Source: DUKE UNIVERSITY submitted to NRP
DELLA-ARF/IAA INTERACTIONS MEDIATE CROSSTALK BETWEEN GIBBERELLIN AND AUXIN SIGNALING IN REGULATING FRUIT DEVELOPMENT IN TOMATO
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
Reporting Frequency
Annual
Accession No.
1014764
Grant No.
2018-67013-27395
Cumulative Award Amt.
$475,000.00
Proposal No.
2017-06338
Multistate No.
(N/A)
Project Start Date
Jan 1, 2018
Project End Date
Dec 31, 2021
Grant Year
2018
Program Code
[A1152]- Physiology of Agricultural Plants
Recipient Organization
DUKE UNIVERSITY
BOX 90340 PHYTOTRON BUILDING
DURHAM,NC 27708
Performing Department
Biology
Non Technical Summary
The plant hormones auxin and GA play central roles in promoting fruit initiation. Although increased auxin or GA levels or signaling can lead to seedless fruit formation, the molecular mechanism involved remains unclear. In this proposal, we will use multifaceted approaches to elucidate the key molecular events in auxin- and GA-mediated fruit initiation in tomato, which is a model system for studying fleshy fruit development. Seedless fruit is a desirable agronomic trait. Although seedless mutants are available in many species, most have additional unfavorable phenotypes. Our work will provide valuable knowledge for developing novel seedless fruits and vegetables.
Animal Health Component
(N/A)
Research Effort Categories
Basic
90%
Applied
(N/A)
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20114601050100%
Goals / Objectives
The phytohormones auxin and gibberellin (GA) play central roles in fruit initiation. In this project, we will study the role of a novel auxin signaling repressor and its interaction with the GA signaling repressor in regulating fruit set using genetics and biochemical approaches. We will also dissect the complex gene networks regulated by GA and auxin pathways using genomics approaches as well as a synthetic yeast system.
Project Methods
Multifaceted approaches will be taken, including genetics, transgenics, biochemical and genomics approaches. We will also a synthetic yeast system to dissect the complex interactions among key components in auxin and GA signaling pathways.

Progress 01/01/18 to 12/31/21

Outputs
Target Audience:The results of this project were incorporated into an undergraduate course at Duke: Genetic Engineering & Biotechnology. Students learned how our studies using tomato as a model system will shed light on improving fruit quality. We are also preparing a manuscript for publication. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?A postdoctoral fellow (Dr. Jianhong Hu) and a graduate student (Xiao Li) have participated in this project. The PI met with each postdoctoral researcher/graduate student individually weekly to discuss experimental design and data analysis. Each postdoc/student was encouraged to formulate new hypotheses, design experiments to test the hypotheses, and develop problem solving skills. There were also plenty opportunities for these researchers to give oral presentations. The lab has weekly meetings. Each lab member presents once every 1-2 months. Yearly, each researcher also presents their data at the Developmental, Cell and Molecular Biology seminar series within the Biology Department at Duke, and/or at the NC Plant Molecular Biology Consortium annual retreat. In addition, each researcher was encouraged to present at domestic and international conferences. To prepare for presentations outside the lab, the PI worked with each researcher to improve the quality of the presentation. As for improving writing skills, the PI worked with the researcher to write the manuscript, and to prepare figures. The postdoc also participated in grant writing. How have the results been disseminated to communities of interest?Results will be published in a peer-reviewed journal, and will be presented at international meetings What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We have generated new tomato auxin response factor mutant lines using the CRISPR-Cas9 method. They display parthenocarpy phenotypes, although with different fruit morphology. We have also generated higher order mutants by genetic crosses to study the function of four SlARFs and SlDELLA in tomato fruit initiation and subsequent fruit growth. Transcriptome analysis was performed to identify downstream target genes of SlARFs and SlDELLA.

Publications

  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Sun, T. (2021) Novel nucleocytoplasmic protein O-fucosylation by SPINDLY regulates diverse developmental processes in plants. Current Opinion in Structural Biology 68, 113-121


Progress 01/01/20 to 12/31/20

Outputs
Target Audience:The results of this project were incorporated into an undergraduate course at Duke: Genetic Engineering & Biotechnology. Students learned how our studies using tomato as a model system will shed light on improving fruit quality. We are also preparing a manuscript for publication. Changes/Problems:The COVID-19 pandemic has affected this project significantly. Our experiments with the newly generated transgenic tomato lines were delayed because the Duke facility (greenhouse and laboratories) was shut down for 2 months (Apr-May), followed by restricted entries starting June this year. Therefore, a 1-year no-cost extension is requested to complete the proposed work. What opportunities for training and professional development has the project provided?The PI met with each postdoctoral researcher/graduate student individually bi-weekly to discuss experimental design and data analysis. Each postdoc/student was encouraged to formulate new hypotheses, design experiments to test the hypotheses, and develop problem solving skills. There were also plenty opportunities for the postdocs to give oral presentations. The lab has weekly meetings. Each lab member presents once every 1-2 months. Yearly, each researcher also presents their data at the Developmental, Cell and Molecular Biology seminar series within the Biology Department at Duke, and/or at the NC Plant Molecular Biology Consortium annual retreat. In addition, each researcher was encouraged to present at domestic and international conferences. To prepare for presentations outside the lab, the PI worked with each researcher to improve the quality of the presentation. As for improving writing skills, the PI worked with the researcher to write manuscripts, and to prepare figures. The postdoc also participated in grant writing. How have the results been disseminated to communities of interest?Results will be published in a peer-reviewed journal, and will be presented at international meetings. What do you plan to do during the next reporting period to accomplish the goals? To study the roles of SlARFs and SlDELLA in tomato fruit initiation, we have generated higher order mutants, which will be used for phenotypic and transcriptome analysis.

Impacts
What was accomplished under these goals? We have generated new tomato auxin response factor mutant lines using the CRISPR-Cas9 method. They display parthenocarpic phenotypes, although with different fruit morphology. We have also generated higher order mutants by genetic crosses to study the function of these ARFs in tomato fruit initiation.

Publications


    Progress 01/01/19 to 12/31/19

    Outputs
    Target Audience:The results of this project were discussed in 2 scientific meetings in 2019. They were also incorporated into an undergraduate course at Duke: Genetic Engineering & Biotechnology. Students learned how our studies using tomato as a model system will shed light on improving fruit quality. The PI also discussed the research data at several research institutes. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The PI met with each postdoctoral researcher individually bi-weekly to discuss experimental design and data analysis. Each postdoc was encouraged to formulate new hypotheses, design experiments to test the hypotheses, and develop problem solving skills. There were also plenty opportunities for the postdocs to give oral presentations. The lab has weekly meetings. Each lab member presents once every 1-2 months. Yearly, each postdoc also presents his data at the Developmental, Cell and Molecular Biology seminar series within the Biology Department at Duke, and/or at the NC Plant Molecular Biology Consortium annual retreat. In addition, each postdoc was encouraged to present at domestic and international conferences. To prepare for presentations outside the lab, the PI worked with each postdoc to improve the quality of the presentation. As for improving writing skills, the PI worked with the postdoc to write manuscripts, and to prepare figures. The postdoc also participated in grant writing. How have the results been disseminated to communities of interest?Publications and oral presentations at meetings What do you plan to do during the next reporting period to accomplish the goals? We will continue to study the roles of SlARFs and SlDELLA in tomato fruit initiation by generating higher order mutants and by biochemical analysis.

    Impacts
    What was accomplished under these goals? We have generated new tomato auxin response factor mutant lines using the CRISPR-Cas9 method. We are in the process of characterizing these mutants to study the function of ARFs in tomato fruit initiation.

    Publications


      Progress 01/01/18 to 12/31/18

      Outputs
      Target Audience:The results of this project were incorporated into an undergraduate course at Duke: Genetic Engineering & Biotechnology. Students learned how our studies using tomato as a model system will shed light on improving fruit quality. The PI also discussed the research data at several research institutes. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Three postdoctoral fellows have participated in this project. The PI met with each postdoctoral researcher individually bi-weekly to discuss experimental design and data analysis. Each postdoc was encouraged to formulate new hypotheses, design experiments to test the hypotheses, and develop problem solving skills. There were also plenty opportunities for the postdocs to give oral presentations. The lab has weekly meetings. Each lab member presents once every 1-2 months. Yearly, each postdoc also presents his data at the Developmental, Cell and Molecular Biology seminar series within the Biology Department at Duke, and/or at the NC Plant Molecular Biology Consortium annual retreat. In addition, each postdoc was encouraged to present at domestic and international conferences. To prepare for presentations outside the lab, the PI worked with each postdoc to improve the quality of the presentation. As for improving writing skills, the PI worked with the postdoc to write manuscripts, and to prepare figures. The postdoc also participated in grant writing. How have the results been disseminated to communities of interest?Publications and oral presentations at meetings What do you plan to do during the next reporting period to accomplish the goals? We will continue to study the roles of SlARFs and SlDELLA in tomato fruit initiation by characterizing transgenic plants containing mutations in these genes and by biochemical analysis.

      Impacts
      What was accomplished under these goals? In this study, we shed new light into the complex interactions between auxin and gibberellin (GA) pathways in regulating fruit initiation in tomato. Our mutant analysis showed that auxin-induced seedless fruit set in tomato depends on active GA signaling. Our biochemical and molecular studies also showed that GA and auxin regulate tomato fruit initiation through direct crosstalk between GA repressor SlDELLA and auxin signaling components SlARFs/SlIAA9.

      Publications

      • Type: Journal Articles Status: Published Year Published: 2018 Citation: 1. Hu J, Israeli A, Ori, N & Sun, T-p (2018) The Interaction Between DELLA and ARF/IAA Mediates Crosstalk between Gibberellin and Auxin Signaling to Control Fruit Initiation in Tomato. Plant Cell, 30, 1710-1728.
      • Type: Journal Articles Status: Published Year Published: 2018 Citation: 2. Shinozaki Y, Ezura K, Hu J, Okabe Y, BĂ©nard C, Prodhomme D, Gibon Y, Sun T-p, Ezura H, Ariizumi T (2018) Identification and functional study of a mild allele of SlDELLA gene conferring the potential for improved yield in tomato. Scientific Reports. 8: 12043.