Abstract
We have previously proposed a new and simple growing system to dissect morphology and elongation by continuous mechanical stimulation on Arabidopsis roots: roots are allowed to grow on dialysis membrane-covered agar plate placed horizontally, resulting in providing continuous mechanical stimulation upon root tip during bending downward. Growth of horizontally grown Arabidopsis thaliana seedlings was found to be almost half as compared to that of vertical control and the reduced elongation of horizontal roots was attributed to enhancement of the ethylene response without that of the ethylene production.
In an effort to understand the effects of continuous mechanical stimulation on Arabidopsis root morphology and elongation, we analyzed hormonal cross-talk especially between ethylene and auxin. The role of auxin in the morphology and elongation will also be discussed based on the DR5::GUS and IAA2::GUS expression studies and the estimation of auxin responsive genes by real-time PCR.
