Dopamine in Plants and Animals: Biosynthesis, Physiological Roles, and Therapeutic Potential

Abstract Dopamine is a well-known neurotransmitter in animals that is critical for reward, motivation, and movement control. Recent investigations demonstrated that dopamine is also a pivotal secondary metabolite in plants, aiding in the regulation of growth, adaptability to stressors, and defense capabilities. The review delves into the various dopamine biosynthetic routes identified in animals and plants, paying attention to the key enzyme systems that enable the transformation of tyrosine to dopamine via L-DOPA. Dopamine is essential for plant development and nutrient uptake, but it is also essential for the adaptation of plants to abiotic conditions such as drought, salinity, and heavy metals. Dopamine is critical to the nervous system of animals, and dysregulation of this neurotransmitter is linked to disorders such as schizophrenia and Parkinson’s disease. The review explores the potential of utilizing plant-derived L-DOPA for therapeutic purposes, especially in the treatment of neurodegenerative diseases. The review also discusses metabolic engineering approaches designed to boost L-DOPA production in plants, encompassing both transgenic and non-transgenic methods. While the prospect of enhanced L-DOPA yield appears promising, the review highlights obstacles such as oxidative stress induced by elevated L-DOPA levels, alongside ethical considerations concerning genetic manipulation. This thorough review underscores the multifaceted role of dopamine across diverse biological domains and its capacity to establish a connection between botanical research and human health.