15th International Conference on Arabidopsis Research - TAIR

T03-045
Identification and Characterisation of the Arabidopsis
thaliana DISTORTED Mutant GNARLED
Ilona Zimmermann(1), Moola Mutondo(1), Rainer Saedler(1), Martin Hülskamp(1)
1-Botanical Institute III, University of Cologne, Gyrhofstr. 13, 50931 Köln, Germany
We use Arabidopsis leaf trichomes as a model system to study plant morphogenesis.
A class of eight mutants called “DISTORTED” mutants revealed
insight in the role of the actin cytoskeleton in the directionality of expansion
growth. DIS1, DIS2, WRM and CRK have recently been cloned and shown to
encode subunits of the ARP2/3 complex, which is essential for actin filament
nucleation. Here we show that GNARLED encodes a homolog of the ARP2/3
regulating gene NAP125. A phenotypic characterisation of the mutant and
the potential function of the encoded protein will be discussed.
15 th <strong>International</strong> <strong>Conference</strong> on Arabidopsis Research 2004 · Berlin
T03-046
Screen for plasmodesmal associated proteins
Marcella B. Pott(1), Mark Kearley(2), David Ehrhardt(1)
1-Carnegie Institution of Washington, Department of Plant Biology, 260 Panama Street, Stanford,
CA 94305
2-Sonoma State University, Department of Chemistry, 1801 East Cotati Ave, Rohnert Park, CA
94928
In a microscopic screen of a GFP::cDNA library expressed in Arabidopsis
thaliana (Cutler et al., 2000) a protein fragment was detected which showed
localization consistant with plasmodesmata. These structures are unique
to plants and play a crucial role in symplastic cell-to-cell and long distance
communication and in systemic movement of viruses. Despite these
important functions, the molecular composition and means of biosynthesis
of plasmodesmata are widely unknown. The newly identified clone D41, a
truncated syntaxin, is now been used to identify interacting proteins that are
responsible for its localization and may be part of plasmodesmal channels.
Two constructs have been synthesized for purification of protein complexes:
T7-His6-GFP-D41 and His6-FLAG-GFP-D41. Both constructs were used to
transform Arabidopsis plants. The GFP allows for easy screening of positive
tranformants and can, like the other two tags, be used to purify D41 from
the plant extract. Probable interacting proteins that are isolated together with
D41 will subsequently be identified via LC-MS/MS. Promising candidates
from this screen can then be tested for their possible roles in plasmodesmal
synthesis, structure, or function, and in a similar manner be used to identify
further components of plasmodesmata.
Cutler, S.R.; Ehrhardt, D.W.; Griffitts, J.S.; Somerville, C.R. (2000)
Proc Natl Acad Sci USA 97: 3718-3723
T03 Cell Biology