# Beyond neurotransmission: dopamine as an emerging biotic and abiotic stress regulator in plants

## TL;DR

Dopamine helps plants handle environmental stresses like drought and disease by regulating redox balance and signaling pathways.

## Contribution

This paper highlights dopamine's novel role as a stress regulator in plants, beyond its known function as a neurotransmitter in animals.

## Key findings

- Dopamine stabilizes photosynthesis and improves root architecture under stress.
- It activates antioxidant systems and interacts with phytohormones to balance growth and defense.
- Dopamine signaling involves ROS, calcium cascades, and transcription factors like WRKY and ERF.

## Abstract

Dopamine (DA) is a catecholamine that plays a role in both animals and plants. Popularly known as a neurotransmitter hormone in animals involved in motor control and reward sensing, it also has a defense-related function in the plant kingdom. In plants, DA functions as a redox-active metabolite, a signalling regulator, and a metabolic modulator, rather than a classical neurotransmitter. Accumulating evidence demonstrates that DA enhances tolerance to diverse abiotic and biotic stresses, including drought, salinity, heavy metals, nutrient imbalance, temperature extremes, and pathogen attack, by stabilizing photosynthetic machinery, optimizing root architecture, improving water and nutrient use efficiency, and activating antioxidant and detoxification systems. Mechanistically, DA operates through coordinated regulation of reactive oxygen species (ROS) signalling, calcium-mediated secondary messenger cascades, transcription factor activation (WRKY, ERF, NAC), and reprogramming of nutrient and ion transporter networks. DA also exhibits extensive crosstalk with phytohormones, fine-tuning growth defence trade-offs in a species and stress-specific manner. Collectively, these findings position DA as a central signalling hub integrating redox balance, metabolic plasticity, and transcriptional control in plants. Understanding the conserved structure yet divergent biosynthesis and signalling logic of DA across kingdoms provides critical insights into its distinct modes of action and highlights its potential as a next-generation regulator for enhancing plant resilience under changing environmental conditions.