Expression of the Arabidopsis high-affinity hexose transporter STP13 correlates with programmed cell death

We report the biochemical characterization ill Xenopus oocytes of the Arabidopsis thaliana membrane protein, STP13, as a high affinity, hexose-specific H+-symporter. Studies with kinase activators suggest that it is negatively regulated by phosphorylation. STP13 promoter GFP reporter lines show CFP expression only in the vascular tissue in emerging petals under non-stressed conditions. Quantitative PCR and the pSTP13-GFP plants show induction of STP13 in programmed cell death (PCD) obtained by treatments with the fungal toxin fumonisin B1 and the pathogen Pseudomonas syringae. A role for STP13 in PCD is supported by microarray data from e.g. plants undergoing senescence and a strong correlation between STP13 transcripts and the PCD phenotype in different accelerated cell death (acd11) mutants. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.