PUB - Publikationen an der Universität Bielefeld

**Objective**
Bananas are one of the most popular fruits in the world, providing food security and employment opportunities in several developing countries. Increasing the anthocyanin content of banana fruit could improve the health-promoting properties. Anthocyanin biosynthesis is largely regulated at the transcriptional level. However, relatively little is known about the transcriptional activation of anthocyanin biosynthesis in banana. **Results**
We analysed the regulatory activity of threeMusa acuminataMYBs that were predicted by bioinformatic analysis to transcriptionally regulate anthocyanin biosynthesis in banana.MaMYBA1, MaMYBA2andMaMYBPA2did not complement the anthocyanin-deficient phenotype of theArabidopsis thaliana pap1/pap2mutant. However, co-transfection experiments inA. thalianaprotoplasts showed thatMaMYBA1,MaMYBA2 andMaMYBPA2 function as components of a transcription factor complex with a bHLH and WD40 protein, the so called MBW complex, resulting in the activation of theA. thaliana ANTHOCYANIDIN SYNTHASEandDIHYDROFLAVONOL 4-REDUCTASEpromoters. The activation potential ofMaMYBA1,MaMYBA2 andMaMYBPA2 was increased when combined with the monocotZea maysbHLHZmR instead of the dicotAtEGL3. This work paves the path towards decoding the MBW complex-mediated transcriptional activation of anthocyanin biosynthesis in banana. It will also facilitate research towards increased anthocyanin content in banana and other monocot crops.