The eTM-miR858-MYB62-like module regulates anthocyanin biosynthesis under low-nitrogen conditions in Malus spectabilis

center dot The anthocyanin content increases in Malus spectabilis leaves under low-nitrogen conditions. Noncoding RNAs are indicated to play key regulatory roles in anthocyanin biosynthesis. However, the functional roles of noncoding RNAs in anthocyanin biosynthesis under low-nitrogen conditions remain elusive. center dot In this study, miR858 was screened as a key regulator of anthocyanin biosynthesis under low-nitrogen conditions through whole-transcriptome sequencing. Then, we used miR858 as an entry point to explore the regulatory network of lncRNA-miRNA-mRNA by dual-luciferase reporter assays and GUS histochemical staining assays, as well as to identify the mechanism of this regulatory network in anthocyanin biosynthesis by both transient and stable transforma-tion experiments in Malus. center dot MiR858 overexpression increased total anthocyanin content. MiR858 acted by negatively regulating its target gene, MsMYB62-like, under the low-nitrogen condition. MsMYB62-like inhibited the expression of MsF3 ' H, thereby negatively regulating anthocyanin biosynthesis. In addition, eTM858-1 and eTM858-2 were identified as endogenous target mimics of miR858 that bind to miR858 to prevent cleavage of MsMYB62-like and thereby negatively regulate anthocyanin biosynthesis. center dot The results clarify the mechanism through which the eTM-miR858-MYB62-like module regulates anthocyanin biosynthesis in Malus under low-nitrogen conditions.