Skip to main content
bioRxiv
  • Home
  • About
  • Submit
  • ALERTS / RSS
Advanced Search
New Results

The Tension-sensitive Ion Transport Activity of MSL8 is Critical for its Function in Pollen Hydration and Germination

Eric S. Hamilton, View ORCID ProfileElizabeth S. Haswell
doi: https://doi.org/10.1101/084988
Eric S. Hamilton
Department of Biology, Box 1137, Washington University in St. Louis, 1 Brookings Drive, Saint Louis, MO, 63130, USA.
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Elizabeth S. Haswell
Department of Biology, Box 1137, Washington University in St. Louis, 1 Brookings Drive, Saint Louis, MO, 63130, USA.
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Elizabeth S. Haswell
  • Abstract
  • Full Text
  • Info/History
  • Metrics
  • Supplementary material
  • Preview PDF
Loading

Abstract

All cells respond to osmotic challenges, including those imposed during normal growth and development. Mechanosensitive (MS) ion channels provide a conserved mechanism for regulating osmotic forces by conducting ions in response to increased membrane tension. We previously demonstrated that the MS ion channel MscS-Like 8 (MSL8) is required for pollen to survive multiple osmotic challenges that occur during the normal process of fertilization, and that it can inhibit pollen germination. However, it remained unclear whether these physiological functions required ion flux through a mechanically gated channel provided by MSL8. We introduced two point mutations into the predicted pore-lining domain of MSL8 that disrupted normal channel function in different ways. The Ile711Ser mutation increased the tension threshold of the MSL8 channel while leaving conductance unchanged, and the Phe720Leu mutation severely disrupted the MSL8 channel. Both of these mutations impaired the ability of MSL8 to preserve pollen viability during hydration and to maintain the integrity of the pollen tube when expressed at endogenous levels. When overexpressed in a msl8-4 null background, MSL8I711S could partially rescue loss-of-function phenotypes, while MSL8F720L could not. When overexpressed in the wild type Ler background, MSL8I711S suppressed pollen germination, similar to wild type MSL8. In contrast, MSL8F720L failed to suppress pollen germination and increased pollen bursting, thereby phenocopying the msl8-4 mutant. Thus, an intact MSL8 channel is required to for normal pollen function during hydration and germination. These data establish MSL8 as the first plant MS channel to fulfill previously established criteria for assignment as a mechanotransducer.

  • Abbreviations

    cRNA
    capped RNA
    MS
    mechanosensitive
    MscL
    Mechanosensitive channel of Large conductance
    MscS
    Mechanosensitive channel of Small conductance
    MSL8
    MscS-Like 8
    MSL10
    MscS-Like 10
    PEG
    polyethylene glycol
    TM
    transmembrane
  • Copyright 
    The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission.
    Back to top
    PreviousNext
    Posted November 02, 2016.
    Download PDF

    Supplementary Material

    Email

    Thank you for your interest in spreading the word about bioRxiv.

    NOTE: Your email address is requested solely to identify you as the sender of this article.

    Enter multiple addresses on separate lines or separate them with commas.
    The Tension-sensitive Ion Transport Activity of MSL8 is Critical for its Function in Pollen Hydration and Germination
    (Your Name) has forwarded a page to you from bioRxiv
    (Your Name) thought you would like to see this page from the bioRxiv website.
    CAPTCHA
    This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
    Share
    The Tension-sensitive Ion Transport Activity of MSL8 is Critical for its Function in Pollen Hydration and Germination
    Eric S. Hamilton, Elizabeth S. Haswell
    bioRxiv 084988; doi: https://doi.org/10.1101/084988
    Digg logo Reddit logo Twitter logo Facebook logo Google logo LinkedIn logo Mendeley logo
    Citation Tools
    The Tension-sensitive Ion Transport Activity of MSL8 is Critical for its Function in Pollen Hydration and Germination
    Eric S. Hamilton, Elizabeth S. Haswell
    bioRxiv 084988; doi: https://doi.org/10.1101/084988

    Citation Manager Formats

    • BibTeX
    • Bookends
    • EasyBib
    • EndNote (tagged)
    • EndNote 8 (xml)
    • Medlars
    • Mendeley
    • Papers
    • RefWorks Tagged
    • Ref Manager
    • RIS
    • Zotero
    • Tweet Widget
    • Facebook Like
    • Google Plus One

    Subject Area

    • Plant Biology
    Subject Areas
    All Articles
    • Animal Behavior and Cognition (3686)
    • Biochemistry (7774)
    • Bioengineering (5668)
    • Bioinformatics (21244)
    • Biophysics (10563)
    • Cancer Biology (8160)
    • Cell Biology (11909)
    • Clinical Trials (138)
    • Developmental Biology (6738)
    • Ecology (10388)
    • Epidemiology (2065)
    • Evolutionary Biology (13843)
    • Genetics (9694)
    • Genomics (13056)
    • Immunology (8123)
    • Microbiology (19956)
    • Molecular Biology (7832)
    • Neuroscience (42971)
    • Paleontology (318)
    • Pathology (1276)
    • Pharmacology and Toxicology (2256)
    • Physiology (3350)
    • Plant Biology (7208)
    • Scientific Communication and Education (1309)
    • Synthetic Biology (1999)
    • Systems Biology (5528)
    • Zoology (1126)