Gruenwald et al. (2008) showed that the auxin-inducibe transcription factor AtWRKY23 was expressed during infection of Arabidopsis roots by H. schachtii. Recently, Grunewald et al. (2012) demonstrated that regulation of WRKY23 is controlled by the AUXIN RESPONSE FACTOR 7 (ARF7) and ARF19 pathway and that WRKY23 stimulates flavonol biosynthesis. This evidence concerns the gene ARL14 and infection.