A novel tobacco gene coding for a product similar to bacterial two-component regulators

The two-component signaling system has been studied in bacteria. It takes p art in signal transduction of adaptive behavior. Recent studies have shown that a similar two-component system is also present in eukaryotes. Examples of this are ETR1 and CKI1 genes which may involve the signal transduction of plant hormone ethylene and cytokinin respectively. The cloning and chara cterization of a novel gene (NTHK1) fragment from tobacco are presented. It s partial sequence codes for a product which shows similarity to many two-c omponent signaling proteins. Southern blot analysis indicated that there ar e 2 to 3 copies of NTHK1 gene in tobacco genome (allotetraploid). Homologou s genes may also exist in other plants such as Arabidopsis, soybean and spi nach. The expression of NTHK1 gene has also been analyzed in tobacco. Furth er studies on the isolation of full-length cDNA of NTHK1 gene will elucidat e more clearly its function in signal perception and transduction.