@entity19164 (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. Here the identification and functional characterization of sensor @entity3793 kinases homologous to @entity958 CK receptors @entity24618 and @entity24619 in winter @entity4335 are presented. Five CHASE-containing His kinases were identified in @entity4335 . Tapidor ( @entity68270 - @entity68271 ) by heterologous hybridization of its genomic library with gene-specific probes from @entity958 . The identified bacterial artificial chromosome (BAC) clones were fingerprinted and representative clones in five distinct groups were sequenced. Using a bioinformatic approach and cDNA cloning, the precise gene and putative protein domain structures were determined. Based on phylogenetic analysis, four @entity24618 ( @entity68270 - @entity68272 ) homologues and one @entity24619 ( @entity68271 ) homologue were defined. It is further suggested that @entity68270 and BnCHK3, and @entity68271 are orthologues of @entity24618 and @entity24619 , originally from the B. rapa A genome, respectively. @entity68270 , BnCHK3, and @entity68271 displayed high affinity for @entity30119 (1-3nM) in a live-cell competitive receptor assay, but not with other plant hormones ( @entity9634 , @entity15150 , and @entity2271 ), confirming the prediction that they are genuine CK receptors. It is shown that @entity68270 and BnCHK3, and @entity68271 display distinct preferences for various CK bases and metabolites, characteristic of their AHK counterparts, @entity24618 and @entity24619 , respectively. Interestingly, the @entity24618 homologues could be divided into two subfamilies ( @entity68270 /BnCK2 and BnCHK3/ @entity68272 ) that differ in putative transmembrane domain topology and CK binding specificity, thus implying potential functional divergence.

Identification of @entity24618 - and @entity24619 -like cytokinin receptors in XXXX reveals two subfamilies of @entity24618 orthologues.

@entity68270 :: ('106390821', 'Gene') :: ['BnCHK1'] @entity68272 :: ('106439797', 'Gene') :: ['BnCHK4'] @entity2271 :: ('MESH:D000040', 'Chemical') :: ['abscisic acid'] @entity24619 :: ('839621(Tax:3702)', 'Gene') :: ['AHK3'] @entity4335 :: ('3708', 'Species') :: ['oilseed rape', 'Brassica napus var'] @entity3793 :: ('CHEBI:27570', 'Chemical') :: ['histidine'] @entity958 :: ('3702', 'Species') :: ['Arabidopsis'] @entity68271 :: ('106358089', 'Gene') :: ['BnCHK5'] @entity24618 :: ('833552(Tax:3702)', 'Gene') :: ['AHK2'] @entity19164 :: ('CHEBI:23530', 'Chemical') :: ['Cytokinin'] @entity30119 :: ('CHEBI:16522', 'Chemical') :: ['trans-zeatin'] @entity15150 :: ('CHEBI:28833', 'Chemical') :: ['GA3'] @entity9634 :: ('MESH:C030737', 'Chemical') :: ['indole acetic acid']
@entity4335 :: (3708,Species) :: ['Brassica napus']
