Abstract
Significance Most plants exhibit a pronounced apical growth dominance. However, when the resource demand of the primary organ decreases or the nutritional status of the plant increases, apical growth dominance is broken, and lateral organ growth unleashed. In our work, we have unraveled a developmental function of the sugar-controlled S 1-basic-leucine-zipper (S 1-bZIPs) transcription factors in mediating apical growth dominance, by controlling tissue-specific expression of genes involved in sugar (C)-partitioning or control of organic nitrogen-(N) homeostasis. By these means, S 1-bZIPs could act as rheostat to tune lateral organ outgrowth, by restricting their C/N-supply. Known to be repressed at high-sugar levels, S 1-bZIPs have the capacity to integrate information on resource availability into growth plasticity, which is of great relevance for breeding strategies.