Cell/Development/Systems

Abstract

CS-10-1 - The role of auxin-induced, MLO-dependent extracellular alkalinization in root growth inhibition

Sunday, July 15
3:18 PM - 3:38 PM

The plant hormone auxin regulates a multitude of plant growth and developmental processes. While many of these processes are known to be under transcriptional control via the TIR1/AFB-AUX/IAA co-receptor system, other processes, such as auxin-induced, CNGC14-dependent ion signaling and growth inhibition in roots are initiated within seconds and appear to be regulated posttranslationally. We have previously shown that Ca2+ signaling and growth inhibition processes are functionally linked, but the mechanisms translating Ca2+ transients into growth responses are not understood. Auxin-induced Ca2+-signaling triggers rapid extracellular alkalinization in expanding root cells and according to the long-standing acid growth hypothesis, such cell wall alkalinization may cause a reduction in cell elongation. We have identified a subset of MILDEW RESISTANCE LOCUS O proteins that are key to linking Ca2+ and pH signaling in response to auxin. Loss-of-function mlo mutants exhibit normal auxin-induced Ca2+ elevation but lack the subsequent pH response. Site-directed mutagenesis and bimolecular fluorescence complementation analyses are being performed to test whether MLO proteins heterooligomerize and to determine the functional importance of C-terminal calmodulin-binding domains. These studies should provide novel insights into the biochemical activity of MLO proteins and allow us to genetically dissect the roles of Ca2+ and cell wall alkalinization in controlling cell expansion.


 

Co-Authors

Cody DePew – Pennsylvania State University

Gabriele B. Monshausen, PhD

Associate Professor of Biology
Pennsylvania State University

University of Bonn, Germany Ph.D. (advisor: Andreas Sievers)
University of Karlsruhe, Karlsruhe, Germany post doc (advisor: Manfred Weisenseel)
University of Wisconsin, Madison, WI postdoc (advisor: Simon Gilroy)
Pennsylvania State University, University Park, Pa Assistant/Associate Professor of Biology

Presentation(s):

Send Email for Gabriele Monshausen


Assets

CS-10-1 - The role of auxin-induced, MLO-dependent extracellular alkalinization in root growth inhibition



Attendees who have favorited this

Please enter your access key

The asset you are trying to access is locked. Please enter your access key to unlock.

Send Email for The role of auxin-induced, MLO-dependent extracellular alkalinization in root growth inhibition