Measurement of mechanical forces on floral meristem inducing morphological changes of floral development in Arabidopsis thaliana

Abstract

The external mechanical forces on a floral meristem play a key role in floral development. A novel experimental system was developed to apply mechanical forces on the floral meristem of Arabidopsis thaliana, causing various morphological changes in floral development. A micromanipulator with a silicon device (= micro device), which is shaped to fit the contour of the abaxial side of the young primordium on a floral meristem, is used to apply contact pressure on the floral primordia. Mechanical forces were successfully applied on the floral primordia using this experimental system, and morphological changes were induced in floral development. One of the important issues in this experimental system is measuring the mechanical forces imposed on the floral primordia, and I tried to apply “Pollination Simulation” for the measurement. “Pollination Simulation” is a device which equips a double-bending load cell as its microforce sensor, and it was originally developed to measure the forces needed to release the lever mechanism in the genus Salvia exerted by pollinators. In this novel experimental system, the mechanical forces on the floral meristem were measured in several nano-Newton order by the device. The measurements depend on the shapes of the micro devices and floral primordia. These results demonstrate that the device “Pollination Simulation” is applicable to measure the mechanical forces on the floral meristem, inducing the morphological changes in floral development in the novel experimental system.