Molecular Mechanisms behind the Regulation of Rice Tiller Angle: An Update

Crop plant architecture is an important agronomic trait that contributes greatly to crop yield. Tiller angle is one of the most critical components that determine crop plant architecture, which in turn substantially affects grain yield mainly owing to its large influence on plant density. Gravity is a fundamental physical force that acts on all organisms on earth. Plant organs sense gravity to control their growth orientation, including tiller angle in rice (Oryza sativa). This review summarizes recent research advances made using rice tiller angle as a research model, providing insights into domestication of rice tiller angle, genetic regulation of rice tiller angle, and shoot gravitropism. Finally, we propose that current discoveries in rice can shed light on shoot gravitropism and improvement of plant tiller angle in other species, thereby contributing to agricultural production in the future.