# Integrated transcriptome and metabolome analysis reveal the sesquiterpenoid biosynthesis mechanism of Atractylodes chinensis under drought stress

## TL;DR

This study explores how drought stress affects the production of sesquiterpenoids in Atractylodes chinensis, a traditional Chinese medicine, by analyzing gene and metabolite changes.

## Contribution

The study identifies key genes and metabolites involved in sesquiterpenoid biosynthesis under drought stress in A. chinensis.

## Key findings

- Moderate drought stress increased the levels of atractylodin, β-eudesmol, and atractylenolide I.
- Thousands of differentially expressed genes and metabolites were identified across drought stress levels.
- Key genes and a critical metabolite were linked to the sesquiterpenoid biosynthesis pathway under drought stress.

## Abstract

As a traditional Chinese medicine abundant in sesquiterpenoids, Atractylodes chinensis has various pharmacological activities. Nevertheless, the synthesis and metabolism mechanisms of its sesquiterpenoids under drought stress are still not fully elucidated.

Therefore, this study investigated changes in sesquiterpenoid component contents, gene expression profiles, and metabolite accumulation of A. chinensis under drought stress.

Results showed that the moderate drought stress (MDS) significantly increased the contents of atractylodin, β-eudesmol, and atractylenolide I. Compared with the control group (CK), 10,528, 9,755, and 10,562 differentially expressed genes (DEGs) were identified in the light drought stress (LDS), MDS, and severe drought stress (SDS) groups, respectively. These DEGs are involved in plant–pathogen interaction, plant hormone signal transduction, plant MAPK signal transduction, and starch and sucrose metabolism. Metabolic analysis detected 2,101, 2,112, and 2,144 differentially accumulated metabolites (DAMs) in the LDS, MDS, and SDS groups, including atractylodin, β-eudesmol, and atractylenolide I. These DAMs are primarily enriched in three pathways: “ABC transporters”, “D-amino acid metabolism”, and “aminoacyl-tRNA biosynthesis”. Furthermore, we screened and characterized the expression patterns of DEGs and accumulation levels of DAMs involved in the sesquiterpenoid biosynthesis pathway. Notably, the genes TRINITY_DN12874_c1_g1, TRINITY_DN114406_c0_g1, TRINITY_DN2331_c0_g2, TRINITY_DN7401_c0_g1, TRINITY_DN11676_c0_g1, along with the compound Germacra-1(10),4,11(13)-trien-12-ol, are speculated to be key genes and critical metabolite responding to drought stress, respectively.

These findings enhance our understanding of the mechanisms by which drought stress modulates the sesquiterpenoid biosynthesis pathways in A. chinensis.