A gene regulatory network critical for axillary bud dormancy directly controlled by Arabidopsis BRANCHED1

Abstract

The control of branch outgrowth is critical for plant fitness, stress resilience and crop yield. The Arabidopsis thaliana transcription factor BRANCHED1 (BRC1) plays a pivotal role in this process as it integrates signals that inhibit axillary bud growth to control shoot branching. Despite the remarkable activity of BRC1 as a potent growth inhibitor, the mechanisms by which it promotes and maintains bud dormancy are still largely unknown.Here we combine ChIP-seq, transcriptomic and systems biology approaches to characterise the BRC1-regulated gene network. We identify a group of BRC1 direct target genes encoding transcription factors (BTFs) that orchestrate, together with BRC1, an intricate transcriptional network enriched in abscisic acid signalling components. The BRC1 network is enriched in feed-forward loops and feed-back loops, robust against noise and mutation, reversible in response to stimuli, and stable once established. This knowledge is fundamental to adapt plant architecture and crop production to ever-changing environmental conditions.

The activation of Arabidopsis axillary buds involves a switch from slow to rapid committed outgrowth regulated by auxin and strigolactone

“…Previous work characterising the downstream transcriptional targets of BRC1 does not identify ABCB19 . Extensive links with ABA were identified (González‐Grandío et al ., 2013, 2017; Yang et al ., 2018; Van Es et al ., 2023), supporting its role in BRC1 ‐mediated bud dormancy. Therefore, our observed low BRC1 expression in abcb19 buds suggests an indirect ABCB19‐BRC1 interplay.…”

The miR156-targetedSlSBP15represses tomato shoot branching via modulating auxin transport and interacting withGOBLETandBRANCHED1b

“…S4A). Screening for BRC1-like and SBP-like consensus binding sites (González-Grandío et al ., 2017; Van Es et al ., 2020; Wang and Wang, 2015) revealed partially conserved core motifs in the SlNCED and SlPIN9 promoter regions (∼1.6 kb and ∼2.2 Kb, respectively) for both proteins (Supplementary Fig. S5).…”

Cereal Architecture and Its Manipulation

“…External, resource and long-distance signals from the shoot (auxin) and root (SL) are integrated by TB1 to control tillering (2,28,42,81,89,157,158,339,369,377,428). Besides MOC1, other upstream regulators of TB1 include Ideal Plant Architecture 1 (IPA1), a SPL transcription factor, which directly binds to the OsTB1 promoter to suppress tillering (224).…”