1. Plant Biology
Download icon

Synthetic hormone-responsive transcription factors can monitor and re-program plant development

  1. Arjun Khakhar
  2. Alexander R Leydon
  3. Andrew C Lemmex
  4. Eric Klavins
  5. Jennifer L Nemhauser  Is a corresponding author
  1. University of Washington, United States
Tools and Resources
  • Cited 12
  • Views 4,753
  • Annotations
Cite this article as: eLife 2018;7:e34702 doi: 10.7554/eLife.34702

Abstract

Developmental programs sculpt plant morphology to meet environmental challenges, and these same programs have been manipulated to increase agricultural productivity1,2. Hormones coordinate these programs, creating chemical circuitry3 that has been represented in mathematical models4,5; however, model-guided engineering of plant morphology has been limited by a lack of tools6,7. Here, we introduce a novel set of synthetic and modular hormone activated Cas9-based repressors (HACRs) in Arabidopsis thaliana that respond to three hormones: auxin, gibberellins and jasmonates. We demonstrate that HACRs are sensitive to both exogenous hormone treatments and local differences in endogenous hormone levels associated with development. We further show that this capability can be leveraged to reprogram development in an agriculturally relevant manner by changing how the hormonal circuitry regulates target genes. By deploying a HACR to re-parameterize the auxin-induced expression of the auxin transporter PIN-FORMED1 (PIN1), we decreased shoot branching and phyllotactic noise, as predicted by existing models4,5.

Article and author information

Author details

  1. Arjun Khakhar

    Department of Electrical Engineering, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4676-6533
  2. Alexander R Leydon

    Department of Biology, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Andrew C Lemmex

    Department of Biology, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Eric Klavins

    Department of Electrical Engineering, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Jennifer L Nemhauser

    Department of Biology, University of Washington, Seattle, United States
    For correspondence
    jn7@uw.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8909-735X

Funding

National Science Foundation (MCB-1411949)

  • Eric Klavins

National Institutes of Health (R01-GM107084)

  • Jennifer L Nemhauser

Howard Hughes Medical Institute (Faculty Scholars Program)

  • Jennifer L Nemhauser

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Dominique C Bergmann, Stanford University/HHMI, United States

Publication history

  1. Received: January 2, 2018
  2. Accepted: April 30, 2018
  3. Accepted Manuscript published: May 1, 2018 (version 1)
  4. Version of Record published: May 30, 2018 (version 2)

Copyright

© 2018, Khakhar et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 4,753
    Page views
  • 852
    Downloads
  • 12
    Citations

Article citation count generated by polling the highest count across the following sources: Scopus, Crossref, PubMed Central.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)

Further reading

    1. Cell Biology
    2. Plant Biology
    M Regina Scarpin et al.
    Research Article Updated

    Target of rapamycin (TOR) is a protein kinase that coordinates eukaryotic metabolism. In mammals, TOR specifically promotes translation of ribosomal protein (RP) mRNAs when amino acids are available to support protein synthesis. The mechanisms controlling translation downstream from TOR remain contested, however, and are largely unexplored in plants. To define these mechanisms in plants, we globally profiled the plant TOR-regulated transcriptome, translatome, proteome, and phosphoproteome. We found that TOR regulates ribosome biogenesis in plants at multiple levels, but through mechanisms that do not directly depend on 5′ oligopyrimidine tract motifs (5′TOPs) found in mammalian RP mRNAs. We then show that the TOR-LARP1-5′TOP signaling axis is conserved in plants and regulates expression of a core set of eukaryotic 5′TOP mRNAs, as well as new, plant-specific 5′TOP mRNAs. Our study illuminates ancestral roles of the TOR-LARP1-5′TOP metabolic regulatory network and provides evolutionary context for ongoing debates about the molecular function of LARP1.

    1. Cell Biology
    2. Plant Biology
    Vesa Havurinne, Esa Tyystjärvi
    Research Article

    Sacoglossan sea slugs are able to maintain functional chloroplasts inside their own cells, and mechanisms that allow preservation of the chloroplasts are unknown. We found that the slug Elysia timida induces changes to the photosynthetic light reactions of the chloroplasts it steals from the alga Acetabularia acetabulum. Working with a large continuous laboratory culture of both the slugs (>500 individuals) and their prey algae, we show that the plastoquinone pool of slug chloroplasts remains oxidized, which can suppress reactive oxygen species formation. Slug chloroplasts also rapidly build up a strong proton motive force upon a dark-to-light transition, which helps them to rapidly switch on photoprotective non-photochemical quenching of excitation energy. Finally, our results suggest that chloroplasts inside E. timida rely on oxygen-dependent electron sinks during rapid changes in light intensity. These photoprotective mechanisms are expected to contribute to the long-term functionality of the chloroplasts inside the slugs.