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Vongnhay V, Shukla MR, Ayyanath MM, Sriskantharajah K, Saxena PK. Enhanced In Vitro Plant Morphogenesis of Tobacco: Unveiling Indoleamine-Modulated Adaptogenic Properties of Tulsi ( Ocimum sanctum L.). PLANTS (BASEL, SWITZERLAND) 2024; 13:1370. [PMID: 38794439 PMCID: PMC11125241 DOI: 10.3390/plants13101370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/08/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024]
Abstract
The medicinal plant tulsi (Ocimum sanctum L.) is acknowledged for its invigorating and healing properties that enhance resilience to stress in various human and animal models by modulating antioxidant compounds. While extensive research has documented these effects in humans, the adaptogenic potential of tulsi in stressful in vitro plant systems has not been explored. This study aimed to elucidate the adaptogenic properties of tulsi leaf extract on the in vitro regeneration of tobacco leaf explants through an investigation of the indoleamines at different developmental stages. Shoot regeneration from leaf explants on the medium supplemented with tulsi extract (20%) was compared to the control, and the differences in indoleamine compounds were analyzed using ultra-performance liquid chromatography. Treatment of the explants with the extract resulted in an almost two-fold increase in the number of regenerants after four weeks of culture, and 9% of the regenerants resembled somatic embryo-like structures. The occurrence of browning in the extract-treated explants stopped on day 10, shoots began to develop, and a significant concentration of tryptamine and N-acetyl-serotonin accumulated. A comparative analysis of indoleamine compounds in intact and cut tobacco leaves also revealed the pivotal role of melatonin and 2-hydroxymelatonin functioning as antioxidants during stress adaptation. This study demonstrates that tulsi is a potent adaptogen that is capable of modulating plant morphogenesis in vitro, paving the way for further investigations into the role of adaptogens in plant stress biology.
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Affiliation(s)
| | | | | | | | - Praveen K. Saxena
- Department of Plant Agriculture, Gosling Research Institute for Plant Preservation, University of Guelph, Guelph, ON N1G 2W1, Canada; (V.V.); (M.R.S.); (M.-M.A.); (K.S.)
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Corpas FJ, González-Gordo S, Palma JM. Ascorbate peroxidase in fruits and modulation of its activity by reactive species. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:2716-2732. [PMID: 38442039 PMCID: PMC11066807 DOI: 10.1093/jxb/erae092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 03/04/2024] [Indexed: 03/07/2024]
Abstract
Ascorbate peroxidase (APX) is one of the enzymes of the ascorbate-glutathione cycle and is the key enzyme that breaks down H2O2 with the aid of ascorbate as an electron source. APX is present in all photosynthetic eukaryotes from algae to higher plants and, at the cellular level, it is localized in all subcellular compartments where H2O2 is generated, including the apoplast, cytosol, plastids, mitochondria, and peroxisomes, either in soluble form or attached to the organelle membranes. APX activity can be modulated by various post-translational modifications including tyrosine nitration, S-nitrosation, persulfidation, and S-sulfenylation. This allows the connection of H2O2 metabolism with other relevant signaling molecules such as NO and H2S, thus building a complex coordination system. In both climacteric and non-climacteric fruits, APX plays a key role during the ripening process and during post-harvest, since it participates in the regulation of both H2O2 and ascorbate levels affecting fruit quality. Currently, the exogenous application of molecules such as NO, H2S, H2O2, and, more recently, melatonin is seen as a new alternative to maintain and extend the shelf life and quality of fruits because they can modulate APX activity as well as other antioxidant systems. Therefore, these molecules are being considered as new biotechnological tools to improve crop quality in the horticultural industry.
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Affiliation(s)
- Francisco J Corpas
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Spanish National Research Council (CSIC), Granada, Spain
| | - Salvador González-Gordo
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Spanish National Research Council (CSIC), Granada, Spain
| | - José M Palma
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, Spanish National Research Council (CSIC), Granada, Spain
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Xu L, Xue X, Yan Y, Zhao X, Li L, Sheng K, Zhang Z. Silicon Combined with Melatonin Reduces Cd Absorption and Translocation in Maize. PLANTS (BASEL, SWITZERLAND) 2023; 12:3537. [PMID: 37896001 PMCID: PMC10609755 DOI: 10.3390/plants12203537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/30/2023] [Accepted: 10/07/2023] [Indexed: 10/29/2023]
Abstract
Cadmium (Cd) is one of the most toxic and widely distributed heavy metal pollutants, posing a huge threat to crop production, food security, and human health. Corn is an important food source and feed crop. Corn growth is subject to Cd stress; thus, reducing cadmium stress, absorption, and transportation is of great significance for achieving high yields, a high efficiency, and sustainable and safe corn production. The use of silicon or melatonin alone can reduce cadmium accumulation and toxicity in plants, but it is unclear whether the combination of silicon and melatonin can further reduce the damage caused by cadmium. Therefore, pot experiments were conducted to study the effects of melatonin and silicon on maize growth and cadmium accumulation. The results showed that cadmium stress significantly inhibited the growth of maize, disrupted its physiological processes, and led to cadmium accumulation in plants. Compared to the single treatment of silicon or melatonin, the combined application of melatonin and silicon significantly alleviated the inhibition of the growth of maize seedlings caused by cadmium stress. This was demonstrated by the increased plant heights, stem diameters, and characteristic root parameters and the bioaccumulation in maize seedlings. Under cadmium stress, the combined application of silicon and melatonin increased the plant height and stem diameter by 17.03% and 59.33%, respectively, and increased the total leaf area by 43.98%. The promotion of corn growth is related to the reduced oxidative damage under cadmium stress, manifested in decreases in the malondialdehyde content and relative conductivity and increases in antioxidant enzyme superoxide dismutase and guaiacol peroxidase activities, as well as in soluble protein and chlorophyll contents. In addition, cadmium accumulation in different parts of maize seedlings and the health risk index of cadmium were significantly reduced, reaching 48.44% (leaves), 19.15% (roots), and 20.86% (health risk index), respectively. Therefore, melatonin and silicon have a significant synergistic effect in inhibiting cadmium absorption and reducing the adverse effects of cadmium toxicity.
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Affiliation(s)
- Lina Xu
- College of Agriculture, Henan Institute of Science and Technology, Xinxiang 453003, China; (L.X.); (X.X.); (Y.Y.); (X.Z.); (L.L.)
| | - Xing Xue
- College of Agriculture, Henan Institute of Science and Technology, Xinxiang 453003, China; (L.X.); (X.X.); (Y.Y.); (X.Z.); (L.L.)
| | - Yan Yan
- College of Agriculture, Henan Institute of Science and Technology, Xinxiang 453003, China; (L.X.); (X.X.); (Y.Y.); (X.Z.); (L.L.)
| | - Xiaotong Zhao
- College of Agriculture, Henan Institute of Science and Technology, Xinxiang 453003, China; (L.X.); (X.X.); (Y.Y.); (X.Z.); (L.L.)
| | - Lijie Li
- College of Agriculture, Henan Institute of Science and Technology, Xinxiang 453003, China; (L.X.); (X.X.); (Y.Y.); (X.Z.); (L.L.)
| | - Kun Sheng
- School of Hydraulic Engineering, Yellow River Conservancy Technical Institute, Kaifeng 475004, China;
| | - Zhiyong Zhang
- College of Agriculture, Henan Institute of Science and Technology, Xinxiang 453003, China; (L.X.); (X.X.); (Y.Y.); (X.Z.); (L.L.)
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Gao Y, Chen H, Chen D, Hao G. Genetic and evolutionary dissection of melatonin response signaling facilitates the regulation of plant growth and stress responses. J Pineal Res 2023; 74:e12850. [PMID: 36585354 DOI: 10.1111/jpi.12850] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/19/2022] [Accepted: 12/24/2022] [Indexed: 01/01/2023]
Abstract
The expansion of gene families during evolution could generate functional diversity among their members to regulate plant growth and development. Melatonin, a phylogenetically ancient molecule, is vital for many aspects of a plant's life. Understanding the functional diversity of the molecular players involved in melatonin biosynthesis, signaling, and metabolism will facilitate the regulation of plant phenotypes. However, the molecular mechanism of melatonin response signaling elements in regulating this network still has many challenges. Here, we provide an in-depth analysis of the functional diversity and evolution of molecular components in melatonin signaling pathway. Genetic analysis of multiple mutants in plant species will shed light on the role of gene families in melatonin regulatory pathways. Phylogenetic analysis of these genes was performed, which will facilitate the identification of melatonin-related genes for future study. Based on the abovementioned signal networks, the mechanism of these genes was summarized to provide reference for studying the regulatory mechanism of melatonin in plant phenotypes. We hope that this work will facilitate melatonin research in higher plants and finely tuned spatio-temporal regulation of melatonin signaling.
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Affiliation(s)
- Yangyang Gao
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, P. R. China
| | - Huimin Chen
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, China
| | - Dongyu Chen
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, P. R. China
| | - Gefei Hao
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang, P. R. China
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, China
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Ahmad I, Song X, Hussein Ibrahim ME, Jamal Y, Younas MU, Zhu G, Zhou G, Adam Ali AY. The role of melatonin in plant growth and metabolism, and its interplay with nitric oxide and auxin in plants under different types of abiotic stress. FRONTIERS IN PLANT SCIENCE 2023; 14:1108507. [PMID: 36866369 PMCID: PMC9971941 DOI: 10.3389/fpls.2023.1108507] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 01/09/2023] [Indexed: 06/01/2023]
Abstract
Melatonin is a pleiotropic signaling molecule that reduces the adverse effects of abiotic stresses, and enhances the growth and physiological function of many plant species. Several recent studies have demonstrated the pivotal role of melatonin in plant functions, specifically its regulation of crop growth and yield. However, a comprehensive understanding of melatonin, which regulates crop growth and yield under abiotic stress conditions, is not yet available. This review focuses on the progress of research on the biosynthesis, distribution, and metabolism of melatonin, and its multiple complex functions in plants and its role in the mechanisms of metabolism regulation in plants grown under abiotic stresses. In this review, we focused on the pivotal role of melatonin in the enhancement of plant growth and regulation of crop yield, and elucidated its interactions with nitric oxide (NO) and auxin (IAA, indole-3-acetic acid) when plants are grown under various abiotic stresses. The present review revealed that the endogenousapplication of melatonin to plants, and its interactions with NO and IAA, enhanced plant growth and yield under various abiotic stresses. The interaction of melatonin with NO regulated plant morphophysiological and biochemical activities, mediated by the G protein-coupled receptor and synthesis genes. The interaction of melatonin with IAA enhanced plant growth and physiological function by increasing the levels of IAA, synthesis, and polar transport. Our aim was to provide a comprehensive review of the performance of melatonin under various abiotic stresses, and, therefore, further explicate the mechanisms that plant hormones use to regulate plant growth and yield under abiotic stresses.
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Affiliation(s)
- Irshad Ahmad
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Xudong Song
- Department of Agronomy, Institute of Agricultural, Sudan University of Science and Technology, Khartoum, Sudan
| | - Muhi Eldeen Hussein Ibrahim
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, College of Agriculture, Yangzhou University, Yangzhou, China
- Jiangsu Yanjiang Area, Institute of Agricultural Sciences, Nantong, China
| | - Yousaf Jamal
- Department of Agronomy, Faculty of Agriculture, University of Swabi, Swabi, Pakistan
| | - Muhammad Usama Younas
- Department of Crop Genetics and Breeding, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Guanglong Zhu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, College of Agriculture, Yangzhou University, Yangzhou, China
| | - Guisheng Zhou
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education of China, College of Agriculture, Yangzhou University, Yangzhou, China
- Key Lab of Crop Genetics & Physiology of Jiangsu Province, Yangzhou University, Yangzhou, China
| | - Adam Yousif Adam Ali
- Department of Agronomy, Faculty of Agricultural and Environmental Science, University of Gadarif, Al Gadarif, Sudan
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Khalid M, Rehman HM, Ahmed N, Nawaz S, Saleem F, Ahmad S, Uzair M, Rana IA, Atif RM, Zaman QU, Lam HM. Using Exogenous Melatonin, Glutathione, Proline, and Glycine Betaine Treatments to Combat Abiotic Stresses in Crops. Int J Mol Sci 2022; 23:12913. [PMID: 36361700 PMCID: PMC9657122 DOI: 10.3390/ijms232112913] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/14/2022] [Accepted: 10/19/2022] [Indexed: 08/06/2023] Open
Abstract
Abiotic stresses, such as drought, salinity, heat, cold, and heavy metals, are associated with global climate change and hamper plant growth and development, affecting crop yields and quality. However, the negative effects of abiotic stresses can be mitigated through exogenous treatments using small biomolecules. For example, the foliar application of melatonin provides the following: it protects the photosynthetic apparatus; it increases the antioxidant defenses, osmoprotectant, and soluble sugar levels; it prevents tissue damage and reduces electrolyte leakage; it improves reactive oxygen species (ROS) scavenging; and it increases biomass, maintains the redox and ion homeostasis, and improves gaseous exchange. Glutathione spray upregulates the glyoxalase system, reduces methylglyoxal (MG) toxicity and oxidative stress, decreases hydrogen peroxide and malondialdehyde accumulation, improves the defense mechanisms, tissue repairs, and nitrogen fixation, and upregulates the phytochelatins. The exogenous application of proline enhances growth and other physiological characteristics, upregulates osmoprotection, protects the integrity of the plasma lemma, reduces lipid peroxidation, increases photosynthetic pigments, phenolic acids, flavonoids, and amino acids, and enhances stress tolerance, carbon fixation, and leaf nitrogen content. The foliar application of glycine betaine improves growth, upregulates osmoprotection and osmoregulation, increases relative water content, net photosynthetic rate, and catalase activity, decreases photorespiration, ion leakage, and lipid peroxidation, protects the oxygen-evolving complex, and prevents chlorosis. Chemical priming has various important advantages over transgenic technology as it is typically more affordable for farmers and safe for plants, people, and animals, while being considered environmentally acceptable. Chemical priming helps to improve the quality and quantity of the yield. This review summarizes and discusses how exogenous melatonin, glutathione, proline, and glycine betaine can help crops combat abiotic stresses.
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Affiliation(s)
- Memoona Khalid
- Centre for Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture Faisalabad, Faisalabad 38000, Pakistan
| | - Hafiz Mamoon Rehman
- Centre for Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture Faisalabad, Faisalabad 38000, Pakistan
- Center for Soybean Research of the Partner State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Nisar Ahmed
- Centre for Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture Faisalabad, Faisalabad 38000, Pakistan
| | - Sehar Nawaz
- Centre for Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture Faisalabad, Faisalabad 38000, Pakistan
| | - Fozia Saleem
- Centre for Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture Faisalabad, Faisalabad 38000, Pakistan
| | - Shakeel Ahmad
- Seed Center, Ministry of Environment, Water & Agriculture, Riyadh 14712, Saudi Arabia
| | - Muhammad Uzair
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Iqrar Ahmad Rana
- Centre for Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture Faisalabad, Faisalabad 38000, Pakistan
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad Pakistan, Punjab 38000, Pakistan
| | - Rana Muhammad Atif
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad Pakistan, Punjab 38000, Pakistan
| | - Qamar U. Zaman
- Center for Advanced Studies in Agriculture and Food Security, University of Agriculture Faisalabad Pakistan, Punjab 38000, Pakistan
| | - Hon-Ming Lam
- Center for Soybean Research of the Partner State Key Laboratory of Agrobiotechnology and School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong
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Corpas FJ, Rodríguez-Ruiz M, Muñoz-Vargas MA, González-Gordo S, Reiter RJ, Palma JM. Interactions of melatonin, reactive oxygen species, and nitric oxide during fruit ripening: an update and prospective view. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5947-5960. [PMID: 35325926 PMCID: PMC9523826 DOI: 10.1093/jxb/erac128] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/23/2022] [Indexed: 05/10/2023]
Abstract
Fruit ripening is a physiological process that involves a complex network of signaling molecules that act as switches to activate or deactivate certain metabolic pathways at different levels, not only by regulating gene and protein expression but also through post-translational modifications of the involved proteins. Ethylene is the distinctive molecule that regulates the ripening of fruits, which can be classified as climacteric or non-climacteric according to whether or not, respectively, they are dependent on this phytohormone. However, in recent years it has been found that other molecules with signaling potential also exert regulatory roles, not only individually but also as a result of interactions among them. These observations imply the existence of mutual and hierarchical regulations that sometimes make it difficult to identify the initial triggering event. Among these 'new' molecules, hydrogen peroxide, nitric oxide, and melatonin have been highlighted as prominent. This review provides a comprehensive outline of the relevance of these molecules in the fruit ripening process and the complex network of the known interactions among them.
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Affiliation(s)
| | - Marta Rodríguez-Ruiz
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín (Spanish National Research Council, CSIC), C/ Profesor Albareda, 1, 18008 Granada, Spain
| | - María A Muñoz-Vargas
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín (Spanish National Research Council, CSIC), C/ Profesor Albareda, 1, 18008 Granada, Spain
| | - Salvador González-Gordo
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín (Spanish National Research Council, CSIC), C/ Profesor Albareda, 1, 18008 Granada, Spain
| | - Russel J Reiter
- Department of Cell Systems and Anatomy, Joe R. and Teresa Lozano Long School of Medicine, UT Health San Antonio, San Antonio, TX 78229, USA
| | - José M Palma
- Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín (Spanish National Research Council, CSIC), C/ Profesor Albareda, 1, 18008 Granada, Spain
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Liu Y, Wang X, Lv H, Cao M, Li Y, Yuan X, Zhang X, Guo YD, Zhang N. Anabolism and signaling pathways of phytomelatonin. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5801-5817. [PMID: 35430630 DOI: 10.1093/jxb/erac158] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Phytomelatonin is a small multifunctional molecule found ubiquitously in plants, which plays an important role in plant growth, development, and biotic and abiotic stress responses. The classical biosynthetic and metabolic pathways of phytomelatonin have been elucidated, and uncovering alternative pathways has deepened our understanding of phytomelatonin synthesis. Phytomelatonin functions mainly via two pathways. In the direct pathway, phytomelatonin mediates the stress-induced reactive oxygen species burst through its strong antioxidant capacity. In the indirect pathway, phytomelatonin acts as a signal to activate signaling cascades and crosstalk with other plant hormones. The phytomelatonin receptor PMTR1/CAND2 was discovered in 2018, which enhanced our understanding of phytomelatonin function. This review summarizes the classical and potential pathways involved in phytomelatonin synthesis and metabolism. To elucidate the functions of phytomelatonin, we focus on the crosstalk between phytomelatonin and other phytohormones. We propose two models to explain how PMTR1 transmits the phytomelatonin signal through the G protein and MAPK cascade. This review will facilitate the identification of additional signaling molecules that function downstream of the phytomelatonin signaling pathway, thus improving our understanding of phytomelatonin signal transmission.
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Affiliation(s)
- Ying Liu
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Xiaoyun Wang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Hongmei Lv
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Meng Cao
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Yongchong Li
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Xiaowei Yuan
- Huasheng Agriculture Co. Ltd, Qingzhou, Shandong, 262500, China
| | - Xichun Zhang
- School of Plant Science and Technology, Beijing Agricultural University, Beijing, 102206, China
| | - Yang-Dong Guo
- College of Horticulture, China Agricultural University, Beijing, 100193, China
- Sanya Institute of China Agricultural University, Sanya, 572000, China
| | - Na Zhang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
- Sanya Institute of China Agricultural University, Sanya, 572000, China
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9
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Xie Q, Zhang Y, Cheng Y, Tian Y, Luo J, Hu Z, Chen G. The role of melatonin in tomato stress response, growth and development. PLANT CELL REPORTS 2022; 41:1631-1650. [PMID: 35575808 DOI: 10.1007/s00299-022-02876-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/19/2022] [Accepted: 04/20/2022] [Indexed: 05/27/2023]
Abstract
Melatonin has attracted widespread attention after its discovery in higher plants. Tomato is a key model economic crop for studying fleshy fruits. Many studies have shown that melatonin plays important role in plant stress resistance, growth, and development. However, the research progress on the role of melatonin and related mechanisms in tomatoes have not been systematically summarized. This paper summarizes the detection methods and anabolism of melatonin in tomatoes, including (1) the role of melatonin in combating abiotic stresses, e.g., drought, heavy metals, pH, temperature, salt, salt and heat, cold and drought, peroxidation hydrogen and carbendazim, etc., (2) the role of melatonin in combating biotic stresses, such as tobacco mosaic virus and foodborne bacillus, and (3) the role of melatonin in tomato growth and development, such as fruit ripening, postharvest shelf life, leaf senescence and root development. In addition, the future research directions of melatonin in tomatoes are explored in combination with the role of melatonin in other plants. This review can provide a theoretical basis for enhancing the scientific understanding of the role of melatonin in tomatoes and the improved breeding of fruit crops.
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Affiliation(s)
| | - Yu Zhang
- Chongqing University, Chongqing, China
| | | | | | | | - Zongli Hu
- Chongqing University, Chongqing, China
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Martínez-Lorente SE, Pardo-Hernández M, Martí-Guillén JM, López-Delacalle M, Rivero RM. Interaction between Melatonin and NO: Action Mechanisms, Main Targets, and Putative Roles of the Emerging Molecule NOmela. Int J Mol Sci 2022; 23:ijms23126646. [PMID: 35743084 PMCID: PMC9223470 DOI: 10.3390/ijms23126646] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/07/2022] [Accepted: 06/13/2022] [Indexed: 12/15/2022] Open
Abstract
Melatonin (MEL), a ubiquitous indolamine molecule, has gained interest in the last few decades due to its regulatory role in plant metabolism. Likewise, nitric oxide (NO), a gasotransmitter, can also affect plant molecular pathways due to its function as a signaling molecule. Both MEL and NO can interact at multiple levels under abiotic stress, starting with their own biosynthetic pathways and inducing a particular signaling response in plants. Moreover, their interaction can result in the formation of NOmela, a very recently discovered nitrosated form of MEL with promising roles in plant physiology. This review summarizes the role of NO and MEL molecules during plant development and fruit ripening, as well as their interactions. Due to the impact of climate-change-related abiotic stresses on agriculture, this review also focuses on the role of these molecules in mediating abiotic stress tolerance and the main mechanisms by which they operate, from the upregulation of the entire antioxidant defense system to the post-translational modifications (PTMs) of important molecules. Their individual interaction and crosstalk with phytohormones and H2S are also discussed. Finally, we introduce and summarize the little information available about NOmela, an emerging and still very unknown molecule, but that seems to have a stronger potential than MEL and NO separately in mediating plant stress response.
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Affiliation(s)
- Sara E. Martínez-Lorente
- Center of Edaphology and Applied Biology of Segura CEBAS-CSIC, Campus Universitario Espinardo, 30100 Murcia, Spain; (S.E.M.-L.); (M.P.-H.); (J.M.M.-G.); (M.L.-D.)
| | - Miriam Pardo-Hernández
- Center of Edaphology and Applied Biology of Segura CEBAS-CSIC, Campus Universitario Espinardo, 30100 Murcia, Spain; (S.E.M.-L.); (M.P.-H.); (J.M.M.-G.); (M.L.-D.)
| | - José M. Martí-Guillén
- Center of Edaphology and Applied Biology of Segura CEBAS-CSIC, Campus Universitario Espinardo, 30100 Murcia, Spain; (S.E.M.-L.); (M.P.-H.); (J.M.M.-G.); (M.L.-D.)
- Faculty of Biology, Department of Plant Physiology, University of Murcia, Campus Universitario Espinardo, 30100 Murcia, Spain
| | - María López-Delacalle
- Center of Edaphology and Applied Biology of Segura CEBAS-CSIC, Campus Universitario Espinardo, 30100 Murcia, Spain; (S.E.M.-L.); (M.P.-H.); (J.M.M.-G.); (M.L.-D.)
| | - Rosa M. Rivero
- Center of Edaphology and Applied Biology of Segura CEBAS-CSIC, Campus Universitario Espinardo, 30100 Murcia, Spain; (S.E.M.-L.); (M.P.-H.); (J.M.M.-G.); (M.L.-D.)
- Correspondence: ; Tel.: +34-968396200 (ext. 445379)
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Lee HY, Back K. The Antioxidant Cyclic 3-Hydroxymelatonin Promotes the Growth and Flowering of Arabidopsis thaliana. Antioxidants (Basel) 2022; 11:antiox11061157. [PMID: 35740053 PMCID: PMC9219689 DOI: 10.3390/antiox11061157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 06/10/2022] [Accepted: 06/11/2022] [Indexed: 12/10/2022] Open
Abstract
In plants, melatonin is metabolized into several compounds, including the potent antioxidant cyclic 3-hydroxymelatonin (3-OHM). Melatonin 3-hydroxylase (M3H), a member of the 2-oxo-glutarate-dependent enzyme family, is responsible for 3-OHM biosynthesis. Although rice M3H has been cloned, its roles are unclear, and no homologs in other plant species have been characterized. Here, we cloned and characterized Arabidopsis thaliana M3H (AtM3H). The purified recombinant AtM3H exhibited Km and Vmax values of 100 μM and 20.7 nmol/min/mg protein, respectively. M3H was localized to the cytoplasm, and its expression peaked at night. Based on a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, 3-OHM exhibited 15-fold higher antioxidant activity than melatonin. An Arabidopsis M3H knockout mutant (m3h) produced less 3-OHM than the wildtype (WT), thus reducing antioxidant activity and biomass and delaying flowering. These defects were caused by reduced expression of FLOWERING LOCUS T (FT) and gibberellin-related genes, which are responsible for flowering and growth. Exogenous 3-OHM, but not exogenous melatonin, induced FT expression. The peak of M3H expression at night matched the FT expression pattern. The WT and m3h exhibited similar responses to salt stress and pathogens. Collectively, our findings indicate that 3-OHM promotes growth and flowering in Arabidopsis.
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12
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Qari SH, Hassan MU, Chattha MU, Mahmood A, Naqve M, Nawaz M, Barbanti L, Alahdal MA, Aljabri M. Melatonin Induced Cold Tolerance in Plants: Physiological and Molecular Responses. FRONTIERS IN PLANT SCIENCE 2022; 13:843071. [PMID: 35371159 PMCID: PMC8967244 DOI: 10.3389/fpls.2022.843071] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 01/31/2022] [Indexed: 05/24/2023]
Abstract
Cold stress is one of the most limiting factors for plant growth and development. Cold stress adversely affects plant physiology, molecular and biochemical processes by determining oxidative stress, poor nutrient and water uptake, disorganization of cellular membranes and reduced photosynthetic efficiency. Therefore, to recover impaired plant functions under cold stress, the application of bio-stimulants can be considered a suitable approach. Melatonin (MT) is a critical bio-stimulant that has often shown to enhance plant performance under cold stress. Melatonin application improved plant growth and tolerance to cold stress by maintaining membrane integrity, plant water content, stomatal opening, photosynthetic efficiency, nutrient and water uptake, redox homeostasis, accumulation of osmolytes, hormones and secondary metabolites, and the scavenging of reactive oxygen species (ROS) through improved antioxidant activities and increase in expression of stress-responsive genes. Thus, it is essential to understand the mechanisms of MT induced cold tolerance and identify the diverse research gaps necessitating to be addressed in future research programs. This review discusses MT involvement in the control of various physiological and molecular responses for inducing cold tolerance. We also shed light on engineering MT biosynthesis for improving the cold tolerance in plants. Moreover, we highlighted areas where future research is needed to make MT a vital antioxidant conferring cold tolerance to plants.
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Affiliation(s)
- Sameer H. Qari
- Department of Biology, Al-Jumum University College, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Muhammad Umair Hassan
- Research Center on Ecological Sciences, Jiangxi Agricultural University, Nanchang, China
| | | | - Athar Mahmood
- Department of Agronomy, University of Agriculture, Faisalabad, Pakistan
| | - Maria Naqve
- Department of Botany, University of Agriculture, Faisalabad, Pakistan
| | - Muhammad Nawaz
- Department of Agricultural Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, Pakistan
| | - Lorenzo Barbanti
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Maryam A. Alahdal
- Department of Biology, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Maha Aljabri
- Department of Biology, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
- Department of Biology, Research Laboratories Centre, Faculty of Applied Science, Umm Al-Qura University, Makkah, Saudi Arabia
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13
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Zeng W, Mostafa S, Lu Z, Jin B. Melatonin-Mediated Abiotic Stress Tolerance in Plants. FRONTIERS IN PLANT SCIENCE 2022; 13:847175. [PMID: 35615125 PMCID: PMC9125191 DOI: 10.3389/fpls.2022.847175] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 04/19/2022] [Indexed: 05/07/2023]
Abstract
Melatonin is a multi-functional molecule that is ubiquitous in all living organisms. Melatonin performs essential roles in plant stress tolerance; its application can reduce the harmful effects of abiotic stresses. Plant melatonin biosynthesis, which usually occurs within chloroplasts, and its related metabolic pathways have been extensively characterized. Melatonin regulates plant stress responses by directly inhibiting the accumulation of reactive oxygen and nitrogen species, and by indirectly affecting stress response pathways. In this review, we summarize recent research concerning melatonin biosynthesis, metabolism, and antioxidation; we focus on melatonin-mediated tolerance to abiotic stresses including drought, waterlogging, salt, heat, cold, heavy metal toxicity, light and others. We also examine exogenous melatonin treatment in plants under abiotic stress. Finally, we discuss future perspectives in melatonin research and its applications in plants.
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Affiliation(s)
- Wen Zeng
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
| | - Salma Mostafa
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
- Department of Floriculture, Faculty of Agriculture, Alexandria University, Alexandria, Egypt
| | - Zhaogeng Lu
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
- *Correspondence: Zhaogeng Lu,
| | - Biao Jin
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, China
- Biao Jin,
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14
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Zhang Y, Wang J, Chen X, Lu X, Wang D, Wang J, Wang S, Chen C, Guo L, Malik WA, Fan Y, Rui C, Cui R, Wang Q, Lei Y, Ye W. Genome-wide identification and characteristic analysis of the downstream melatonin metabolism gene GhM2H in Gossypium hirsutum L. Biol Res 2021; 54:36. [PMID: 34736526 PMCID: PMC8567562 DOI: 10.1186/s40659-021-00358-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 10/16/2021] [Indexed: 12/13/2022] Open
Abstract
Background Melatonin 2-hydroxylase (M2H) is the first enzyme in the catabolism pathway of melatonin, which catalyzes the production of 2-hydroxymelatonin (2-OHM) from melatonin. The content of 2-hydroxymelatonin in plants is much higher than that of melatonin. So M2H may be a key enzyme in the metabolic pathway of melatonin. Method We conducted a systematic analysis of the M2H gene family in Gossypium hirsutum based on the whole genome sequence by integrating the structural characteristics, phylogenetic relationships, expression profile, and biological stress of the members of the Gossypium hirsutum M2H gene family. Result We identified 265 M2H genes in the whole genome of Gossypium hirsutum, which were divided into 7 clades (clades I-VII) according to phylogenetic analysis. Most M2H members in each group had similar motif composition and gene structure characteristics. More than half of GhM2H members contain ABA-responsive elements and MeJA-responsive elements. Under different stress conditions, the expression levels of the gene changed, indicating that GhM2H members were involved in the regulation of abiotic stress. Some genes in the GhM2H family were involved in regulating melatonin levels in cotton under salt stress, and some genes were regulated by exogenous melatonin. Conclusion This study is helpful to explore the function of GhM2H, the downstream metabolism gene of melatonin in cotton, and lay the foundation for better exploring the molecular mechanism of melatonin improving cotton's response to abiotic stress. Supplementary Information The online version contains supplementary material available at 10.1186/s40659-021-00358-y.
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Affiliation(s)
- Yuexin Zhang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Jing Wang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Xiugui Chen
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Xuke Lu
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Delong Wang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Junjuan Wang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Shuai Wang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Chao Chen
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Lixue Guo
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Waqar Afzal Malik
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Yapeng Fan
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Cun Rui
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Ruifeng Cui
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Qinqin Wang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Yuqian Lei
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China
| | - Wuwei Ye
- State Key Laboratory of Cotton Biology/Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Zhengzhou Research Base, School of Agricultural Sciences, Zhengzhou University Research Base, Zhengzhou University/Key Laboratory for Cotton Genetic Improvement, MOA, Anyang, Henan, China.
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15
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Lee HY, Back K. 2-Hydroxymelatonin, Rather Than Melatonin, Is Responsible for RBOH-Dependent Reactive Oxygen Species Production Leading to Premature Senescence in Plants. Antioxidants (Basel) 2021; 10:antiox10111728. [PMID: 34829600 PMCID: PMC8614918 DOI: 10.3390/antiox10111728] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 10/27/2021] [Accepted: 10/27/2021] [Indexed: 12/12/2022] Open
Abstract
Unlike animals, plants amply convert melatonin into 2-hydroxymelatonin (2-OHM) and cyclic 3-hydroxymelatonin (3-OHM) through the action of melatonin 2-hydroxylase (M2H) and melatonin 3-hydroxylase (M3H), respectively. Thus, the effects of exogenous melatonin treatment in plants may be caused by melatonin, 2-OHM, or 3-OHM, or some combination of these compounds. Indeed, studies of melatonin's effects on reactive oxygen species (ROS) production have reported conflicting results. In this study, we demonstrated that 2-OHM treatment induced ROS production, whereas melatonin did not. ROS production from 2-OHM treatment occurred in old arabidopsis leaves in darkness, consistent with an ethylene-mediated senescence mechanism. Transgenic tobacco plants containing overexpressed rice M2H exhibited dwarfism and leaf necrosis of the upper leaves and early senescence of the lower leaves. We also demonstrated that 2-OHM-mediated ROS production is respiratory burst NADPH oxidase (RBOH)-dependent and that 2-OHM-induced senescence genes require ethylene and the abscisic acid (ABA) signaling pathway in arabidopsis. In contrast to melatonin, 2-OHM treatment induced senescence symptoms such as leaf chlorosis and increased ion leakage in arabidopsis. Senescence induction is known to begin with decreased levels of proteins involved in chloroplast maintenance, including Lhcb1 and ClpR1. Together, these results show that 2-OHM acts as a senescence-inducing factor by inducing ROS production in plants.
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16
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Melatonin Confers Plant Cadmium Tolerance: An Update. Int J Mol Sci 2021; 22:ijms222111704. [PMID: 34769134 PMCID: PMC8583868 DOI: 10.3390/ijms222111704] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 02/07/2023] Open
Abstract
Cadmium (Cd) is one of the most injurious heavy metals, affecting plant growth and development. Melatonin (N-acetyl-5-methoxytryptamine) was discovered in plants in 1995, and it is since known to act as a multifunctional molecule to alleviate abiotic and biotic stresses, especially Cd stress. Endogenously triggered or exogenously applied melatonin re-establishes the redox homeostasis by the improvement of the antioxidant defense system. It can also affect the Cd transportation and sequestration by regulating the transcripts of genes related to the major metal transport system, as well as the increase in glutathione (GSH) and phytochelatins (PCs). Melatonin activates several downstream signals, such as nitric oxide (NO), hydrogen peroxide (H2O2), and salicylic acid (SA), which are required for plant Cd tolerance. Similar to the physiological functions of NO, hydrogen sulfide (H2S) is also involved in the abiotic stress-related processes in plants. Moreover, exogenous melatonin induces H2S generation in plants under salinity or heat stress. However, the involvement of H2S action in melatonin-induced Cd tolerance is still largely unknown. In this review, we summarize the progresses in various physiological and molecular mechanisms regulated by melatonin in plants under Cd stress. The complex interactions between melatonin and H2S in acquisition of Cd stress tolerance are also discussed.
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17
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Altaf MA, Shahid R, Ren MX, Mora-Poblete F, Arnao MB, Naz S, Anwar M, Altaf MM, Shahid S, Shakoor A, Sohail H, Ahmar S, Kamran M, Chen JT. Phytomelatonin: An overview of the importance and mediating functions of melatonin against environmental stresses. PHYSIOLOGIA PLANTARUM 2021; 172:820-846. [PMID: 33159319 DOI: 10.1111/ppl.13262] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/09/2020] [Accepted: 10/27/2020] [Indexed: 05/06/2023]
Abstract
Recently, melatonin has gained significant importance in plant research. The presence of melatonin in the plant kingdom has been known since 1995. It is a molecule that is conserved in a wide array of evolutionary distant organisms. Its functions and characteristics have been found to be similar in both plants and animals. The review focuses on the role of melatonin pertaining to physiological functions in higher plants. Melatonin regulates physiological functions regarding auxin activity, root, shoot, and explant growth, activates germination of seeds, promotes rhizogenesis (growth of adventitious and lateral roots), and holds up impelled leaf senescence. Melatonin is a natural bio-stimulant that creates resistance in field crops against various abiotic stress, including heat, chemical pollutants, cold, drought, salinity, and harmful ultra-violet radiation. The full potential of melatonin in regulating physiological functions in higher plants still needs to be explored by further research.
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Affiliation(s)
| | - Rabia Shahid
- School of Economics, Hainan University, Haikou, China
| | - Ming-Xun Ren
- Center for Terrestrial Biodiversity of the South China Sea, College of Ecology and Environment, Hainan University, Haikou, China
| | | | - Marino B Arnao
- Department of Plant Biology (Plant Physiology), Faculty of Biology, University of Murcia, Murcia, Spain
| | - Safina Naz
- Department of Horticulture, Faculty of Agricultural Science and Technology, Bahauddin Zakariya University, Multan, Pakistan
| | - Muhammad Anwar
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China
| | | | - Sidra Shahid
- Institute for Clinical Chemistry, University Medical Center Goettingen, Goettingen, Germany
| | - Awais Shakoor
- Department of Environment and Soil Sciences, University of Lleida, Lleida, Spain
| | - Hamza Sohail
- College of Horticulture and Forestry Sciences, Huazhong Agricultural University/Key Laboratory of Horticultural Plant Biology, Ministry of Education, Wuhan, China
| | - Sunny Ahmar
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Muhammad Kamran
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Jen-Tsung Chen
- Department of Life Sciences, National University of Kaohsiung, Kaohsiung, Taiwan
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18
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Shah AA, Azna, Yasin NA, Ahmed S, Abbas M, Abbasi GH. 4-Hydroxymelatonin alleviates nickel stress, improves physiochemical traits of Solanum melongena: Regulation of polyamine metabolism and antioxidative enzyme. SCIENTIA HORTICULTURAE 2021; 282:110036. [DOI: 10.1016/j.scienta.2021.110036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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19
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Jiménez-Arias D, García-Machado FJ, Morales-Sierra S, García-García AL, Herrera AJ, Valdés F, Luis JC, Borges AA. A Beginner's Guide to Osmoprotection by Biostimulants. PLANTS (BASEL, SWITZERLAND) 2021; 10:363. [PMID: 33668668 PMCID: PMC7917748 DOI: 10.3390/plants10020363] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 05/04/2023]
Abstract
Water is indispensable for the life of any organism on Earth. Consequently, osmotic stress due to salinity and drought is the greatest threat to crop productivity. Ongoing climate change includes rising temperatures and less precipitation over large areas of the planet. This is leading to increased vulnerability to the drought conditions that habitually threaten food security in many countries. Such a scenario poses a daunting challenge for scientists: the search for innovative solutions to save water and cultivate under water deficit. A search for formulations including biostimulants capable of improving tolerance to this stress is a promising specific approach. This review updates the most recent state of the art in the field.
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Affiliation(s)
- David Jiménez-Arias
- Chemical Plant Defence Activators Group, Department of Agrobiology, IPNA-CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Canary Islands, Spain; (F.J.G.-M.); (A.L.G.-G.); (A.J.H.)
| | - Francisco J. García-Machado
- Chemical Plant Defence Activators Group, Department of Agrobiology, IPNA-CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Canary Islands, Spain; (F.J.G.-M.); (A.L.G.-G.); (A.J.H.)
- Applied Plant Biology Group (GBVA), Department of Botany, Ecology and Plant Physiology–Faculty of Pharmacy, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, 38071 La Laguna, Tenerife, Canary Islands, Spain; (S.M.-S.); (F.V.); (J.C.L.)
| | - Sarai Morales-Sierra
- Applied Plant Biology Group (GBVA), Department of Botany, Ecology and Plant Physiology–Faculty of Pharmacy, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, 38071 La Laguna, Tenerife, Canary Islands, Spain; (S.M.-S.); (F.V.); (J.C.L.)
| | - Ana L. García-García
- Chemical Plant Defence Activators Group, Department of Agrobiology, IPNA-CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Canary Islands, Spain; (F.J.G.-M.); (A.L.G.-G.); (A.J.H.)
- Applied Plant Biology Group (GBVA), Department of Botany, Ecology and Plant Physiology–Faculty of Pharmacy, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, 38071 La Laguna, Tenerife, Canary Islands, Spain; (S.M.-S.); (F.V.); (J.C.L.)
| | - Antonio J. Herrera
- Chemical Plant Defence Activators Group, Department of Agrobiology, IPNA-CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Canary Islands, Spain; (F.J.G.-M.); (A.L.G.-G.); (A.J.H.)
| | - Francisco Valdés
- Applied Plant Biology Group (GBVA), Department of Botany, Ecology and Plant Physiology–Faculty of Pharmacy, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, 38071 La Laguna, Tenerife, Canary Islands, Spain; (S.M.-S.); (F.V.); (J.C.L.)
| | - Juan C. Luis
- Applied Plant Biology Group (GBVA), Department of Botany, Ecology and Plant Physiology–Faculty of Pharmacy, Universidad de La Laguna, Avda. Astrofísico Francisco Sánchez s/n, 38071 La Laguna, Tenerife, Canary Islands, Spain; (S.M.-S.); (F.V.); (J.C.L.)
| | - Andrés A. Borges
- Chemical Plant Defence Activators Group, Department of Agrobiology, IPNA-CSIC, Avda. Astrofísico Francisco Sánchez 3, 38206 La Laguna, Tenerife, Canary Islands, Spain; (F.J.G.-M.); (A.L.G.-G.); (A.J.H.)
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Physiological and Molecular Responses to Acid Rain Stress in Plants and the Impact of Melatonin, Glutathione and Silicon in the Amendment of Plant Acid Rain Stress. Molecules 2021; 26:molecules26040862. [PMID: 33562098 PMCID: PMC7915782 DOI: 10.3390/molecules26040862] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 02/01/2021] [Accepted: 02/03/2021] [Indexed: 12/21/2022] Open
Abstract
Air pollution has been a long-term problem, especially in urban areas, that eventually accelerates the formation of acid rain (AR), but recently it has emerged as a serious environmental issue worldwide owing to industrial and economic growth, and it is also considered a major abiotic stress to agriculture. Evidence showed that AR exerts harmful effects in plants, especially on growth, photosynthetic activities, antioxidant activities and molecular changes. Effectiveness of several bio-regulators has been tested so far to arbitrate various physiological, biochemical and molecular processes in plants under different diverse sorts of environmental stresses. In the current review, we showed that silicon (tetravalent metalloid and semi-conductor), glutathione (free thiol tripeptide) and melatonin (an indoleamine low molecular weight molecule) act as influential growth regulators, bio-stimulators and antioxidants, which improve plant growth potential, photosynthesis spontaneity, redox-balance and the antioxidant defense system through quenching of reactive oxygen species (ROS) directly and/or indirectly under AR stress conditions. However, earlier research findings, together with current progresses, would facilitate the future research advancements as well as the adoption of new approaches in attenuating the consequence of AR stress on crops, and might have prospective repercussions in escalating crop farming where AR is a restraining factor.
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Murch SJ, Erland LAE. A Systematic Review of Melatonin in Plants: An Example of Evolution of Literature. FRONTIERS IN PLANT SCIENCE 2021; 12:683047. [PMID: 34249052 PMCID: PMC8270005 DOI: 10.3389/fpls.2021.683047] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/10/2021] [Indexed: 05/06/2023]
Abstract
Melatonin (N-acetyl-5-methoxy-tryptamine) is a mammalian neurohormone, antioxidant and signaling molecule that was first discovered in plants in 1995. The first studies investigated plant melatonin from a human perspective quantifying melatonin in foods and medicinal plants and questioning whether its presence could explain the activity of some plants as medicines. Starting with these first handful of studies in the late 1990s, plant melatonin research has blossomed into a vibrant and active area of investigation and melatonin has been found to play critical roles in mediating plant responses and development at every stage of the plant life cycle from pollen and embryo development through seed germination, vegetative growth and stress response. Here we have utilized a systematic approach in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocols to reduce bias in our assessment of the literature and provide an overview of the current state of melatonin research in plants, covering 1995-2021. This review provides an overview of the biosynthesis and metabolism of melatonin as well as identifying key themes including: abiotic stress responses, root development, light responses, interkingdom communication, phytohormone and plant signaling. Additionally, potential biases in the literature are investigated and a birefringence in the literature between researchers from plant and medical based which has helped to shape the current state of melatonin research. Several exciting new opportunities for future areas of melatonin research are also identified including investigation of non-crop and non-medicinal species as well as characterization of melatonin signaling networks in plants.
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22
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Sun C, Liu L, Wang L, Li B, Jin C, Lin X. Melatonin: A master regulator of plant development and stress responses. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2021; 63:126-145. [PMID: 32678945 DOI: 10.1111/jipb.12993] [Citation(s) in RCA: 159] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 07/16/2020] [Indexed: 05/18/2023]
Abstract
Melatonin is a pleiotropic molecule with multiple functions in plants. Since the discovery of melatonin in plants, numerous studies have provided insight into the biosynthesis, catabolism, and physiological and biochemical functions of this important molecule. Here, we describe the biosynthesis of melatonin from tryptophan, as well as its various degradation pathways in plants. The identification of a putative melatonin receptor in plants has led to the hypothesis that melatonin is a hormone involved in regulating plant growth, aerial organ development, root morphology, and the floral transition. The universal antioxidant activity of melatonin and its role in preserving chlorophyll might explain its anti-senescence capacity in aging leaves. An impressive amount of research has focused on the role of melatonin in modulating postharvest fruit ripening by regulating the expression of ethylene-related genes. Recent evidence also indicated that melatonin functions in the plant's response to biotic stress, cooperating with other phytohormones and well-known molecules such as reactive oxygen species and nitric oxide. Finally, great progress has been made towards understanding how melatonin alleviates the effects of various abiotic stresses, including salt, drought, extreme temperature, and heavy metal stress. Given its diverse roles, we propose that melatonin is a master regulator in plants.
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Affiliation(s)
- Chengliang Sun
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Lijuan Liu
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Luxuan Wang
- Department of Agriculture and Environment, McGill University, Montreal, Quebec, H9X 3V9, Canada
| | - Baohai Li
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Chongwei Jin
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Xianyong Lin
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, China
- Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province, College of Environmental & Resource Sciences, Zhejiang University, Hangzhou, 310058, China
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ROS and NO Regulation by Melatonin Under Abiotic Stress in Plants. Antioxidants (Basel) 2020; 9:antiox9111078. [PMID: 33153156 PMCID: PMC7693017 DOI: 10.3390/antiox9111078] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 01/02/2023] Open
Abstract
Abiotic stress in plants is an increasingly common problem in agriculture, and thus, studies on plant treatments with specific compounds that may help to mitigate these effects have increased in recent years. Melatonin (MET) application and its role in mitigating the negative effects of abiotic stress in plants have become important in the last few years. MET, a derivative of tryptophan, is an important plant-related response molecule involved in the growth, development, and reproduction of plants, and the induction of different stress factors. In addition, MET plays a protective role against different abiotic stresses such as salinity, high/low temperature, high light, waterlogging, nutrient deficiency and stress combination by regulating both the enzymatic and non-enzymatic antioxidant defense systems. Moreover, MET interacts with many signaling molecules, such as reactive oxygen species (ROS) and nitric oxide (NO), and participates in a wide variety of physiological reactions. It is well known that NO produces S-nitrosylation and NO2-Tyr of important antioxidant-related proteins, with this being an important mechanism for maintaining the antioxidant capacity of the AsA/GSH cycle under nitro-oxidative conditions, as extensively reviewed here under different abiotic stress conditions. Lastly, in this review, we show the coordinated actions between NO and MET as a long-range signaling molecule, regulating many responses in plants, including plant growth and abiotic stress tolerance. Despite all the knowledge acquired over the years, there is still more to know about how MET and NO act on the tolerance of plants to abiotic stresses.
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Melatonin-Induced Water Stress Tolerance in Plants: Recent Advances. Antioxidants (Basel) 2020; 9:antiox9090809. [PMID: 32882822 PMCID: PMC7554692 DOI: 10.3390/antiox9090809] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/15/2020] [Accepted: 08/18/2020] [Indexed: 11/16/2022] Open
Abstract
Water stress (drought and waterlogging) is severe abiotic stress to plant growth and development. Melatonin, a bioactive plant hormone, has been widely tested in drought situations in diverse plant species, while few studies on the role of melatonin in waterlogging stress conditions have been published. In the current review, we analyze the biostimulatory functions of melatonin on plants under both drought and waterlogging stresses. Melatonin controls the levels of reactive oxygen and nitrogen species and positively changes the molecular defense to improve plant tolerance against water stress. Moreover, the crosstalk of melatonin and other phytohormones is a key element of plant survival under drought stress, while this relationship needs further investigation under waterlogging stress. In this review, we draw the complete story of water stress on both sides-drought and waterlogging-through discussing the previous critical studies under both conditions. Moreover, we suggest several research directions, especially for waterlogging, which remains a big and vague piece of the melatonin and water stress puzzle.
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Moustafa-Farag M, Mahmoud A, Arnao MB, Sheteiwy MS, Dafea M, Soltan M, Elkelish A, Hasanuzzaman M, Ai S. Melatonin-Induced Water Stress Tolerance in Plants: Recent Advances. Antioxidants (Basel) 2020. [PMID: 32882822 DOI: 10.20944/preprints202008.0359.v1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
Water stress (drought and waterlogging) is severe abiotic stress to plant growth and development. Melatonin, a bioactive plant hormone, has been widely tested in drought situations in diverse plant species, while few studies on the role of melatonin in waterlogging stress conditions have been published. In the current review, we analyze the biostimulatory functions of melatonin on plants under both drought and waterlogging stresses. Melatonin controls the levels of reactive oxygen and nitrogen species and positively changes the molecular defense to improve plant tolerance against water stress. Moreover, the crosstalk of melatonin and other phytohormones is a key element of plant survival under drought stress, while this relationship needs further investigation under waterlogging stress. In this review, we draw the complete story of water stress on both sides-drought and waterlogging-through discussing the previous critical studies under both conditions. Moreover, we suggest several research directions, especially for waterlogging, which remains a big and vague piece of the melatonin and water stress puzzle.
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Affiliation(s)
- Mohamed Moustafa-Farag
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
- Horticulture Research Institute, Agriculture Research Center, 9 Gmaa St, Giza 12619, Egypt
| | - Ahmed Mahmoud
- Horticulture Research Institute, Agriculture Research Center, 9 Gmaa St, Giza 12619, Egypt
- Laboratory of Germplasm Innovation and Molecular Breeding, Institute of Vegetable Science, Zhejiang University, Hangzhou 310058, China
| | - Marino B Arnao
- Department of Plant Physiology, Faculty of Biology, University of Murcia, 30100 Murcia, Spain
| | - Mohamed S Sheteiwy
- Department of Agronomy, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt
| | - Mohamed Dafea
- Horticulture Research Institute, Agriculture Research Center, 9 Gmaa St, Giza 12619, Egypt
| | - Mahmoud Soltan
- Horticulture and Crop Science Department, Ohio Agricultural Research and Development Center, Columbus, The Ohio State University, Columbus, OH 43210, USA
- Vegetable Production under Modified Environment Department, Horticulture Research Institute, Agriculture Research Center, Cairo 11865, Egypt
| | - Amr Elkelish
- Botany Department, Faculty of Science, Suez Canal University, Ismailia 41522, Egypt
| | - Mirza Hasanuzzaman
- Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka 1207, Bangladesh
| | - Shaoying Ai
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
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Debnath B, Li M, Liu S, Pan T, Ma C, Qiu D. Melatonin-mediate acid rain stress tolerance mechanism through alteration of transcriptional factors and secondary metabolites gene expression in tomato. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 200:110720. [PMID: 32470680 DOI: 10.1016/j.ecoenv.2020.110720] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 04/27/2020] [Accepted: 05/03/2020] [Indexed: 05/03/2023]
Abstract
Acid rain is a widespread environmental issue intensely affecting normal plant growth of crops. Melatonin is well known pleiotropic molecule which improves abiotic and biotic stress tolerance of plants through physiological and molecular mediation. However, the impact of exogenous melatonin on molecular activities under acid rain conditions in plants has never been studied. The objective of the study is to expose the possible role of exogenous melatonin on physiological and molecular changes against acid rain stress in tomato. Transcriptome profile through RNA-sequence analysis identified 1228, 1120 and 1537 differentially expressed genes (DEGs) in control plant (Ctr) vs simulated acid rain stressed plant (P25) comparison, control plant vs melatonin treatment in simulated acid rain stressed plant (P25M) comparison and P25 vs P25M comparison, respectively. Among them, 152 differentially expressed genes (DEGs) were commonly expressed and the expression of secondary metabolites related gene was noticeably observed in all comparison. Moreover, transcript families such as ERF, WRKY, MYB and bZIP related gene accounted more in all treatment comparison. The RNA-sequence and qPCR results indicated that exogenous melatonin is closely associated with acid rain stress moderator and might be involved in alteration of differentially expressed genes (DEGs), biosynthesis of plant secondary metabolites and transcriptional factor encoding genes expression which might have potential application against environmental hazardous conditions.
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Affiliation(s)
- Biswojit Debnath
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China; Department of Horticulture, Sylhet Agricultural University, Sylhet, 3100, Bangladesh
| | - Min Li
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Shuang Liu
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Tengfei Pan
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Cuilan Ma
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Dongliang Qiu
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China.
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Tan DX, Reiter RJ. An evolutionary view of melatonin synthesis and metabolism related to its biological functions in plants. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4677-4689. [PMID: 32413108 DOI: 10.1093/jxb/eraa235] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/07/2020] [Indexed: 05/22/2023]
Abstract
Plant melatonin research is a rapidly developing field. A variety of isoforms of melatonin's biosynthetic enzymes are present in different plants. Due to the different origins, they exhibit independent responses to the variable environmental stimuli. The locations for melatonin biosynthesis in plants are chloroplasts and mitochondria. These organelles have inherited their melatonin biosynthetic capacities from their bacterial ancestors. Under ideal conditions, chloroplasts are the main sites of melatonin biosynthesis. If the chloroplast pathway is blocked for any reason, the mitochondrial pathway will be activated for melatonin biosynthesis to maintain its production. Melatonin metabolism in plants is a less studied field; its metabolism is quite different from that of animals even though they share similar metabolites. Several new enzymes for melatonin metabolism in plants have been cloned and these enzymes are absent in animals. It seems that the 2-hydroxymelatonin is a major metabolite of melatonin in plants and its level is ~400-fold higher than that of melatonin. In the current article, from an evolutionary point of view, we update the information on plant melatonin biosynthesis and metabolism. This review will help the reader to understand the complexity of these processes and promote research enthusiasm in these fields.
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Affiliation(s)
| | - Russel J Reiter
- Department of Anatomy and Cell System, UT Health San Antonio, San Antonio, Texas, USA
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Onik JC, Wai SC, Li A, Lin Q, Sun Q, Wang Z, Duan Y. Melatonin treatment reduces ethylene production and maintains fruit quality in apple during postharvest storage. Food Chem 2020; 337:127753. [PMID: 32777566 DOI: 10.1016/j.foodchem.2020.127753] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 07/31/2020] [Accepted: 08/01/2020] [Indexed: 12/22/2022]
Abstract
The effects of treatment with melatonin on ripening of 'Fuji' apples during storage at 1 °C for 56 d were investigated. The apples were harvested at the commercial ripening stage and treated with 1 mmol L-1 melatonin. Compared with the control, melatonin treated apples had significant reduced ethylene production (28 d-56 d) and weight loss (14 d-56 d) during storage (p < 0.05). Also, the melatonin treatment maintained better apple skin structure throughout storage. The reduced ethylene production was regulated by the decreased expressions of MdACO1, MdACS1, MdAP2.4 and MdERF109, based on RNA-Seq analysis, which was validated using qRT-PCR analysis. Moreover, the activity of 3 enzymes, including peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT), were significantly increased in melatonin treated fruit (p < 0.05). Taken together, this study highlights the inhibitory effects of melatonin in ethylene biosynthesis and factors influencing postharvest quality in apple.
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Affiliation(s)
- Jakaria Chowdhury Onik
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/ Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Su Chit Wai
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/ Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Ang Li
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/ Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Qiong Lin
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/ Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China.
| | - Qianqian Sun
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/ Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Zhidong Wang
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/ Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China
| | - Yuquan Duan
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/ Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, People's Republic of China.
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Lee SH, Hwang JW, Han Y, Lee KY. Synergistic stimulating effect of 2-hydroxymelatonin and BMP-4 on osteogenic differentiation in vitro. Biochem Biophys Res Commun 2020; 527:941-946. [PMID: 32439177 DOI: 10.1016/j.bbrc.2020.04.126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 04/24/2020] [Indexed: 10/24/2022]
Abstract
2-Hydroxymelatonin is a metabolite produced when melatonin 2-hydroxylase catalyzes melatonin. Recent studies have reported the important roles of melatonin in bone metabolism. However, the roles of 2-hydroxymelatonin in bone metabolism remains poorly understood. The purpose of this study is to present evidence of the effect of 2-hydroxymelatonin on osteogenic differentiation in C2C12 cells. In this study, we demonstrated the synergistic stimulating effect of 2-hydroxymelatonin and bone morphogenetic protein (BMP)-4 on osteogenic differentiation in vitro, using alkaline phosphatase (ALP) staining, Alizarin red S (ARS) staining, qPCR, and luciferase reporter assay. The combination of 2-hydroxymelatonin and BMP-4 revealed a synergistic effect on osteogenic differentiation in vitro. This finding provides evidence that optimal concentrations of both 2-hydroxymelatonin and BMP-4 are beneficial for anabolic effects on bone in vitro.
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Affiliation(s)
- Sung Ho Lee
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jin Wook Hwang
- INSERM UMR-S 935, Université Paris Sud, 94800 Villejuif, France and ESTeam Paris Sud, Université Paris Sud, 94800, Villejuif, France
| | - Younho Han
- Department of Oral Pharmacology, College of Dentistry, Wonkwang University, Iksan, Republic of Korea.
| | - Kwang Youl Lee
- College of Pharmacy & Research Institute of Drug Development, Chonnam National University, Gwangju, 500-757, Republic of Korea.
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Shah AA, Ahmed S, Ali A, Yasin NA. 2-Hydroxymelatonin mitigates cadmium stress in cucumis sativus seedlings: Modulation of antioxidant enzymes and polyamines. CHEMOSPHERE 2020; 243:125308. [PMID: 31722261 DOI: 10.1016/j.chemosphere.2019.125308] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/30/2019] [Accepted: 11/03/2019] [Indexed: 05/18/2023]
Abstract
Cadmium level is continuously increasing in agricultural soils mainly due to anthropogenic activities. Cadmium is one of the most phytotoxic metals in the soils. The present study investigates the possible role of 2-hydroxymelatonin (2-OHMT) in assuagement of Cd-toxicity in cucumber (Cucumis sativus L.) plants. 2-OHMT is an important metabolite produced through interaction of melatonin with oxygenated compounds. Cadmium stress decreased the activity of antioxidant enzymes and polyamines. However, exogenously applied 2-OHMT enhanced plant growth attributes including photosynthetic rate, intercellular CO2 concentration, stomatal conductance and transpiration rate in treated plants. In addition, 2-OHMT induced enhancement of the activity of PAs biosynthesizing enzymes (putrescine, spermidine and spermine) in conjunction with reduction in activity of polyamine oxidase (PAO). 2-OHMT mitigated Cd stress through up-regulation in expression of stress related CS-ERS gene along with the amplified activity of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) in treated seedlings. The improved activity of antioxidant scavengers played central role in reduction of hydrogen peroxide (H2O2), electrolyte leakage (EL) and malondialdehyde (MDA) in plants under Cd stress. Recent findings also advocate the positive correlation between PAs and ethylene, as both possess common precursor. The current study reveals that priming seeds with 2-OHMT reduces Cd-toxicity and makes it possible to cultivate cucumber in Cd-contaminated areas. Future experiments will perhaps help in elucidation of 2-OHMT intervened stress mitigation procedure in C. sativus crop. Furthermore, research with reference to potential of 2-OHMT for stress alleviation in other horticultural and agronomic crops will assist in enhancement of crop productivity.
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Affiliation(s)
- Anis Ali Shah
- Department of Botany, University of the Punjab, Lahore, Pakistan
| | - Shakil Ahmed
- Department of Botany, University of the Punjab, Lahore, Pakistan
| | - Aamir Ali
- Department of Botany, University of Sargodha, Pakistan
| | - Nasim Ahmad Yasin
- Senior Superintendent Garden, University of the Punjab, Lahore, Pakistan.
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Sun L, Song F, Guo J, Zhu X, Liu S, Liu F, Li X. Nano-ZnO-Induced Drought Tolerance Is Associated with Melatonin Synthesis and Metabolism in Maize. Int J Mol Sci 2020; 21:ijms21030782. [PMID: 31991760 PMCID: PMC7037681 DOI: 10.3390/ijms21030782] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/20/2020] [Accepted: 01/23/2020] [Indexed: 01/11/2023] Open
Abstract
The applications of ZnO nanoparticles in agriculture have largely contributed to crop growth regulation, quality enhancement, and induction of stress tolerance, while the underlying mechanisms remain elusive. Herein, the involvement of melatonin synthesis and metabolism in the process of nano-ZnO induced drought tolerance was investigated in maize. Drought stress resulted in the changes of subcellular ultrastructure, the accumulation of malondialdehyde and osmolytes in leaf. The nano-ZnO (100 mg L-1) application promoted the melatonin synthesis and activated the antioxidant enzyme system, which alleviated drought-induced damage to mitochondria and chloroplast. These changes were associated with upregulation of the relative transcript abundance of Fe/Mn SOD, Cu/Zn SOD, APX, CAT, TDC, SNAT, COMT, and ASMT induced by nano-ZnO application. It was suggested that modifications in endogenous melatonin synthesis were involved in the nano-ZnO induced drought tolerance in maize.
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Affiliation(s)
- Luying Sun
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; (L.S.); (J.G.); (S.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fengbin Song
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; (L.S.); (J.G.); (S.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (F.S.); (X.L.); Tel.: +86-431-8253-6087 (X.L.); Fax: +86-431-8253-6087 (X.L.)
| | - Junhong Guo
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; (L.S.); (J.G.); (S.L.)
| | - Xiancan Zhu
- College of Life Sciences, Anhui Normal University, Wuhu 241000, China;
| | - Shengqun Liu
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; (L.S.); (J.G.); (S.L.)
| | - Fulai Liu
- Department of Plant and Environmental Sciences, University of Copenhagen, Taastrup 2630, Denmark;
| | - Xiangnan Li
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China; (L.S.); (J.G.); (S.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (F.S.); (X.L.); Tel.: +86-431-8253-6087 (X.L.); Fax: +86-431-8253-6087 (X.L.)
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Abstract
Melatonin (N-acetyl-5-methoxytryptamine) is of particular importance as a chronobiological hormone in mammals, acting as a signal of darkness that provides information to the brain and peripheral organs. It is an endogenous synchronizer for both endocrine (i.e., via neurotransmitter release) and other physiological rhythms. In this work we will try to add to the series of scientific events and discoveries made in plants that, surprisingly, confirm the great similarity of action of melatonin in animals and plants. The most relevant milestones on the 25 years of phytomelatonin studies are presented, from its discovery in 1995 to the discovery of its receptor in plants in 2018, suggesting it should be regarded as a new plant hormone.
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Suppression of Melatonin 2-Hydroxylase Increases Melatonin Production Leading to the Enhanced Abiotic Stress Tolerance against Cadmium, Senescence, Salt, and Tunicamycin in Rice Plants. Biomolecules 2019; 9:biom9100589. [PMID: 31597397 PMCID: PMC6843340 DOI: 10.3390/biom9100589] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/01/2019] [Accepted: 10/04/2019] [Indexed: 12/15/2022] Open
Abstract
Melatonin 2-hydroxylase (M2H) catalyzes the conversion of melatonin into 2hydroxymelatonin (2OHM), which is present in plants at a higher concentration than melatonin. Although M2H has been cloned, the in vivo function of its product is unknown. Here, we generated stable T2 homozygous transgenic rice plants in which expression of endogenous M2H was suppressed (RNAi lines). However, we failed to generate M2H overexpression transgenic rice due to failure of somatic embryogenesis. The M2H transcript level showed a diurnal rhythm with a peak at night concomitantly with the peak concentration of 2OHM. RNAi rice showed a reduced M2H mRNA level and 2OHM and melatonin concentrations. The unexpected decrease in the melatonin concentration was caused by redirection of melatonin into cyclic 3hydroxymelatonin via a detour catabolic pathway. Thus, the decrease in the melatonin concentration in M2H RNAi rice led to slowed seedling growth and delayed germination. By contrast, the transient increase in the melatonin concentration was of greater magnitude in the M2H RNAi than the wild-type rice upon cadmium treatment due to possible suppression of melatonin degradation. Due to its higher concentration of melatonin, the M2H RNAi rice displayed tolerance to senescence, salt, and tunicamycin stresses. Therefore, the increase in the melatonin concentration caused by suppression of melatonin degradation or by overexpression of melatonin biosynthetic genes enhances stress tolerance in rice.
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Li J, Liu J, Zhu T, Zhao C, Li L, Chen M. The Role of Melatonin in Salt Stress Responses. Int J Mol Sci 2019; 20:E1735. [PMID: 30965607 PMCID: PMC6479358 DOI: 10.3390/ijms20071735] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 03/30/2019] [Accepted: 04/04/2019] [Indexed: 12/20/2022] Open
Abstract
Melatonin, an indoleamine widely found in animals and plants, is considered as a candidate phytohormone that affects responses to a variety of biotic and abiotic stresses. In plants, melatonin has a similar action to that of the auxin indole-3-acetic acid (IAA), and IAA and melatonin have the same biosynthetic precursor, tryptophan. Salt stress results in the rapid accumulation of melatonin in plants. Melatonin enhances plant resistance to salt stress in two ways: one is via direct pathways, such as the direct clearance of reactive oxygen species; the other is via an indirect pathway by enhancing antioxidant enzyme activity, photosynthetic efficiency, and metabolite content, and by regulating transcription factors associated with stress. In addition, melatonin can affect the performance of plants by affecting the expression of genes. Interestingly, other precursors and metabolite molecules associated with melatonin can also increase the tolerance of plants to salt stress. This paper explores the mechanisms by which melatonin alleviates salt stress by its actions on antioxidants, photosynthesis, ion regulation, and stress signaling.
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Affiliation(s)
- Junpeng Li
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, China.
| | - Jing Liu
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, China.
| | - Tingting Zhu
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, China.
| | - Chen Zhao
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, China.
| | - Lingyu Li
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, China.
| | - Min Chen
- Shandong Provincial Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, China.
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Debnath B, Islam W, Li M, Sun Y, Lu X, Mitra S, Hussain M, Liu S, Qiu D. Melatonin Mediates Enhancement of Stress Tolerance in Plants. Int J Mol Sci 2019; 20:E1040. [PMID: 30818835 PMCID: PMC6429401 DOI: 10.3390/ijms20051040] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/18/2019] [Accepted: 02/22/2019] [Indexed: 02/07/2023] Open
Abstract
Melatonin is a multifunctional signaling molecule, ubiquitously distributed in different parts of plants and responsible for stimulating several physiological responses to adverse environmental conditions. In the current review, we showed that the biosynthesis of melatonin occurred in plants by themselves, and accumulation of melatonin fluctuated sharply by modulating its biosynthesis and metabolic pathways under stress conditions. Melatonin, with its precursors and derivatives, acted as a powerful growth regulator, bio-stimulator, and antioxidant, which delayed leaf senescence, lessened photosynthesis inhibition, and improved redox homeostasis and the antioxidant system through a direct scavenging of reactive oxygen species (ROS) and reactive nitrogen species (RNS) under abiotic and biotic stress conditions. In addition, exogenous melatonin boosted the growth, photosynthetic, and antioxidant activities in plants, confirming their tolerances against drought, unfavorable temperatures, salinity, heavy metals, acid rain, and pathogens. However, future research, together with recent advancements, would support emerging new approaches to adopt strategies in overcoming the effect of hazardous environments on crops and may have potential implications in expanding crop cultivation against harsh conditions. Thus, farming communities and consumers will benefit from elucidating food safety concerns.
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Affiliation(s)
- Biswojit Debnath
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
- Department of Horticulture, Sylhet Agricultural University, Sylhet 3100, Bangladesh.
| | - Waqar Islam
- College of Geographical Sciences, Fujian Normal University, Fuzhou, Fujian 350007, China.
| | - Min Li
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
| | - Yueting Sun
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
| | - Xiaocao Lu
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
| | - Sangeeta Mitra
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
| | - Mubasher Hussain
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
| | - Shuang Liu
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
| | - Dongliang Qiu
- College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
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Xu L, Xiang G, Sun Q, Ni Y, Jin Z, Gao S, Yao Y. Melatonin enhances salt tolerance by promoting MYB108A-mediated ethylene biosynthesis in grapevines. HORTICULTURE RESEARCH 2019; 6:114. [PMID: 31645968 PMCID: PMC6804660 DOI: 10.1038/s41438-019-0197-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/03/2019] [Accepted: 08/14/2019] [Indexed: 05/19/2023]
Abstract
The signal molecules melatonin and ethylene play key roles in abiotic stress tolerance. The interplay between melatonin and ethylene in regulating salt tolerance and the underlying molecular mechanism of this interplay remain unclear. Here, we found that both melatonin and 1-aminocyclopropane-1-carboxylic acid (ACC, a precursor of ethylene) enhanced the tolerance of grapevine to NaCl; additionally, ethylene participated in melatonin-induced salt tolerance. Further experiments indicated that exogenous treatment and endogenous induction of melatonin increased the ACC content and ethylene production in grapevine and tobacco plants, respectively. The expression of MYB108A and ACS1, which function as a transcription factor and a key gene involved in ethylene production, respectively, was strongly induced by melatonin treatment. Additionally, MYB108A directly bound to the promoter of ACS1 and activated its transcription. MYB108A expression promoted ACC synthesis and ethylene production by activating ACS1 expression in response to melatonin treatment. The suppression of MYB108A expression partially limited the effect of melatonin on the induction of ethylene production and reduced melatonin-induced salt tolerance. Collectively, melatonin promotes ethylene biosynthesis and salt tolerance through the regulation of ACS1 by MYB108A.
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Affiliation(s)
- Lili Xu
- State Key Laboratory of Crop Biology, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018 China
| | - Guangqing Xiang
- State Key Laboratory of Crop Biology, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018 China
| | - Qinghua Sun
- State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai-An, Shandong 271018 China
| | - Yong Ni
- State Key Laboratory of Crop Biology, College of Life Science, Shandong Agricultural University, Tai-An, Shandong 271018 China
| | - Zhongxin Jin
- State Key Laboratory of Crop Biology, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018 China
| | - Shiwei Gao
- State Key Laboratory of Crop Biology, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018 China
| | - Yuxin Yao
- State Key Laboratory of Crop Biology, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, Shandong 271018 China
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Kanwar MK, Yu J, Zhou J. Phytomelatonin: Recent advances and future prospects. J Pineal Res 2018; 65:e12526. [PMID: 30256447 DOI: 10.1111/jpi.12526] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/16/2018] [Accepted: 09/18/2018] [Indexed: 12/13/2022]
Abstract
Melatonin (MEL) has been revealed as a phylogenetically conserved molecule with a ubiquitous distribution from primitive photosynthetic bacteria to higher plants, including algae and fungi. Since MEL is implicated in numerous plant developmental processes and stress responses, the exploration of its functions in plant has become a rapidly progressing field with the new paradigm of involvement in plants growth and development. The pleiotropic involvement of MEL in regulating the transcripts of numerous genes confirms its vital involvement as a multi-regulatory molecule that architects many aspects of plant development. However, the cumulative research in plants is still preliminary and fragmentary in terms of its established functions compared to what is known about MEL physiology in animals. This supports the need for a comprehensive review that summarizes the new aspects pertaining to its functional role in photosynthesis, phytohormonal interactions under stress, cellular redox signaling, along with other regulatory roles in plant immunity, phytoremediation, and plant microbial interactions. The present review covers the latest advances on the mechanistic roles of phytomelatonin. While phytomelatonin is a sovereign plant growth regulator that can interact with the functions of other plant growth regulators or hormones, its qualifications as a complete phytohormone are still to be established. This review also showcases the yet to be identified potentials of phytomelatonin that will surely encourage the plant scientists to uncover new functional aspects of phytomelatonin in plant growth and development, subsequently improving its status as a potential new phytohormone.
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Affiliation(s)
- Mukesh Kumar Kanwar
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zijingang Campus, Zhejiang University, Hangzhou, China
| | - Jingquan Yu
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zijingang Campus, Zhejiang University, Hangzhou, China
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Hangzhou, China
| | - Jie Zhou
- Department of Horticulture, Zhejiang Provincial Key Laboratory of Horticultural Plant Integrative Biology, Zijingang Campus, Zhejiang University, Hangzhou, China
- Key Laboratory of Horticultural Plants Growth, Development and Quality Improvement, Agricultural Ministry of China, Hangzhou, China
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Lee HY, Back K. Melatonin induction and its role in high light stress tolerance in Arabidopsis thaliana. J Pineal Res 2018; 65:e12504. [PMID: 29770489 DOI: 10.1111/jpi.12504] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/26/2018] [Indexed: 12/20/2022]
Abstract
In plants, melatonin is a potent bioactive molecule involved in the response against various biotic and abiotic stresses. However, little is known of its defensive role against high light (HL) stress. In this study, we found that melatonin was transiently induced in response to HL stress in Arabidopsis thaliana with a simultaneous increase in the expression of melatonin biosynthetic genes, including serotonin N-acetyltransferase1 (SNAT1). Transient induction of melatonin was also observed in the flu mutant, a singlet oxygen (1 O2 )-producing mutant, upon light exposure, suggestive of melatonin induction by chloroplastidic 1 O2 against HL stress. An Arabidopsis snat1 mutant was devoid of melatonin induction upon HL stress, resulting in high susceptibility to HL stress. Exogenous melatonin treatment mitigated damage caused by HL stress in the snat1 mutant by reducing O2- production and increasing the expression of various ROS-responsive genes. In analogy, an Arabidopsis SNAT1-overexpressing line showed increased tolerance of HL stress concomitant with a reduction in malondialdehyde and ion leakage. A complementation line expressing an Arabidopsis SNAT1 genomic fragment in the snat1 mutant completely restored HL stress susceptibility in the snat1 mutant to levels comparable to that of wild-type Col-0 plants. The results of the analysis of several Arabidopsis genetic lines reveal for the first time at the genetic level that melatonin is involved in conferring HL stress tolerance in plants.
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Affiliation(s)
- Hyoung Yool Lee
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
| | - Kyoungwhan Back
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
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Lee K, Hwang OJ, Reiter RJ, Back K. Flavonoids inhibit both rice and sheep serotonin N-acetyltransferases and reduce melatonin levels in plants. J Pineal Res 2018; 65:e12512. [PMID: 29851162 DOI: 10.1111/jpi.12512] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 05/25/2018] [Indexed: 12/29/2022]
Abstract
The plant melatonin biosynthetic pathway has been well characterized, but inhibitors of melatonin synthesis have not been well studied. Here, we found that flavonoids potently inhibited plant melatonin synthesis. For example, flavonoids including morin and myricetin significantly inhibited purified, recombinant sheep serotonin N-acetyltransferase (SNAT). Flavonoids also dose-dependently and potently inhibited purified rice SNAT1 and SNAT2. Thus, myricetin (100 μmol/L) reduced rice SNAT1 and SNAT2 activity 7- and 10-fold, respectively, and also strongly inhibited the N-acetylserotonin methyltransferase activity of purified, recombinant rice caffeic acid O-methyltransferase. To explore the in vivo effects, rice leaves were treated with flavonoids and then cadmium. Flavonoid-treated leaves had lower melatonin levels than the untreated control. To explore the direct roles of flavonoids in melatonin biosynthesis, we first functionally characterized a putative rice flavonol synthase (FLS) in vitro and generated flavonoid-rich transgenic rice plants that overexpressed FLS. Such plants produced more flavonoids but less melatonin than the wild-type, which suggests that flavonoids indeed inhibit plant melatonin biosynthesis.
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Affiliation(s)
- Kyungjin Lee
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, Korea
| | - Ok Jin Hwang
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, Korea
| | - Russel J Reiter
- Department of Cellular and Structural Biology, The Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Kyoungwhan Back
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, Korea
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Yu Y, Lv Y, Shi Y, Li T, Chen Y, Zhao D, Zhao Z. The Role of Phyto-Melatonin and Related Metabolites in Response to Stress. Molecules 2018; 23:E1887. [PMID: 30060559 PMCID: PMC6222801 DOI: 10.3390/molecules23081887] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/26/2018] [Accepted: 07/26/2018] [Indexed: 11/29/2022] Open
Abstract
Plant hormone candidate melatonin has been widely studied in plants under various stress conditions, such as heat, cold, salt, drought, heavy metal, and pathogen attack. Under stress, melatonin usually accumulates sharply by modulating its biosynthesis and metabolic pathways. Beginning from the precursor tryptophan, four consecutive enzymes mediate the biosynthesis of tryptamine or 5-hydroxytryptophan, serotonin, N-acetylserotonin or 5-methoxytryptamine, and melatonin. Then, the compound is catabolized into 2-hydroxymelatonin, cyclic-3-hydroxymelatonin, and N¹-acetyl-N²-formyl-5-methoxyknuramine through 2-oxoglutarate-dependent dioxygenase catalysis or reaction with reactive oxygen species. As an ancient and powerful antioxidant, melatonin directly scavenges ROS induced by various stress conditions. Furthermore, it confreres stress tolerance by activating the plant's antioxidant system, alleviating photosynthesis inhibition, modulating transcription factors that are involved with stress resisting, and chelating and promoting the transport of heavy metals. Melatonin is even proven to defense against pathogen attacks for the plant by activating other stress-relevant hormones, like salicylic acid, ethylene, and jasmonic acid. Intriguingly, other precursors and metabolite molecules involved with melatonin also can increase stress tolerance for plant except for unconfirmed 5-methoxytryptamine, cyclic-3-hydroxymelatonin, and N¹-acetyl-N²-formyl-5-methoxyknuramine. Therefore, the precursors and metabolites locating at the whole biosynthesis and catabolism pathway of melatonin could contribute to plant stress resistance, thus providing a new perspective for promoting plant stress tolerance.
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Affiliation(s)
- Yang Yu
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan University, Kunming 650091, China.
| | - Yan Lv
- School of Agriculture, Yunnan University, Kunming 650504, China.
| | - Yana Shi
- Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming 650205, China.
| | - Tao Li
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan University, Kunming 650091, China.
| | - Yanchun Chen
- School of Agriculture, Yunnan University, Kunming 650504, China.
| | - Dake Zhao
- Biocontrol Engineering Research Center of Plant Disease & Pest, Yunnan University, Kunming 650504, China.
- Biocontrol Engineering Research Center of Crop Disease & Pest, Yunnan University, Kunming 650504, China.
| | - Zhiwei Zhao
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan University, Kunming 650091, China.
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41
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Erland LAE, Saxena PK, Murch SJ. Melatonin in plant signalling and behaviour. FUNCTIONAL PLANT BIOLOGY : FPB 2018; 45:58-69. [PMID: 32291021 DOI: 10.1071/fp16384] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/29/2017] [Indexed: 05/23/2023]
Abstract
Melatonin is an indoleamine neurotransmitter that has recently become well established as an important multi-functional signalling molecule in plants. These signals have been found to induce several important physiological responses that may be interpreted as behaviours. The diverse processes in which melatonin has been implicated in plants have expanded far beyond the traditional roles for which it has been implicated in mammals, which include sleep, tropisms and reproduction. These functions, however, appear to also be important melatonin mediated processes in plants, though the mechanisms underlying these functions have yet to be fully elucidated. Mediation or redirection of plant physiological processes induced by melatonin can be summarised as a series of behaviours including, among others: herbivore defence, avoidance of undesirable circumstances or attraction to opportune conditions, problem solving and response to environmental stimulus. As the mechanisms of melatonin action are elucidated, its involvement in plant growth, development and behaviour is likely to expand beyond the aspects discussed in this review and hold promise for applications in diverse fundamental and applied plant sciences including conservation, cryopreservation, morphogenesis, industrial agriculture and natural health products.
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Affiliation(s)
- Lauren A E Erland
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, 50 Stone Road E, Guelph, Ontario, N1G 2W1, Canada
| | - Praveen K Saxena
- Gosling Research Institute for Plant Preservation, Department of Plant Agriculture, University of Guelph, 50 Stone Road E, Guelph, Ontario, N1G 2W1, Canada
| | - Susan J Murch
- Chemistry, University of British Columbia, Okanagan, Kelowna, British Columbia, V1V 1V7, Canada
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Hu W, Yang H, Tie W, Yan Y, Ding Z, Liu Y, Wu C, Wang J, Reiter RJ, Tan DX, Shi H, Xu B, Jin Z. Natural Variation in Banana Varieties Highlights the Role of Melatonin in Postharvest Ripening and Quality. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:9987-9994. [PMID: 29077394 DOI: 10.1021/acs.jafc.7b03354] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
This study aimed to investigate the role of melatonin in postharvest ripening and quality in various banana varieties with contrasting ripening periods. During the postharvest life, endogenous melatonin showed similar performance with ethylene in connection to ripening. In comparison to ethylene, melatonin was more correlated with postharvest banana ripening. Exogenous application of melatonin resulted in a delay of postharvest banana ripening. Moreover, this effect is concentration-dependent, with 200 and 500 μM treatments more effective than the 50 μM treatment. Exogenous melatonin also led to elevated endogenous melatonin content, reduced ethylene production through regulation of the expression of MaACO1 and MaACS1, and delayed sharp changes of quality indices. Taken together, this study highlights that melatonin is an indicator for banana fruit ripening in various varieties, and the repression of ethylene biosynthesis and postharvest ripening by melatonin can be used for biological control of postharvest fruit ripening and quality.
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Affiliation(s)
- Wei Hu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences , Xueyuan Road 4, Haikou, Hainan 571101, People's Republic of China
| | - Hai Yang
- National Engineering Research Center for Nanomedicine, College of Life Science and Technology, Huazhong University of Science and Technology , Luoyu Road 1037, Wuhan, Hubei 430074, People's Republic of China
| | - Weiwei Tie
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences , Xueyuan Road 4, Haikou, Hainan 571101, People's Republic of China
| | - Yan Yan
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences , Xueyuan Road 4, Haikou, Hainan 571101, People's Republic of China
| | - Zehong Ding
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences , Xueyuan Road 4, Haikou, Hainan 571101, People's Republic of China
| | - Yang Liu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences , Xueyuan Road 4, Haikou, Hainan 571101, People's Republic of China
| | - Chunlai Wu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences , Xueyuan Road 4, Haikou, Hainan 571101, People's Republic of China
| | - Jiashui Wang
- Key Laboratory of Genetic Improvement of Bananas, Hainan Province, Haikou Experimental Station, China Academy of Tropical Agricultural Sciences , Haikou, Hainan 570102, People's Republic of China
| | - Russel J Reiter
- Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio , 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Dun-Xian Tan
- Department of Cellular and Structural Biology, The University of Texas Health Science Center at San Antonio , 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Haitao Shi
- Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources and College of Biology, Institute of Tropical Agriculture and Forestry, Hainan University , Haikou, Hainan 570228, People's Republic of China
| | - Biyu Xu
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences , Xueyuan Road 4, Haikou, Hainan 571101, People's Republic of China
| | - Zhiqiang Jin
- Key Laboratory of Biology and Genetic Resources of Tropical Crops, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences , Xueyuan Road 4, Haikou, Hainan 571101, People's Republic of China
- Key Laboratory of Genetic Improvement of Bananas, Hainan Province, Haikou Experimental Station, China Academy of Tropical Agricultural Sciences , Haikou, Hainan 570102, People's Republic of China
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Hardeland R. Taxon- and Site-Specific Melatonin Catabolism. Molecules 2017; 22:molecules22112015. [PMID: 29160833 PMCID: PMC6150314 DOI: 10.3390/molecules22112015] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 11/20/2017] [Accepted: 11/20/2017] [Indexed: 01/14/2023] Open
Abstract
Melatonin is catabolized both enzymatically and nonenzymatically. Nonenzymatic processes mediated by free radicals, singlet oxygen, other reactive intermediates such as HOCl and peroxynitrite, or pseudoenzymatic mechanisms are not species- or tissue-specific, but vary considerably in their extent. Higher rates of nonenzymatic melatonin metabolism can be expected upon UV exposure, e.g., in plants and in the human skin. Additionally, melatonin is more strongly nonenzymatically degraded at sites of inflammation. Typical products are several hydroxylated derivatives of melatonin and N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK). Most of these products are also formed by enzymatic catalysis. Considerable taxon- and site-specific differences are observed in the main enzymatic routes of catabolism. Formation of 6-hydroxymelatonin by cytochrome P450 subforms are prevailing in vertebrates, predominantly in the liver, but also in the brain. In pineal gland and non-mammalian retina, deacetylation to 5-methoxytryptamine (5-MT) plays a certain role. This pathway is quantitatively prevalent in dinoflagellates, in which 5-MT induces cyst formation and is further converted to 5-methoxyindole-3-acetic acid, an end product released to the water. In plants, the major route is catalyzed by melatonin 2-hydroxylase, whose product is tautomerized to 3-acetamidoethyl-3-hydroxy-5-methoxyindolin-2-one (AMIO), which exceeds the levels of melatonin. Formation and properties of various secondary products are discussed.
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Affiliation(s)
- Rüdiger Hardeland
- Johann Friedrich Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Bürgerstr 50, D-37073 Göttingen, Germany.
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44
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Lee K, Choi GH, Back K. Cadmium-induced melatonin synthesis in rice requires light, hydrogen peroxide, and nitric oxide: Key regulatory roles for tryptophan decarboxylase and caffeic acid O-methyltransferase. J Pineal Res 2017; 63. [PMID: 28793366 DOI: 10.1111/jpi.12441] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 08/04/2017] [Indexed: 12/21/2022]
Abstract
In plants, melatonin production is induced by stimuli such as cold and drought, and cadmium (Cd) is the best elicitor of melatonin production in rice. However, the mechanism by which Cd induces melatonin synthesis in plants remains unknown. We challenged rice seedlings with Cd under different light conditions and found that continuous light produced the highest levels of melatonin, while continuous dark failed to induce melatonin production. Transcriptional and translational induction of tryptophan decarboxylase contributed to the light induction of melatonin during Cd treatment, whereas the protein level of light-induced caffeic acid O-methyltransferase (COMT) was decreased by Cd treatment. In analogy, COMT enzyme activity was inhibited in vitro by Cd in a dose-dependent manner. Notably, the Cd-induced melatonin synthesis was significantly impaired by treatment with either an H2 O2 production inhibitor (DPI) or an NO scavenger (cPTIO). The combination of both inhibitors almost completely abolished Cd-induced melatonin synthesis, suggesting an absolute requirement for H2 O2 and NO. However, neither serotonin nor N-acetylserotonin (NAS) was induced by H2 O2 alone. In contrast, NO significantly induced serotonin production but not NAS or melatonin production. This indicated that serotonin did not enter chloroplasts, where serotonin N-acetyltransferase (SNAT) is constitutively expressed. This suggests that chloroplastidic SNAT expression prevents increased melatonin production after exposure to stress, ultimately leading to the maintenance of a steady-state melatonin level inside cells.
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Affiliation(s)
- Kyungjin Lee
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, Korea
| | - Geun-Hee Choi
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, Korea
| | - Kyoungwhan Back
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, Korea
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45
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Lee HY, Back K. Cadmium Disrupts Subcellular Organelles, Including Chloroplasts, Resulting in Melatonin Induction in Plants. Molecules 2017; 22:E1791. [PMID: 29065548 PMCID: PMC6151721 DOI: 10.3390/molecules22101791] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 10/18/2017] [Accepted: 10/21/2017] [Indexed: 11/23/2022] Open
Abstract
Cadmium is a well-known elicitor of melatonin synthesis in plants, including rice. However, the mechanisms by which cadmium induces melatonin induction remain elusive. To investigate whether cadmium influences physical integrities in subcellular organelles, we treated tobacco leaves with either CdCl₂ or AlCl₃ and monitored the structures of subcellular organelles-such as chloroplasts, mitochondria, and the endoplasmic reticulum (ER)-using confocal microscopic analysis. Unlike AlCl₃ treatment, CdCl₂ (0.5 mM) treatment significantly disrupted chloroplasts, mitochondria, and ER. In theory, the disruption of chloroplasts enabled chloroplast-expressed serotonin N-acetyltransferase (SNAT) to encounter serotonin in the cytoplasm, leading to the synthesis of N-acetylserotonin followed by melatonin synthesis. In fact, the disruption of chloroplasts by cadmium, not by aluminum, gave rise to a huge induction of melatonin in rice leaves, which suggests that cadmium-treated chloroplast disruption plays an important role in inducing melatonin in plants by removing physical barriers, such as chloroplast double membranes, allowing SNAT to gain access to the serotonin substrate enriched in the cytoplasm.
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Affiliation(s)
- Hyoung-Yool Lee
- Department of Biotechnology, Bioenergy Research Center, College of Agriculture and Life Sciences, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, Korea.
| | - Kyoungwhan Back
- Department of Biotechnology, Bioenergy Research Center, College of Agriculture and Life Sciences, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 61186, Korea.
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Gong X, Shi S, Dou F, Song Y, Ma F. Exogenous Melatonin Alleviates Alkaline Stress in Malus hupehensis Rehd. by Regulating the Biosynthesis of Polyamines. Molecules 2017; 22:molecules22091542. [PMID: 28902159 PMCID: PMC6151414 DOI: 10.3390/molecules22091542] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 09/07/2017] [Accepted: 09/11/2017] [Indexed: 12/25/2022] Open
Abstract
Since melatonin was identified in plants decades ago, much attention has been devoted to discovering its role in plant science. There is still a great deal to learn about the functional importance of melatonin, as well as its functional mode. In this paper, we examine the role of melatonin treatment in the response of Malus hupehensis Rehd. to alkaline conditions. Stressed seedlings showed chlorosis and suppressed growth. However, this phenotype was ameliorated when 5 µM melatonin was added to the irrigation solution. This supplementation was also associated with a reduction in cell membrane damage and maintenance of a normal root system architecture. Fewer reactive oxygen species (ROS) were accumulated due to the enhanced scavenging activity of antioxidant enzymes superoxide dismutase, peroxidase, and catalase. In addition, alkaline-stressed seedlings that received the melatonin supplement accumulated more polyamines compared with untreated seedlings. Transcript levels of six genes involved in polyamine synthesis, including SAMDC1, -3, and -4, and SPDS1, -3, and -5, -6, were upregulated in response to melatonin application. All of these results demonstrate that melatonin has a positive function in plant tolerance to alkaline stress because it regulates enzyme activity and the biosynthesis of polyamines.
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Affiliation(s)
- Xiaoqing Gong
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| | - Shuting Shi
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| | - Fangfang Dou
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| | - Yi Song
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
| | - Fengwang Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A & F University, Yangling 712100, Shaanxi, China.
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Choi GH, Lee HY, 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. [PMID: 28378373 DOI: 10.1111/jpi.12412] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 03/31/2017] [Indexed: 12/29/2022]
Abstract
Recent analyses of the enzymatic features of various melatonin biosynthetic genes from bacteria, animals, and plants have led to the hypothesis that melatonin could be synthesized via the 5-methoxytryptamine (5-MT) pathway. 5-MT is known to be synthesized in vitro from serotonin by the enzymatic action of O-methyltransferases, including N-acetylserotonin methyltransferase (ASMT) and caffeic acid O-methyltransferase (COMT), leading to melatonin synthesis by the subsequent enzymatic reaction with serotonin N-acetyltransferase (SNAT). Here, we show that 5-MT was produced and served as a precursor for melatonin synthesis in plants. When rice seedlings were challenged with senescence treatment, 5-MT levels and melatonin production were increased in transgenic rice seedlings overexpressing the rice COMT in chloroplasts, while no such increases were observed in wild-type or transgenic seedlings overexpressing the rice COMT in the cytosol, suggesting a 5-MT transport limitation from the cytosol to chloroplasts. In contrast, cadmium treatment led to results different from those in senescence. The enhanced melatonin production was not observed in the chloroplast COMT lines relative over the cytosol COMT lines although 5-MT levels were equally induced in all genotypes upon cadmium treatment. The transgenic seedlings with enhanced melatonin in their chloroplasts exhibited improved seedling growth vs the wild type under continuous light conditions. This is the first report describing enhanced melatonin production in chloroplasts via the 5-MT pathway with the ectopic overexpression of COMT in chloroplasts in plants.
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Affiliation(s)
- Geun-Hee Choi
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
| | - Hyoung Yool Lee
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
| | - Kyoungwhan Back
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, South Korea
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2-Hydroxymelatonin, a Predominant Hydroxylated Melatonin Metabolite in Plants, Shows Antitumor Activity against Human Colorectal Cancer Cells. Molecules 2017; 22:molecules22030453. [PMID: 28335402 PMCID: PMC6155377 DOI: 10.3390/molecules22030453] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 03/07/2017] [Accepted: 03/11/2017] [Indexed: 12/22/2022] Open
Abstract
2-Hydroxymelatonin is a predominant hydroxylated melatonin metabolite in plants. To investigate whether it has potent cytotoxic effects on colorectal cancer cells, four colorectal cancer cell lines, Caco2, HCT116, DLD1, and CT26, were treated with 2-hydroxymelatonin and melatonin. 2-Hydroxymelatonin had a much lower IC50 value than melatonin in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cytotoxic effect of 2-hydroxymelatonin was much stronger than that of melatonin at high concentrations (1000 or 2000 μM) in HCT116, DLD1, and CT26 cells, but only at intermediate concentrations (250 or 500 μM) in Caco2 cells. The cytotoxicity of 2-hydroxymelatonin was induced through activation of the apoptotic signaling pathway, as confirmed by Hoechst staining and Annexin V-FITC/propidium iodide double labeling of cells treated with a lethal dose (1 mM). However, sub-lethal doses of 2-hydroxymelatonin inhibited the invasive ability of Caco2 cells. Epithelial-mesenchymal transition (EMT) markers were significantly regulated by 2-hydroxymelatonin. Overall, the anti-cancer activity of 2-hydroxymelatonin is more potent than that of melatonin. Taken together, 2-hydroxymelatonin exhibits potent anti-cancer activity against human colorectal cancer cells via induction of apoptosis and inhibition of EMT.
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Tan DX, Manchester LC, Qin L, Reiter RJ. Melatonin: A Mitochondrial Targeting Molecule Involving Mitochondrial Protection and Dynamics. Int J Mol Sci 2016; 17:ijms17122124. [PMID: 27999288 PMCID: PMC5187924 DOI: 10.3390/ijms17122124] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 11/28/2016] [Accepted: 12/07/2016] [Indexed: 01/19/2023] Open
Abstract
Melatonin has been speculated to be mainly synthesized by mitochondria. This speculation is supported by the recent discovery that aralkylamine N-acetyltransferase/serotonin N-acetyltransferase (AANAT/SNAT) is localized in mitochondria of oocytes and the isolated mitochondria generate melatonin. We have also speculated that melatonin is a mitochondria-targeted antioxidant. It accumulates in mitochondria with high concentration against a concentration gradient. This is probably achieved by an active transportation via mitochondrial melatonin transporter(s). Melatonin protects mitochondria by scavenging reactive oxygen species (ROS), inhibiting the mitochondrial permeability transition pore (MPTP), and activating uncoupling proteins (UCPs). Thus, melatonin maintains the optimal mitochondrial membrane potential and preserves mitochondrial functions. In addition, mitochondrial biogenesis and dynamics is also regulated by melatonin. In most cases, melatonin reduces mitochondrial fission and elevates their fusion. Mitochondrial dynamics exhibit an oscillatory pattern which matches the melatonin circadian secretory rhythm in pinealeocytes and probably in other cells. Recently, melatonin has been found to promote mitophagy and improve homeostasis of mitochondria.
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Affiliation(s)
- Dun-Xian Tan
- Department of Cell System and Anatomy, The University of Texas Health Science Center, San Antonio, TX 78229, USA.
| | - Lucien C Manchester
- Department of Cell System and Anatomy, The University of Texas Health Science Center, San Antonio, TX 78229, USA.
| | - Lilan Qin
- Department of Cell System and Anatomy, The University of Texas Health Science Center, San Antonio, TX 78229, USA.
| | - Russel J Reiter
- Department of Cell System and Anatomy, The University of Texas Health Science Center, San Antonio, TX 78229, USA.
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Back K, Tan DX, Reiter RJ. Melatonin biosynthesis in plants: multiple pathways catalyze tryptophan to melatonin in the cytoplasm or chloroplasts. J Pineal Res 2016; 61:426-437. [PMID: 27600803 DOI: 10.1111/jpi.12364] [Citation(s) in RCA: 244] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 09/02/2016] [Indexed: 02/06/2023]
Abstract
Melatonin is an animal hormone as well as a signaling molecule in plants. It was first identified in plants in 1995, and almost all enzymes responsible for melatonin biosynthesis had already been characterized in these species. Melatonin biosynthesis from tryptophan requires four-step reactions. However, six genes, that is, TDC, TPH, T5H, SNAT, ASMT, and COMT, have been implicated in the synthesis of melatonin in plants, suggesting the presence of multiple pathways. Two major pathways have been proposed based on the enzyme kinetics: One is the tryptophan/tryptamine/serotonin/N-acetylserotonin/melatonin pathway, which may occur under normal growth conditions; the other is the tryptophan/tryptamine/serotonin/5-methoxytryptamine/melatonin pathway, which may occur when plants produce large amounts of serotonin, for example, upon senescence. The melatonin biosynthetic capacity associated with conversion of tryptophan to serotonin is much higher than that associated with conversion of serotonin to melatonin, which yields a low level of melatonin synthesis in plants. Many melatonin intermediates are produced in various subcellular compartments, such as the cytoplasm, endoplasmic reticulum, and chloroplasts, which either facilitates or impedes the subsequent enzymatic steps. Depending on the pathways, the final subcellular sites of melatonin synthesis vary at either the cytoplasm or chloroplasts, which may differentially affect the mode of action of melatonin in plants.
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Affiliation(s)
- Kyoungwhan Back
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, Korea.
| | - Dun-Xian Tan
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Russel J Reiter
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX, USA
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