Functional analysis of Arabidopsis ethylene-responsive element binding protein conferring resistance to Bax and abiotic stress-induced plant cell death.
Arabidopsis (Arabidopsis thaliana) ethylene-responsive element binding protein (AtEBP) gene was isolated as a suppressor of Bax-induced cell death by functional screening in yeast (Saccharomyces cerevisiae). To further examine the cell death suppressive action of AtEBP in plant cells, we established transgenic tobacco (Nicotiana tabacum) plants overexpressing AtEBP as well as transgenic tobacco plants ectopically expressing mouse Bax protein under a dexamethasone-inducible promoter. We prepared the crosses of the selective lines of each transgenic plant, which were evaluated in terms of cell death suppression activity. Results indicate that AtEBP suppressed Bax-induced cell death in tobacco plants, an action also associated with a lowered level of ion leakage. Furthermore, tobacco Bright Yellow-2 cells overexpressing AtEBP conferred resistance to hydrogen peroxide (H(2)O(2)) and heat treatments. AtEBP protein localized in the nucleus and functioned as an in vivo transcription activator as confirmed in transient assays and experiments using stable transgenic system. Up-regulation of defense genes was observed in transgenic Arabidopsis plants overexpressing AtEBP. Based on the analysis of mRNA accumulation in ethylene-related mutants, the position of AtEBP in signaling pathway is presented.
Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan.
Taro
T
Ogawa
Ling
L
Pan
Maki
M
Kawai-Yamada
Li-Hua
LH
Yu
Saburo
S
Yamamura
Tomotsugu
T
Koyama
Sakihito
S
Kitajima
Masaru
M
Ohme-Takagi
Fumihiko
F
Sato
Hirofumi
H
Uchimiya
D017360:Arabidopsis / Q000166:cytology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D015152:Blotting, Northern; D016923:Cell Death / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D007501:Iron / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics / Q000254:growth & development; D014157:Transcription Factors / Q000378:metabolism; D051028:bcl-2-Associated X Protein
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D010940:Plant Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D051028:bcl-2-Associated X Protein; D013481:Superoxides; C093680:ethylene-responsive element binding protein; D006861:Hydrogen Peroxide; D007501:Iron