BnCHK1, BnCHK3, and BnCHK5 displayed high affinity for trans-zeatin (1–3nM) in a live-cell competitive receptor assay, but not with other plant hormones (indole acetic acid, GA 3, and abscisic acid), confirming the prediction that they are genuine CK receptors.

It is further suggested that BnCHK1 and BnCHK3, and BnCHK5 are orthologues of AHK2 and AHK3, originally from the B. Based on phylogenetic analysis, four AHK2 ( BnCHK1–BnCHK4) homologues and one AHK3 ( BnCHK5) homologue were defined. Using a bioinformatic approach and cDNA cloning, the precise gene and putative protein domain structures were determined.

The identified bacterial artificial chromosome (BAC) clones were fingerprinted and representative clones in five distinct groups were sequenced. Tapidor (BnCHK1–BnCHK5) by heterologous hybridization of its genomic library with gene-specific probes from Arabidopsis. Five CHASE-containing His kinases were identified in Brassica napus var. Here the identification and functional characterization of sensor histidine kinases homologous to Arabidopsis CK receptors AHK2 and AHK3 in winter oilseed rape are presented. Cytokinin (CK) signalling is known to play key roles in the regulation of plant growth and development, crop yields, and tolerance to both abiotic stress and pathogen defences, but the mechanisms involved are poorly characterized in dicotyledonous crops.

Ahk 2