CRES-T for the Functional Analysis of Transcription Factors and Modification of Morphological Traits in Plants

The development of new methods for the genetic modification of plant traits is important to both basic and applied research. In particular, the engineering of transcription factors (TFs) is especially desirable, as TFs regulate the expression of numerous genes involved in various aspects of the plant life cycle. A common strategy to reveal TF function is the loss-of-function analysis. Although potentially able to uncover defective phenotypes induced by inhibiting the activity of the TF, the traditional methods of examining the loss-of-function of TFs quite frequently do not generate an informative phenotype. Plant genomes often encode TFs with similar, overlapping sequences and functions. These redundant TFs may regulate the target genes in the absence of the inhibited TF. To overcome the challenge attributed to TF redundancy, the Chimeric REpressor Silencing Technology (CRES-T) was developed. CRES-T is a simple and unique method that employs the construction of a TF gene fused with the ERF-associated amphiphilic repression (EAR) motif, a transcriptional repression domain. This fused gene is then subsequently transformed into plants. The chimeric repressor, the product of the fused gene, suppresses the expression of putative target genes in the presence of native and redundant TFs, thus leading to induction of defective phenotypes. CRES-T greatly enhances the functional analysis of TFs, and its use has been expanded to modification of morphological traits of interest, such as the ornamental morphology of flowers. Therefore, this report presents an overview of CRES-T, as well as its advantages and recent advances in basic and applied research.