Mechanosensitive channel MSL8 regulates osmotic forces during pollen hydration and germination.
Pollen grains undergo dramatic changes in cellular water potential as they deliver the male germ line to female gametes, and it has been proposed that mechanosensitive ion channels may sense the resulting mechanical stress. Here, we identify and characterize MscS-like 8 (MSL8), a pollen-specific, membrane tension-gated ion channel required for pollen to survive the hypoosmotic shock of rehydration and for full male fertility. MSL8 negatively regulates pollen germination but is required for cellular integrity during germination and tube growth. MSL8 thus senses and responds to changes in membrane tension associated with pollen hydration and germination. These data further suggest that homologs of bacterial MscS have been repurposed in eukaryotes to function as mechanosensors in multiple developmental and environmental contexts.
Department of Biology, Washington University in Saint Louis, Saint Louis, MO 63130, USA.
Eric S
ES
Hamilton
Department of Biology, Washington University in Saint Louis, Saint Louis, MO 63130, USA.
Gregory S
GS
Jensen
Department of Biology, Washington University in Saint Louis, Saint Louis, MO 63130, USA.
Grigory
G
Maksaev
Department of Biology, Washington University in Saint Louis, Saint Louis, MO 63130, USA.
Andrew
A
Katims
Department of Biology, Washington University in Saint Louis, Saint Louis, MO 63130, USA.
Ashley M
AM
Sherp
Department of Biology, Washington University in Saint Louis, Saint Louis, MO 63130, USA. ehaswell@wustl.edu.
Elizabeth S
ES
Haswell
D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D018525:Germination / Q000235:genetics / Q000502:physiology*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000235:genetics / Q000502:physiology*; D040542:Mechanotransduction, Cellular / Q000235:genetics / Q000502:physiology*; D009865:Oocytes; D009997:Osmotic Pressure / Q000502:physiology*; D054817:Pollination / Q000235:genetics / Q000502:physiology*; D013500:Surface Tension; D014867:Water / Q000502:physiology; D014982:Xenopus laevis
D029681:Arabidopsis Proteins; D007473:Ion Channels; C000602853:MSL8 protein, Arabidopsis; D014867:Water