Figure 1.

Schematic diagrams of a device for gravistimulation and a photon-counting system. A, A plate of Arabidopsis seedlings was mounted under an ultrasensitive PCC or a PMT in a light-tight dark box connected to a stepping motor, enabling gravistimulation while monitoring the intensity of aequorin luminescence. B, The luminescence intensity was monitored with a photon counter and stored in a personal computer. The rotational speed and angle of the stepping motor was controlled by the same personal computer. C, Time course of changes in the rotational speed (black circle) and angle (white circle) while turning 180° at the speed of 6 rpm.