The Role of and in Methyleugenol Biosynthesis by

Many aromatic plant volatile compounds contain methyleugenol, which is an attractant for insect pollination and has antibacterial, antioxidant, and other properties. The essential oil of leaves contains 90.46% methyleugenol, which is an ideal material for studying the biosynthetic pathway of methyleugenol. Eugenol synthase (EGS) is one of the key enzymes involved in the synthesis of methyleugenol. We recently reported two eugenol synthase genes ( and ) present in , where and were mainly expressed in flowers, followed by leaves, and had the lowest expression levels in stems. In this study, the functions of and in the biosynthesis of methyleugenol were investigated using transient gene expression technology and virus-induced gene silencing (VIGS) technology in . Here, in the genes overexpression group, the transcription levels of the gene and gene were increased 13.46 times and 12.47 times, respectively, while the methyleugenol levels increased 18.68% and 16.48%. We further verified the function of the genes by using VIGS, as the transcript levels of the and genes were downregulated by 79.48% and 90.35%, respectively, and the methyleugenol content in decreased by 28.04% and 19.45%, respectively. The results indicated that the and genes were involved in the biosynthesis of methyleugenol, and the transcript levels of the and genes correlated with the methyleugenol content in .