Transcripts of MYB14 are induced by Al3+depending on actin
The R2R3-MYB-type transcription factor MYB14 has been shown to activate the stilbene synthase promoter (Höll et al., 2013). Later, differences in the inducibility of MYB14 promoter alleles from wild (V. sylvestris ) versus domesticated (V. vinifera ) grapes were shown to correlate with the stress-specific differences in the expression of stilbene synthase observed between the respective genotypes (Duan et al., 2016). Therefore, in the current study, we tested, whether MYB14 transcripts were induced by aluminium, and, if so, whether this induction was dependent on actin in the same manner as PAL, RS , and STS . As shown in Figure4 , Al3+ caused a significant induction ofMYB14 , albeit to a lower amplitude (only around 2-fold), as compared to PAL, RS and STS (Figure 3A ) that were induced between 5-fold (STS ) and 7-fold (RS ) This induction of MYB14 by aluminium was suppressed by pretreatment with Latrunculin B (Figure 4 ). In contrast to PAL ,RS , and STS (Figure 3A ), Latrunculin B, if administered alone, did not cause any induction. These results demonstrate that the activation of transcription factor MYB14 is dependent on actin.