Current perspectives on shoot branching regulation

Abstract

Shoot branching is regulated by the complex interactions among hormones, development, and environmental factors. Recent studies into the regulatory mecha-nisms of shoot branching have focused on strigolactones, which is a new area of investigation in shoot branching regulation. Elucidation of the function of the D53 gene has allowed exploration of detailed mechanisms of action of strigolactones in regulating shoot branching. In addition, the recent discovery that sucrose is key for axillary bud release has challenged the established auxin theory, in which auxin is the principal agent in the control of apical dominance. These developments increase our understan-ding of branching control and indicate that regulation of shoot branching involves a complex network. Here, we first summarize advances in the systematic regulatory network of plant shoot branching based on current information. Then we describe recent developments in the synthesis and signal transduction of strigolactones. Based on these considerations, we further summarize the plant shoot branching regulatory network, including long distance systemic signals and local gene activity mediated by strigolactones following perception of external envi-ronmental signals, such as shading, in order to provide a comprehensive overview of plant shoot branching.

Keywords

apical dominance / decapitation / shade / shoot branching / strigolactones / sugar demand

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Acknowledgements

This work was supported by grants from the China Postdoctoral Science Foundation (2014M550891), National Higher-Education Institution General Research and Development Funding (2014BH027), and the National High Technology Research and Development Program of China (2011AA10020801).

Cunquan Yuan, Lin Xi, Yaping Kou, Yu Zhao and Liangjun Zhao declare that they have no conflict of interest or financial conflicts to disclose.

This article is a review and does not contain any studies with human or animal subjects performed by any of the authors.

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