The complex regulation of WRKY53 during leaf senescence of Arabidopsis thaliana.

Many different agriculturally important traits, e.g. number and quality of seeds, timing of seed set, fruit ripening, are affected by senescence. Despite the importance of the senescence processes in plants, our knowledge on regulatory mechanisms of senescence is still poor. A central step is a massive reprogramming of the transcriptome, implying an important role of transcription factors. In Arabidopsis 12-16% of all genes are up- or down-regulated. WRKY transcription factors play a central role in controlling leaf senescence in Arabidopsis. One important member of this family, WRKY53, is tightly regulated by different unexpected mechanisms and is a convergence node between senescence and biotic and abiotic stress responses. Copyright 2009 Elsevier GmbH. All rights reserved.