CO-EXPRESSION AND HORMONAL REGULATION OF GENES IN RESPONSE TO GRAVITY AND MECHANICAL STIMULATION IN THE ARABIDOPSIS ROOT APEX.

Plant roots direct their growth in response to gravity, light, and mechanical stimuli. Spatial changes in the rates of cell elongation and division are responsible for the directional growth. Local changes in hormone concentration and/or sensitivity have been shown to be part of the signal transduction and response mechanisms that result in those tropic growth responses. Part of most hormone regulated mechanisms are regulation of transcription and transcript stability. We have focused our analysis of whole genome microarrays on the differential regulation of transcript abundance changes during the first hour after gravity and mechanical stimulation with respect to the involvement of hormones – especially auxins and brassinosteroids.