Progress 06/15/20 to 08/13/22
Outputs
Target Audience:The target audiences reached during the duration of the project were primarily other scientists, graduate students, and undergraduate students. They were reached through direct mentorship, conference presentations, invited talks, and laboratory presentations. Grapevine growers were an additional audience that was reached byfindings from the project being used to informextension presentations. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?PD Fleishman has engaged in several activities to develop skills in laboratory and bioinformatic omic techniques (obj. 1) and how to connect those findings to physiological outcomes in field conditions (obj. 2). In order to conduct laboratory extractions and bioinformatics on metabolomics data PD Fleishman audited coursework and connected with the Kellogg lab at PSU to refine a protocol and analyze the metabolomics data. In order to conduct laboratory extractions and bioinformatics on RNAseq, PD Fleishman did substantial remote correspondence in the fall of 2021 and completed a 2.5 month visit to UC Davis where deepened collaborations with Dr Dario Cantu, Dr. Rosa Balderas, and Dr. Melanie Massonnet. This included professional development opportunities to connect with other UC Davis researchers and present project results in lab meetings. Substantial time has also been spent on reading papers, attending seminars, and other efforts for PD Fleishman to develop an expertise on the research topics within this project. In addition to developing research skills, PD Fleishman has completed several important efforts in order to further develop her outreach and coordination skills as a scientist. This included mentoring two undergraduates (Hayden Bock and Grant Hoffer) in the publication process, resulting in a co-authored publications in Fall of 2021 (accepted) and Fall of 2022 (under review). Additionally, the PD engaged in approximately 5 planning meetings with mentor Eissenstat, other scientists, and planning professionals in order to successfully set up a website and schedule for the 8thInternational Symposium on Physiological Processes in Roots of Woody Plants. This event took place in July after postponement due to the COVID-19 pandemic and involved international participation. PD Fleishman also performed outreach and deepened connections through presenting results at 3 conferences between June 2022 and September 2022. Professional development will continue beyond the project end date, with the creation of extension outreach materials related to the project. How have the results been disseminated to communities of interest?The results of this project have been disseminated to communities of interest through a few avenues. The details of the methodological development and results for the project has been shared with fellow researchers through conference presentations (3 from June 2022 to Sept. 2022) and through one-on-one discussions with fellow researchers at Penn State. The aboveground research from this study has been combined with other years of research at the site for a publication currently in review with an applied-research journal with the target audience of scientists that support grower decision making. The information from this study also informed an extension presentation to grape growers by the Penn State Viticulture Extension Professor, Michela Centinari, on March 2, 2022 at the Pennsylvania Grape and Wine Industry Winter Conference. Lastly, the detailed root multi-omics and physiology research project is in preparation for submission to a research journal to target a broad scientific audience that may be interested in root responses to N-competition. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Progress Towards Research Project Objectives The research project objectives focused on root-function (obj. 1) and aboveground growth (obj. 2) for grapevines competing with and without groundcover and on rootstocks that vary in vigor during the 2020 growing season. Objective 1 was addressed through two field experiments during the 2020 growing season. A nitrogen (N)-uptake experiment (obj. 1.1) was completed in July 2020 by using a labeled 15N approach to monitoring whether the N-uptake rate of grapevine roots was modified by the rootstock and groundcover treatments. Results from the experiment were highly variable, which is not uncommon in studies of root N-uptake. Analyses of the results from the 15N depleted from solution did not have statistical differences between treatments and suggest that N-uptake did not necessarily differ between groundcover or rootstock treatments at the mid-depth. However, when the 15N concentration of the roots was measured to further explore the results of the experiment, mean values did indicate a potential difference between treatments. Grapevines on both rootstocks had more 15N in the roots when under groundcover competition (p <0.03), which cannot be directly linked to higher N-uptake rates and could also be an indication of the exposure of these roots to lower N concentrations prior to the experiment. The second experiment during July, 2020 involved root sampling for measurements on root metabolism, root gene expression and root growth (obj. 1.2 and 1.3). Analyses of root growth show that at shallow depths (0-33 cm) and mid depths (34-66 cm), grapevines growing with groundcover decreased root mass 27% (P = 0.01) and 25% (P = 0.04), respectively. Deep root mass (67-100 cm) was unaffected by groundcover (P = 0.55), but there was evidence that grapevines may have substantially increased the proportion of new (white) roots at depth. Under the groundcover treatment and in comparison to the no-groundcover treatment, the proportion of new roots at shallow depths was lower by 29% (P = 0.02) and at deep depths was higher by 15% (P < 0.01). Despite previous evidence at the site that the root distributions differed based on rootstock, including in their response to groundcover, we did not find evidence that rootstock vigor influenced root mass or production. These shifts in response to groundcover suggest that altered root distributions is one way that grapevines cope with groundcover competition. Root samples were flash frozen in the field in 2020 and extracted for RNA and metabolites in December 2021. Development of a protocol for RNA extraction from the grapevine roots is a key outcome of note, as it required substantial troubleshooting and resulted in a change in knowledge by providing an updated protocol for two labs: The Cantu Lab at UC Davis and the Rosa Lab at Penn State. RNAseq was completed on the RNA extracts and bioinformatics analyses were completed to compare the differential gene expression of N-uptake genes (atNRT and atNPF gene families) due to groundcover and at each depth, but for rootstocks separately. The sample clustering on PCAs and trends in differential expression analysis suggests that in response to groundcover the low vigor rootstock altered gene expression substantially at both shallow and mid depths, but the medium vigor rootstock had the largest shifts in gene expression at only the shallowest depth. The ways the genes shifted suggest that genes associated with N-stress under low nitrate conditions were upregulated (i.e., NRT 2.5) while other genes associated with N-status and are inducible under high nitrate conditions were downregulated (i.e., NPF 6.3). Targeted metabolomics was performed on the metabolite extracts to estimate the concentration of 14 L-amino acids in the roots. The results of the amino acid analyses were highly variable and trends in PCAs suggest that a factor not measured in this study may be driving the variation in amino acids between samples. Nevertheless, there was some evidence that groundcover may have led to a deepening of N-metabolic activity. When the amino acids were grouped by family the groundcover treatment increased the amount of amino acids in the Aspartate family (involved in N assimilation and protein synthesis) at the deepest depth (p = 0.023). Additionally, there was some statistical evidence (p = 0.078) that groundcover may be increasing amino acids in the Glutamate family (involved in N assimilation and storage) particularly at the mid and deep depths. These results informed the field sampling techniques and metabolomic analyses of another student at Penn State, whose research is building upon the research study for this fellowship (MS student Lily Cao). In order to link these belowground experiments to shifts in aboveground nutrition and growth, biomass measurements were taken in August 2020 and yield was taken in September 2020 (obj. 2). Grapevine shoot samples were separated into petioles, leaves, clusters, and stems, dried and weighed, and submitted to the Penn State Agricultural analytical lab for analysis. There was only marginal evidence that grapevine shoots decreased in total dry mass due to groundcover competition (8%; P = 0.09). The only tissue with significant evidence of a reduction in growth due to groundcover were the shoots, with a decrease in mass of 14% (P = 0.04). There was greater evidence of groundcover competition as measured by reductions in N concentrations in the tissues. Groundcover competition reduced petiole N 22% (P = 0.01), leaf N 10% (P = 0.01), and cluster N 15% (P = 0.01); however, there was only marginal evidence stem N was reduced by 14% (P = 0.09). Tissue N concentrations were unaffected by the rootstock treatment and yield was unaffected by either the rootstock or the groundcover treatment. Values of yield, pruning weights, and petiole nutrient concentrations from this sampling were reported alongside samplings from 2017-2021 in a publication currently under review. In summary, despite the reductions in growth and N concentration in tissues for grapevines competing with groundcovers in 2020, the reductions are lower than the first twoyears at the site. This could suggest that over time the grapevines are acclimating to the N competition from groundcovers. The results from root experiments do suggest that this acclimation may be in part due to adjustments in the root system. In addition to redistributing roots deeper, grapevines may be deepening N-uptake and N metabolic activity. It is also worth noting that depending on the factor measured, the root systems of the two rootstocks did differ in their response to N-competition. We found the low vigor rootstock differed in N-uptake gene expression at the shallow and mid depths, yet the medium vigor rootstock primarily differed at the shallowest depth-these differences in gene expression do parallel shifts in root distribution documented in 2019 at the site. Although this does suggest that the rootstocks may differ in their precise depth of response and the magnitude of their responses to groundcover competition, there was no evidence that the differing root system responses to groundcover between the two rootstocks resulted in differences in aboveground growth or tissue N concentrations. Overall, this study provided useful insights into the mechanisms by which grapevines acclimate to groundcover competitionand these findings may have broad applications examinations of plant competition in other (agro)ecosystems.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Fleishman, S, TH Bell, D Cantu, DM Eissenstat, M Centinari. Agroecosystem management modifies the rhizosphere microbiome via soil and host responses: an integrated study of host physiology and root multiomics. International Phytobiomes Conference. 2022 Sept 13; Denver, CO.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Fleishman, S, M Massonnet, D Cantu, DM Eissenstat, M Centinari. Direct comparisons of grapevine rootstock gene expression expand insights into root responses to N competition. Botany 2022 Conference. 2022 July 26; Anchorage, AK.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2022
Citation:
Fleishman SF, Eissenstat DM, Centinari M*. 2022. Cover crops and devigorating rootstocks can impart substantial agroecosystem services to high-resource vineyards: a multi-year study.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Fleishman, S, TH Bell, D Cantu, DM Eissenstat, M Centinari. Competition for soil nitrogen shifts grapevine root gene expression, metabolism, and microbial associations in a depth-dependent manner. 8th International Symposium on Physiological Processes in Roots of Woody Plants. 2022 July 12; State College, PA.
|
Progress 06/15/21 to 06/14/22
Outputs
Target Audience:The target audiences reached during this reporting period were primarily other scientists and graduate students. They were reached through conference presentations, invited talks, and laboratory presentations. Changes/Problems:Due to staffing issues and delays due to the covid-19 pandemic, the project bioinformatics visit to UC Davis and the metabolomics analyses were delayed. Thus the fellowship was extended until Mid-August for the goals and objectives of the project to be fully addressed. What opportunities for training and professional development has the project provided??In addition to the specific professional development objectives as a part of the fellowship project, there are several additional professional development activities that have been made possible with the awarding of this predoctoral fellowship. In each of these activities, PD Fleishman has been able to take on leadership roles, network with senior researchers, and engage in mentorship of junior researchers. These activities include: 1) mentorship of fellow graduate student Meredith Persico, including guidance on Persico's NIFA Predoctoral Fellowship application (2020) and bioinformatic approaches for a future co-authored manuscript; 2) successful awarding of a invited talk to the Phytobiomes conference; 3) Successful inviting of a talk for a Phytobiomes webinar; 4) Application and award of the PSU Alumni Dissertation Award, the highest honor given for a PhD dissertation; 5) adapting a co-co-developed "Inclusive Mentorship" for the lab meeting setting How have the results been disseminated to communities of interest?A webinar was given to the Phytobiomes group. Attendees included industry scientists and academic scientists. What do you plan to do during the next reporting period to accomplish the goals?The next reporting period is brief due to a short extension (From June 14 to Aug. 12). During this reportingperiod, the results from metabolomics will be received, allowing for final analyses and dissemination of results to be completed. The preliminary results from the project will be presented at two conferences, Woody Root 8 and Botany 2022, focusing on two different facets of the project.
Impacts
What was accomplished under these goals?
Progress Towards Research Project Objectives The research project objectives focus on root-function (obj. 1) and aboveground growth (obj. 2) for grapevines competing with and without groundcover and on rootstocks that vary in vigor during the 2020 growing season. Objective 1 was addressed through two field activities during the 2020 growing season. A nitrogen (N)-uptake experiment (obj. 1.1) was completed in July 2020 by using a labeled 15N approach to monitoring whether N-uptake rate was different between rootstock and groundcover treatments. Results of the N-uptake experiment were analyzed in Spring 2022 and indicate that both rootstocks may have similarly responded to groundcover competition by reducing uptake at a mid-depth (p < 0.10) and also responded by preferentially storing 15N in roots (p <0.05), suggesting slowed uptake. Root sampling was conducted in July 2020 for measurements on root metabolism, root gene expression and root growth (obj. 1.2 and 1.3). Analyses of root growth show that at shallow depths (0-33 cm) and mid depths (34-66 cm), root mass was decreased 27% (P = 0.01) and 25% (P = 0.04), respectively. Deep root mass (67-100 cm) was unaffected by groundcover (P = 0.55), but there was evidence that grapevines may have increased the proportion of new (white) roots at depth. Under the groundcover treatment and in comparison to the no-groundcover treatment, the proportion of new roots at shallow depths was lower by 29% (P = 0.02) and at deep depths was higher by 15% (P < 0.01). Despite previous evidence at the site that the root distributions differed based on rootstock, including in their response to groundcover, we did not find evidence that rootstock vigor influenced root mass or production. These shifts in response to groundcover suggest that altered root distributions is one way that grapevines cope with groundcover competition. Once these growth results are combined with omics and the N-uptake results, it will clarify what other physiological processes are allowing grapevines to cope with groundcover competition. Root samples were flash frozen in the field in 2020 and extracted for RNA and metabolites in December 2021. Metabolite data will arrive in the next reporting period. RNAseq was completed on the RNA extracts and bioinformatics analyses were completed to compare the differential gene expression of N-uptake genes due to groundcover and at each depth, but for rootstocks separately. Preliminary PCAs suggests that in response to groundcover the low vigor rootstock altered gene expression at shallow and mid depths, but the medium vigor rootstock only altered gene expression at the shallowest depth. Next steps include final cleaning of the data, phylogenetic trees to compare the rootstocks cohesively, and a final analysis for publication. In order to examine whether groundcovers reduce aboveground nutrition and growth, biomass measurements were taken in August 2020 and yield was taken in September 2020 (obj. 2). Grapevine shoot samples were separated into petioles, leaves, clusters, and stems, dried and weighed, and submitted to the Penn State Agricultural analytical lab for analysis. There was only marginal evidence that grapevine shoots decreased in total dry mass due to groundcover competition (8%; P = 0.09). The only tissue with significant evidence of a reduction in growth due to groundcover were the shoots, with a decrease in mass of 14% (P = 0.04). There was greater evidence of groundcover competition as measured by reductions in N concentrations in the tissues. Groundcover competition reduced petiole N 22% (P = 0.01), leaf N 10% (P = 0.01), and cluster N 15% (P = 0.01); however, there was only marginal evidence stem N was reduced by 14% (P = 0.09). Tissue N concentrations were unaffected by the rootstock treatment and yield was unaffected by either the rootstock or the groundcover treatment. Despite the reductions in growth and N concentration in tissues for grapevines competing with groundcovers, these reductions are lower than in previous years at the site. This could suggest that over time the grapevines are acclimating to the N competition from groundcovers and are utilizing some of the aforementioned methods (root redistribution, metabolism, and N-uptake) as ways to cope with the competition. However, it is also possible that season-specific factors, such as lower rainfall in 2020 than previous years, contribute to our observations. It is also clear from the preliminary evidence that grapevines on the two rootstocks having root responses that contrast to groundcover competition for soil N; however, there is little-to-no evidence that this has resulted in interactive responses in terms of N-uptake and/or reductions in vegetative growth. Progress Towards Professional Development Objectives PD Fleishman has engaged in several activities to develop skills in laboratory and bioinformatic omic techniques (obj. 1) and how to connect those findings to physiological outcomes in field conditions (obj. 2). In order to conduct laboratory extractions and bioinformatics on RNAseq, PD Fleishman did substantial remote correspondence in the fall and completed a 2.5 month visit to UC Davis where deepened collaborations with Dr Dario Cantu, Dr. Rosa Balderas, and Dr. Melanie Massonnet. This included professional development opportunities to connect with other UC Davis researchers and present project results in lab meetings. Substantial time has also been spent on reading papers, attending seminars, and other efforts for PD Fleishman to develop a background on the research topics within this project. In addition to developing research skills, PD Fleishman has completed several important efforts in order to further develop her research skills as a scientist. PD Fleishman also engaged in approximately 5 planning meetings with mentor Eissenstat, other scientists, and planning professionals in order to successfully set up a website and schedule for the 8thInternational Symposium on Physiological Processes in Roots of Woody Plants; this event took place in July after postponement due to the COVID-19 pandemic. Lastly, in order to further PD Fleishman's professional development (obj. 3), she has found ways to develop leadership, facilitation, and communication skills by embracing the remote communication necessitated by the covid-19 pandemic. This included mentoring an undergraduate (Hayden Bock) in the publication process, resulting in a co-authored publication in Fall of 2021. Lastly, PD Fleishman successfully defended her dissertation in early June 2022, with a final publication of the dissertation and graduation in August. In summary, over the second year of this fellowship, the project has successfully completed the lab analysis portions of the research project and completed bioinformatic training at UC Davis, and successfully defended her PhD dissertation. Furthermore, the PD graduate student in professional development through connecting to established researchers at UC Davis and several conference presentations. During this second year the groundwork has been laid to complete the finalize and disseminate the results from the project during the Project extension (until Aug. 12, 2022). Future insights from this project on how grapevines cope with competition will allow for advisement of growers on best practices and enhanced scientific understanding of how root gene expression and metabolism is associated with resource uptake.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Fleishman, S, W King, C Yates, M Persico, J Guo, M Centinari, T Bell, D Eissenstat. Opportunities to advance rhizosphere microbiome research with functionally and spatially explicit root sampling. Plant and Animal Genome Conference. 2022 Jan 12; Virtual Presentation.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Jones L, Brochu K, Fleishman S, Lopez-Uribe M, Yates C. Special Session: First steps to introduce DEI efforts in your lab, department, and beyond. Ecological Society for America Conference. 2021 August 2-6; Virtual Presentation
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2022
Citation:
Fleishman, S, HW Bock, TH Bell, D Eissenstat, M Centinari. Replacing herbicides with vegetation in vineyards alters root distributions, edaphic factors, and microbial diversity in a depth-dependent manner. Ecological Society for America Conference. 2021 August 2-6; Virtual Presentation
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
Fleishman SF , Bock HW !, Eissenstat DM, Centinari M* (2021) Undervine groundcover substantially increases shallow but not deep soil carbon in a temperate vineyard. Agric Ecosyst Environ. https://doi.org/10.1016/j.agee.2021.107362
- Type:
Theses/Dissertations
Status:
Under Review
Year Published:
2022
Citation:
Fleishman, Suzanne. 2020. Belowground interactions at multiple scales in a grapevine-groundcover agroecosystem. Penn State University. PhD Dissertation
|
Progress 06/15/20 to 06/14/21
Outputs
Target Audience:
Nothing Reported
Changes/Problems:The main challenges and delays in the project have been a consequence of the COVID-19 pandemic. Due to university policies and uncertainties in access to university facilities, the full visit to the Cantu lab at UC Davis has been postponed until Fall 2021. Instead of completing both the laboratory and bioinformatic analyses during that visit, this summer it will be evaluated if the laboratory analyses can take place at Penn State instead to speed the process along. A bulk of the funding for research activities in the fellowship are related to this trip, so this postponement has caused a significant delay on the rate of expenditure from the fellowship budget. Additional issues related to the COVID-19 pandemic include the cancellation of conferences proposed for attendance. Primarily, the cancellation of the 8thInternational Symposium on Physiological Processes in Roots of Woody Plants has meant that professional development activities related to implementing the conference and a workshop have been cancelled; PD Fleishman will still have opportunities to be involved in the planning process for the 2023 symposium and is exploring alternative options to host a workshop. Other conferences planned for attendance have also been cancelled (Group of International Experts for Cooperation on Vitivinicultural Systems Conference) or have reduced costs due to being remote (Ecological Society of America). This has contributed to a delay in expenditure, but it is anticipated that funds that were allocated to attend conferences in 2021 that are either cancelled or remote will easily be used to attend in-person conferences in early 2022. In general, the impact of these cancellations on professional development have been mitigated by the increased use of zoom by all researchers in the past year. PD Fleishman has been able to attend seminars and speak with seminar speakers from various national and international locations over Zoom which would have been cost or time prohibitive otherwise. An additional delay has been due to issues regarding the 15N laboratory analysis. It is difficult to know whether the 15N to 14N content and ratio are at ideal values for laboratory analyses until the samples are analyzed. The original submission of 15N analyses for the N-uptake experiment were not at recommended values for the assay. Back-up samples are currently being prepared for resubmission at values that are expected to be appropriate for the analysis, according to the laboratory staff. These results are expected by July 2021. What opportunities for training and professional development has the project provided?In addition to the specific professional development objectives as a part of the fellowship project, there are several additional professional development activities that have been made possible with the awarding of this predoctoral fellowship. In each of these activities, PD Fleishman has been able to take on leadership roles, network with senior researchers, and engage in mentorship of junior researchers. These activities include: 1) mentorship of fellow graduate student Meredith Persico, including guidance on Persico's NIFA Predoctoral Fellowship application (2020) and bioinformatic approaches for a future co-authored manuscript; 2) participation in the Center for Root and Rhizosphere Biology journal club; 3) creating and leading a "Current Issues in Agriculture Book Club", with participation including both Penn State faculty and graduate students; 4) co-developing and leading an "Inclusive Mentorship" two-part workshop for the Ecosystem, Science, and Management Department graduate students. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals?This project is on track to meet its goals and objectives by the next reporting period. Substantial progress has been made in each of the research objectives and results for research obj. 2 (grapevine growth) have been fully acquired and analyzed. Remaining work towards the research objectives includes: labwork for obj. 1, data analyses for obj. 1, and interpretation and dissemination of results for all research objectives. During summer 2021 it is anticipated that the N-uptake results (objective 1.1) will be obtained and fully analyzed and that substantial progress will be made on the omic analyses on root samples (obj. 1.2 and 1.3). While the Covid-19 pandemic postponed the exchange with the Cantu lab at UC Davis, this visit will take place in the fall following completion of the omic laboratory analyses. This visit will act as a concentrated time period where gene-expression (transcriptomic) data analysis will take place. Spring 2022 will be focused on finalizing the analysis of results and preparing articles for extension outreach and journal publications. For the Professional Development objectives, most of these will be reached through completing the research objectives. Additionally, it is anticipated that during the visit to the Cantu Lab at UC Davis there will be several opportunities to network and connect with other researchers. Finally, through the fulfillment of publication process and disseminating results through extension in Spring 2022, professional development objectives 1 and 2 will be fulfilled.
Impacts
What was accomplished under these goals?
Groundcovers have many potential benefits for fruit and nut agroecosystems, in particular for reducing environmental impact. However, there are variable impacts on growth when groundcovers are planted in vineyards. So far research has been unable to fully explain how grapevines are able to cope with competition. This project aims to improve the application of sustainable management practices in vineyards by applying agroecological research methods to better understand the mechanisms of grapevine-groundcover competition. This research will have short-term impacts by providing directly applicable information to growers and long-term impacts by furthering scientific understanding of how root nitrogen uptake relates to root gene expression and metabolism. As a predoctoral fellowship, the activities in completing this project will also assist in the professional development of PD and graduate student Suzanne Fleishman. Progress Towards Research Project Objectives The research project objectives focus on root-function (obj. 1) and aboveground growth (obj. 2) for grapevines competing with and without groundcover and on rootstocks that vary in vigor during the 2020 growing season. Objective 1 was addressed through two field activities during the 2020 growing season. A nitrogen (N)-uptake experiment (obj. 1.1) was completed in July 2020 by using a labeled 15N approach to monitoring whether N-uptake rate was different between rootstock and groundcover treatments. Necessary samples were taken to complete the experiment and analyses of those samples is currently in progress; data and final calculations for the N-uptake experiment are expected by July 2021. Root sampling was conducted in July 2020 for measurements on root metabolism, root gene expression and root growth (obj. 1.2 and 1.3). Roots are currently stored for later omic (gene expression and metabolism) analyses with results expected in fall of 2021. Preliminary analyses of root growth show that at shallow depths (0-33 cm) and mid depths (34-66 cm), root mass was decreased 27% (P = 0.01) and 25% (P = 0.04), respectively. Deep root mass (67-100 cm) was unaffected by groundcover (P = 0.55), but there was evidence that grapevines may have increased the proportion of new (white) roots at depth. Under the groundcover treatment and in comparison to the no-groundcover treatment, the proportion of new roots at shallow depths was lower by 29% (P = 0.02) and at deep depths was higher by 15% (P < 0.01). Despite previous evidence at the site that the root distributions differed based on rootstock, including in their response to groundcover, we did not find evidence that rootstock vigor influenced root mass or production. These shifts in response to groundcover suggest that altered root distributions is one way that grapevines cope with groundcover competition. Once these growth results are combined with omics and the N-uptake results, it will clarify what other physiological processes are allowing grapevines to cope with groundcover competition. In order to examine whether groundcovers reduce aboveground nutrition and growth, biomass measurements were taken in August 2020 and yield was taken in September 2020 (obj. 2). Grapevine shoot samples were separated into petioles, leaves, clusters, and stems, dried and weighed, and submitted to the Penn State Agricultural analytical lab for analysis. There was only marginal evidence that grapevine shoots decreased in total dry mass due to groundcover competition (8%; P = 0.09). The only tissue with significant evidence of a reduction in growth due to groundcover were the shoots, with a decrease in mass of 14% (P = 0.04). There was greater evidence of groundcover competition as measured by reductions in N concentrations in the tissues. Groundcover competition reduced petiole N 22% (P = 0.01), leaf N 10% (P = 0.01), and cluster N 15% (P = 0.01); however, there was only marginal evidence stem N was reduced by 14% (P = 0.09). Tissue N concentrations were unaffected by the rootstock treatment and yield was unaffected by either the rootstock or the groundcover treatment. Despite the reductions in growth and N concentration in tissues for grapevines competing with groundcovers, these reductions are lower than in previous years at the site. This could suggest that over time the grapevines are acclimating to the N competition from groundcovers and are utilizing some of the aforementioned methods (root redistribution, metabolism, and N-uptake) as ways to cope with the competition. However, it is also possible that season-specific factors, such as lower rainfall in 2020 than previous years, contribute to our observations. Progress Towards Professional Development Objectives PD Fleishman has engaged in several activities to develop skills in laboratory and bioinformatic omic techniques (obj. 1) and how to connect those findings to physiological outcomes in field conditions (obj. 2) In order to prepare for the field experiment in 2020 and to make decisions regarding laboratory analyses, PD Fleishman interacted with and formed connections with Dr Dario Cantu at UC Davis, Dr. Liana Burghart at Penn State, and Dr. Astrid Volder at UC Davis. The COVID-19 pandemic did not allow for the originally planned online course in metabolomics from U. of Birmingham (UK), but PD Fleishman was able to audit a new course at Penn State on design and analysis of Metabolomic experiments (VBSC 497: Principles of Metabolomics). Substantial time has also been spent on reading papers, attending seminars, and other efforts for PD Fleishman to develop a background on the research topics within this project. In the coming year, this training will become hands-on with the completion of the planned laboratory and bioinformatic analyses and through an exchange at the Cantu lab at UC Davis. In addition to developing research skills, PD Fleishman has completed several important efforts in order to further develop her research skills as a scientist. This has included the successful mentoring of the undergraduate Grant Hoffer since June 2020, including guiding his successful undergraduate research grant ($2000) from Penn State. PD Fleishman also engaged in approximately 10 planning meetings with mentor Eissenstat, other scientists, and planning professionals in order to successfully set up a website and schedule for the 8thInternational Symposium on Physiological Processes in Roots of Woody Plants; unfortunately, due to the COVID-19 pandemic, the conference was ultimately cancelled. Lastly, in order to further PD Fleishman's professional development, she has found ways to develop leadership, facilitation, and communication skills by embracing the remote communication necessitated by the covid-19 pandemic. Summary In summary, over the first year of this fellowship, the project has successfully completed the field portion of the research project and engaged the PD graduate student in professional development through advising an undergraduate, connecting her to established researchers in the field, and supporting her learning process. During this first year the groundwork has been laid to complete the laboratory and data analyses from the field project and ultimately disseminate these results. Future insights from this project on how grapevines cope with competition will allow for advisement of growers on best practices and enhanced scientific understanding of how root gene expression and metabolism is associated with resource uptake.
Publications
|
|