The possible involvement of a phosphate-induced transcription factor encoded by phi-2 gene from tobacco in ABA-signaling pathways.
A novel phosphate-induced gene, phi-2, has been identified by its induction on addition of phosphate to phosphate-starved tobacco BY-2 cells. The predicted gene product of phi-2 has significant homology to a group of bZIP proteins involved in ABA-signaling pathways, and phi-2 also responded to ABA treatment. A previously isolated phosphate-induced gene, phi-1, (Sano et al. (1999) Plant Cell Physiol. 40: 1) was also responsive to ABA. Although phosphate addition induced semi-synchronous cell division in phosphate-starved tobacco BY-2 cells, ABA adversely affected cell division. Detailed examination revealed that the high levels of phosphate required to induce semi-synchronous cell division seemed to be perceived as indicators of stress by the cells. One of the stress indicators perceived by the cells is a cytoplasmic pH change, to which phi-2 and phi-1 genes respond. The different components of the cell's response to phosphate induction are discussed.
Sano
Toshio
T
Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan.
Nagata
Toshiyuki
T
D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D002352:Carrier Proteins / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D051790:G-Box Binding Factors; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D047908:Intracellular Signaling Peptides and Proteins; D016350:Leucine Zippers / Q000235:genetics; D008940:Mitotic Index; D008969:Molecular Sequence Data; D010710:Phosphates / Q000494:pharmacology*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000187:drug effects*; D013997:Time Factors; D014026:Nicotiana / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D016335:Zinc Fingers / Q000235:genetics
D050976:Basic-Leucine Zipper Transcription Factors; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D051790:G-Box Binding Factors; D047908:Intracellular Signaling Peptides and Proteins; D010710:Phosphates; D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors; C015482:protein kinase modulator; D000040:Abscisic Acid; C118827:PHI-1 protein, Nicotiana tabacum; D006180:Proton-Translocating ATPases