Poster: Signaling, cell-to-cell
Abs #
444: Expression profiling and T-DNA knockout analysis of the Arabidopsis thaliana annexin multigene family
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Presenter: |
Clark, Greg , gclark@ccwf.cc.utexas.edu |
Authors | Clark, Greg (A) Barthakur, Sharmistha (A) Cantero–Garcia, Araceli (A) Roux, Stanley J (A) | | Affiliations: |
(A): Molecular Cell & Developmental Biology/University of Texas
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Annexins are a diverse, multifunctional gene family of calcium-dependent membrane-binding proteins found in most eukaryotic cells. In plant cells, annexins have been localized at the cell periphery of highly secretory cell types and have been hypothesized to play a role in Golgi-mediated secretion of new wall materials and plasma membrane. They have also been implicated in imparting tolerance to various abiotic stresses. In Arabidopsis, there are eight different annexins, which range from 30% to 82% in deduced amino acid sequence identity. In this study, we are using real time PCR and T-DNA annexin knockouts to try and understand the function of individual Arabidopsis annexins in cell signaling. Expression profiles of these annexins are being studied in response to exposure to salt, drought, high and low temperature conditions. We examined annexin expression after germinating the seeds of ecotype Columbia in varying concentrations of NaCl or after treating grown seedlings with NaCl solutions, and preliminary results indicate that the expression of several annexin genes is differentially regulated by salt. We are also assessing the function of each of the eight Arabidopsis annexins by analyzing the phenotype of mutants for each individual gene. To achieve this goal, we have obtained putative T-DNA insertions for all eight Arabidopsis annexins and are determining which of these lead to gene disruption and “knockouts” for these genes. Thus far we have confirmed knock out alleles for the annexin genes AnnAt1, AnnAt5 and AnnAt7. Phenotypic data for annexin mutants available and expression data for all eight annexin genes will be presented. (Supported by NASA: NAGW 1519).
