Relationship between Expression of Chalcone Synthase Genes and Chromones in Artificial Agarwood induced by Formic Acid Stimulation Combined with Fusarium sp. A2 Inoculation.

Agarwood (gaharu) is a fragrant resin produced in the heartwood of resinous and species. Artificial agarwood samples were obtained from (Lour.) Gilg using formic acid (FA) stimulation combined with sp. A2 inoculation. The relationship between the expression of chalcone synthase genes () and dynamic changes in chromone content was explored in resin-deposited parts of the trunks of . gene expression levels were detected by qRT-PCR analysis. The chemical composition of agarwood obtained from the heartwood of before and within 1 year after induction was determined by GC-MS. After induction with FA stimulation combined with . sp. A2 inoculation, the 1 gene showed relatively high expression, whereas the 2 gene showed low expression. The relative gene expression level of 1 peaked at 12 months, with a 153.1-fold increase, and the dominant period of the 2 gene expression was 10 months with a 14.13-fold increase. Moreover, chromones were not detected until after 2 months, and a large proportion of chromone compounds were detected after 4 months. Chromone content increased with time and peaked at 12 months. 1 gene expression was significantly correlated with 6-hydroxy-2-(2-phenylethyl)chromone accumulation, and 2 gene expression was significantly correlated with 5-hydroxy-6-methoxy-2-(2-phenylethyl)chromone accumulation. gene expression was extremely sensitive to FA stimulation combined with . sp. A2 inoculation and responded to late-onset injury. genes expression also preceded the chromone accumulation. This work laid the foundation for studies on the mechanism by which genes regulate chromone biosynthesis pathways during the formation of agarwood resin in .