Melatonin Function under Normal and Stressful Conditions: History
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Contributor:
Murtaza Khan
,
Sajid Ali
,
Hakim Manghwar
,
Saddam Saqib
,
Fazal Ullah
,
Asma Ayaz
,
Wajid Zaman

Plants are exposed to a variety of environmental stresses (biotic and abiotic) during the course of development. Stressful conditions alter the basic metabolism of the affected plants. Plants must cope with environmental constraints to effectively complete their life cycle. Plant produce and regulate various biomolecules to adapt to adverse environmental conditions. Melatonin (N-acetyl-5-methoxytryptamine) is a ubiquitous molecule that is present in plants, animals, and microorganisms. It has been revealed as an indolic chemical compound with structural similarities with other vital compounds such as tryptophan, serotonin, and indole-3-acetic acid (IAA). In plants, melatonin is a putative hormone involved in the regulation of plant growth and productivity, even under biotic and abiotic stress conditions.

  • melatonin
  • phytohormone
  • biotic stress
  • abiotic stress
  • plant growth

1. Introduction

The discovery of melatonin in plants paved the way for its understanding and revealed that melatonin is a common and multipurpose metabolite in the plant world. It is found in almost all parts of the plants, including the leaves, stems, roots, flowers, fruits, and seeds of numerous plants [1]. It is involved in the regulation of plant growth, leaf development, root organogenesis, fruit maturation, and senescence [2]. Furthermore, it significantly contributes to the responses of plants to environmental stresses including heat, salinity, drought, oxidative stress, and ultraviolet-B (UV-B) radiation [3].
In plants, melatonin production can be induced by a variety of conditions, including light, temperature extremes, and UV-B radiation [3]. Tryptophan serves as the precursor for the production of melatonin in a variety of plants. Tryptophan decarboxylase (TDC) catalyzes its conversion to tryptamine, which is then turned to serotonin by the enzyme tryptamine 5-hydroxylase (T5H) [4]. Serotonin N-acetyltransferase (SNAT)/arylalkyl amine N-acetyltransferase (AANAT) converts serotonin into N-acetyl serotonin. N-acetyl serotonin is converted into melatonin by the action of N-acetyl-serotonin methyltransferase (ASMT)/hydroxyindole-O-methyltransferase (HIOMT). In addition, SNAT can catalyze the conversion of tryptamine into N-acetyl-tryptamine (Figure 1). However, T5H cannot convert it into N-acetyl-serotonin. Whether there is a mechanism for turning N-acetyl-tryptamine into N-acetyl-serotonin is unclear. The second pathway involves the enzyme HIOMT, which changes serotonin into 5-methoxy-tryptamine, and the enzyme SNAT, which transfers 5-methoxy-tryptamine into melatonin [5]. Furthermore, in the reverse melatonin pathway, N-acetyl-serotonin deacetylase converts N-acetyl-serotonin into serotonin [6]. Additionally, tryptophan is a precursor for both melatonin and IAA, which indicates that melatonin has several functions in plants.
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Figure 1. Schematic pathway of melatonin expression. This figure was created with BioRender.com (accessed on 15 September 2022).

2. Role of Melatonin in Plant Growth and Development

Several phytohormones, mainly auxin, play a crucial role in the growth and development of plants. Melatonin and indole acetic acid share the same precursor, tryptophan, making them both types of indoleamines. As such, melatonin should be involved in the control of plant growth and development (Figure 2). Previous results indicated that melatonin regulates the plant’s circadian rhythms in the Chenopodium rubrum [7]. Furthermore, in Chenopodium rubrum, melatonin’s application also affected the development of flowers in the early stage of the photoperiod [8]. After being treated with melatonin, the soybean plant’s leaf size, plant height, pod size, and production of seeds all dramatically increased, indicating that the application of melatonin may enhance the soybean plant’s growth and seed production [9]. Melatonin’s shielding effect in the senescence process of plants was shown by the fact that it reduced the breakdown of chlorophyll in the leaves of barley plants [10]. Melatonin could encourage the growth of etiolated cotyledons in Lupinus albus, which is similar to how IAA works [11].
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Figure 2. Role of melatonin in plant growth and development. This figure was created with BioRender.com (accessed on 7 September 2022).
Additionally, melatonin’s effects on plants vary depending on its concentration. Low melatonin concentrations (10–20 µM) exhibited no discernible impact on root length in Arabidopsis seedlings. On the other hand, fresh weight at high melatonin content (200–400 µM) was greatly suppressed, and the ideal melatonin level for promoting plant growth and development was 40 µM [12].

3. Role of Melatonin under Abiotic Stress

Throughout their existence, plants are subject to a variety of environmental pressures. Plants, which are sessile organisms, have developed a variety of coping mechanisms to deal with challenging situations, maintaining their survival and ability to reproduce [13][14]. Melatonin is a universal abiotic stress regulator in plants [15]. Exogenously applied melatonin increases plant tolerance against abiotic stresses, including drought, waterlogging, extreme temperatures, salinity, and heavy metals toxicity, by modifying the production of endogenous melatonin and antioxidant systems [16] (Figure 3).
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Figure 3. Role of melatonin under abiotic stress. This figure was created with BioRender.com (accessed on 7 September 2022).

3.1. Role of Melatonin under Water Stress

Drought stress dramatically reduces plant growth and development [17]. The morphological, physiological, biochemical, and molecular properties of plants are altered by drought stress, which poses a major threat to agricultural productivity and quality [18]. Under abiotic stress, endogenous melatonin levels are increased [19]. The Arabidopsis plant’s ability to withstand drought was significantly improved by the overexpression of the melatonin production gene, MzASMT1 [20]. Thus, exogenous melatonin could be used to alleviate abiotic stresses. For example, melatonin application improved drought tolerance in drought-sensitive and drought-resistant species of apple plants [21]. Similarly, melatonin supplementation reduced the adverse effects of drought stress on the photosynthetic and antioxidant systems of grapes [22].
Waterlogging adversely affects plant growth and development. This process substantially restricts gas diffusion, causing hypoxic stress brought on by anaerobic respiration in the roots and encouraging the buildup of reactive oxygen species (ROS) [23]. Melatonin takes a role in the control of plant reactions to waterlogging. In plants, in response to waterlogging stress conditions, the transcript accumulation of the genes involved in melatonin is dramatically increased [24]. Under waterlogging conditions, exogenously applied melatonin significantly increased seedling viability in apples [25]. Furthermore, melatonin was found to be able to improve cucumber and Prunus persica resistance to waterlogging by stimulating root development, increasing antioxidant enzyme activity, and improving photosynthetic efficiency [25].

3.2. Role of Melatonin under Extreme Temperature

Cold stress adversely affects plant growth and survival. It may cause an excessive ROS buildup and redox imbalance. Melatonin tends to accumulate in extreme cold conditions to shield plants from deadly injuries. For instance, melatonin plays a protective role in plants’ ability to withstand low temperatures, as shown by SNAT transgenic rice, which is less sensitive to cold than wild-type plants [26]. Exogenously applied melatonin may improve the cold and drought tolerance of tobacco, tomato, and cucumber [27]. The application of melatonin significantly enhanced the germination rate of cucumber seeds from 4% to 83% at 10 °C [28]. Wheat seedlings supplemented with melatonin showed increased levels of osmoprotectants and antioxidant enzyme activity, indicating that melatonin may increase the plant’s ability to withstand low temperatures by scavenging ROS and regulating redox equilibrium [29]. Exogenously applied melatonin can sustain the quality of fruits, vegetables, and cut flowers by conferring chilling tolerance. For instance, pre-treating loquat fruit with melatonin before storage causes a buildup of phenolic chemicals and a decrease in lignin, relieving taste and nutrient loss brought on by chilling damage when exposed to cold storage [30].
Heat stress also adversely affects the growth and survival of plants and is becoming a worldwide concern because of global warming. Heat stress adversely affects the physical, biochemical, and molecular properties of the plants [31]. Additionally, by raising endogenous melatonin, ASMT and SNAT overexpression dramatically enhances thermotolerance [32]. Melatonin concentration was significantly enhanced when the plants were challenged by heat stress [33]. Thus, melatonin treatment might improve the plant’s resistance to heat stress. Exogenously applied melatonin dramatically improved the germination percentage of Arabidopsis thaliana [34]. Melatonin therapy increased heat stress tolerance in tomato seedlings by maintaining redox homeostasis while regulating polyamine and nitric oxide production [35]. Melatonin treatment improved the production of SA and lowered the concentration of ABA in soybean seedlings to decrease fatal heat-induced injuries [36].

3.3. Role of Melatonin under Salt Stress

Salt stress has emerged as a serious global issue, restricting agricultural output and causing significant economic losses globally [37]. Melatonin has reportedly been linked to an increase in plants’ resistance to salt stress in recent years. Melatonin treatment increased salt tolerance in several plants, including barley, wheat, cucumbers, soybeans, bermudagrass, and apples [38]. Similarly, in cucumber plants, the adverse effects of salt stress on the root system were significantly reduced via the application of melatonin [39]. Furthermore, melatonin treatment increased salt tolerance and regulated transcript accumulation of the genes related to salt stress [9]. Melatonin application also increased the expression of the genes related to the production and catabolism of abscisic acid (ABA) and gibberellic acid (GA) in cucumber plants during salt-induced stress [40].

3.4. Role of Melatonin under Heavy Metal Stress

Pollution from heavy metals (HMs) poses a major threat to all types of living things, notably to plants [41][42]. HMs application, including cadmium, lead, and zinc, significantly increased the production of endogenous melatonin in algae, and exogenous melatonin application improved the algae’s ability to withstand cadmium stress [33][43]. Furthermore, exogenous melatonin application dramatically induced the tolerance of the plants to HMs stress [35]. For example, exogenously applied melatonin substantially reduced the toxicity caused by cadmium in tomatoes [44]. Melatonin and nitrogen oxide interaction enhanced Pb and Cd stress tolerance [38]. Melatonin treatments at concentrations of 1 and 10 µM boosted seed germination and seedling growth when exposed to copper stress, whereas the application of 100 µM melatonin showed opposite effects and increased copper’s harmful effects [45].
Melatonin controls antioxidant levels as well as the uptake and sequestration of heavy metals, which helps to modulate the tolerance to heavy metals. For example, vanadium was excluded or sequestered from the plants via melatonin application [46].

3.5. Role of Melatonin under Light-Induced Stress

Plants are harmed by light-induced oxidative bursts. In plants, UV radiation can cause the production of free radicals [47]. After exposure to UV-B light for a brief period, endogenous melatonin concentration was shown to increase in plants, indicating that it plays a role in the UV-B response [48]. Under UV-B exposure, exogenous melatonin increased the number of isoflavone monomers in 4-day-old germinated soybeans [49]. In Arabidopsis, melatonin application induced UV-B tolerance [50].

4. Role of Melatonin in Biotic Stress

To combat biotic stressors, plants often have a highly developed immune system. First, physical barriers to plants, including waxes, thick cuticles, and unique trichomes, prevent pathogens or insects from adhering to them [51][52][53]. Plants have two pathways that they can use to recognize pathogens and launch defense mechanisms. The first one is the pattern recognition receptors (PRRs), which recognize pathogen-associated molecular patterns (PAMPs) such as flagellin to induce PAMP-triggered immunity (PTI) [54]. Plant resistance (R) proteins, the second route of the immune system, detect the specific effectors of pests or pathogens (avirulent proteins) and trigger the plant defense response through a mechanism known as effector-triggered immunity (ETI) [54][55]. ETI induces a hypersensitive response (HR), an intentional cell suicide of the infected cells [54]. A number of plant hormones, including ethylene (ET), jasmonic acid (JA), and salicylic acid, are particularly prominent in the signaling pathways induced by PTI and ETI (SA). Plants frequently induce the ET and JA pathways in response to chewing insects and necrotrophic infections, but the SA mechanism enhances resistant protection against hemi-biotrophic and biotrophic pathogens [54][56]. The first is known as systemic acquired resistance (SAR), which becomes active during primary infection with a necrotizing pathogen and is associated with rising concentrations of SA and related pathogenesis proteins [54]. The second type of plant resistance is induced systemic resistance (ISR), which is triggered by particular strains of nonpathogenic root-colonizing bacteria and requires JA and ET for signaling [51][57]. By identifying the conserved herbivore-associated elicitors of the invading insect, phytophagous insects force plants to exhale volatiles to attract their foes and warn their neighbor plants of impending hazards [58][59].
Melatonin may be a cost-effective alternative method to induce plant protection against biotic stress because it is an eco-friendly chemical (Figure 4). Animal studies have shown that melatonin possesses immunomodulatory, antioxidant, anti-inflammatory, and neuroprotective properties [60], making it a potential therapeutic alternative for the treatment of microbial illnesses. Similarly, several significant discoveries have recently demonstrated the positive role that melatonin plays in plant–pathogen interactions. In this context, extra pertinent information is covered in-depth in the following subsections.
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Figure 4. Role of melatonin in biotic stress. This figure was created with BioRender.com (accessed on 7 September 2022).

4.1. Antiviral Effects of Melatonin

Melatonin’s antiviral activity in animals has been proven in numerous studies. In comparison with infected control mice, melatonin therapy drastically reduced blood and brain viruses [61]. Similarly, mice infected with the influenza virus survived longer when given melatonin along with the antiviral medication ribavirin [62]. Melatonin’s great antioxidation efficacy and capacity to reduce endoplasmic reticulum stress make it a candidate in this situation for regulating the autophagy process during various viral infections [63][64][65]. Few researchers have examined the antiviral properties of melatonin in plants up until this point. Tobacco mosaic virus (TMV) viral RNA and virus concentration were reduced in infected Nicotiana glutinosa and Solanum lycopersicum seedlings after treatment with exogenous melatonin. The rise in SA concentrations in the NO-dependent pathway was thought to be the cause of melatonin’s beneficial effects [66]. Additionally, the apple stem grooving virus (ASGV) of "Gala" apple shoots that had been infected in vitro was successfully destroyed by melatonin, suggesting that it may be possible to grow plants devoid of viruses [67].

4.2. Antibacterial Effects of Melatonin

Both in vitro and in vivo studies have been conducted to examine the defense mechanisms of melatonin against bacterial infections in animals. Melatonin’s ability to kill bacteria that are resistant to many drugs, including carbapenem-resistant Pseudomonas aeruginosa, Acinetobacter baumannii, and methicillin-resistant Staphylococcus aureus, has been demonstrated in vitro [68]. Melatonin application also showed a strong inhibitory action against Mycobacterium TB (H37Rv strain) [51]. Melatonin has demonstrated efficient antibacterial activity against phytobacterial pathogens in plant–bacteria interactions. One study found that melatonin application reduced the occurrence of a bacterial leaf streak (BLS) in rice [69].
Melatonin, along with nitric oxide, increased the transcript accumulation of SA pathway-related genes [70]. Additionally, in Pseudomonas syringae pathovar tomato (Pst)-DC3000-infected Arabidopsis thaliana, melatonin can trigger MAPK cascades to induce SA production [71]. Transcriptomic data have recently shown that melatonin application triggers ETI- and PTI-associated genes in watermelon and Arabidopsis [72]. 

4.3. Antifungal Effects of Melatonin

Melatonin was shown to have therapeutic advantages in animal models of Candida sepsis and conventional antimycotic therapy, where it could reduce interleukin-6 concentrations and shorten the amount of time needed for recovery from Candida sepsis in rats [73]. Melatonin promoted tomato fruit resistance to Botrytis cinerea by controlling the production of H2O2 and the jasmonic acid signaling pathway [74]. In watermelon and other cucurbits, a rise in melatonin accumulation in plants increases resistance to foliar diseases, such as powdery mildew and soil-borne oomycetes, through alterations in the transcript accumulation of the genes linked to PTI and ETI [72]. The prevalence of Plasmodiophora brassicae infection of A. thaliana and the number of pathogen sporangia decreased following melatonin treatment. This decrease was ascribed to the high expression of the JA-responsive PR3 and PR4 genes [51].
Melatonin and ethylicin, an oomycete antifungal, work synergistically to prevent the growth of Phytophthora nicotianae in vitro and in vivo by disrupting the fungus’ amino acid metabolic homeostasis [75]. Melatonin is exogenously applied to replant soil to promote apple seedling growth, boost potassium levels, and induce photosynthesis, all of which alleviate replant disease [76]. Other fungi, such as Botrytis spp., Penicillium spp., Fusarium spp., P. nicotianae, and Alternaria spp., also showed similar results [51]. Additionally, several studies have examined the function of endophytic rhizobacteria in enhancing plants’ capacity to synthesize melatonin [77]. A number of different theories have explained melatonin’s preventive function against plant fungal infections. For example, some scientists have suggested that melatonin’s defense mechanism involves its capacity to maintain H2O2 cellular concentrations and the production and control of antioxidant enzyme activities [78].
Transcriptomic data have recently shown that exogenous melatonin administration activates PTI- and ETI-related genes in watermelon and A. thaliana [72]. Additionally, melatonin is essential for controlling the levels of ROS and reactive nitrogen species (RNS) in plants, which are signals for numerous cellular and physiological responses to biotic and abiotic stresses. These responses can be triggered directly by ROS/RNS scavengers or indirectly by genes that control the redox network [79].

This entry is adapted from the peer-reviewed paper 10.3390/genes13101699

References

  1. Fan, J.; Xie, Y.; Zhang, Z.; Chen, L. Melatonin: A multifunctional factor in plants. Int. J. Mol. Sci. 2018, 19, 1528.
  2. Arnao, M.B.; Hernández-Ruiz, J. Melatonin: A new plant hormone and/or a plant master regulator? Trends Plant Sci. 2019, 24, 38–48.
  3. Zeng, W.; Mostafa, S.; Lu, Z.; Jin, B. Melatonin-mediated abiotic stress tolerance in plants. Front. Plant Sci. 2022, 13, 847175.
  4. Posmyk, M.M.; Janas, K.M. Melatonin in plants. Acta Physiol. Plant. 2009, 31, 1.
  5. Choi, G.H.; Lee, H.Y.; Back, K. Chloroplast overexpression of rice caffeic acid O-methyltransferase increases melatonin production in chloroplasts via the 5-methoxytryptamine pathway in transgenic rice plants. J. Pineal Res. 2017, 63, e12412.
  6. Lee, K.; Lee, H.Y.; Back, K. Rice histone deacetylase 10 and Arabidopsis histone deacetylase 14 genes encode N-acetylserotonin deacetylase, which catalyzes conversion of N-acetylserotonin into serotonin, a reverse reaction for melatonin biosynthesis in plants. J. Pineal Res. 2018, 64, e12460.
  7. Kolář, J.; Macháčková, I.; Eder, J.; Prinsen, E.; Van Dongen, W.; Van Onckelen, H.; Illnerová, H. Melatonin: Occurrence and daily rhythm in Chenopodium rubrum. Phytochemistry 1997, 44, 1407–1413.
  8. Kolář, J.; Johnson, C.H.; Macháčková, I. Exogenously applied melatonin (N-acetyl-5-methoxytryptamine) affects flowering of the short-day plant Chenopodium rubrum. Physiol. Plant. 2003, 118, 605–612.
  9. Wei, W.; Li, Q.-T.; Chu, Y.-N.; Reiter, R.J.; Yu, X.-M.; Zhu, D.-H.; Zhang, W.-K.; Ma, B.; Lin, Q.; Zhang, J.-S. Melatonin enhances plant growth and abiotic stress tolerance in soybean plants. J. Exp. Bot. 2015, 66, 695–707.
  10. Arnao, M.B.; Hernández-Ruiz, J. Protective effect of melatonin against chlorophyll degradation during the senescence of barley leaves. J. Pineal Res. 2009, 46, 58–63.
  11. Wen, D.; Gong, B.; Sun, S.; Liu, S.; Wang, X.; Wei, M.; Yang, F.; Li, Y.; Shi, Q. Promoting roles of melatonin in adventitious root development of Solanum lycopersicum L. by regulating auxin and nitric oxide signaling. Front. Plant Sci. 2016, 7, 718.
  12. Bajwa, V.S.; Shukla, M.R.; Sherif, S.M.; Murch, S.J.; Saxena, P.K. Role of melatonin in alleviating cold stress in Arabidopsis thaliana. J. Pineal Res. 2014, 56, 238–245.
  13. Saqib, S.; Zaman, W.; Ayaz, A.; Habib, S.; Bahadur, S.; Hussain, S.; Muhammad, S.; Ullah, F. Postharvest disease inhibition in fruit by synthesis and characterization of chitosan iron oxide nanoparticles. Biocatal. Agric. Biotechnol. 2020, 28, 101729.
  14. Ayaz, A.; Saqib, S.; Huang, H.; Zaman, W.; Lü, S.; Zhao, H. Genome-wide comparative analysis of long-chain acyl-CoA synthetases (LACSs) gene family: A focus on identification, evolution and expression profiling related to lipid synthesis. Plant Physiol. Biochem. 2021, 161, 1–11.
  15. Wang, Y.; Reiter, R.J.; Chan, Z. Phytomelatonin: A universal abiotic stress regulator. J. Exp. Bot. 2018, 69, 963–974.
  16. Sun, C.; Liu, L.; Wang, L.; Li, B.; Jin, C.; Lin, X. Melatonin: A master regulator of plant development and stress responses. J. Integr. Plant Biol. 2021, 63, 126–145.
  17. Al Azzawi, T.N.I.; Khan, M.; Hussain, A.; Shahid, M.; Imran, Q.M.; Mun, B.-G.; Lee, S.-U.; Yun, B.-W. Evaluation of Iraqi rice cultivars for their tolerance to drought stress. Agronomy 2020, 10, 1782.
  18. Rolly, N.K.; Imran, Q.M.; Shahid, M.; Imran, M.; Khan, M.; Lee, S.-U.; Hussain, A.; Lee, I.-J.; Yun, B.-W. Drought-induced AtbZIP62 transcription factor regulates drought stress response in Arabidopsis. Plant Physiol. Biochem. 2020, 156, 384–395.
  19. Shi, H.; Jiang, C.; Ye, T.; Tan, D.-X.; Reiter, R.J.; Zhang, H.; Liu, R.; Chan, Z. Comparative physiological, metabolomic, and transcriptomic analyses reveal mechanisms of improved abiotic stress resistance in bermudagrass by exogenous melatonin. J. Exp. Bot. 2015, 66, 681–694.
  20. Zuo, B.; Zheng, X.; He, P.; Wang, L.; Lei, Q.; Feng, C.; Zhou, J.; Li, Q.; Han, Z.; Kong, J. Overexpression of MzASMT improves melatonin production and enhances drought tolerance in transgenic Arabidopsis thaliana plants. J. Pineal Res. 2014, 57, 408–417.
  21. Wang, P.; Sun, X.; Li, C.; Wei, Z.; Liang, D.; Ma, F. Long-term exogenous application of melatonin delays drought-induced leaf senescence in apple. J. Pineal Res. 2013, 54, 292–302.
  22. Meng, J.F.; Xu, T.F.; Wang, Z.Z.; Fang, Y.L.; Xi, Z.M.; Zhang, Z.W. The ameliorative effects of exogenous melatonin on grape cuttings under water-deficient stress: Antioxidant metabolites, leaf anatomy, and chloroplast morphology. J. Pineal Res. 2014, 57, 200–212.
  23. Wu, Q.; Su, N.; Huang, X.; Cui, J.; Shabala, L.; Zhou, M.; Yu, M.; Shabala, S. Hypoxia-induced increase in GABA content is essential for restoration of membrane potential and preventing ROS-induced disturbance to ion homeostasis. Plant Commun. 2021, 2, 100188.
  24. Moustafa-Farag, M.; Mahmoud, A.; Arnao, M.B.; Sheteiwy, M.S.; Dafea, M.; Soltan, M.; Elkelish, A.; Hasanuzzaman, M.; Ai, S. Melatonin-induced water stress tolerance in plants: Recent advances. Antioxidants 2020, 9, 809.
  25. Gu, X.; Xue, L.; Lu, L.; Xiao, J.; Song, G.; Xie, M.; Zhang, H. Melatonin enhances the waterlogging tolerance of Prunus persica by modulating antioxidant metabolism and anaerobic respiration. J. Plant Growth Regul. 2021, 40, 2178–2190.
  26. Kang, K.; Lee, K.; Park, S.; Kim, Y.S.; Back, K. Enhanced production of melatonin by ectopic overexpression of human serotonin N-acetyltransferase plays a role in cold resistance in transgenic rice seedlings. J. Pineal Res. 2010, 49, 176–182.
  27. Lee, H.-J.; Back, K. 2-Hydroxymelatonin confers tolerance against combined cold and drought stress in tobacco, tomato, and cucumber as a potent anti-stress compound in the evolution of land plants. Melatonin Res. 2019, 2, 35–46.
  28. Posmyk, M.M.; Bałabusta, M.; Wieczorek, M.; Sliwinska, E.; Janas, K.M. Melatonin applied to cucumber (Cucumis sativus L.) seeds improves germination during chilling stress. J. Pineal Res. 2009, 46, 214–223.
  29. Turk, H.; Erdal, S.; Genisel, M.; Atici, O.; Demir, Y.; Yanmis, D. The regulatory effect of melatonin on physiological, biochemical and molecular parameters in cold-stressed wheat seedlings. Plant Growth Regul. 2014, 74, 139–152.
  30. Wang, D.; Chen, Q.; Chen, W.; Guo, Q.; Xia, Y.; Wu, D.; Jing, D.; Liang, G. Melatonin treatment maintains quality and delays lignification in loquat fruit during cold storage. Sci. Hortic. 2021, 284, 110126.
  31. Zhao, J.; Lu, Z.; Wang, L.; Jin, B. Plant responses to heat stress: Physiology, transcription, noncoding RNAs, and epigenetics. Int. J. Mol. Sci. 2020, 22, 117.
  32. Wang, X.; Zhang, H.; Xie, Q.; Liu, Y.; Lv, H.; Bai, R.; Ma, R.; Li, X.; Zhang, X.; Guo, Y.-D. SlSNAT interacts with HSP40, a molecular chaperone, to regulate melatonin biosynthesis and promote thermotolerance in tomato. Plant Cell Physiol. 2020, 61, 909–921.
  33. Tal, O.; Haim, A.; Harel, O.; Gerchman, Y. Melatonin as an antioxidant and its semi-lunar rhythm in green macroalga Ulva sp. J. Exp. Bot. 2011, 62, 1903–1910.
  34. Hernández, I.G.; Gomez, F.J.V.; Cerutti, S.; Arana, M.V.; Silva, M.F. Melatonin in Arabidopsis thaliana acts as plant growth regulator at low concentrations and preserves seed viability at high concentrations. Plant Physiol. Biochem. 2015, 94, 191–196.
  35. Jahan, M.S.; Guo, S.; Baloch, A.R.; Sun, J.; Shu, S.; Wang, Y.; Ahammed, G.J.; Kabir, K.; Roy, R. Melatonin alleviates nickel phytotoxicity by improving photosynthesis, secondary metabolism and oxidative stress tolerance in tomato seedlings. Ecotoxicol. Environ. Saf. 2020, 197, 110593.
  36. Imran, M.; Shazad, R.; Bilal, S.; Imran, Q.M.; Khan, M.; Kang, S.-M.; Khan, A.L.; Yun, B.-W.; Lee, I.-J. Exogenous Melatonin mediates the regulation of endogenous nitric oxide in Glycine max L. to reduce effects of drought stress. Environ. Exp. Bot. 2021, 188, 104511.
  37. Su, J.; Yang, X.; Shao, Y.; Chen, Z.; Shen, W. Molecular hydrogen–induced salinity tolerance requires melatonin signalling in Arabidopsis thaliana. Plant Cell Environ. 2021, 44, 476–490.
  38. Nawaz, K.; Chaudhary, R.; Sarwar, A.; Ahmad, B.; Gul, A.; Hano, C.; Abbasi, B.H.; Anjum, S. Melatonin as master regulator in plant growth, development and stress alleviator for sustainable agricultural production: Current status and future perspectives. Sustainability 2020, 13, 294.
  39. Zhang, N.; Zhang, H.J.; Zhao, B.; Sun, Q.Q.; Cao, Y.Y.; Li, R.; Wu, X.X.; Weeda, S.; Li, L.; Ren, S. The RNA-seq approach to discriminate gene expression profiles in response to melatonin on cucumber lateral root formation. J. Pineal Res. 2014, 56, 39–50.
  40. Zhang, H.J.; Zhang, N.A.; Yang, R.C.; Wang, L.; Sun, Q.Q.; Li, D.B.; Cao, Y.Y.; Weeda, S.; Zhao, B.; Ren, S. Melatonin promotes seed germination under high salinity by regulating antioxidant systems, ABA and GA 4 interaction in cucumber (Cucumis sativus L.). J. Pineal Res. 2014, 57, 269–279.
  41. Khan, M.; Rolly, N.K.; Al Azzawi, T.N.I.; Imran, M.; Mun, B.-G.; Lee, I.-J.; Yun, B.-W.J.A. Lead (Pb)-Induced Oxidative Stress Alters the Morphological and Physio-Biochemical Properties of Rice (Oryza sativa L.). Agronomy 2021, 11, 409.
  42. Khan, M.; Al Azzawi, T.N.I.; Imran, M.; Hussain, A.; Mun, B.-G.; Pande, A.; Yun, B.-W. Effects of lead (Pb)-induced oxidative stress on morphological and physio-biochemical properties of rice. Biocell 2021, 45, 1413.
  43. Kamal, A.; Haroon, U.; Manghwar, H.; Alamer, K.H.; Alsudays, I.M.; Althobaiti, A.T.; Iqbal, A.; Akbar, M.; Anar, M.; Nazish, M. Biological Applications of Ball-Milled Synthesized Biochar-Zinc Oxide Nanocomposite Using Zea mays L. Molecules 2022, 27, 5333.
  44. Hasan, M.K.; Ahammed, G.J.; Yin, L.; Shi, K.; Xia, X.; Zhou, Y.; Yu, J.; Zhou, J. Melatonin mitigates cadmium phytotoxicity through modulation of phytochelatins biosynthesis, vacuolar sequestration, and antioxidant potential in Solanum lycopersicum L. Front. Plant Sci. 2015, 6, 601.
  45. Posmyk, M.M.; Kuran, H.; Marciniak, K.; Janas, K.M. Presowing seed treatment with melatonin protects red cabbage seedlings against toxic copper ion concentrations. J. Pineal Res. 2008, 45, 24–31.
  46. Nawaz, M.A.; Jiao, Y.; Chen, C.; Shireen, F.; Zheng, Z.; Imtiaz, M.; Bie, Z.; Huang, Y. Melatonin pretreatment improves vanadium stress tolerance of watermelon seedlings by reducing vanadium concentration in the leaves and regulating melatonin biosynthesis and antioxidant-related gene expression. J. Plant Physiol. 2018, 220, 115–127.
  47. Nazir, M.; Asad Ullah, M.; Mumtaz, S.; Siddiquah, A.; Shah, M.; Drouet, S.; Hano, C.; Abbasi, B.H. Interactive effect of melatonin and UV-C on phenylpropanoid metabolite production and antioxidant potential in callus cultures of purple basil (Ocimum basilicum L. var purpurascens). Molecules 2020, 25, 1072.
  48. Wei, Z.; Li, C.; Gao, T.; Zhang, Z.; Liang, B.; Lv, Z.; Zou, Y.; Ma, F. Melatonin increases the performance of Malus hupehensis after UV-B exposure. Plant Physiol. Biochem. 2019, 139, 630–641.
  49. Yin, Y.; Tian, X.; Yang, J.; Yang, Z.; Tao, J.; Fang, W. Melatonin mediates isoflavone accumulation in germinated soybeans (Glycine max L.) under ultraviolet-B stress. Plant Physiol. Biochem. 2022, 175, 23–32.
  50. Yao, J.W.; Ma, Z.; Ma, Y.Q.; Zhu, Y.; Lei, M.Q.; Hao, C.Y.; Chen, L.Y.; Xu, Z.Q.; Huang, X. Role of melatonin in UV-B signaling pathway and UV-B stress resistance in Arabidopsis thaliana. Plant Cell Environ. 2021, 44, 114–129.
  51. Moustafa-Farag, M.; Almoneafy, A.; Mahmoud, A.; Elkelish, A.; Arnao, M.B.; Li, L.; Ai, S. Melatonin and its protective role against biotic stress impacts on plants. Biomolecules 2019, 10, 54.
  52. Moon, Y.-S.; Ali, S. A fruitful decade of bacterial ACC deaminase biotechnology: A pragmatic approach towards abiotic stress relief in plants. Theor. Exp. Plant Physiol. 2022, 34, 109–129.
  53. Gul, S.L.; Moon, Y.-S.; Hamayun, M.; Khan, S.A.; Iqbal, A.; Khan, M.A.; Hussain, A.; Shafique, M.; Kim, Y.-H.; Ali, S. Porostereum spadiceum-AGH786 Regulates the Growth and Metabolites Production in Triticum aestivum L. Under Salt Stress. Curr. Microbiol. 2022, 79, 159.
  54. Khan, M.; Nazar, T.; Pande, A.; Mun, B.-G.; Lee, D.; Hussain, A.; Lee, B.-H.; Yun, B.-W.J.F. The Role of Nitric Oxide-Induced ATILL6 in Growth and Disease Resistance in Arabidopsis thaliana. Front. Plant Sci. 2021, 12, 1314.
  55. Shahid, M.; Imran, Q.M.; Hussain, A.; Khan, M.; Lee, S.U.; Mun, B.G.; Yun, B.-W. Comprehensive analyses of nitric oxide-induced plant stem cell-related genes in Arabidopsis thaliana. Genes 2019, 10, 190.
  56. Khan, A.H.; Min, L.; Ma, Y.; Wu, Y.; Ding, Y.; Li, Y.; Xie, S.; Ullah, A.; Shaban, M.; Manghwar, H. High day and night temperatures distinctively disrupt fatty acid and jasmonic acid metabolism, inducing male sterility in cotton. J. Exp. Bot. 2020, 71, 6128–6141.
  57. Ali, Q.; Zheng, H.; Rao, M.J.; Ali, M.; Hussain, A.; Saleem, M.H.; Nehela, Y.; Sohail, M.A.; Ahmed, A.M.; Kubar, K.A. Advances, limitations, and prospects of biosensing technology for detecting phytopathogenic bacteria. Chemosphere 2022, 296, 133773.
  58. Santamaria, M.E.; Martínez, M.; Cambra, I.; Grbic, V.; Diaz, I. Understanding plant defence responses against herbivore attacks: An essential first step towards the development of sustainable resistance against pests. Transgenic Res. 2013, 22, 697–708.
  59. Hussain, A.; Ding, X.; Alariqi, M.; Manghwar, H.; Hui, F.; Li, Y.; Cheng, J.; Wu, C.; Cao, J.; Jin, S. Herbicide resistance: Another hot agronomic trait for plant genome editing. Plants 2021, 10, 621.
  60. Nabavi, S.M.; Nabavi, S.F.; Sureda, A.; Xiao, J.; Dehpour, A.R.; Shirooie, S.; Silva, A.S.; Baldi, A.; Khan, H.; Daglia, M. Anti-inflammatory effects of Melatonin: A mechanistic review. Crit. Rev. Food Sci. Nutr. 2019, 59, S4–S16.
  61. Vielma, J.R.; Bonilla, E.; Chacín-Bonilla, L.; Mora, M.; Medina-Leendertz, S.; Bravo, Y. Effects of melatonin on oxidative stress, and resistance to bacterial, parasitic, and viral infections: A review. Acta Trop. 2014, 137, 31–38.
  62. Huang, S.-H.; Liao, C.-L.; Chen, S.-J.; Shi, L.-G.; Lin, L.; Chen, Y.-W.; Cheng, C.-P.; Sytwu, H.-K.; Shang, S.-T.; Lin, G.-J. Melatonin possesses an anti-influenza potential through its immune modulatory effect. J. Funct. Foods 2019, 58, 189–198.
  63. Boga, J.A.; Caballero, B.; Potes, Y.; Perez-Martinez, Z.; Reiter, R.J.; Vega-Naredo, I.; Coto-Montes, A. Therapeutic potential of melatonin related to its role as an autophagy regulator: A review. J. Pineal Res. 2019, 66, e12534.
  64. Zhou, Y.; Manghwar, H.; Hu, W.; Liu, F. Degradation Mechanism of Autophagy-Related Proteins and Research Progress. Int. J. Mol. Sci. 2022, 23, 7301.
  65. Cheng, S.; Wang, Q.; Manghwar, H.; Liu, F. Autophagy-Mediated Regulation of Different Meristems in Plants. Int. J. Mol. Sci. 2022, 23, 6236.
  66. Zhao, L.; Chen, L.; Gu, P.; Zhan, X.; Zhang, Y.; Hou, C.; Wu, Z.; Wu, Y.F.; Wang, Q.C. Exogenous application of melatonin improves plant resistance to virus infection. Plant Pathol. 2019, 68, 1287–1295.
  67. Chen, L.; Wang, M.R.; Li, J.W.; Feng, C.H.; Cui, Z.H.; Zhao, L.; Wang, Q.C. Exogenous application of melatonin improves eradication of apple stem grooving virus from the infected in vitro shoots by shoot tip culture. Plant Pathol. 2019, 68, 997–1006.
  68. Tekbas, O.F.; Ogur, R.; Korkmaz, A.; Kilic, A.; Reiter, R.J. Melatonin as an antibiotic: New insights into the actions of this ubiquitous molecule. J. Pineal Res. 2008, 44, 222–226.
  69. Chen, X.; Sun, C.; Laborda, P.; He, Y.; Zhao, Y.; Li, C.; Liu, F. Melatonin treatments reduce the pathogenicity and inhibit the growth of Xanthomonas oryzae pv. oryzicola. Plant Pathol. 2019, 68, 288–296.
  70. Shi, H.; Chen, Y.; Tan, D.X.; Reiter, R.J.; Chan, Z.; He, C. Melatonin induces nitric oxide and the potential mechanisms relate to innate immunity against bacterial pathogen infection in Arabidopsis. J. Pineal Res. 2015, 59, 102–108.
  71. Lee, H.Y.; Back, K. Melatonin is required for H2O2− and NO− mediated defense signaling through MAPKKK 3 and OXI 1 in Arabidopsis thaliana. J. Pineal Res. 2017, 62, e12379.
  72. Mandal, M.K.; Suren, H.; Ward, B.; Boroujerdi, A.; Kousik, C. Differential roles of melatonin in plant-host resistance and pathogen suppression in cucurbits. J. Pineal Res. 2018, 65, e12505.
  73. Yavuz, T.; Kaya, D.; Behçet, M.; Ozturk, E.; Yavuz, Ö. Effects of melatonin on Candida sepsis in an experimental rat model. Adv. Ther. 2007, 24, 91–100.
  74. Liu, C.; Chen, L.; Zhao, R.; Li, R.; Zhang, S.; Yu, W.; Sheng, J.; Shen, L. Melatonin induces disease resistance to Botrytis cinerea in tomato fruit by activating jasmonic acid signaling pathway. J. Agric. Food Chem. 2019, 67, 6116–6124.
  75. Zhang, S.; Liu, S.; Zhang, J.; Reiter, R.J.; Wang, Y.; Qiu, D.; Luo, X.; Khalid, A.R.; Wang, H.; Feng, L. Synergistic anti-oomycete effect of melatonin with a biofungicide against oomycetic black shank disease. J. Pineal Res. 2018, 65, e12492.
  76. Li, C.; Zhao, Q.; Gao, T.; Wang, H.; Zhang, Z.; Liang, B.; Wei, Z.; Liu, C.; Ma, F. The mitigation effects of exogenous melatonin on replant disease in apple. J. Pineal Res. 2018, 65, e12523.
  77. Ma, Y.; Jiao, J.; Fan, X.; Sun, H.; Zhang, Y.; Jiang, J.; Liu, C. Endophytic bacterium Pseudomonas fluorescens RG11 may transform tryptophan to melatonin and promote endogenous melatonin levels in the roots of four grape cultivars. Front. Plant Sci. 2017, 7, 2068.
  78. Aghdam, M.S.; Fard, J.R. Melatonin treatment attenuates postharvest decay and maintains nutritional quality of strawberry fruits (Fragaria × anannasa cv. Selva) by enhancing GABA shunt activity. Food Chem. 2017, 221, 1650–1657.
  79. Arnao, M.B.; Hernández-Ruiz, J. Melatonin as a chemical substance or as phytomelatonin rich-extracts for use as plant protector and/or biostimulant in accordance with EC legislation. Agronomy 2019, 9, 570.
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