Plant Biol (Stuttg) 2007; 9(3): 366-373
DOI: 10.1055/s-2006-924725
Research Paper

Georg Thieme Verlag Stuttgart KG · New York

Hybrid Lethality in Interspecific F1 Hybrid Nicotiana gossei × N. tabacum Involves a MAP-Kinases Signalling Cascade

M. Mino1 , M. Kubota1 , T. Nogi1 , S. Zhang2 , M. Inoue1
  • 1Graduate School of Agriculture, Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto 606-8255, Japan
  • 2Department of Biochemistry, University of Missouri-Columbia, 117 Schweitzer Hall, Columbia, MO 65221, USA
Further Information

Publication History

Received: June 22, 2006

Accepted: September 29, 2006

Publication Date:
19 January 2007 (online)

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Abstract

A cultured cell line, GTH4 (Nicotiana gossei Domin × N. tabacum L.), which exhibits hybrid lethality, died at 26 °C, but not at 37 °C. Pharmacological experiments using inhibitors of protein phosphatases and protein kinases indicated the involvement of a protein kinase signalling pathway in the cell death process. Immunoblot analysis revealed that salicylic acid-induced protein kinase (SIPK) was phosphorylated soon after the shift in temperature from 37 °C to 26 °C. Cultured cells of the hybrid of N. gossei × transgenic N. tabacum harboring a steroid (dexamethasone; DEX)-inducible NtMEK2DD or NtMEK2KR, constitutively active and inactive forms of NtMEK2, respectively, were established. Induction of NtMEK2DD by DEX in the hybrid cells induced the activation of SIPK, the generation of hydrogen peroxide (H2O2), and cell death at 37 °C. The activation of SIPK, generation of H2O2, and cell death at 26 °C were compromised by DEX treatment in hybrid cells harbouring NtMEK2KR. This study provides evidence for the involvement of MAPK signalling in the regulation of cell death in hybrids.

References

M. Mino

Graduate School of Agriculture
Kyoto Prefectural University

1-5 Hangi-cho, Shimogamo

Sakyo-ku, Kyoto 606-8255

Japan

Email: mino@kpu.ac.jp

Editor: J. Cullimore