Progress 10/01/19 to 09/30/20
Outputs
Target Audience: Scientific research communities involved in plant chemical ecology, phenology, and herbivore-plant interactions. Landscape industry specializing in poison ivy removal and remediation. General public interested in understanding poison ivy allergenic dermatitis and climate changed-induced weedy noxious plants. Changes/Problems:No major changes to report. What opportunities for training and professional development has the project provided?This project provided training and professional development for seven undergraduate researchers. Two of these undergraduate researchers presented results at a departmental-level graduate student poster session. Unfortunately, due to the COVID pandemic, in the spring of 2020, the university mandated the cessation of all in-laboratory research activities. However, in the Fall 2020 semester, two of these undergraduate researchers returned to the laboratory and commenced research activities under my direct in-person supervision. It goes without saying that the effective shutdown of the laboratory from March to September diminished the productivity of the laboratory. How have the results been disseminated to communities of interest?Results from these findings were disseminated to diverse communities as follows. One manuscript was published in 2020 in the online Open Access journal "Molecules". These results were also disseminated to a wider scholarly audience as a poster presented by two undergraduate researchers working in the lab. What do you plan to do during the next reporting period to accomplish the goals?We will continue to follow the research objectives outlined in this Hatch grant proposal.
Impacts
What was accomplished under these goals?
1) Characterize urushiol accumulation levels in response to ontology, seasonal variation, and simulated herbivory. The observational study of 20 poison ivy liana urushiol and herbivory reported last year required complementary experiments to better contextualize those findings. One such study involved recording liana branch phenology observations (e.g. leaf number, branch length, etc.) over the course of the 2020 growing season. An additional study that was performed this year was examining the effects of simulated insect herbivory on young poison ivy seedlings grown in vitro. These additional studies nicely contextualize the previous findings indicating that urushiol appears to be a preformed chemical. Moreover, the intended target for the urushiol chemical defense does not appear to be insect herbivores. These findings will be the topic of a manuscript for submission to a peer-reviewed journal. A major finding from the above study was the substantial degree of variation in urushiol levels between individual plants. To further investigate this phenomenon, the lab initiated experiments investigating the allometric relationship between leaf biomass and urushiol levels and congener composition of plants derived from geographically-isolated locations. Another new line of investigation was evaluating the effects of three plant stress hormones (i.e. jasmonic acid, salicylic acid, and abscisic acid) on the urushiol levels of vitro poison ivy seedlings. Consistent with the hypothesis that urushiol is a preformed chemical defense, none of these treatments resulted in significantly elevated urushiol levels. Inspired by the COVID pandemic university mandated laboratory shutdown, I initiated a new research project focused on quantifying variation in poison ivy leaf morphology using publicly available poison ivy images. Four undergraduates were trained in leaf morphology terminology and assigned 400 images of both poison ivy and hog peanut, respectively. Various leaf anatomical features were coded using an ordinal scale and then aggregated into a composite leaf complexity score. Statistical analysis of these data indicated a high degree of variability in poison ivy leaf complexity, whereas the comparison hog peanut showed very little variation. This study provides the first statistical analysis of often anecdotally noted hypervariability in poison ivy leaf morphology. These results will be combined with other studies into a future manuscript for peer review in a journal. 2) Evaluate poison ivy preferred habitat using the Appalachian Trail as a natural laboratory. A revised manuscript addressing previous reviewer's comments is currently under review in a geography-oriented scientific peer-reviewed journal. 3) Investigate poison ivy chemical ecology. The poison ivy seedling recruitment and herbivore exclusion manuscript reported last year was submitted and declined by a peer-reviewed journal. A substantially revised manuscript with a revised focus will be submitted to a different journal in early 2021. Last year's findings on poison ivy volatile and urushiol natural product levels in flowers and leaves were described in a manuscript submitted to a peer-reviewed journal. The manuscript was declined and is currently being revised for submission to a different scientific journal. 4) Evaluate the poison ivy drupe microbiome. Nothing to report in this time period. 5) Develop poison ivy genomic, transcriptomic, and stable DNA transformation resources. This year we published a peer-reviewed journal article describing the development of a stable genetic transformation and regeneration of poison ivy hairy root cultures containing a foreign recombinant transgene. This published report establishes a proof-of-concept for creating transgenic regenerated poison ivy tissues suitable for implementing genome editing (gene knockout) technologies in poison ivy. In addition, this report identified the previously postulated but not validated urushiol precursor metabolite anacardic acid in poison ivy. 6) Identify urushiol biosynthetic genes. Most methods to identify plant genes involved in secondary metabolic pathways utilize differential gene expression between two organs or treatments that significantly differ in the metabolite of interest. Both the literature and observations in this lab indicate that urushiol is present in all plant organs at fairly similar levels. However, we recently identified poison ivy drupes as having significantly higher urushiol levels than other organs. Thus, developing drupes will likely have significantly higher mRNA levels for urushiol biosynthetic genes. This finding will be used in future studies to identify urushiol biosynthetic genes using differential transcriptional profiling methods. 7) Investigate poison ivy - Colletotrichum fioriniae molecular plant-pathogen interactions. Nothing to report this year.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2020
Citation:
Lott, A. A., Freed, C. P., Dickinson, C. C., Whitehead, S. R., Collakova, E., & Jelesko, J. G. (2020). Poison ivy hairy root cultures enable a stable transformation system suitable for detailed investigation of urushiol metabolism. Plant Direct, 4(8), e00243. doi:10.1002/pld3.243
- Type:
Journal Articles
Status:
Submitted
Year Published:
2020
Citation:
Resler, L. M., Fry, J. T., Leman, S., and Jelesko, J. G.. (submitted) Assessing Poison Ivy (Toxicodendron radicans) Presence and Functional Traits in Relation to Land Cover and Biophysical Factors, Physical Geography.
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Progress 10/01/18 to 09/30/19
Outputs
Target Audience:1. Scientific research communities involved in plant chemical ecology, phenology, and herbivore-plantinteractions. 2. Landscape industry specializing in poison ivy removal and remediation. 3. General public interested in understanding poison ivy allergenic dermatitis and climate changed-inducedweedy noxious plants. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The graduate student on this project completed his Ph.D. in the spring of 2019. One undergraduate working on this project graduated with a B.S. degree and is currently a graduate student at the Univ. of Florida Plant Molecular and Cellular Biology department. One undergraduate was awarded a Fralin Summer Undergraduate Research Fellowship for doing poison ivy research over last summer in my lab and is currently working in my lab along with three other undergraduate researchers. How have the results been disseminated to communities of interest?Results from these findings were disseminated to diverse communities as follows. One manuscript was published in 2019 in the online Open Access journal "Molecules". The results from the poison ivy stable transformation hairy root regeneration protocol are currently a manuscript under review. The results from the poison ivy recruitment and herbivory study are likewise a manuscript currently under review at scientific journal. These results were also disseminated to a wider general public audience in four-invited talks to horticulture/landscape enthusiasts and workers. One audio podcast about my poison ivy research was published by the Virginia Tech Biocomplexity Institute. What do you plan to do during the next reporting period to accomplish the goals?We will continue to follow the research objectives outlined in this Hatch grant proposal.
Impacts
What was accomplished under these goals?
IMPACT: Poison ivy exposure causes millions of cases of the dreaded "poison ivy rash" each year. The afflicted typically suffer from distracting itching, swollen, puss-dripping, skin irritation leading to secondary infections and sleep loss by these distracting symptoms. The poison ivy natural product responsible for these dreaded symptoms is called urushiol, and poison ivy plants produce more allergenic forms of urushiol in the presence of increased atmospheric carbon dioxide levels, which are expected to increase in the next few decades. Thus, understanding poison ivy ecology and urushiol biosynthesis and chemical ecology are important over-arching goals of this research project. A combination of field- and laboratory-oriented experiments are designed to provide new knowledge about poison ivy ecology and urushiol production. The findings from this project will aid scientists in understanding how poison ivy will likely thrive in future ecosystems that are anticipated to undergo increasing stress levels. Likewise, this project will provide foundational knowledge about the molecular processes in poison ivy responsible for urushiol production. This knowledge will be valuable in potentially developing interventions for reducing poison ivy urushiol production or allergenicity. Overview of progress in each of the eight research objectives this year. 1) Characterize urushiol accumulation levels in response to ontology, seasonal variation, and simulated herbivory. The statistical analyses from the collection of twenty poison ivy lianas were completed. This study revealed that urushiol congener composition varied dramatically between individual poison ivy plants growing in the same environments. Moreover, the response of urushiol levels to insect herbivory was also quantified and was statistically evaluated. These results suggest that urushiol production is primarily a preformed chemical defense against herbivory. These findings will be used to draft a manuscript for submission to a peer-reviewed journal in early 2020. 2) Evaluate poison ivy preferred habitat using the Appalachian Trail as a natural laboratory. The manuscript reporting the findings of this project is currently being substantially revised for submission to a geography-oriented scientific peer reviewed journal in late 2019 or early 2020. 3) Investigate poison ivy chemical ecology. Two two-year field-oriented experiments examining poison ivy seedling recruitment and herbivore exclusion concluded this year. The results from these studies indicate that nascent germinated poison ivy seedlings were very susceptible to complete destruction by herbivores. On the other hand, more established poison ivy plants were foraged upon by many animals ranging from insects to small mammals, to large herbivores. The large animals (e.g. deer) showed significantly greater herbivory on poison ivy plants than the impact of all other herbivores. These studies provide the first quantitative-evaluation of herbivore impacts on poison ivy in native environments. These results are in a manuscript that is currently out for peer review at a scientific journal. A second study focused on volatile and urushiol natural product levels in female and male poison ivy plants. Poison ivy foliar and floral volatile composition and levels were evaluated for the first time. Several volatiles were specific to either leaf or flowers. However, no abundant volatiles were specific to either male or female poison ivy flowers, suggesting that poison ivy pollination is likely achieved by generalist insect pollinators. Foliar urushiol levels identified individual poison ivy plants with higher heptadic(en)yl-urushiol levels than pentadec(en)yl-urushiol levels, which a novel finding. Interestingly, floral tissues showed much higher pentadec(en)yl-urushiol accumulation levels than foliar tissues. These findings are currently being drafted into a manuscript for submission to a scientific peer-reviewed journal in 2020. 4) Evaluate the poison ivy drupe microbiome. Nothing to report in this time period. 5) Develop poison ivy genomic, transcriptomic, and stable DNA transformation resources. Experiments over the past two years have established a poison ivy hairy root stable transformation protocol using Agrobacterium rhizogenes. This protocol enables the stable transformation of foreign transgenes into poison ivy cells that subsequently regenerate into hormone-independent growth hairy root cultures that can be cultivated indefinitely. Moreover, if the Agrobacterium rhizogenes harbors a T-DNA binary plasmid with an intron-containing luciferase reporter gene, then approximately 50% of the resulting poison ivy hairy root cultures showed luciferase bioluminescent activity, indicating stable transformation of the bioluminescent poison ivy hairy root cultures. All hairy root cultures produced to date, seem to produce significantly less total urushiol levels than wild type roots. This result fortuitously enabled the identification of anacardic acids that are hypothesized to be metabolic precursors in urushiol biosynthesis. This poison ivy transformation/regeneration protocol is a major advancement in poison ivy research because it enables a variety of genome editing reverse genetic protocols to be used in poison ivy research. The results from these studies are described in a manuscript that is currently in review at a scientific journal. 6) Identify urushiol biosynthetic genes. During the past year, we used Golden Gate cloning methods to create four plasmids containing CRISPR-Cas9 constructs suitable for mutating polyketide synthase-like poison ivy gene families some of which are believed to be involved in the first biosynthetic step in urushiol biosynthesis. These plasmid constructs will be used in poison ivy hairy root transformation-regeneration experiments next year oriented towards identifying which poison ivy PKS-like gene(s) are necessary for urushiol biosynthesis in poison ivy. 7) Investigate poison ivy - Colletotrichum fioriniae molecular plant-pathogen interactions. Nothing to report this year.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2019
Citation:
Lott, N., and J. G. Jelesko, Development of Transgenic Poison Ivy Hairy Root Cultures:
A Platform for Genome Editing Studies, 2019 Translational Plant Science Symposium, Holtzman Conference Center, Virginia Tech, Blacksburg, VA, 24061. Feb 15, 2019.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2019
Citation:
Hudack, J., Lott, N., and Jelesko, J.G., CRISPR Genome Editing in Poison Ivy Hairy Roots. Virginia Tech 50th Alumni Reunion, Skelton Conference Center, Virginia Tech, Blacksburg, Virginia, October 18th, 2019.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Lott, A. A.; Baklajian, E. R.; Dickinson, C.C.; Collakova, E.; and Jelesko, J.G., (Accepted) Accession-level differentiation of urushiol levels, and identification of cardanols in nascent emerged poison ivy seedlings., Molecules.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2019
Citation:
Lott, A. A., Freed, C.P., Dickinson, C.C., Whitehead, S.R., Collakova, E.; and Jelesko, J.G. (submitted) Development of Poison Ivy Hairy Root Cultures Identified Anacardic Acid Congeners Proposed For Urushiol Biosynthesis.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2019
Citation:
Dickinson, C.C., Jelesko, J.G., and Barney, J.N., (under review) Habitat suitability and establishment limitations of a problematic and expanding native liana, AoBPlants.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2019
Citation:
Christopher C. Dickinson, 2019, The Curious Poisoned Weed: Poison Ivy Ecology and Physiology, Ph.D. Dissertation, Virginia Tech, Blacksburg, VA, May 21, 2019.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
John Jelesko, New insights into urushiol chemical diversity in poison ivy , 2019 Philadelphia Poison Ivy Conference, Philadelphia Zoo, Philadelphia, PA, 19104 March 26-27.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
John Jelesko, Has poison ivy become ecologically unhinged? , 2019 Philadelphia Poison Ivy Conference, Philadelphia Zoo, Philadelphia, PA, 19104 March 26-27
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
John Jelesko, Seeking to understand the familiar stranger poison ivy , 2019 Horticultural Horizons Symposium, Lewis Ginter Botanical Gardens, Richmond, 23228, VA, April 30th.
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Progress 07/01/18 to 09/30/18
Outputs
Target Audience:There are three target audiences for this research project: Scientific research communities involved in plant chemical ecology, phenology, and herbivore-plant interactions. Landscape industry specializing in poison ivy removal and remediation. General public interested in understanding poison ivy allergenic dermatitis and climate changed-induced weedy noxious plants. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Formal laboratory training was provided to one graduate student and four undergraduate researchers. The PD was responsible for the mentoring and training of all students in all laboratory tasks. How have the results been disseminated to communities of interest?We presented our results from this project to eight scientific meetings, and 14 community service/outreach organizations or internet/radio/television media publications. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Given this is the first year of this project and there are seven research objectives, most of the activity this year was initiating many lines of investigation and collecting various data. A brief synopsis for each major objective is outlined below by research objective. Obj. 1) Characterize urushiol accumulation levels in response to ontology, seasonal variation, and simulated herbivory. A phenology study of poison ivy drupes and leaves was initiated by collecting organs from single branches from twenty female plants. Urushiol levels were measured by GC-MS and the data is currently being statistically evaluated for significant differences. Obj. 2) Evaluate poison ivy preferred habitat using the Appalachian Trail as a natural laboratory. Previous GIS information of poison ivy incidence on 60 miles of the Appalachian Trail (AT) in Virginia was analyzed using custom spatial Bayesian statistical model. These results indicated that poison ivy was not evenly distributed along this sampling of the AT. Poison ivy incidence and growth habit were differentially affected by specific landscape features. Moreover, poison ivy incidence was positively correlated with proximity to increasing levels of human land use patterns. These results are currently being compiled into a journal article manuscript for submission early 2019. Obj. 3) Investigate poison ivy chemical ecology. Nothing to report. Obj. 4) Evaluate the poison ivy drupe microbiome. Drupes collected in two previous years were subjected to ribosomal DNA sequencing using illumina DNA sequencing by a fee-for-service DNA sequencing facility. The raw data awaits DNA sequence analysis. Obj. 5) Develop poison ivy genomic, transcriptomic, and stable DNA transformation resources. In collaboration with Dr. David Haak, a draft poison ivy genome was sequenced using PacBio and Illumina methods. A reference genome was de novo assembled. To evaluate population genomic-level insights, 100 poison ivy samples were collected along selected regions of the AT previously traversed, and were subjected to genotyping-by-sequencing. These GBS data are currently the focus of ongoing bioinformatic studies to evaluate the poison ivy population structure along this section of the AT. 6) Identify urushiol biosynthetic genes. It is proposed that the initial step in urushiol biosynthesis is the formation of a tetraketide intermediate from fatty acid starter molecules by a type III polyketide synthase (PKS) activity. Using a variety of known plant PKS enzyme sequences, we queried the poison ivy transcriptome and identified three most closely related predicted TrPKS1-3 enzyme sequences and their corresponding cDNAs. Full length cDNAs were amplified using gene specific primers because all available poison ivy accessions and all poison ivy tissues produce/accumulate substantial urushiol levels. Thus, it is necessary to identify tissues or accessions that show substantial differential urushiol accumulation levels to utilize for differential TrPKS mRNA accumulation. Initial results suggest that differential urushiol accumulation levels between leaf veins and inter-veinal blade tissues show a corresponding differential TrPKS mRNA accumulation patterns, suggesting specific TrPKS gene expression correlates with urushiol accumulation. 7) Investigate poison ivy - Colletotrichum fioriniae molecular plant-pathogen interactions. Nothing to report.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Dickinson, C. C., A. J. Weisberg and J. G. Jelesko (2018). "Transient Heterologous Gene Expression Methods for Poison Ivy Leaf and Cotyledon Tissues." Hortscience 53(2): 242-246.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Emily Baklajian, Cody Dickinson, Nye Lott, Jesse Pinkman, & John Jelesko, Determining Urushiol Concentrations in Poison Ivy Seedlings, 2018 Translational Plant Science Symposium, February 23rd, Virginia Tech, Skelton Conference Center, Blacksburg, VA, 24061.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Nye Lott and John G. Jelesko, Developing Stably Transformed Poison Ivy Hairy Root Cultures, 2018 Translational Plant Science Symposium, February 23rd, Virginia Tech, Skelton Conference Center, Blacksburg, VA, 24061.
- Type:
Other
Status:
Other
Year Published:
2018
Citation:
John G. Jelesko, Poison Ivy Research at Virginia Tech, Farm Bureau Federation Womens Committee, 311 Latham Hall, Blacksburg campus, 24061, March 17, 2018.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
John G. Jelesko, Jacob Barney, Elise Benhase, David Haak, Lynn Resler, J.T. Fry, & Scotland Leman, Using Big Data and the Appalachian Trail to Evaluate Poison Ivy Preferred Habitat and Population Structure in Southwest Virginia, 2018 Meeting of the Southern Section of the American Society of Plant Biologists, Hotel Le Pavillon, New Orleans, Louisiana, March 24-26, 2018.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
John G. Jelesko, Jacob Barney, Elise Benhase, David Haak, Lynn Resler, J.T. Fry, and Scotland Leman. (Oral presentation) Investigating Poison Ivy Habitat and Population Structure in Southwest Virginia. Translational Plant Science Discussion Group. Virginia Tech, Blacksburg, Virginia, 24060, May 1, 2018
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
John G. Jelesko, Nye Lott, and Emily Baklajian, First empirical evidence for cardanol as the penultimate metabolite in poison ivy urushiol biosynthesis, 35th Mid-Atlantic Plant Molecular Biology Society, Patuxent National Wildlife Visitor Center, Laurel, MD, August 14-15 2018.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Nye Lott, Catherine Freed, and John G. Jelesko, Development of transgenic poison ivy (Toxicodendron radicans) hairy root cultures: a transformation-regeneration platform for future genome editing studies of an irritating native weed. 35th Mid-Atlantic Plant Molecular Biology Society, Patuxent National Wildlife Visitor Center, Laurel, MD, August 14-15 2018.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
John G. Jelesko, Poison Ivy Research, 2018 Pesticide Safety Educators Workshop, Hotel Roanoke, Roanoke, VA, 24016, September 6th, 2018.
- Type:
Other
Status:
Other
Year Published:
2018
Citation:
John Jelesko, Demystifying the Familiar Stranger: Poison Ivy, Lifelong Learning Institute, Warm Hearth Community Center, Blacksburg, VA, Feb 23 2018.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
John Jelesko, Four Vignettes about Poison Ivy Research at Virginia Tech, 2018 Philadelphia Poison Ivy Conference, Philadelphia Zoo, Philadelphia, PA, March 13-14, 2018.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2018
Citation:
John G. Jelesko, Recent Urushiol Chemical Diversity Studies, 2018 Philadelphia Poison Ivy Conference, Philadelphia Zoo, Philadelphia, PA, March 13-14, 2018.
- Type:
Other
Status:
Other
Year Published:
2018
Citation:
John G. Jelesko, Evaluating Poison Ivy Preferred Habitat and Adaptation to Local Environments. , CALS Retired Faculty Breakfast, Hahn Horticultural Gardens, Virginia Tech, VA, 24060, Sept 18th 2018.
- Type:
Other
Status:
Other
Year Published:
2018
Citation:
Nashville Public Radio web page article Dont Touch: Spotting a Familiar Stranger Could Keep Poison Ivy from Ruining Your Summer . http://nashvillepublicradio.org/post/dont-touch-spotting-familiar-stranger-could-keep-poison-ivy-ruining-your-summer#stream/0. I was interviewed and quoted for this news piece. June 1st 2018, 2 min radio spot.
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