Identification and characterization of two O-methyltransferases involved in methylated 2-(2-phenethyl) chromones biosynthesis in agarwood

Wenli Wu; Tingting Yan; Xiaochen Sun; Iain Wilson; Gaiyun Li; Zhou Hong; Fenjuan Shao; Deyou Qiu

doi:10.1093/jxb/erae130

Identification and characterization of two O-methyltransferases involved in methylated 2-(2-phenethyl) chromones biosynthesis in agarwood

J Exp Bot. 2024 Mar 18:erae130. doi: 10.1093/jxb/erae130. Online ahead of print.

Authors

Wenli Wu¹, Tingting Yan², Xiaochen Sun¹, Iain Wilson³, Gaiyun Li², Zhou Hong⁴, Fenjuan Shao¹, Deyou Qiu¹

Affiliations

¹ State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China.
² Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing, 100091, China.
³ CSIRO Agriculture and Food, Canberra, ACT, Australia.
⁴ Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, 510520, China.

PMID: 38497815
DOI: 10.1093/jxb/erae130

Abstract

The 2-(2-phenethyl)chromones (PECs) are the signature constituents responsible for the fragrance and pharmacological properties of agarwood. O-methyltransferases (OMTs) are necessary for the methylated PECs biosynthesis, however, there is little information known about OMTs in Aquilaria sinensis. In this study, we identified 29 OMT genes from the A. sinensis genome. Expression analysis showed they were differentially expressed in different tissues and responded to drill wounding. Comprehensive analysis of the gene expression and methylated PECs content revealed that the AsOMT2, AsOMT8, AsOMT11, AsOMT16, and AsOMT28 could potentially be involved in methylated PECs biosynthesis. The vitro enzyme assays and functional analysis in Nicotiana benthamiana demonstrated that AsOMT11 and AsOMT16 could methylate 6-hydroxy-2-(2-phenylethyl)chromone to form 6-methoxy-2-(2-phenylethyl) chromone. The transient overexpression experiment in Qi-Nan revealed that AsOMT11 and AsOMT16 could significantly promote the accumulation of three major methylated PECs. Our results provide candidate genes for the mass production of methylated PECs using synthetic biology.

Keywords: Aquilaria sinensis; O-methyltransferases; drilling treatment; expression pattern; functional characterization; methylated 2-(2-phenethyl) chromones.