Planta

, Volume 226, Issue 1, pp 125–137 | Cite as

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

Abstract

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.

Keywords

Atwrky70 mutants Dark-induced senescence Salicylic acid Signaling crosstalk 

Abbreviations

ET

Ethylene

JA

Jasmonic acid

SA

Salicylic acid

Notes

Acknowledgment

We thank Dr. Karolina Pajerowska-Mukhtar for critically reading of the manuscript. M.S.M was supported by International Max Planck Research School (Max Planck Society, Munich, Germany). Financial support of B.U. was partly provided by the EU-funded REGIA project.

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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

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