New Grower Melatonin

[Doad]

Just reading about melatonin being found in roots, stems, leaves, and buds. Anyone know if it would be beneficial to add to feeding, or a tea?

 

[namvet25]

Post the link ware you saw this.

 

[Eekman]

Are you talkiing about feeding your plants with it?

Or ingesting for your own sleep aid?

 

[Eyes on Fire]

Abstract
Melatonin (N-acetyl-5-methoxytryptamine), a well-known animal hormone, was discovered in plants in 1995 but very little research into it has been carried out since. It is present in different parts of all the plant species studied, including leaves, stems, roots, fruits and seeds. This brief review will attempt to provide an overview of melatonin (its discovery, presence and functions in different organisms, biosynthetic route, etc.) and to compile a practically complete bibliography on this compound in plants. The common biosynthetic pathways shared by the auxin, indole-3-acetic, and melatonin suggest a possible coordinated regulation in plants. More specifically, our knowledge to date of the role of melatonin in the vegetative and reproductive physiology of plants is presented in detail. The most interesting aspects for future physiological studies are presented.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2635004/


The de novo biosynthesis of IAA in plants has been extensively studied and two main pathways have been established, one tryptophan-dependent and the other tryptophan-independent.43–46 Figure 1 shows a schematic representation of the biosynthesis of IAA, in which the tryptophan-dependent pathway is depicted. In the other pathway, present in bacteria, fungi and plants, IAA is synthetized from chorismate, generating, indole-3-glycerol-phosphate, which is converted into tryptophan and IAA.

The tryptophan-dependent biosynthetic pathway of IAA is induced by many factors, including light, temperature, wounding and pathogen infection. In plants, tryptophan is converted to IAA through three possible routes: (a) the indole-3-acetaldoxime, (b) the indole-3-pyruvic acid and (c) the tryptamine pathways. This last appears as a loop, taking in indole-3-acetaldehyde as a common metabolite with the indole-3-pyruvic acid route. In the indole-3-acetaldoxime pathway, the intermediate indole-3-acetonitrile can be converted to IAA through the action of the enzyme nitrilase. This pathway (characteristic of Brassicaceae) is also fed from the indolic glucosinolate pool through the action of myrosinases. The indole-3-acetamide pathway (no picture in Fig. 1) has mainly been described in bacteria.

The biosynthetic pathway of melatonin has been clearly determined in mammals, including humans, and other groups (amphibian, reptilian, avian) (Fig. 1).4,6,47–53 Melatonin is synthetized from serotonin (5-hydroxy tryptamine) via an acetylation reaction catalyzed by arylalkylamine N-acetyltransferase, also called serotonin N-acetyltransferase (NAT) (EC 2.3.1.87), a regulated enzyme that controls melatonin biosynthesis. The last step is catalyzed by hydroxyindole O-methyltransferase (HIOMT) (EC 2.1.1.4). Serotonin is generated from 5-hydroxytryptophan in a reaction catalyzed by the aminoacid decarboxylase (EC 4.1.1.28). This enzyme also acts on tryptophan, giving rise to tryptamine. Tryptamine can be transformed into serotonin by the action of tryptophan 5-hydroxylase (EC 1.14.16.4), which can also act on tryptophan, forming 5-hydroxytryptophan. Tryptamine is also a substrate of NAT, forming N-acetyltryptamine, which can be hydroxylated to form N-acetylserotonin. All the enzymes shown have been isolated and characterized in animal tissues, but not in plant material. One exception is the enzyme tryptophan decarboxylase (Fig. 1), which has been studied in many plant species, according to InterPro, UniProt, IntEnz and Brenda databases. This pyridoxal-dependent decarboxylase is present in all the kingdoms, from bacteria to human, and has been related, in plants, with tryptamine formation (IAA biosynthesis) but not with the formation of serotonin. This enzyme has been characterized in Arabidopsis thaliana, Oryza sativa, Catharanthus roseus, Papaver somniferum and others. The other melatonin biosynthesis enzymes, tryptophan 5-hydroxylase, serotonin N-acetyltransferase and hydroxyindole O-methyltransferase (Fig. 1) do not appear to have been studied in plants according to the above mentioned databases. Obviously, the generic activities (hydroxylases, acetyltransferases, methyltransferases) have been extensively described in plants in diverse metabolic pathways, but never in relation with melatonin metabolism. The biosynthesis of melatonin and IAA presents some common precursors, such as tryptophan and tryptamine (see Fig. 1). As regards the routes, while the catalyzed steps to form IAA in plants have largely been elucidated by radioactive and biochemical assays, our knowledge on melatonin biosynthesis in plants is practically nil. In this respect, the work of Murch's group on melatonin biosynthesis in plants is unique.54,55 In this study, the radioactivity from 14C-tryptophan was recovered as 14C-indole-3-acetic acid, 14C-tryptamine, 14C- 5-hydroxytryptophan, 14C-serotonin and 14C-melatonin in 1 hour-treated in vitro Hypericum perforatum L. plants, showing the interrelation between melatonin and IAA metabolism. Also, some enzymological data on serotonin biosynthesis in walnut seeds have been published.56 Luckily, the investigations into melatonin in mammals and other groups are well advanced and much of the information can be applied to melatonin metabolism in plants.

An interesting aspect is the relation between structure and activity. Auxinic compounds such as IAA and phenylacetic acid, or other synthetic auxinic-plant growth regulators such as α-naphthalene acetic acid and 2,4-dichlorophenoxy acetic acid, present a strong negative charge on the carboxyl group of the side chain that is separated from a weaker positive charge on the ring structure by a distance of about 0.5 nm. This charge separation seems to be an essential structural requirement for auxin activity.57–61 In the case of melatonin, crystallographic data point to a distance between the indolic ring and the carbonyl group of ∼0.52 nm (Arnao MB, unpublished data). In 1994, Edgerton and colleagues62 proposed a set of molecular requirements for auxin activity based on studies of the capacity of distinct analogs of IAA to bind to auxin-binding protein-1 (ABP-1). Basically, there are three requirements: the existence of a planar aromatic ring, a carboxylic acid-binding site (electronegative charge region) and a hydrophobic transition region that separates the two binding sites. Melatonin seemingly fulfils these conditions (the carbonyl group may simulates the electronegative charge region), although specific experiments still need to be carried out to confirm this.

Go to:
Possible Physiological Functions of Melatonin in Plants
As mentioned above, the relation between melatonin and vascular plants has been studied almost exclusively from a phytochemical viewpoint. However, the limited number of papers published cover the approaches followed to discover a possible role for melatonin in plants. These approaches look at its role: (1) in reproductive development, including circadian rhythms; (2) in cell protection, and (3) in vegetative development. In this section we present the most relevant data for each. Table 1 shows some of the most relevant studies on melatonin in physiological processes, including the plant species, the technique used and the main objectives of the studies.

 

[namvet25]

So if i give my plants a melatonin tablet they will fall asleep.

 

[2Stoned2Care]

So if i give my plants a melatonin tablet they will fall asleep.

hahaha i was thinking the same thing my daughter takes melatonin to help her fall asleep as she has ADHD,i also take it for my insomnia

 

[pop22]

Very, very interesting, thank you!

Abstract
Melatonin (N-acetyl-5-methoxytryptamine), a well-known animal hormone, was discovered in plants in 1995 but very little research into it has been carried out since. It is present in different parts of all the plant species studied, including leaves, stems, roots, fruits and seeds. This brief review will attempt to provide an overview of melatonin (its discovery, presence and functions in different organisms, biosynthetic route, etc.) and to compile a practically complete bibliography on this compound in plants. The common biosynthetic pathways shared by the auxin, indole-3-acetic, and melatonin suggest a possible coordinated regulation in plants. More specifically, our knowledge to date of the role of melatonin in the vegetative and reproductive physiology of plants is presented in detail. The most interesting aspects for future physiological studies are presented.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2635004/


The de novo biosynthesis of IAA in plants has been extensively studied and two main pathways have been established, one tryptophan-dependent and the other tryptophan-independent.43–46 Figure 1 shows a schematic representation of the biosynthesis of IAA, in which the tryptophan-dependent pathway is depicted. In the other pathway, present in bacteria, fungi and plants, IAA is synthetized from chorismate, generating, indole-3-glycerol-phosphate, which is converted into tryptophan and IAA.

The tryptophan-dependent biosynthetic pathway of IAA is induced by many factors, including light, temperature, wounding and pathogen infection. In plants, tryptophan is converted to IAA through three possible routes: (a) the indole-3-acetaldoxime, (b) the indole-3-pyruvic acid and (c) the tryptamine pathways. This last appears as a loop, taking in indole-3-acetaldehyde as a common metabolite with the indole-3-pyruvic acid route. In the indole-3-acetaldoxime pathway, the intermediate indole-3-acetonitrile can be converted to IAA through the action of the enzyme nitrilase. This pathway (characteristic of Brassicaceae) is also fed from the indolic glucosinolate pool through the action of myrosinases. The indole-3-acetamide pathway (no picture in Fig. 1) has mainly been described in bacteria.

The biosynthetic pathway of melatonin has been clearly determined in mammals, including humans, and other groups (amphibian, reptilian, avian) (Fig. 1).4,6,47–53 Melatonin is synthetized from serotonin (5-hydroxy tryptamine) via an acetylation reaction catalyzed by arylalkylamine N-acetyltransferase, also called serotonin N-acetyltransferase (NAT) (EC 2.3.1.87), a regulated enzyme that controls melatonin biosynthesis. The last step is catalyzed by hydroxyindole O-methyltransferase (HIOMT) (EC 2.1.1.4). Serotonin is generated from 5-hydroxytryptophan in a reaction catalyzed by the aminoacid decarboxylase (EC 4.1.1.28). This enzyme also acts on tryptophan, giving rise to tryptamine. Tryptamine can be transformed into serotonin by the action of tryptophan 5-hydroxylase (EC 1.14.16.4), which can also act on tryptophan, forming 5-hydroxytryptophan. Tryptamine is also a substrate of NAT, forming N-acetyltryptamine, which can be hydroxylated to form N-acetylserotonin. All the enzymes shown have been isolated and characterized in animal tissues, but not in plant material. One exception is the enzyme tryptophan decarboxylase (Fig. 1), which has been studied in many plant species, according to InterPro, UniProt, IntEnz and Brenda databases. This pyridoxal-dependent decarboxylase is present in all the kingdoms, from bacteria to human, and has been related, in plants, with tryptamine formation (IAA biosynthesis) but not with the formation of serotonin. This enzyme has been characterized in Arabidopsis thaliana, Oryza sativa, Catharanthus roseus, Papaver somniferum and others. The other melatonin biosynthesis enzymes, tryptophan 5-hydroxylase, serotonin N-acetyltransferase and hydroxyindole O-methyltransferase (Fig. 1) do not appear to have been studied in plants according to the above mentioned databases. Obviously, the generic activities (hydroxylases, acetyltransferases, methyltransferases) have been extensively described in plants in diverse metabolic pathways, but never in relation with melatonin metabolism. The biosynthesis of melatonin and IAA presents some common precursors, such as tryptophan and tryptamine (see Fig. 1). As regards the routes, while the catalyzed steps to form IAA in plants have largely been elucidated by radioactive and biochemical assays, our knowledge on melatonin biosynthesis in plants is practically nil. In this respect, the work of Murch's group on melatonin biosynthesis in plants is unique.54,55 In this study, the radioactivity from 14C-tryptophan was recovered as 14C-indole-3-acetic acid, 14C-tryptamine, 14C- 5-hydroxytryptophan, 14C-serotonin and 14C-melatonin in 1 hour-treated in vitro Hypericum perforatum L. plants, showing the interrelation between melatonin and IAA metabolism. Also, some enzymological data on serotonin biosynthesis in walnut seeds have been published.56 Luckily, the investigations into melatonin in mammals and other groups are well advanced and much of the information can be applied to melatonin metabolism in plants.

An interesting aspect is the relation between structure and activity. Auxinic compounds such as IAA and phenylacetic acid, or other synthetic auxinic-plant growth regulators such as α-naphthalene acetic acid and 2,4-dichlorophenoxy acetic acid, present a strong negative charge on the carboxyl group of the side chain that is separated from a weaker positive charge on the ring structure by a distance of about 0.5 nm. This charge separation seems to be an essential structural requirement for auxin activity.57–61 In the case of melatonin, crystallographic data point to a distance between the indolic ring and the carbonyl group of ∼0.52 nm (Arnao MB, unpublished data). In 1994, Edgerton and colleagues62 proposed a set of molecular requirements for auxin activity based on studies of the capacity of distinct analogs of IAA to bind to auxin-binding protein-1 (ABP-1). Basically, there are three requirements: the existence of a planar aromatic ring, a carboxylic acid-binding site (electronegative charge region) and a hydrophobic transition region that separates the two binding sites. Melatonin seemingly fulfils these conditions (the carbonyl group may simulates the electronegative charge region), although specific experiments still need to be carried out to confirm this.

Go to:
Possible Physiological Functions of Melatonin in Plants
As mentioned above, the relation between melatonin and vascular plants has been studied almost exclusively from a phytochemical viewpoint. However, the limited number of papers published cover the approaches followed to discover a possible role for melatonin in plants. These approaches look at its role: (1) in reproductive development, including circadian rhythms; (2) in cell protection, and (3) in vegetative development. In this section we present the most relevant data for each. Table 1 shows some of the most relevant studies on melatonin in physiological processes, including the plant species, the technique used and the main objectives of the studies.

 

[Eyes on Fire]

Your welcome