Nuclear factors are increasingly important in playing part in regulating the expression of genes. Eukaryotic transcriptional initiation is controlled by complecated interactions between cis-acting DNA motifs and trans-acting proteins, which consist of nuclear factors. Four sequences involved in DNA sequence recognition have been determined as follows; zinc fingers : leucine-zippers; helix-turn-helix and helix-loop-helix motifs. Research from viral and animal systems turn to plant gene expression systems. Evidence has shown that the interaction of nuclear factors is the basis and pre-requisite for the regulation of gene expression.