New insights on neurotransmitters signaling mechanisms in plants

Abstract

Neurotransmitters (NTs) such as acetylcholine, biogenic amines (dopamine, noradrenaline, adrenaline, histamine), indoleamines [(melatonin (MEL) & serotonin (SER)] have been found not only in mammalians, but also in diverse living organisms-microorganisms to plants. These NTs have emerged as potential signaling molecules in the last decade of investigations in various plant systems. NTs have been found to play important roles in plant life including-organogenesis, flowering, ion permeability, photosynthesis, circadian rhythm, reproduction, fruit ripening, photomorphogenesis, adaptation to environmental changes. This review will provide an overview of recent advancements on the physiological and molecular mechanism of NTs in plants. Moreover, molecular crosstalk of SER and MEL with various biomolecules is also discussed. The study of these NTs may serve as new understanding of the mechanisms of signal transmission and cell sensing in plants subjected to various environmental stimulus.

Impact of Biogenic Amines on the Growth of Green Microalgae

“…In the literature, there is evidence that many algal species, including a number of representatives of Chlorophyta, Charophyta, Ochrophyta, and Rhodophyta, synthesize large quantities of such neuroactive amines as dopamine, serotonin, histamine, tyramine, and acetylcholine [11][12]. For instance, histamine accumulates up to concentrations of 60-500 mg/g of biomass in the red alga Claviceps purpurea [13].…”

“…High dopamine concentrations are also released by such macroalgae as Ulvaria. In the literature, evidence has been presented that Ulvaria-produced dopamine functions as an antimicrobial agent and as a kairomone, i.e., a protective substance preventing the consumption of Ulvaria by sea urchins, gastropods, and arthropods [13,15,16]. Presumably, the data reported in this work enable us to consider dopamine and plausibly other neurochemicals from a new perspective: these neuroactive substances are likely to function as growth-stimulating agents for microalgae in the natural ecosystems of ponds, lakes, and other water bodies.…”

“…Interestingly, not only Ulvaria but also other macroalgae, e.g., Nitella flexilis and Chara vulgaris, and also higher plats growing on the water surface such as the duckweed (Lemna minor) produce biogenic amines and release them into the environment [13,17] Submicromolar or micromolar concentrations of dopamine, norepinephrine, and serotonin are produced by a number of coastal plant species exemplified by tropical trees and shrubs growing around lakes and ponds in southern China (e.g., in Shenzhen [4]). Generally speaking, many higher plants both contain neurochemicals and respond to them [18,19].…”

“…The chromatographer was calibrated using a mixture of the tested biogenic amines; the concentrations of all these substances were 0.5 µM. The amine concentrations contained in the samples were calculated by the internal standard method that is based on determining the ratio between the peak area in the standard mixture and that in the samples [13].…”

Inter-Kingdom Signaling of Stress Hormones: Sensing, Transport and Modulation of Bacterial Physiology

“…This is caused by discharge from synaptic vesicles at noradrenergic nerve endings. Catecholamines (dopamine, norepinephrine, and epinephrine) are found throughout the plant and animal kingdoms (Akula and Mukherjee, 2020). In mammals, they can stimulate lipolysis and glycogenolysis and mobilize energy more rapidly than cortisol, as the latter's activity requires transcription of genes.…”