Abstract
Trichomes (epidermal hairs) of plants have diverse functions, one of which is a structural barrier against herbivorous insects. Interestingly, several plant species including Arabidopsis thaliana are known to develop new leaves with increased trichome density in response to the damage to older leaves. This would be an induced defensive response of plants against herbivores. To reveal the mechanisms involved in the regulation of epidermal patterning of the new leaves by previous wounding, which in turn determine the trichome density, we have been taking a molecular genetic approach using Arabidopsis. We found that both wound-induced biosynthesis, and SCFCOI1 complex-mediated signaling of the wound hormone, jasmonic acid, are essential for trichome density upregulation. Next, we established an assay system to easily detect changes in trichome density. Using this system, we examined the role of known trichome-related transcription factors during trichome density shift. We also identified several mutants defective in trichome density upregulation.
