Recommend Plant Signaling & Behavior (PS&B) to your librarian for 2008. Download form here.

Sign up for Table of Contents Alerts!

PS&B is the official journal of the Society for Plant Neurobiology. Full membership ($60 annually) and student membership ($30 annually) include online access to the journal. Click here to join.

Email this page

Print this page

Article Addendum

Do ARG1 and ARL2 form an actin-based gravity-signaling chaperone complex in root statocytes?

Benjamin Harrison and Patrick H. Masson

This is an open-access article

 Download PDF

If the document does not open, please right-click on the link (control-click on a Macintosh) and select the option to save the file to disk.

Plants are acutely sensitive to the directional information provided by gravity. They have evolved statocytes, which are specialized cells that sense gravity and, upon integration of the corresponding information with that of other environmental stimuli, control the growth behavior of their organs. The cellular mechanisms that allow statocytes to sense and transduce gravitational information likely involve detecting the sedimentation of, or the tension/pressure exerted by, starch-filled amyloplasts - the presumptive statoliths - within their cytoplasm. Gravity signaling in root statocytes controls the direction of transport of signaling compounds, especially auxin, across the root cap, establishing a lateral gradient that is transmitted to cells in the elongation zone and results in gravitropic curvature. The Arabidopsis J-domain proteins ARG1 and ARL2 function as gravity-signal transducers in root statocytes. In the January issue of Plant Journal, we reported that ARG1 and ARL2 function non-redundantly in a common gravity signaling pathway required for accumulation of the auxin efflux facilitator PIN3 on the new bottom side of statocytes following gravity stimulation, and lateral redistribution of auxin toward the new lower flank of stimulated roots. Here we present data suggesting that ARG1 physically associates with ARL2, the J-domain co-chaperone HSC70, and actin in vivo. We briefly discuss potential mechanisms by which ARG1 and ARL2 might function in gravity signaling in light of this information.

Authors

Benjamin Harrison

University of Wisconsin-Madison; Madison, Wisconsin USA

Patrick H. Masson

University of Wisconsin-Madison; Madison, Wisconsin USA

This is an open-access article

 Download PDF

If the document does not open, please right-click on the link (control-click on a Macintosh) and select the option to save the file to disk.