Figure 2. The reduced contents of volatile compounds in leaf exudates of transgenic plants. Gas chromatography-mass spectrometry (GC-MS) was used to measure the young-leaf exudates from ten-weeks-old WT and transgenic plants. The exudates were obtained by brief extraction with tert-methyl butyl ether buffer (MTBE). WT, wild-type plants. AS, SlIAA15 downregulated plants. Numbers 1–5 represent the different monoterpenes respectively: 1, α-Terpinene, 2, β-Phellandrene, 3, γ-Elemene, 4, β-Caryophyllene, 5, α-Humulene.