Nature Communications (Apr 2018)

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

  • Mingtang Xie,
  • Hongyu Chen,
  • Ling Huang,
  • Ryan C. O’Neil,
  • Maxim N. Shokhirev,
  • Joseph R. Ecker

DOI
https://doi.org/10.1038/s41467-018-03921-6
Journal volume & issue
Vol. 9, no. 1
pp. 1 – 13

Abstract

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Abstract Cytokinin fulfills its diverse roles in planta through a series of transcriptional responses. We identify the in vivo DNA binding site profiles for three genetically redundant type-B ARABIDOPSIS RESPONSE REGULATORS (B-ARRs): ARR1, ARR10, and ARR12. The expression and genome-wide DNA binding locations of the three B-ARRs extensively overlap. Constructing a primary cytokinin response transcriptional network reveals a recurring theme of widespread cross-regulation between the components of the cytokinin pathway and other plant hormone pathways. The B-ARRs are found to have similar DNA binding motifs, though sequences flanking the core motif were degenerate. Cytokinin treatments amalgamate the three different B-ARRs motifs to identical DNA binding signatures (AGATHY, H(a/t/c), Y(t/c)) which suggests cytokinin may regulate binding activity of B-ARR family members. Furthermore, we find that WUSCHEL, a key gene required for apical meristem maintenance, is a cytokinin-dependent B-ARR target gene, demonstrating the importance of the cytokinin transcription factor network in shoot development.