A team at the National Center for Plant Gene Research at this institute around Assoc Professor SUN Jiajiang has found that phototropism in A. thaliana, which depends on blue light and auxin, is regulated by transcription factors PIF4 and PIF5 located downstream of the BL (blue light) receptor.
Jiaquian Sun et al., The Plant Cell June 2013, doi: http://dx.doi.org/10.1105/tpc.113.112417