The hormonal, metabolic, and environmental regulation of plant shoot branching

Plants have evolved varied structures for environmental adaptation. Shoot branching, as a part of plant architecture, influences the allocation of sugars produced by photosynthesis and thus greatly impacts crop yields. The activity of axillary meristem, and apical dominance governs the shoot branching patterns. In this review, we summarize the key factors involved in the formation of lateral branches, and the mechanisms of how these factors are interconnected. In particular, we focus on recent advances in understanding how sugar and environmental signals affect the hormonal signaling network to regulate apical dominance. Ultimately, we propose that epigenetic modifications are critical mechanisms underlying the plasticity of shoot branching, and that precise targeted gene editing is promising for shaping the ideal plant architecture.