Skip to main content
. 2016 Jan 5;14(1):e1002332. doi: 10.1371/journal.pbio.1002332

Fig 2. The germacrene A synthase ToGAS1 mediates the first committed step in latex TA-G biosynthesis.

Fig 2

A. Partial biosynthetic pathway of TA-G. B. Phylogenetic tree of the newly identified T. officinale germacrene A synthases ToGAS1/2 and known Asteraceae terpene synthases (neighbor-joining method, n = 1,000 replicates). Bootstrap values are shown next to each node. Accession numbers can be found in S4 Table. C. GC-MS analysis of enzyme products from recombinant ToGAS1/2 expressed in Escherichia coli and incubated with the substrate FDP. Germacrene A is converted to β-elemene during hot GC injection. cont, contamination. GC-MS = gas chromatograph coupled to a mass spectrometer. D. Expression of T. officinale germacrene A synthase genes (ToGAS1 and ToGAS2) in the entire main root, latex, and outer main root cortex as determined by RT-qPCR. Statistics of two-way ANOVA and pairwise comparison according to Tukey’s post hoc test are shown. Mean Sq = Mean of squares. n = 3. E. Silencing of ToGAS1 by RNAi generated three independently silenced lines with strongly depleted TA-G concentrations and two transformed, nonsilenced lines with similar TA-G concentrations as the parental wild type. N = 3. Underlying data can be found in S1 Data.