Progress 05/01/19 to 09/30/21
Outputs
Target Audience:Scientific Community: I identified development- & organ-specific AtJAZ4 expression patterning that changes throughout plant development, and I have now determined the underlying JAZ4-mediated hormone signaling crosstalk mechanisms regulating multiple aspects of seedling root growth. Identification of these regulatory pathways is an important step in expanding knowledge of jasmonate signaling specificity, and more generally, furthering our understanding of hormone signaling regulation with regards to plant growth, development, and defense. Changes/Problems:The only major problem during the project was our ability to generate tomato mutant germplasms to observe SlJAZ3 biological function. Due to the coronavirus pandemic, the UC Davis Plant Transformation Facility has been operating on a limited basis and has severely delayed progress on obtaining these mutated germplasms. However, in light of our inability to change this outcome, we shifted our focus to AtJAZ4 for more in-depth characterization than originally planned. What opportunities for training and professional development has the project provided?I have participated in two professional development activities. The first such activity occurred during July 2019 in which I attended the International Congress of Molecular Plant Microbe Interactions research conference in Glasgow, Scotland, UK. The conference consisted of a full week of seminars presented by leaders in my field of research in which I was able to expand upon my knowledge and stay up-to-date on research topics and activities in the realm of Plant Pathology. This conference also provided me the opportunity to present my work that I have completed both during and prior to my NIFA project initiation. This awarded me the possibility to network with professionals in my field and gain valuable feedback and ideas to pursue moving forward. The second professional development activity that I have participated in is a competitive fellowship program specific to the University of California system, Leader's For The Future (LFTF), that is funded through the state governing body. LFTF focuses on providing pre- and post-doctoral fellows with business and professional development skills through workshops and networking events. The goal of the fellowship is for fellows to interact with leader's in industry to learn valuable skills and determine how to be successful post-graduation. I was accepted into the LFTF fellowship program in June 2019 and the program completed in May 2020. 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?
Nothing Reported
Impacts
What was accomplished under these goals?
In regards to Objective 1, I have fully mapped organ-, tissue-, and developmental-specific expression patterns of natural isoforms of AtJAZ4 using quantitative and qualitative methods. What I found was that spatial expression is highly dynamic and localized, and the location of maximal expression fluctuates throughout development within specific organs, most notably root and reproductive tissues. To aid in determining transcriptional regulation of AtJAZ4, we sought to utilize a large-scale, high-throughput Yeast OneHybrid (Y1H) screen. To do this, I created clones of JAZ4 and other JAZ promoters and, with the help of the UC Davis Proteomics Core, screened these against >2,000 transcription factors from Arabidopsis. The results from this large dataset are still currently being analyzed, but have already provided much insight into specific and redundant regulation of JAZ4 and other JAZ promoters.Outcomes of Objective 1 provide an advancement in knowledge on the specificity of jasmonate and alternative hormonesignaling networks and are both reported in my recent publication, DeMott et al., 2021, as well asin another manuscript and my dissertation, both of which are in preparation for publication. Toinvestigate spatiotemporal AtJAZ4 biological function, I performed many large-scale -omics experiments using wild-type and jaz4-1 knockout mutant, including RNA-Seq, Metabolomics, and Proteomics with the aid of Novogene and UCD Proteomics Core. This -omics data, along with growth and defense phenotyping, have suggested a role of AtJAZ4 as a negative regulator in both shoot growth and organogenesis as well as in the basal immune response. RNA-seq data and follow-up experiments highlight AtJAZ4 functions within multiple hormone signaling networks and is transcriptionally regulated as part of a feedback mechanism to control signaling output. Using overexpression germplasms of AtJAZ4.1, JAZ4.2, and JAZ4?Jas, were have been able to pinpoint JAZ4 protein domainsnecessary and sufficient for certain biological functions. We also have been able to elucidate whether or not these biological functions are controlled by JA signaling or through an alternative pathway. All of this work was reported in my recent publication, DeMott et al., 2021, or is in the current manuscript in preparation for publication, as well as my dissertation.
Publications
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Progress 05/01/20 to 04/30/21
Outputs
Target Audience: Scientific Community:Building upon my previousobservation oforgan-specific AtJAZ4 expression patterningthat changes throughout plant development, I have now determined theunderlying JAZ4-mediatedhormone signalingcrosstalk mechanisms regulatingmultiple aspects of seedling root growth. Identification of these regulatory pathwaysis an important step in expanding knowledge of jasmonate signaling specificity, and more generally, furthering our understanding of hormone signaling regulation with regards to plant growth, development, and defense. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Some results from the current and prior period are in revision for publication in a peer-reviewed journal. We anticipate acceptance within the next few months. What do you plan to do during the next reporting period to accomplish the goals?I am currently finishing experiments highlightingAtJAZ4-mediated growth and defense phenotypes and will begin translational experiments to determine conserved function, if any, of SlJAZ3 once CRISPR germplasms are confirmed and propagated. I plan to get my publication accepted and finish analyzing all datasets generated, including the Y1H, RNA-Seq, metabolomics, and proteomics. This data will be used to write two additional manuscripts for submission to peer-reviewed journalsin 2021.
Impacts
What was accomplished under these goals?
To aid in determining transcriptional regulation of AtJAZ4, we sought to utilize a large-scale, high-throughput Yeast One-Hybrid (Y1H)screen. To do this, I created clones of JAZ4 and other JAZ promoters and, with the help of the UC Davis Proteomics Core, screened these against >2,000 transcription factors from Arabidopsis. The results from this large dataset are still currently being analyzed, but have already provided much insight into specificand redundant regulationofJAZ4 and other JAZ promoters. To compare biological function of AtJAZ4 and SlJAZ3, I am in the process of creating new germplasms of CRISPR-derivedSljaz3knockout mutants in tomato. To further investigate spatiotemporal AtJAZ4 biological function, I performed many large-scale -omics experiments using wild-type andjaz4-1 knockout mutant, including RNA-Seq, Metabolomics, and Proteomics with the aid of Novogene and UCD Proteomics Core.
Publications
- Type:
Journal Articles
Status:
Under Review
Year Published:
2021
Citation:
DeMott, L., Oblessuc, P.R., Pierce, A., Student, J., Melotto, M. (2021). Spatiotemporal regulation of JAZ4 expression and splicing contribute to ethylene- and auxin-mediated responses in Arabidopsis roots. The Plant Journal. In Revision.
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Progress 05/01/19 to 04/30/20
Outputs
Target Audience: Scientific Community:Recently, I have observed organ-specific expression patterningof a naturally occurring JAZ isoform that changes throughout plant development. I hypothesize this change in expression localization coincides with hormonal signaling crosstalk to regulate plant growth responses.Identification of such changes is an important step in expanding knowledge of jasmonate signaling specificity, and more generally, furthering our understanding of hormone signaling regulation with regards to plant growth, development, and defense. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?During the current reporting period as part of this project, I have participated in two professional development activities.The first such activity occurred during July 2019 in which I attended the International Congress of Molecular Plant Microbe Interactions research conference in Glasgow, Scotland, UK.The conference consisted of a full week of seminars presented by leaders in my field of research in which I was able to expand upon my knowledge and stay up-to-date on research topics and activities in the realm of Plant Pathology.This conference also provided me the opportunity to present my work that I have completed both during and prior to my NIFA project initiation.This awarded me the possibility to network with professionals in my field and gain valuable feedback and ideas to pursue moving forward. The second professional development activity that I have participated in and continue to do so virtually during these unprecedented times is a competitive fellowship program specific to the University of California system, Leader's For The Future (LFTF), that is funded through the state governing body.LFTF focuses on providing pre- and post-doctoral fellows with business and professional development skills through workshops and networking events.The goal of the fellowship is for fellows to interact with leader's in industry to learn valuable skills and determine how to be successful post-graduation.I was accepted into the LFTF fellowship program in June 2019, in which program completion occurs in May 2020. 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?
Nothing Reported
Impacts
What was accomplished under these goals?
Tomato (Solanum lycopersicum) is one of the most consumed vegetable crops worldwide, with California being the world's largest producer of processing tomatoes and accounting for 94% of U.S. production.However, an estimated 40% of pre-harvest vegetable production is lost each year due to negative environmental impacts.Plants become stressed due to these biotic and abiotic factors, such as pathogens and drought, respectively.Plants adapt and respond to these stresses through hormone signaling, in which a plant with high levels of stress will be less productive and have reduced yield.Thus, producing plants with higher levels of fitness that can better adapt to these environmental factors in the field is paramount. The long-term goal of this project is to address the underlying mechanisms of JA signaling which regulate both plant growth and defense, ultimately controlling overall plant health and production in economically important crops.Objectives relevant to the goal of this project are outlined above.In regards to Objective 1, I have fully mapped organ-, tissue-, and developmental-specific expression patterns of natural isoforms ofAtJAZ4using quantitative and qualitative methods.What I found was that spatial expression is highly dynamic and localized, and the location of maximal expression fluctuates throughout development within specific organs, most notably root and reproductive tissues.Outcomes of Objective 1 provide an advancement in knowledge on the specificity of jasmonate signaling and are currently in preparation for publication. In regards to Objective 2, experiments are currently in progress to understand how AtJAZ4 and SlJAZ3 regulate plant growth and defense.Preliminary data suggests AtJAZ4 significantly controls plant root growth by regulating hormone pathways in addition to jasmonate signaling.These findings are striking and are fundamentally important for the scientific community, and as such are included in the manuscript mentioned for Objective 1.Activities and data collection pertaining to Objective 3 will begin during the next reporting period.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
DeMott, L., Oblessuc, P., and Melotto, M. 2019. JAZ4 functions as positive or negative regulator of jasmonate signaling in different Arabidopsis organs. (Abstr.) Molecular Plant-Microbe Interactions 32:S1.1. https://doi.org/10.1094/MPMI-32- 10-S1.1
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