摘要Anthocyanins are secondary metabolites induced by environmental stimuli and developmental signals.The positive regulators of anthocyanin biosynthesis have been reported,whereas the anthocyanin re-pressors have been neglected.Although the signal transduction pathways of gibberellin(GA)and jas-monic acid(JA)and their regulation of anthocyanin biosynthesis have been investigated,the cross-talk between GA and JA and the antagonistic mechanism of regulating anthocyanin biosynthesis remain to be investigated.In this study,we identified the antho-cyanin repressor MdbHLH162 in apple and revealed its molecular mechanism of regulating anthocyanin biosynthesis by integrating the GA and JA signals.MdbHLH162 exerted passive repression by inter-acting with MdbHLH3 and MdbHLH33,which are two recognized positive regulators of anthocyanin biosynthesis.MdbHLH162 negatively regulated an-thocyanin biosynthesis by disrupting the formation of the anthocyanin-activated MdMYB1-MdbHLH3/33 complexes and weakening transcriptional activation of the anthocyanin biosynthetic genes MdDFR and MdUF3GT by MdbHLH3 and MdbHLH33.The GA repressor MdRGL2a antagonized MdbHLH162-mediated inhibition of anthocyanins by sequestering MdbHLH162 from the MdbHLH162-MdbHLH3/33 complex.The JA repressors MdJAZ1 and MdJAZ2 interfered with the antagonistic regulation of MdbHLH162 by MdRGL2a by titrating the formation of the MdRGL2a-MdbHLH162 complex.Our findings reveal that MdbHLH162 integrates the GA and JA signals to negatively regulate anthocyanin biosyn-thesis.This study provides new information for dis-covering more anthocyanin biosynthesis repressors and explores the cross-talk between hormone signals.