Laser capture microdissection(LCM) combined with gas chromatography-mass spectrometry(GC-MS) was employed to investigate the distribution of volatile compound in the secretory cavities of different tissues(cortex, phloem, xylem, and pith) in different rhizome sections of wild Atractylodes lancea. The same method was used to study the metabolic characteristics of the volatile compounds in the secretory cavities of different rhizome tissues of A. lancea transplanted for 1-3 years. In the rhizome of wild A. lancea, the accumulation of volatile compounds such as atractylodin, atractylon, and atractylenolide Ⅰ in the secretory cavities of the cortex was significantly higher in the middle sections(sections 2-6) than that at the two ends(sections 1 and 7). In the rhizome of A. lancea transplanted for 1 year, the volatile compounds such as atractylodin, atractylon, atractylenolideⅠ, and atractylenolide Ⅱ were mainly accumulated in the secretory cavities of the cortex. In the rhizome of A. lancea transplanted for 2 years, the tested volatile compounds except selina-4(14),7(11)-dien-8-one were enriched in the secretory cavities of all the tissues. In the rhizome of A. lancea transplanted for 3 years, atractylon, hinesol, and β-eudesmol were mainly accumulated in the secretory cavities of the pith. The overall accumulation of volatile compounds in each rhizome tissue of cultivated A. lancea increased with the increase in transplanting years. Non-targeted metabolomics and absolute quantification confirmed that the volatile compounds were mainly accumulated in the secretory cavities of the cortex in the middle rhizome sections of wild A. lancea. The accumulation in the rhizome of cultivated A. lancea presented a trend from cortex, phloem, xylem to pith over time. In this study, the spatio-temporal distribution map of volatile compounds in the rhizome of A. lancea was established.
Keywords: Atractylodes lancea; gas chromatography-mass spectrometry; laser capture microdissection; secretory cavity; tissue distribution; volatile oil.