produce micro-scale quantities of nanocellulose and develop analytical assays of properties of the resultant nanocellulose.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
He F, Karve AA, Maslov S, Babst BA. 2016. Large-Scale Public Transcriptomic Data Mining Reveals a Tight Connection between the Transport of Nitrogen and Other Transport Processes in Arabidopsis. Frontiers in Plant Science 7, 1207. doi: 1210.3389/fpls.2016.01207.
- Type:
Journal Articles
Status:
Published
Year Published:
2016
Citation:
Knoblauch M, Knoblauch J, Mullendore DL, Savage JA, Babst BA, Beecher SD, Dodgen AC, Jensen KH, Holbrook NM. 2016. Testing the M�nch hypothesis of long distance phloem transport in plants. eLIFE 5, e15341.
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