Methyl jasmonate application and flowering stage affect scent emission of Styrax japonicus

Styrax japonicus is a gorgeous species with high medicinal and ornamental values. Floral scent is an important feature of this species. However, the previous study on its floral scent is limited. To demonstrate the effects of methyl jasmonate on floral scent compounds in Styrax japonicus at different flowering stages, static headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry was adopted. The results showed that 22 volatile compounds were identified in control at initial flowering, full flowering and end flowering stage. Besides, the relative content of these compounds increased with the development of flowers. Linalool, estragole and germacrene-d were main volatiles. Compared to the control, 4 new compounds were determined under methyl jasmonate treatment, including β-elemene, α-muurolene, β-caryophyllene and alloaromadendrene. 26 volatile compounds were found under 200 μmol/L methyl jasmonate treatment with much higher contents of α-pinene and linalool. Meanwhile, 200 μmol/L methyl jasmonate enhanced the relative content of volatile compounds at three flowering stages. This treatment also contributed to the highest content of linalool, followed by control. The linalool content displayed a continuous increasement in both 200 μmol/L methyl jasmonate treatment and control. Our research highlighted that the application of methyl jasmonate, especially with the concentration of 200 μmol/L, had a more positive impact on the type and the relative content of volatile compounds in S japonicus flowers. The results helped to understand the release patterns of volatile compounds in S japonicus flowers and provide important information to regulate the floral scents.