Wu Di, Huang Lin-zhou, Gao Jin, Wang Yong-hong
State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Yi Chuan. 2016 Jul 20;38(7):589-602. doi: 10.16288/j.yczz.16-127.
Gravity is an important environmental factor that regulates plant growth and morphogenesis. In response to gravity stimulus, plants can set the optimum angle between the organs and the gravity vector. Plant gravitropism is divided into four sequential steps, including gravity perception, signal transduction, asymmetrical distribution of auxin, and organ curvature. In recent years, large numbers of mutants with defective gravitropism have been identified and genes involved in the regulation of gravitropism have been functionally characterized. In particular, progress has been achieved on elucidating the molecular mechanisms of gravity perception and asymmetrical distribution of auxin. As one of the most important strategies for plant to adapt environmental changes, gravitropism is also involved in the regulation of rice plant architecture and grain yield through modulating rice tiller angle. Therefore, the investigation of plant gravitropism not only contributes to decipher the regulatory mechanisms of plant growth and development, but also helps to guide the genetic improvement of crop architecture. However, the molecular mechanisms and regulatory network of gravitropism remain to be elusive. In this review, we focus on recent progress on elucidating molecular mechanisms underlying gravitropism and its involvement in regulating rice tiller angle, which is an important agronomic trait that determines rice plant architecture and thus grain yields.
重力是调节植物生长和形态发生的重要环境因素。响应重力刺激，植物能够设定器官与重力矢量之间的最佳角度。植物的向重力性分为四个连续步骤，包括重力感知、信号转导、生长素的不对称分布和器官弯曲。近年来，已鉴定出大量具有向重力性缺陷的突变体，并对参与向重力性调节的基因进行了功能表征。特别是，在阐明重力感知和生长素不对称分布的分子机制方面取得了进展。作为植物适应环境变化的最重要策略之一，向重力性还通过调节水稻分蘖角度参与调控水稻株型和产量。因此，对植物向重力性的研究不仅有助于破解植物生长发育的调控机制，还有助于指导作物株型的遗传改良。然而，向重力性的分子机制和调控网络仍有待明确。在本综述中，我们重点关注阐明向重力性分子机制及其参与调控水稻分蘖角度方面的最新进展，水稻分蘖角度是决定水稻株型进而影响产量的重要农艺性状。
