The Arabidopsis cytosolic thioredoxin h5 gene induction by oxidative stress and its W-box-mediated response to pathogen elicitor.

The AtTRXh5 protein belongs to the cytosolic thioredoxins h family that, in Arabidopsis, contains eight members showing very distinct patterns and levels of expression. Here, we show that the AtTRXh5 gene is up-regulated during wounding, abscission, and senescence, as well as during incompatible interactions with the bacterial pathogen Pseudomonas syringae. By electrophoretic mobility shift assays, a binding activity on a W-box in the AtTRXh5 promoter region was found induced by treatments with the P. syringae-derived elicitor peptide flg22, suggesting that a WRKY transcription factor controls AtTRXh5 induction upon elicitor treatment. Remarkably, AtTRXh5 was up-regulated in plants overexpressing WRKY6. More generally, AtTRXh5 is induced in response to oxidative stress conditions. Collectively, our data indicate a possible implication of the cytosolic thioredoxin AtTRXh5 in response to pathogens and to oxidative stresses. In addition, this regulation is unique to AtTRXh5 among the thioredoxin h family, arguing in favor of a speciation rather than to a redundancy of the members of this multigenic family.

Flanking sequence tags in Arabidopsis thaliana T-DNA insertion lines: a pilot study.

Eight hundred and fifty Arabidopsis thaliana T-DNA insertion lines have been selected on a phenotypic basis. The T-DNA flanking sequences (FST) have been isolated using a PCR amplification procedure and sequenced. Seven hundred plant DNA sequences have been obtained revealing a T-DNA insertion in, or in the immediate vicinity of 482 annotated genes. Limited deletions of plant DNA have been observed at the site of insertion of T-DNA as well as in its left (LB) and right (RB) T-DNA signal sequences. The distribution of the T-DNA insertions along the chromosomes shows that they are essentially absent from the centrometric and pericentrometric regions.