摘要
Gravitropism in plants is key for orienting organs such as the Darwin＇s description of the opposite growth direction of roots and shoots in his book The Power of Movement in Plants more than 100 years ago （Darwin, 1880）. The gravitropic response of an oriented plant is divided into three sequential phases： gravity sensing, signal transmission, and the growth response. As the initial phase of gravitropism, gravity sensing （the conversion of the mechanical stimulus into a biochemical signal） has been intensively studied, but much is still unknown. The statoliths are vital for sense of balance and response to gravity, e.g. in statocytes for invertebrates and in inner ears for vertebrates.
Gravitropism in plants is key for orienting organs such as the Darwin＇s description of the opposite growth direction of roots and shoots in his book The Power of Movement in Plants more than 100 years ago （Darwin, 1880）. The gravitropic response of an oriented plant is divided into three sequential phases： gravity sensing, signal transmission, and the growth response. As the initial phase of gravitropism, gravity sensing （the conversion of the mechanical stimulus into a biochemical signal） has been intensively studied, but much is still unknown. The statoliths are vital for sense of balance and response to gravity, e.g. in statocytes for invertebrates and in inner ears for vertebrates.
基金
This work was supported by the National Basic Research Program of China （Grant No. 2011 CB710902 and 2011 CB710901） and National Natural Science Foundation of China （Grant No. 11104286 and 11372314）.ACKNOWLEDGMENTS We thank Fred Sack for discussion and providing DII-VENUS seeds
Dan Szymanski for dis mutants. No conflict of interest declared.
