Lateral stress initiates bending responses in dandelion peduncles: a clue to geotropism?

Lateral stress applied to vertically held peduncles of Taraxacum officinale (dandelion) under conditions where amyloplast displacement would have been minimal resulted in bending responses. Such responses were similar to those obtained when peduncles were horizontally geostimulated and returned to the vertical position. It is suggested that stress may act as the trigger for geobending without the need for statoliths or could be the mechanism by which amyloplasts normally trigger geotropism.