# Integrated multi-omics analysis uncovers key metabolic and transcriptional regulatory networks in Blumea balsamifera responding to salt stress

## TL;DR

This study explores how the medicinal plant Blumea balsamifera responds to salt stress using multi-omics analysis, revealing key metabolic and transcriptional pathways involved in salt tolerance.

## Contribution

The study provides the first systematic investigation of salt tolerance mechanisms in Blumea balsamifera using integrated multi-omics analysis.

## Key findings

- Blumea balsamifera's photosynthetic and transpiration rates decrease with increasing salt stress.
- Oxidative phosphorylation, flavone biosynthesis, and cell wall-related pathways are core responses to salt stress.
- DAMs and DEGs like fumaric acid and flavonoid 3’-monooxygenase are key regulators of salt tolerance.

## Abstract

Soil salinization is a key limiting factor for global agricultural production and plant growth. However, the salt tolerance response mechanism of the medicinal plant Blumea balsamifera (L.) DC. has not been systematically investigated.

Fivemonthold seedlings of B. balsamifera were used as experimental materials, and five salt treatments were designed: control (CK), low salt (LS), moderate salt (MS), high salt (HS), and extremely high salt (EHS). Growth, photosynthetic, and physiological indices were measured. According to physiological changes, the HS and EHS groups at 12 d of treatment (when plants entered the core stress response stage) were selected for integrated multiomics analysis.

With increasing salt stress, the net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) of B. balsamifera decreased continuously. The activities of superoxide dismutase (SOD) and catalase (CAT) increased first and then decreased, synergistically removing reactive oxygen species (ROS) with peroxidase (POD). Changes in osmotic adjustment substances and elevated lignin (LIG) content implied enhanced cell wall–related processes. Metabolomic analysis identified 677 and 692 differentially accumulated metabolites (DAMs) in HS vs CK and EHS vs CK, respectively, both enriched in flavone and flavonol biosynthesis. Transcriptomic analysis detected 30,213 and 13,644 differentially expressed genes (DEGs) in HS vs CK and EHS vs CK, respectively, both enriched in oxidative phosphorylation. Integrated analysis demonstrated that oxidative phosphorylation, flavone and flavonol biosynthesis, and cutin, suberine, and wax biosynthesis were the core response pathways, which mediated salt tolerance by regulating key DAMs (e.g., fumaric acid, kaempferol3Orutinoside, luteolin) and DEGs (e.g., flavonoid 3’monooxygenase, peroxygenaselike isoform X2).

This study systematically clarifies the salt tolerance mechanism of B. balsamifera, providing a theoretical basis for its salttolerant breeding and the utilization of medicinal plant resources in salinized regions.