2016 Volume 33 Issue 2 Pages 129-132
CAPRICE (CPC) is a key regulator of epidermal cell fate determination, including root hair and trichome formation, in Arabidopsis thaliana. CPC encodes an R3 MYB transcription factor and is known to be involved in the transcriptional repression of the downstream gene GLABRA2 (GL2). We examined transgenic plants harboring CPC fused to a virus-derived transcriptional activator domain (CPC:VP16). Plants carrying 35S::CPC:VP16 showed increased root hair formation, similar to 35S::CPC plants, compared to the wild-type plants. However, transgenic plants harboring CPC:VP16 under the control of CPC promoter (CPC::CPC:VP16) showed similar root hair phenotype to that of the wild-type plants, suggesting an inherent cell-to-cell movement ability of CPC:VP16. In this study, all transgenic plants harboring CPC:VP16 possessed a reduced number of trichomes, nearly identical to that of 35S::CPC plants, compared to the wild type. Furthermore, we observed some unusual tissues with ectopic trichome clusters in all transgenic plants harboring CPC:VP16. These results indicate that VP16 generally does not confer the transcriptional activation ability to CPC.