Abstract
Polyamines are implicated not only in various physiological and developmental processes, but also in (a)biotic stress reponse including high salinity, low temperature, pathogen attack and so on. We have proposed that spermine(Spm) acts a signaling molecule in tobacco mosaic virus(TMV)-induced hypersensitive response (HR). We have also found that a subset of HR-marker genes including HSR203J is likely to be a downstream target of Spm-signaling pathway. Here we report the isolation and characterization of ZFT1, another Spm-responsive clone, in tobacco. This cDNA encodes a Cys2-His2-type zinc finger protein with the highest similarity to petunia ZPT2-3. ZFT1 expression was induced by Spm specifically, not by salicylic acid(SA), jasmonates and ethylene. Furthermore ZFT1 was induced during TMV-induced HR in a SA-independent manner. With a pharmaceutical approach, we verified that ZFT1 positioned downstream of mitochondrial malfunction within the pathway. We will refer the analysis of ZFT1 protein and discuss its role in Spm-signaling pathway.
