Study : A B-ARR-mediated cytokinin transcriptional network directs hormone-cross regulation and shoot development

Identification

Name
A B-ARR-mediated cytokinin transcriptional network directs hormone-cross regulation and shoot development
Identifier
dXJuOkVWQS9zdHVkeS9QUkpOQTM2OTgyNA==
Source
Description
While the biosynthesis, degradation, and signaling pathways for the essential plant hormone cytokinin have been extensively studied, the direct transcriptional targets of B-type ARRs, the key TFs essential for cytokinin action have not been defined. We epitope tagged four B-ARRs (1, 10, 12, and 14) using recombineering techniques and profiled TF binding sites using chromatin immunoprecipitation sequencing (ChIP-seq). The resulting cytokinin transcriptional response network allowed construction of the first cytokinin TF network, identification of numerous direct downstream targets along with the B-ARR-6BA motif and elucidation of one mechanism of activation of WUSCHEL, which requires a high concentration of cytokinin in shoot apical meristem for TF binding. Overall design: we present the profiles of in vivo DNA binding sites for the genetically redundant type-B ARABIDOPSIS RESONSE REGULATORS (B-ARRs): ARR1, ARR10, and ARR12 along with ARR14 using recombineering YFP tagged lines and subsequent chromatin immunoprecipitation sequencing (ChIP-seq) analysis. The expression and genomic protein localization of B-ARRs overlap extensively, demonstrating numerous common targets among the B-ARRs. The negative regulators of cytokinin signaling, the type-A ARRs (A-ARRs), are the top ranked targets of B-ARRs. These findings confirm an immediate negative B-ARR-driven feedback loop in cytokinin signaling. Constructing a cytokinin primary response transcriptional network revealed a recurring theme involving extensive cross-regulation both within the components of the cytokinin pathway and with other plant hormone response pathways.
Active
No

Genotype

Accession number Name Taxon
ARR10ypet Arabidopsis thaliana
ARR12ypet Arabidopsis thaliana
ARR14yept Arabidopsis thaliana