Cold accumulation of SCOF-1 transcripts is associated with transcriptionalactivation and mRNA stability

Cold acclimation enhances the transcription of several cold regulated (COR) genes. However, little is known about whether the elevation of the transcr iptional level of the COR genes is due to transcriptional activation, or mR NA stability by a low temperature. Recently, we cloned a novel cold-inducib le zinc finger protein gene from soybean, SCOF-1, which may function as a p ositive regulator of the COR gene expression [Kim et al. (2001)]. Here we r eport that the elevation of the SCOF-1 transcript level by cold stress is a ssociated with both transcriptional activation and post-transcriptional mRN A stability under a low temperature. A nuclear run-on assay reveals that co ld acclimation elevates the SCOF-1 transcript about three-fold compared to that of non-acclimated soybean nuclei. Furthermore, SCOF-1 transcripts incr eased substantially by a low temperature in transgenic tobacco plants that constitutively expressed SCOF-1 under the control of a constitutive caulifl ower mosaic virus (CaMV) 35S promoter. When a transcription inhibitor, cord ycepin, was treated with the deacclimating soybean cell, the decay level of the SCOF-1 transcripts was delayed significantly. This suggests that it ma y affect de novo protein synthesis, which degrades the SCOF-1 mRNA at room temperature. In addition, a secondary structure may be involved in the mRNA stability of SCOF-1 under a low temperature.