, Volume 226, Issue 1, pp 125–137

The WRKY70 transcription factor of Arabidopsis influences both the plant senescence and defense signaling pathways

  • Bekir Ülker
  • M. Shahid Mukhtar
  • Imre E. Somssich
Original Article

DOI: 10.1007/s00425-006-0474-y

Cite this article as:
Ülker, B., Shahid Mukhtar, M. & Somssich, I.E. Planta (2007) 226: 125. doi:10.1007/s00425-006-0474-y


Regulatory proteins play critical roles in controlling the kinetics of various cellular processes during the entire life span of an organism. Leaf senescence, an integral part of the plant developmental program, is fine-tuned by a complex transcriptional regulatory network ensuring a successful switch to the terminal life phase. To expand our understanding on how transcriptional control coordinates leaf senescence, we characterized AtWRKY70, a gene encoding a WRKY transcription factor that functions as a negative regulator of developmental senescence. To gain insight into the interplay of senescence and plant defense signaling pathways, we employed a collection of mutants, allowing us to specifically define the role of AtWRKY70 in the salicylic acid-mediated signaling cascades and to further dissect the cross-talk of signal transduction pathways during the onset of senescence in Arabidopsis thaliana. Our results provide strong evidence that AtWRKY70 influences plant senescence and defense signaling pathways. These studies could form the basis for further unraveling of these two complex interlinked regulatory networks.


Atwrky70 mutantsDark-induced senescenceSalicylic acidSignaling crosstalk





Jasmonic acid


Salicylic acid

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Bekir Ülker
    • 1
    • 2
  • M. Shahid Mukhtar
    • 1
    • 3
  • Imre E. Somssich
    • 1
  1. 1.Max Planck Institute for Plant Breeding Research, Abteilung Molekulare PhytopathologieCologneGermany
  2. 2.School of Biological and Biomedical SciencesDurham UniversityDurhamUK
  3. 3.Department of BiologyUniversity of North Carolina at Chapel HillChapel HillUSA