The synergism between BR and auxin in the cell elongation has been studied for a long time but lacks enough evidences for the exact mechanism of the synergism. Cell elongation is partly contibuted by the cytoskeleton rearrangemenet through microtubules orientaion and actin microfilaments organization. This paper reported the isolataion of a mutant on ACTIN2 which was insensitive to BR in wavy root response and had unbundle filaments with enhanced filament mobility, enhanced auxin responses and constitutively acitivated BR signaling.They provided the additional evidence for role of BR on cytoskeleton configuration by treateing plants with BL, which affected the filament configuration by unbundling of the actin filament with enhanced mobility and PIN2 delocalization in a similar manner as auxin.  This discovery led us to rethink about the use of ACT2 as a loading control in Transcript level analysis.

Lanza et al., 2012, Dev. Cell 22, 1275-1285