Tissue-specific expression of MnGutB1 in the mulberry plant. A) Proposed pathway of DNJ biosynthesis in mulberry. The blue dashed box represents the DNJ biosynthesis process derived from lysine; the red dashed box represents derived from hexose. B) Relative expression of MnSDR1, MnSDR2, and MnGutB1 in the tissues indicated in Fig. 1A, as quantified by qPCR. The relative expression in the bud was set as 1. MnRPL15 was the internal control. Callus cultured in vitro. The qPCR data are presented as mean value and standard deviations of 3 independent biological replicates. Significance was analyzed with ANOVA (P < 0.05).