PpMYB10 and PpMYB114 have been identified as the key R2R3-MYB transcription factors(TFs)that positively regulate anthocyanin biosynthesis in pear.Our previous study demonstrated that the ethylene-induced Pp ERF9-Pp TP...PpMYB10 and PpMYB114 have been identified as the key R2R3-MYB transcription factors(TFs)that positively regulate anthocyanin biosynthesis in pear.Our previous study demonstrated that the ethylene-induced Pp ERF9-Pp TPL1 co-repressor complex represses the expression of PpMYB114,but not PpMYB10,via histone deacetylation.However,the precise molecular mechanism underlying the ethylene-mediated inhibition of PpMYB10 expression remains to be elucidated.The results of this study reveal a high correlation between the expression patterns of PpMYB114 and PpMYB10 in response to ethylene signaling.Moreover,PpMYB114 was found to promote the expression of PpMYB10 by directly binding to the MYB-binding site(MBS)element within its promoter region.Transient overexpression or silencing of PpMYB114 resulted in the promotion or inhibition of PpMYB10 expression in mature pear fruit,respectively.The overexpression of PpMYB114 in pear calli significantly induced PpMYB10 expression and anthocyanin biosynthesis.Conversely,transient silencing of PpMYB10 in PpMYB114-OE pear calli hindered the promotive effect of PpMYB114 on anthocyanin biosynthesis,indicating that PpMYB114 induces anthocyanin biosynthesis,which is at least partially dependent on the transcriptional activation of PpMYB10.Collectively,these results indicate that ethylene may inhibit the expression of PpMYB10 by repressing PpMYB114.Our findings provide insights into a possible mechanism involving ethylene-inhibited PpMYB10 in pear and reveal the regulatory relationship between the R2R3-MYBs involved in anthocyanin biosynthesis.展开更多
基金supported by the National Natural Science Foundation of China(32072545 and 32272678)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)the Zhejiang Provincial Natural Science Foundation of China(LY22C150003)。
文摘PpMYB10 and PpMYB114 have been identified as the key R2R3-MYB transcription factors(TFs)that positively regulate anthocyanin biosynthesis in pear.Our previous study demonstrated that the ethylene-induced Pp ERF9-Pp TPL1 co-repressor complex represses the expression of PpMYB114,but not PpMYB10,via histone deacetylation.However,the precise molecular mechanism underlying the ethylene-mediated inhibition of PpMYB10 expression remains to be elucidated.The results of this study reveal a high correlation between the expression patterns of PpMYB114 and PpMYB10 in response to ethylene signaling.Moreover,PpMYB114 was found to promote the expression of PpMYB10 by directly binding to the MYB-binding site(MBS)element within its promoter region.Transient overexpression or silencing of PpMYB114 resulted in the promotion or inhibition of PpMYB10 expression in mature pear fruit,respectively.The overexpression of PpMYB114 in pear calli significantly induced PpMYB10 expression and anthocyanin biosynthesis.Conversely,transient silencing of PpMYB10 in PpMYB114-OE pear calli hindered the promotive effect of PpMYB114 on anthocyanin biosynthesis,indicating that PpMYB114 induces anthocyanin biosynthesis,which is at least partially dependent on the transcriptional activation of PpMYB10.Collectively,these results indicate that ethylene may inhibit the expression of PpMYB10 by repressing PpMYB114.Our findings provide insights into a possible mechanism involving ethylene-inhibited PpMYB10 in pear and reveal the regulatory relationship between the R2R3-MYBs involved in anthocyanin biosynthesis.
