15th International Conference on Arabidopsis Research - TAIR

T04-029
Functional characterization of RCI2A and RCI2B
Ballesteros, Maria L.(1, 1), Medina, J.(1, 1), Salinas, J.(1, 1)
1-Departamento de Biotecnologia, INIA, Madrid, Spain
During the year, plants living in temperate regions have to survive to a variety
of adverse environmental conditions, being high salinity, drought and low
temperature among the most significant. Two Rare Cold Inducible genes from
Arabidopsis, RCI2A and RCI2B, that encode two small and highly hydrophobic
proteins were isolated in our laboratory. Their expression is induced not only
by low temperature but also by salt, dehydration and exogenous ABA treatments.
Interestingly RCI2A and RCI2B are able to complement the deletion
of PMP3, a yeast protein involved in the maintaining of the potential of the
plasma membrane. In our laboratory, we are interested on the functional characterization
of RCI2A and RCI2B. We have identified rci2a and rci2b T-DNA
insertion mutants, and we have generated several lines overexpressing RCI2A
and RCI2B. Currently, we are undertaking the molecular and physiological
characterization of both, mutants and overexpressing lines. Our preliminary
results suggest that both proteins have an important role in Arabidopsis
responses to abiotic stresses.
15 th <strong>International</strong> <strong>Conference</strong> on Arabidopsis Research 2004 · Berlin
T04-030
Functional Characterisation of Arabidopsis thaliana
group I GSK-3/Shaggy-like Kinases
Wilfried Rozhon(1), Elena Petutschnig(1), Claudia Jonak(1)
1-Institute of Microbiology and Genetics, University of Vienna
The ten ASK proteins (Arabidopsis thaliana GSK-3/Shaggy-like Kinases) are
homologues of the mammalian GSK-3 (Glycogen Synthase Kinase 3) and the
Drosophila melanogaster Shaggy kinases. The GSK-3/shaggy kinase family
is implicated in a range of biological processes. In plants, GSK-3/shaggy-like
kinases are important factors in plant development as well as hormone and
stress signalling (Jonak and Hirt (2002) TIPS, 7:457).
We will present data on ASKalpha, gamma, and epsilon three members of
group I ASKs. ASKalpha and ASKgamma have previously been shown to
play a role in flower patterning, whereas no function has been assigned to
ASKepsilon so far. In order to study the role of group I AKSs in more detail
T-DNA insertion lines were obtained. T-DNA insertions were verified by
southern analysis, PCR, and sequencing. The absence of transcript is confirmed
by RT-PCR. Phenotypical characterisation of these lines is in progress.
A. thaliana lines over-expressing Myc epitope-tagged group I ASKs were
generated for biochemical and physiological studies. Western blot analysis of
T1 plants confirmed the expression of the tagged proteins. To investigate the
sub-cellular localisation of group I ASKs YFP-tagged versions of ASKalpha,
gamma, and epsilon are transiently and stably transformed into A. thaliana
and Nicotiana tabacum.
T04 Interaction with the Environment 1 (Abiotic)