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Malakar P, Gupta SK, Chattopadhyay D. Role of plant neurotransmitters in salt stress: A critical review. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 211:108601. [PMID: 38696867 DOI: 10.1016/j.plaphy.2024.108601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 03/22/2024] [Accepted: 04/03/2024] [Indexed: 05/04/2024]
Abstract
Neurotransmitters are naturally found in many plants, but the molecular processes that govern their actions still need to be better understood. Acetylcholine, γ-Aminobutyric acid, histamine, melatonin, serotonin, and glutamate are the most common neurotransmitters in animals, and they all play a part in the development and information processing. It is worth noting that all these chemicals have been found in plants. Although much emphasis has been placed on understanding how neurotransmitters regulate mood and behaviour in humans, little is known about how they regulate plant growth and development. In this article, the information was reviewed and updated considering current thinking on neurotransmitter signaling in plants' metabolism, growth, development, salt tolerance, and the associated avenues for underlying research. The goal of this study is to advance neurotransmitter signaling research in plant biology, especially in the area of salt stress physiology.
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Affiliation(s)
- Paheli Malakar
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Santosh K Gupta
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Debasis Chattopadhyay
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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2
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Muhammad I, Ahmad S, Shen W. Melatonin-Mediated Molecular Responses in Plants: Enhancing Stress Tolerance and Mitigating Environmental Challenges in Cereal Crop Production. Int J Mol Sci 2024; 25:4551. [PMID: 38674136 PMCID: PMC11049982 DOI: 10.3390/ijms25084551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Cereal crops are crucial for global food security; however, they are susceptible to various environmental stresses that significantly hamper their productivity. In response, melatonin has emerged as a promising regulator, offering potential benefits for stress tolerance and crop growth. This review explores the effects of melatonin on maize, sorghum, millet, rice, barley, and wheat, aiming to enhance their resilience to stress. The application of melatonin has shown promising outcomes, improving water use efficiency and reducing transpiration rates in millet under drought stress conditions. Furthermore, it enhances the salinity and heavy metal tolerance of millet by regulating the activity of stress-responsive genes. Similarly, melatonin application in sorghum enhances its resistance to high temperatures, low humidity, and nutrient deficiency, potentially involving the modulation of antioxidant defense and aspects related to photosynthetic genes. Melatonin also exerts protective effects against drought, salinity, heavy metal, extreme temperatures, and waterlogging stresses in maize, wheat, rice, and barley crops by decreasing reactive oxygen species (ROS) production through regulating the antioxidant defense system. The molecular reactions of melatonin upregulated photosynthesis, antioxidant defense mechanisms, the metabolic pathway, and genes and downregulated stress susceptibility genes. In conclusion, melatonin serves as a versatile tool in cereal crops, bolstering stress resistance and promoting sustainable development. Further investigations are warranted to elucidate the underlying molecular mechanisms and refine application techniques to fully harness the potential role of melatonin in cereal crop production systems.
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Affiliation(s)
- Ihsan Muhammad
- Guangxi Key Laboratory of Forest Ecology and Conservation, State Key Laboratory for Conservation and Utilization of Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China;
| | - Shakeel Ahmad
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Life Science and Technology, Guangxi University, Nanning 530004, China;
| | - Weijun Shen
- Guangxi Key Laboratory of Forest Ecology and Conservation, State Key Laboratory for Conservation and Utilization of Agro-Bioresources, College of Forestry, Guangxi University, Nanning 530004, China;
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3
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Wang L, Tanveer M, Wang H, Arnao MB. Melatonin as a key regulator in seed germination under abiotic stress. J Pineal Res 2024; 76:e12937. [PMID: 38241678 DOI: 10.1111/jpi.12937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 12/23/2023] [Accepted: 01/02/2024] [Indexed: 01/21/2024]
Abstract
Seed germination (SG) is the first stage in a plant's life and has an immense importance in sustaining crop production. Abiotic stresses reduce SG by increasing the deterioration of seed quality, and reducing germination potential, and seed vigor. Thus, to achieve a sustainable level of crop yield, it is important to improve SG under abiotic stress conditions. Melatonin (MEL) is an important biomolecule that interplays in developmental processes and regulates many adaptive responses in plants, especially under abiotic stresses. Thus, this review specifically summarizes and discusses the mechanistic basis of MEL-mediated SG under abiotic stresses. MEL regulates SG by regulating some stress-specific responses and some common responses. For instance, MEL induced stress specific responses include the regulation of ionic homeostasis, and hydrolysis of storage proteins under salinity stress, regulation of C-repeat binding factors signaling under cold stress, starch metabolism under high temperature and heavy metal stress, and activation of aquaporins and accumulation of osmolytes under drought stress. On other hand, MEL mediated regulation of gibberellins biosynthesis and abscisic acid catabolism, redox homeostasis, and Ca2+ signaling are amongst the common responses. Nonetheless factors such as endogenous MEL contents, plant species, and growth conditions also influence above-mentioned responses. In conclusion, MEL regulates SG under abiotic stress conditions by interacting with different physiological mechanisms.
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Affiliation(s)
- Lei Wang
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Mohsin Tanveer
- State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Hongling Wang
- CAS Research Center for Ecology and Environment of Central Asia, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, China
| | - Marino B Arnao
- Phytohormones & Plant Development Laboratory, Department of Plant Biology (Plant Physiology), University of Murcia, Murcia, Spain
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Kong M, Ali Q, Jing H, Hussain A, Wang F, Liu X, Gao X, Xu HL. Exogenous Melatonin Regulates Plant-Disease Interaction by Inducing Maize Resistance and Decreasing the Pathogenicity of Fusarium graminearum. PHYSIOLOGIA PLANTARUM 2023; 175:e14108. [PMID: 38148237 DOI: 10.1111/ppl.14108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/20/2023] [Indexed: 12/28/2023]
Abstract
Plants cannot avoid environmental challenges and are constantly threatened by diverse biotic and abiotic stresses. However, plants have developed a unique immune system to defend themselves against the invasion of various pathogens. Melatonin, N-acetyl-5-methoxytryptamine has positive physiological effects in plants that are involved in disease resistance. The processes underlying melatonin-induced pathogen resistance in plants are still unknown. The current study explores how melatonin regulates the plant-disease interaction in maize. The results showed that 400 μM melatonin strongly reduced the disease lesion on maize stalks by 1.5 cm and corn by 4.0 cm caused by Fusarium graminearum PH-1. Furthermore, after treatment with melatonin, the plant defense enzymes like SOD significantly increased, while POD and APX significantly decreased compared to the control. In addition, melatonin can also improve maize's innate immunity, which is mediated by melatonin treatments through the salicylic acid signaling pathway, and up-regulate the defense-associated expression of PR1, LOX1, OXR, serPIN, and WIPI genes in maize. Melatonin not only inhibits the disease in the maize stalks and corn, but also down-regulates the deoxynivalenol (DON) production-related expression of genes Tri1, Tri4, Tri5, and Tri6 in maize. Overall, this study sheds new light on the mechanisms by which melatonin regulates antioxidant enzymes and defense-related genes involved in plant immunity to effectively suppress plant diseases.
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Affiliation(s)
- Mengmeng Kong
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Qurban Ali
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, China
| | - Hairong Jing
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Amjad Hussain
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Fuli Wang
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Xiaoyong Liu
- School of Biological Science and Technology, University of Jinan, Jinan, China
| | - Xuewen Gao
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Education, Nanjing, China
| | - Hui-Lian Xu
- School of Biological Science and Technology, University of Jinan, Jinan, China
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Liu X, Wang Y, Feng Y, Zhang X, Bi H, Ai X. SlTDC1 Overexpression Promoted Photosynthesis in Tomato under Chilling Stress by Improving CO 2 Assimilation and Alleviating Photoinhibition. Int J Mol Sci 2023; 24:11042. [PMID: 37446219 DOI: 10.3390/ijms241311042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Chilling causes a significant decline in photosynthesis in tomato plants. Tomato tryptophan decarboxylase gene 1 (SlTDC1) is the first rate-limiting gene for melatonin (MT) biosynthesis and is involved in the regulation of photosynthesis under various abiotic stresses. However, it is not clear whether SlTDC1 participates in the photosynthesis of tomato under chilling stress. Here, we obtained SlTDC1 overexpression transgenic tomato seedlings, which showed higher SlTDC1 mRNA abundance and MT content compared with the wild type (WT). The results showed that the overexpression of SlTDC1 obviously alleviated the chilling damage to seedlings in terms of the lower electrolyte leakage rate and hydrogen peroxide content, compared with the WT after 2 d of chilling stress. Moreover, the overexpression of SlTDC1 notably increased photosynthesis under chilling stress, which was related to the higher chlorophyll content, normal chloroplast structure, and higher mRNA abundance and protein level of Rubisco and RCA, as well as the higher carbon metabolic capacity, compared to the WT. In addition, we found that SlTDC1-overexpressing seedlings showed higher Wk (damage degree of OEC on the PSII donor side), φEo (quantum yield for electron transport in the PSII reaction center), and PIABS (photosynthetic performance index) than WT seedlings after low-temperature stress, implying that the overexpression of SlTDC1 decreased the damage to the reaction center and donor-side and receptor-side electron transport of PSII and promoted PSI activity, as well as energy absorption and distribution, to relieve the photoinhibition induced by chilling stress. Our results support the notion that SlTDC1 plays a vital role in the regulation of photosynthesis under chilling stress.
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Affiliation(s)
- Xutao Liu
- State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China
| | - Yanan Wang
- State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China
| | - Yiqing Feng
- State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China
| | - Xiaowei Zhang
- State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China
| | - Huangai Bi
- State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China
| | - Xizhen Ai
- State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology and Genetic Improvement of Horticultural Crops in Huanghuai Region, Collaborative Innovation Center of Fruit & Vegetable Quality and Efficient Production in Shandong, College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an 271018, China
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Khan MSS, Ahmed S, Ikram AU, Hannan F, Yasin MU, Wang J, Zhao B, Islam F, Chen J. Phytomelatonin: A key regulator of redox and phytohormones signaling against biotic/abiotic stresses. Redox Biol 2023; 64:102805. [PMID: 37406579 PMCID: PMC10363481 DOI: 10.1016/j.redox.2023.102805] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/21/2023] [Accepted: 06/29/2023] [Indexed: 07/07/2023] Open
Abstract
Plants being sessile in nature, are exposed to unwarranted threats as a result of constantly changing environmental conditions. These adverse factors can have negative impacts on their growth, development, and yield. Hormones are key signaling molecules enabling cells to respond rapidly to different external and internal stimuli. In plants, melatonin (MT) plays a critical role in the integration of various environmental signals and activation of stress-response networks to develop defense mechanisms and plant resilience. Additionally, melatonin can tackle the stress-induced alteration of cellular redox equilibrium by regulating the expression of redox hemostasis-related genes and proteins. The purpose of this article is to compile and summarize the scientific research pertaining to MT's effects on plants' resilience to biotic and abiotic stresses. Here, we have summarized that MT exerts a synergistic effect with other phytohormones, for instance, ethylene, jasmonic acid, and salicylic acid, and activates plant defense-related genes against phytopathogens. Furthermore, MT interacts with secondary messengers like Ca2+, nitric oxide, and reactive oxygen species to regulate the redox network. This interaction triggers different transcription factors to alleviate stress-related responses in plants. Hence, the critical synergic role of MT with diverse plant hormones and secondary messengers demonstrates phytomelatonin's importance in influencing multiple mechanisms to contribute to plant resilience against harsh environmental factors.
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Affiliation(s)
| | - Sulaiman Ahmed
- International Genome Center, Jiangsu University, Zhenjiang, 212013, China
| | - Aziz Ul Ikram
- International Genome Center, Jiangsu University, Zhenjiang, 212013, China
| | - Fakhir Hannan
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Muhammad Umair Yasin
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Jin Wang
- School of Life Sciences, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Biying Zhao
- International Genome Center, Jiangsu University, Zhenjiang, 212013, China.
| | - Faisal Islam
- International Genome Center, Jiangsu University, Zhenjiang, 212013, China.
| | - Jian Chen
- International Genome Center, Jiangsu University, Zhenjiang, 212013, China.
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Ma Z, Yang K, Wang J, Ma J, Yao L, Si E, Li B, Ma X, Shang X, Meng Y, Wang H. Exogenous Melatonin Enhances the Low Phosphorus Tolerance of Barley Roots of Different Genotypes. Cells 2023; 12:1397. [PMID: 37408231 PMCID: PMC10217165 DOI: 10.3390/cells12101397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/26/2023] [Accepted: 05/08/2023] [Indexed: 07/07/2023] Open
Abstract
Melatonin (N-acetyl-5-methoxytryptamine) plays an important role in plant growth and development, and in the response to various abiotic stresses. However, its role in the responses of barley to low phosphorus (LP) stress remains largely unknown. In the present study, we investigated the root phenotypes and metabolic patterns of LP-tolerant (GN121) and LP-sensitive (GN42) barley genotypes under normal P, LP, and LP with exogenous melatonin (30 μM) conditions. We found that melatonin improved barley tolerance to LP mainly by increasing root length. Untargeted metabolomic analysis showed that metabolites such as carboxylic acids and derivatives, fatty acyls, organooxygen compounds, benzene and substituted derivatives were involved in the LP stress response of barley roots, while melatonin mainly regulated indoles and derivatives, organooxygen compounds, and glycerophospholipids to alleviate LP stress. Interestingly, exogenous melatonin showed different metabolic patterns in different genotypes of barley in response to LP stress. In GN42, exogenous melatonin mainly promotes hormone-mediated root growth and increases antioxidant capacity to cope with LP damage, while in GN121, it mainly promotes the P remobilization to supplement phosphate in roots. Our study revealed the protective mechanisms of exogenous MT in alleviating LP stress of different genotypes of barley, which can be used in the production of phosphorus-deficient crops.
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Affiliation(s)
- Zengke Ma
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Ke Yang
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Juncheng Wang
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Jingwei Ma
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Lirong Yao
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Erjing Si
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Baochun Li
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Botany, College of Life Sciences and Technology, Gansu Agricultural University, Lanzhou 730070, China
| | - Xiaole Ma
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Xunwu Shang
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Yaxiong Meng
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
| | - Huajun Wang
- State Key Lab of Aridland Crop Science/Gansu Key Lab of Crop Improvement and Germplasm Enhancement, Lanzhou 730070, China; (Z.M.); (K.Y.)
- Department of Crop Genetics and Breeding, College of Agronomy, Gansu Agricultural University, Lanzhou 730070, China
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Huang J, Jing HK, Zhang Y, Chen SY, Wang HY, Cao Y, Zhang Z, Lu YH, Zheng QS, Shen RF, Zhu XF. Melatonin reduces cadmium accumulation via mediating the nitric oxide accumulation and increasing the cell wall fixation capacity of cadmium in rice. JOURNAL OF HAZARDOUS MATERIALS 2023; 445:130529. [PMID: 37055957 DOI: 10.1016/j.jhazmat.2022.130529] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 06/19/2023]
Abstract
Melatonin (MT) is participated in plants' response to cadmium (Cd) tolerance, although its work model remains elusive. Here, the function of MT in adjusting Cd accumulation in rice was investigated. 'Nipponbare' (Nip) was cultured in the -Cd (1/2 Kimura B), -Cd + MT (1/2 Kimura B with 1 μM MT), +Cd (1/2 Kimura B plus 1 μM Cd) and +Cd + MT (1/2 Kimura B with 1 μM Cd and 1 μM MT) nutrient solutions for 7 d. Cd markedly induced the endogenous MT accumulation in rice roots and shoots, even within 1 h. MT applied exogenously elevated the hemicelluloses level, which in turn increased the cell wall's binding capacity to Cd. Furthermore, MT applied exogenously down-regulated the transcription level of Natural Resistance-Associated Macrophage Protein 1 (OsNRAMP1), OsNRAMP5, a major facilitator superfamily gene (OsCd1), and IRON-REGULATED TRANSPORTER 1 (OsIRT1), all of which were responsible for Cd intake, thus less Cd was entered into roots. Moreover, MT applied exogenously also up-regulated transcription level of Cadmium accumulation in Leaf 1 (OsCAL1) and Heavy Metal ATPase 3 (OsHMA3), two genes both attributed to the decreased Cd accumulation in shoots through expelling Cd out of cells and chelating Cd in the vacuoles, respectively. In addition, MT applied exogenously further aggravated the production of nitric oxide (NO) that induced by Cd, while application of a NO donor-SNP mimicked this alleviatory effect of the MT, indicating MT decreased rice Cd accumulation relied on the accumulation of NO.
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Affiliation(s)
- Jing Huang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huai Kang Jing
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Zhang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Si Yuan Chen
- College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Hao Yu Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, China
| | - Yuan Cao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Zheng Zhang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Yun Hao Lu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Qing Song Zheng
- College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Ren Fang Shen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao Fang Zhu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Science, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Chmur M, Bajguz A. Melatonin Involved in Protective Effects against Cadmium Stress in Wolffia arrhiza. Int J Mol Sci 2023; 24:ijms24021178. [PMID: 36674694 PMCID: PMC9867261 DOI: 10.3390/ijms24021178] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/02/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
Melatonin (MT) is a new plant hormone that protects against adverse environmental conditions. In the present study, the responses of Wolffia arrhiza exposed to cadmium (Cd) and MT were analyzed. Quantitative analysis of MT and precursors of its biosynthesis was performed using LC-MS-MS. The photosynthetic pigments and phytochelatins (PCs) contents were determined using HPLC, while protein and monosaccharides, stress markers, and antioxidant levels were determined using spectrophotometric methods. Interestingly, the endogenous level of MT and its substrates in W. arrhiza exposed to 1-100 µM Cd was significantly higher compared to the control. Additionally, the application of 25 µM MT and Cd intensified the biosynthesis of these compounds. The most stimulatory effect on the growth and content of pigments, protein, and sugars was observed in plants treated with 25 µM MT. In contrast, Cd treatment caused a decrease in plant weight and level of these compounds, while the application of 25 µM MT mitigated the inhibitory effect of Cd. Additionally, Cd enhanced the level of stress markers; simultaneously, MT reduced their content in duckweed exposed to Cd. In plants treated with Cd, PC levels were increased by Cd treatment and by 25 µM MT. These results confirmed that MT mitigated the adverse effect of Cd. Furthermore, MT presence was reported for the first time in W. arrhiza. In summary, MT is an essential phytohormone for plant growth and development, especially during heavy metal stress.
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Raza A, Charagh S, García-Caparrós P, Rahman MA, Ogwugwa VH, Saeed F, Jin W. Melatonin-mediated temperature stress tolerance in plants. GM CROPS & FOOD 2022; 13:196-217. [PMID: 35983948 PMCID: PMC9397135 DOI: 10.1080/21645698.2022.2106111] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Global climate changes cause extreme temperatures and a significant reduction in crop production, leading to food insecurity worldwide. Temperature extremes (including both heat and cold stresses) is one of the most limiting factors in plant growth and development and severely affect plant physiology, biochemical, and molecular processes. Biostimulants like melatonin (MET) have a multifunctional role that acts as a "defense molecule" to safeguard plants against the noxious effects of temperature stress. MET treatment improves plant growth and temperature tolerance by improving several defense mechanisms. Current research also suggests that MET interacts with other molecules, like phytohormones and gaseous molecules, which greatly supports plant adaptation to temperature stress. Genetic engineering via overexpression or CRISPR/Cas system of MET biosynthetic genes uplifts the MET levels in transgenic plants and enhances temperature stress tolerance. This review highlights the critical role of MET in plant production and tolerance against temperature stress. We have documented how MET interacts with other molecules to alleviate temperature stress. MET-mediated molecular breeding would be great potential in helping the adverse effects of temperature stress by creating transgenic plants.
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Affiliation(s)
- Ali Raza
- College of Agriculture, Oil Crops Research Institute, Fujian Agriculture and Forestry University (FAFU), Fuzhou, Fujian, China
| | - Sidra Charagh
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Hangzhou, Zhejiang, China
| | - Pedro García-Caparrós
- Agronomy Department of Superior School Engineering, University of Almería, Almería, Spain
| | - Md Atikur Rahman
- Grassland and Forage Division, National Institute of Animal Science, Rural Development Administration, Cheonan, Korea
| | | | - Faisal Saeed
- Department of Agricultural Genetic Engineering, Faculty of Agricultural Sciences and Technologies, Nigde Omer Halisdemir University, Turkey
| | - Wanmei Jin
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, Peking, China
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11
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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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12
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Zhao D, Luan Y, Shi W, Tang Y, Huang X, Tao J. Melatonin enhances stem strength by increasing lignin content and secondary cell wall thickness in herbaceous peony. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5974-5991. [PMID: 35436332 DOI: 10.1093/jxb/erac165] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 04/16/2022] [Indexed: 05/15/2023]
Abstract
Cut flower quality is severely restrained by stem bending due to low stem strength. Melatonin has been shown to function in many aspects of plant growth and development, yet whether it can enhance stem strength, and the corresponding underlying mechanisms remain unclear. We investigated the role of melatonin in enhancement of stem strength in herbaceous peony (Paeonia lactiflora Pall.) by applying exogenous melatonin and changing endogenous melatonin biosynthesis. Endogenous melatonin content positively correlated with lignin content and stem strength in various P. lactiflora cultivars. Supplementation with exogenous melatonin significantly enhanced stem strength by increasing lignin content and the S/G lignin compositional ratio, up-regulating lignin biosynthetic gene expression. Moreover, overexpression of TRYPTOPHAN DECARBOXYLASE GENE (TDC) responsible for the first committed step of melatonin biosynthesis in tobacco, significantly increased endogenous melatonin, which further increased the S/G ratio and stem strength. In contrast, silencing PlTDC in P. lactiflora decreased endogenous melatonin, the S/G ratio and stem strength. Finally, manipulating the expression of CAFFEIC ACID O-METHYLTRANSFERASE GENE (COMT1), which is involved in both melatonin and lignin biosynthesis, showed even greater effects on melatonin, the S/G ratio and stem strength. Our results suggest that melatonin has a positive regulatory effect on P. lactiflora stem strength.
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Affiliation(s)
- Daqiu Zhao
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Yuting Luan
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Wenbo Shi
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Yuhan Tang
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Xingqi Huang
- Department of Biochemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Jun Tao
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
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13
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Menhas S, Yang X, Hayat K, Aftab T, Bundschuh J, Arnao MB, Zhou Y, Zhou P. Exogenous Melatonin Enhances Cd Tolerance and Phytoremediation Efficiency by Ameliorating Cd-Induced Stress in Oilseed Crops: A Review. JOURNAL OF PLANT GROWTH REGULATION 2022; 41:922-935. [PMID: 0 DOI: 10.1007/s00344-021-10349-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/17/2021] [Indexed: 05/20/2023]
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14
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Xie X, Ding D, Bai D, Zhu Y, Sun W, Sun Y, Zhang D. Melatonin biosynthesis pathways in nature and its production in engineered microorganisms. Synth Syst Biotechnol 2022; 7:544-553. [PMID: 35087957 PMCID: PMC8761603 DOI: 10.1016/j.synbio.2021.12.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/14/2021] [Accepted: 12/24/2021] [Indexed: 12/26/2022] Open
Abstract
Melatonin is a biogenic amine that can be found in plants, animals and microorganism. The metabolic pathway of melatonin is different in various organisms, and biosynthetic endogenous melatonin acts as a molecular signal and antioxidant protection against external stress. Microbial synthesis pathways of melatonin are similar to those of animals but different from those of plants. At present, the method of using microorganism fermentation to produce melatonin is gradually prevailing, and exploring the biosynthetic pathway of melatonin to modify microorganism is becoming the mainstream, which has more advantages than traditional chemical synthesis. Here, we review recent advances in the synthesis, optimization of melatonin pathway. l-tryptophan is one of the two crucial precursors for the synthesis of melatonin, which can be produced through a four-step reaction. Enzymes involved in melatonin synthesis have low specificity and catalytic efficiency. Site-directed mutation, directed evolution or promotion of cofactor synthesis can enhance enzyme activity and increase the metabolic flow to promote microbial melatonin production. On the whole, the status and bottleneck of melatonin biosynthesis can be improved to a higher level, providing an effective reference for future microbial modification.
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Affiliation(s)
- Xiaotong Xie
- Dalian Polytechnic University, Dalian, 116000, PR China
| | - Dongqin Ding
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Danyang Bai
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Yaru Zhu
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
| | - Wei Sun
- Tianjin University of science and technology, Tianjin, 300308, PR China
| | - Yumei Sun
- Dalian Polytechnic University, Dalian, 116000, PR China
- Corresponding author.
| | - Dawei Zhang
- Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Biodesign Center, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China
- Corresponding author. Tianjin Institutes of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, PR China.
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15
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Jiao J, Xia Y, Zhang Y, Wu X, Liu C, Feng J, Zheng X, Song S, Bai T, Song C, Wang M, Pang H. Phenylalanine 4-Hydroxylase Contributes to Endophytic Bacterium Pseudomonas fluorescens' Melatonin Biosynthesis. Front Genet 2021; 12:746392. [PMID: 34868217 PMCID: PMC8634680 DOI: 10.3389/fgene.2021.746392] [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: 07/23/2021] [Accepted: 10/13/2021] [Indexed: 11/18/2022] Open
Abstract
Melatonin acts both as an antioxidant and as a growth regulatory substance in plants. Pseudomonas fluorescens endophytic bacterium has been shown to produce melatonin and increase plant resistance to abiotic stressors through increasing endogenous melatonin. However, in bacteria, genes are still not known to be melatonin-related. Here, we reported that the bacterial phenylalanine 4-hydroxylase (PAH) may be involved in the 5-hydroxytryptophan (5-HTP) biosynthesis and further influenced the subsequent production of melatonin in P. fluorescens. The purified PAH protein of P. fluorescens not only hydroxylated phenylalanine but also exhibited l-tryptophan (l-Trp) hydroxylase activity by converting l-Trp to 5-HTP in vitro. However, bacterial PAH displayed lower activity and affinity for l-Trp than l-phenylalanine. Notably, the PAH deletion of P. fluorescens blocked melatonin production by causing a significant decline in 5-HTP levels and thus decreased the resistance to abiotic stress. Overall, this study revealed a possible role for bacterial PAH in controlling 5-HTP and melatonin biosynthesis in bacteria, and expanded the current knowledge of melatonin production in microorganisms.
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Affiliation(s)
- Jian Jiao
- College of Horticulture, Henan Agricultural University, Zhengzhou, China.,Henan Key Laboratory of Fruit and Cucurbit Biology, Zhengzhou, China
| | - Yan Xia
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Yingli Zhang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Xueli Wu
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Chonghuai Liu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou, China
| | - Jiancan Feng
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Xianbo Zheng
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Shangwei Song
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Tuanhui Bai
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Chunhui Song
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Miaomiao Wang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Hongguang Pang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
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16
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5-Methoxyindole, a Chemical Homolog of Melatonin, Adversely Affects the Phytopathogenic Fungus Fusarium graminearum. Int J Mol Sci 2021; 22:ijms222010991. [PMID: 34681652 PMCID: PMC8536143 DOI: 10.3390/ijms222010991] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 01/01/2023] Open
Abstract
Fusarium graminearum is a destructive fungal pathogen that threatens the production and quality of wheat, and controlling this pathogen is a significant challenge. As the cost-effective homolog of melatonin, 5-methoxyindole showed strong activity against F. graminearum. In the present study, our results showed the strong adverse activity of 5-methoxyindole against F. graminearum by inhibiting its growth, formation, and conidia germination. In addition, 5-methoxyindole could induce malformation, reactive oxygen species (ROS) accumulation, and cell death in F. graminearum hyphae and conidia. In response to 5-methoxyindole, F. graminearum genes involved in scavenging reactive oxygen species were significantly downregulated. Overall, these findings reveal the mechanism of antifungal action of melatonin-homolog 5-methoxyindole. To the best of our knowledge, this is the first report that a novel melatonin homolog confers strong antifungal activity against F. graminearum, and 5-methoxyindole is a potential compound for protecting wheat plants from F. graminearum infection.
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17
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Mannino G, Pernici C, Serio G, Gentile C, Bertea CM. Melatonin and Phytomelatonin: Chemistry, Biosynthesis, Metabolism, Distribution and Bioactivity in Plants and Animals-An Overview. Int J Mol Sci 2021; 22:ijms22189996. [PMID: 34576159 PMCID: PMC8469784 DOI: 10.3390/ijms22189996] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 12/21/2022] Open
Abstract
Melatonin is a ubiquitous indolamine, largely investigated for its key role in the regulation of several physiological processes in both animals and plants. In the last century, it was reported that this molecule may be produced in high concentrations by several species belonging to the plant kingdom and stored in specialized tissues. In this review, the main information related to the chemistry of melatonin and its metabolism has been summarized. Furthermore, the biosynthetic pathway characteristics of animal and plant cells have been compared, and the main differences between the two systems highlighted. Additionally, in order to investigate the distribution of this indolamine in the plant kingdom, distribution cluster analysis was performed using a database composed by 47 previously published articles reporting the content of melatonin in different plant families, species and tissues. Finally, the potential pharmacological and biostimulant benefits derived from the administration of exogenous melatonin on animals or plants via the intake of dietary supplements or the application of biostimulant formulation have been largely discussed.
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Affiliation(s)
- Giuseppe Mannino
- Department of Life Sciences and Systems Biology, Plant Physiology Unit, University of Turin, Via Quarello 15/A, 10135 Turin, Italy; (G.M.); (C.P.)
| | - Carlo Pernici
- Department of Life Sciences and Systems Biology, Plant Physiology Unit, University of Turin, Via Quarello 15/A, 10135 Turin, Italy; (G.M.); (C.P.)
| | - Graziella Serio
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, 90128 Palermo, Italy;
| | - Carla Gentile
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, Viale delle Scienze, 90128 Palermo, Italy;
- Correspondence: (C.G.); (C.M.B.); Tel.: +39-091-2389-7423 (C.G.); +39-011-670-6361 (C.M.B.)
| | - Cinzia M. Bertea
- Department of Life Sciences and Systems Biology, Plant Physiology Unit, University of Turin, Via Quarello 15/A, 10135 Turin, Italy; (G.M.); (C.P.)
- Correspondence: (C.G.); (C.M.B.); Tel.: +39-091-2389-7423 (C.G.); +39-011-670-6361 (C.M.B.)
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18
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Zheng S, Zhu Y, Liu C, Fan W, Xiang Z, Zhao A. Genome-wide identification and characterization of genes involved in melatonin biosynthesis in Morus notabilis (wild mulberry). PHYTOCHEMISTRY 2021; 189:112819. [PMID: 34087504 DOI: 10.1016/j.phytochem.2021.112819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/19/2021] [Accepted: 05/16/2021] [Indexed: 06/12/2023]
Abstract
Melatonin is recognized as an important regulator for human health and widely distributed in many plant species, including mulberry (Morus L.). Previous studies suggested mulberry contains high melatonin content, but the molecular mechanisms underlying melatonin biosynthesis in mulberry remain unclear. Here, 37 genes involved in melatonin biosynthesis were identified in mulberry genome, including a tryptophan decarboxylase gene (MnTDC), seven tryptophan 5-hydroxylase genes (MnT5Hs), six serotonin N-acetyltransferase genes (MnSNATs), 20 N-acetylserotonin methyltransferase genes (MnASMTs) and three caffeic acid 3-O-methyltransferase genes (MnCOMTs). Expression analysis showed that MnTDC, MnT5H2, MnSNAT5, MnASMT12 and MnCOMT1 from these genes had highest expression levels within their corresponding families. In vitro enzymatic assays indicated that MnTDC, MnT5H2, MnSNAT5, MnASMT12 and MnCOMT1 play important roles in melatonin biosynthesis. Multiple different pathways for melatonin biosynthesis in mulberry were discovered. In addition, mulberry ASMT showed distinct roles with those of ASTMs in Arabidopsis and rice. The class I ASMT, MnASMT12, and the class III ASMT, MnASMT20, catalyzed the conversion of N-acetylserotonin to melatonin and serotonin to 5-methoxytryptamine. Furthermore, the class II ASMT, MnASMT16, only catalyzed the conversion of N-acetylserotonin to melatonin. This study improved our knowledge on melatonin biosynthesis in mulberry and expands the repertoire of melatonin biosynthesis pathways in plants.
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Affiliation(s)
- Sha Zheng
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, 400716, China
| | - Yingxue Zhu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, 400716, China
| | - Changying Liu
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu, 610106, China
| | - Wei Fan
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, 400716, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, 400716, China
| | - Aichun Zhao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing, 400716, China.
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19
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Negri S, Commisso M, Avesani L, Guzzo F. The case of tryptamine and serotonin in plants: a mysterious precursor for an illustrious metabolite. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5336-5355. [PMID: 34009335 DOI: 10.1093/jxb/erab220] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/13/2021] [Indexed: 06/12/2023]
Abstract
Indolamines are tryptophan-derived specialized metabolites belonging to the huge and ubiquitous indole alkaloids group. Serotonin and melatonin are the best-characterized members of this family, given their many hormonal and physiological roles in animals. Following their discovery in plants, the study of plant indolamines has flourished and their involvement in important processes, including stress responses, growth and development, and reproduction, has been proposed, leading to their classification as a new category of phytohormones. However, the complex indolamine puzzle is far from resolved, particularly the biological roles of tryptamine, the early serotonin precursor representing the central hub of many downstream indole alkaloids. Tryptophan decarboxylase, which catalyzes the synthesis of tryptamine, strictly regulates the flux of carbon and nitrogen from the tryptophan pool into the indolamine pathway. Furthermore, tryptamine accumulates to high levels in the reproductive organs of many plant species and therefore cannot be classed as a mere intermediate but rather as an end product with potentially important functions in fruits and seeds. This review summarizes current knowledge on the role of tryptamine and its close relative serotonin, emphasizing the need for a clear understanding of the functions of, and mutual relations between, these indolamines and their biosynthesis pathways in plants.
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Affiliation(s)
- Stefano Negri
- Department of Biotechnology, University of Verona, Strada Le Grazie, Verona, Italy
| | - Mauro Commisso
- Department of Biotechnology, University of Verona, Strada Le Grazie, Verona, Italy
| | - Linda Avesani
- Department of Biotechnology, University of Verona, Strada Le Grazie, Verona, Italy
| | - Flavia Guzzo
- Department of Biotechnology, University of Verona, Strada Le Grazie, Verona, Italy
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20
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Zhang Z, Zhang Y. Melatonin in plants: what we know and what we don’t. FOOD QUALITY AND SAFETY 2021. [DOI: 10.1093/fqsafe/fyab009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
Melatonin is an endogenous micromolecular compound of indoleamine with multiple physiological functions in various organisms. In plants, melatonin is involved in growth and development, as well as in responses to biotic and abiotic stresses. Furthermore, melatonin functions in phytohormone-mediated signal transduction pathways. There are multiple melatonin biosynthesis pathways, and the melatonin content in plants is greatly affected by intrinsic genetic characteristics and external environmental factors. Although melatonin biosynthesis has been extensively studied in model plants, it remains uncharacterized in most plants. This article focuses on current knowledge on the biosynthesis, regulation and application of melatonin, particularly for fruit quality and preservation. In addition, it highlights the links between melatonin and other hormones, as well as future research directions.
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21
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Liao L, Zhou Y, Xu Y, Zhang Y, Liu X, Liu B, Chen X, Guo Y, Zeng Z, Zhao Y. Structural and Molecular Dynamics Analysis of Plant Serotonin N-Acetyltransferase Reveal an Acid/Base-Assisted Catalysis in Melatonin Biosynthesis. Angew Chem Int Ed Engl 2021; 60:12020-12026. [PMID: 33682300 DOI: 10.1002/anie.202100992] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/22/2021] [Indexed: 01/12/2023]
Abstract
Serotonin N-acetyltransferase (SNAT) is the key rate-limiting enzyme in melatonin biosynthesis. It mediates melatonin biosynthesis in plants by using serotonin and 5-methoxytryptamine (5-MT), but little is known of its underlying mechanisms. Herein, we present a detailed reaction mechanism of a SNAT from Oryza sativa through combined structural and molecular dynamics (MD) analysis. We report the crystal structures of plant SNAT in the apo and binary/ternary complex forms with acetyl-CoA (AcCoA), serotonin, and 5-MT. OsSNAT exhibits a unique enzymatically active dimeric fold not found in the known structures of arylalkylamine N-acetyltransferase (AANAT) family. The key residues W188, D189, D226, N220, and Y233 located around the active pocket are important in catalysis, confirmed by site-directed mutagenesis. Combined with MD simulations, we hypothesize a novel plausible catalytic mechanism in which D226 and Y233 function as catalytic base and acid during the acetyl-transfer reaction.
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Affiliation(s)
- Lijing Liao
- School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China
| | - Yuanze Zhou
- Shandong Provincial Key Laboratory of Microbial Engineering, College of Bioengineering, Qilu University of Technology, Jinan, 250353, Shandong, China.,National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Youdong Xu
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, Sichuan, China
| | - Yuhao Zhang
- Department of Resources Science of Traditional Chinese Medicines and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China
| | - Xikai Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Biao Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Xinxin Chen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Yan Guo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Zhixiong Zeng
- Shandong Provincial Key Laboratory of Microbial Engineering, College of Bioengineering, Qilu University of Technology, Jinan, 250353, Shandong, China
| | - Yucheng Zhao
- Department of Resources Science of Traditional Chinese Medicines and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China
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22
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Liao L, Zhou Y, Xu Y, Zhang Y, Liu X, Liu B, Chen X, Guo Y, Zeng Z, Zhao Y. Structural and Molecular Dynamics Analysis of Plant Serotonin
N
‐Acetyltransferase Reveal an Acid/Base‐Assisted Catalysis in Melatonin Biosynthesis. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Lijing Liao
- School of Pharmacy China Pharmaceutical University Nanjing 210009 Jiangsu China
| | - Yuanze Zhou
- Shandong Provincial Key Laboratory of Microbial Engineering College of Bioengineering Qilu University of Technology Jinan 250353 Shandong China
- National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University Wuhan 430070 Hubei China
| | - Youdong Xu
- College of Pharmacy Chengdu University of Traditional Chinese Medicine Chengdu 611137 Sichuan China
| | - Yuhao Zhang
- Department of Resources Science of Traditional Chinese Medicines and State Key Laboratory of Natural Medicines School of Traditional Chinese Pharmacy China Pharmaceutical University Nanjing 210009 Jiangsu China
| | - Xikai Liu
- National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University Wuhan 430070 Hubei China
| | - Biao Liu
- National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University Wuhan 430070 Hubei China
| | - Xinxin Chen
- National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University Wuhan 430070 Hubei China
| | - Yan Guo
- National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural University Wuhan 430070 Hubei China
| | - Zhixiong Zeng
- Shandong Provincial Key Laboratory of Microbial Engineering College of Bioengineering Qilu University of Technology Jinan 250353 Shandong China
| | - Yucheng Zhao
- Department of Resources Science of Traditional Chinese Medicines and State Key Laboratory of Natural Medicines School of Traditional Chinese Pharmacy China Pharmaceutical University Nanjing 210009 Jiangsu China
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23
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Key Genes in the Melatonin Biosynthesis Pathway with Circadian Rhythm Are Associated with Various Abiotic Stresses. PLANTS 2021; 10:plants10010129. [PMID: 33435489 PMCID: PMC7827461 DOI: 10.3390/plants10010129] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 01/06/2021] [Indexed: 02/04/2023]
Abstract
Melatonin (N-acetyl-5-methoxytryptamine), a well-known animal hormone, is involved in several biological processes including circadian rhythm and the regulation of abiotic stress. A systematic understanding of the circadian regulation of melatonin biosynthesis-related genes has not been achieved in rice. In this study, key genes for all of the enzymes in the melatonin biosynthetic pathway that showed a peak of expression at night were identified by microarray data analysis and confirmed by qRT–PCR analysis. We further examined the expression patterns of the four genes under drought, salt, and cold stresses. The results showed that abiotic stresses, such as drought, salt, and cold, affected the expression patterns of melatonin biosynthetic genes. In addition, the circadian expression patterns of tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), and serotonin N-acetyltransferase (SNAT) genes in wild-type (WT) plants was damaged by the drought treatment under light and dark conditions. Conversely, N-acetylserotonin O-methyltransferase (ASMT) retained the circadian rhythm. The expression of ASMT was down-regulated by the rice gigantea (OsGI) mutation, suggesting the involvement of the melatonin biosynthetic pathway in the OsGI-mediated circadian regulation pathway. Taken together, our results provide clues to explain the relationship between circadian rhythms and abiotic stresses in the process of melatonin biosynthesis in rice.
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Kong M, Sheng T, Liang J, Ali Q, Gu Q, Wu H, Chen J, Liu J, Gao X. Melatonin and Its Homologs Induce Immune Responses via Receptors trP47363-trP13076 in Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2021; 12:691835. [PMID: 34276740 PMCID: PMC8278317 DOI: 10.3389/fpls.2021.691835] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/24/2021] [Indexed: 05/17/2023]
Abstract
Melatonin (N-acetyl-5-methoxytryptamine), a naturally occurring small molecule, can protect plants against abiotic stress after exogenous treatmenting with it. It is not known if melatonin homologs, such as 5-methoxytryptamine and 5-methoxyindole, that are easy and more cost-effective to synthesize can stimulate the plant immune system in the same manner as melatonin. In the present study, we assessed the biological activity of the melatonin homologs, 5-methoxytryptamin and 5-methoxyindole. The results showed that melatonin and its homologs all induced disease resistance against Phytophthora nicotianae in Nicotiana benthamiana plants. The application of all three compounds also induced stomatal closure and the production of reactive oxygen species. Gene expression analysis indicated that the expression of genes involved in hydrogen peroxide (H2O2), nitric oxide (NO) production, and salicylic acid (SA) biosynthesis was significantly upregulated by all three compounds. Four homologs of the melatonin receptors were identified by blasting search with the phytomelatonin receptor in Arabidopsis. Molecular docking studies were also used to identify four putative melatonin receptors in N. benthamiana. Further experimentation revealed that silencing of the melatonin receptors trP47363 and trP13076 in N. benthamiana compromised the induction of stomatal closure, PR-1a gene expression and SA accumulation by all three compounds. Collectively, our data indicate that the induction of defense responses in N. benthamiana by melatonin, 5-methoxytryptamine, and 5-methoxyindole involves the melatonin receptors trP47363 and trP13076.
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Affiliation(s)
- Mengmeng Kong
- Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Department of Plant Pathology, College of Plant Protection, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Tao Sheng
- Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Department of Plant Pathology, College of Plant Protection, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Jing Liang
- Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Department of Plant Pathology, College of Plant Protection, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Qurban Ali
- Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Department of Plant Pathology, College of Plant Protection, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Qin Gu
- Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Department of Plant Pathology, College of Plant Protection, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Huijun Wu
- Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Department of Plant Pathology, College of Plant Protection, Ministry of Education, Nanjing Agricultural University, Nanjing, China
| | - Jian Chen
- International Genome Center, Jiangsu University, Zhenjiang, China
- Jian Chen,
| | - Jia Liu
- Chongqing Key Laboratory of Economic Plant Biotechnology, College of Landscape Architecture and Life Science/Institute of Special Plants, Chongqing University of Arts and Sciences, Chongqing, China
- Jia Liu,
| | - Xuewen Gao
- Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Department of Plant Pathology, College of Plant Protection, Ministry of Education, Nanjing Agricultural University, Nanjing, China
- *Correspondence: Xuewen Gao,
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Back K. Melatonin metabolism, signaling and possible roles in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:376-391. [PMID: 32645752 DOI: 10.1111/tpj.14915] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 06/15/2020] [Accepted: 06/24/2020] [Indexed: 05/20/2023]
Abstract
Melatonin is a multifunctional biomolecule found in both animals and plants. In this review, the biosynthesis, levels, signaling, and possible roles of melatonin and its metabolites in plants is summarized. Tryptamine 5-hydroxylase (T5H), which catalyzes the conversion of tryptamine into serotonin, has been proposed as a target to create a melatonin knockout mutant presenting a lesion-mimic phenotype in rice. With a reduced anabolic capacity for melatonin biosynthesis and an increased catabolic capacity for melatonin metabolism, all plants generally maintain low melatonin levels. Some plants, including Arabidopsis and Nicotiana tabacum (tobacco), do not possess tryptophan decarboxylase (TDC), the first committed step enzyme required for melatonin biosynthesis. Major melatonin metabolites include cyclic 3-hydroxymelatonin (3-OHM) and 2-hydroxymelatonin (2-OHM). Other melatonin metabolites such as N1 -acetyl-N2 -formyl-5-methoxykynuramine (AFMK), N-acetyl-5-methoxykynuramine (AMK) and 5-methoxytryptamine (5-MT) are also produced when melatonin is applied to Oryza sativa (rice). The signaling pathways of melatonin and its metabolites act via the mitogen-activated protein kinase (MAPK) cascade, possibly with Cand2 acting as a melatonin receptor, although the integrity of Cand2 remains controversial. Melatonin mediates many important functions in growth stimulation and stress tolerance through its potent antioxidant activity and function in activating the MAPK cascade. The concentration distribution of melatonin metabolites appears to be species specific because corresponding enzymes such as M2H, M3H, catalases, indoleamine 2,3-dioxygenase (IDO) and N-acetylserotonin deacetylase (ASDAC) are differentially expressed among plant species and even among different tissues within species. Differential levels of melatonin and its metabolites can lead to differential physiological effects among plants when melatonin is either applied exogenously or overproduced through ectopic overexpression.
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Affiliation(s)
- Kyoungwhan Back
- Department of Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
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Sami A, Shah FA, Abdullah M, Zhou X, Yan Y, Zhu Z, Zhou K. Melatonin mitigates cadmium and aluminium toxicity through modulation of antioxidant potential in Brassica napus L. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:679-690. [PMID: 32003103 DOI: 10.1111/plb.13093] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 01/21/2020] [Indexed: 05/03/2023]
Abstract
Melatonin has emerged as an essential molecule in plants, due to its role in defence against metal toxicity. Aluminium (Al) and cadmium (Cd) toxicity inhibit rapeseed seedling growth. In this study, we applied different doses of melatonin (50 and 100 µm) to alleviate Al (25 µm) and Cd (25 µm) stress in rapeseed seedlings. Results show that Al and Cd caused toxicity in rapeseed seedling, as evidenced by a decrease in height, biomass and antioxidant enzyme activity. Melatonin increased the expression of melatonin biosynthesis-related Brassica napus genes for caffeic acid O-methyl transferase (BnCOMT) under Al and Cd stress. The genes BnCOMT-1, BnCOMT-5 and BnCOMT-8 showed up-regulated expression, while BnCOMT-4 and BnCOMT-6 were down-regulated during incubation in water. Melatonin application increased the germination rate, shoot length, root length, fresh and dry weight of seedlings. Melatonin supplementation under Al and Cd stress increased superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, proline, chlorophyll and anthocyanin content, as well as photosynthesis rate. Both Cd and Al treatments significantly increased hydrogen peroxide and malondialdehyde levels in rapeseed seedlings, which were strictly counterbalanced by melatonin. Analysis of Cd and Al in different subcellular compartments showed that melatonin enhanced cell wall and soluble fractions, but reduced the vacuolar and organelle fractions in Al- and Cd-treated seedlings. These results suggest that melatonin-induced improvements in antioxidant potential, biomass, photosynthesis rate and successive Cd and Al sequestration play a pivotal role in plant tolerance to Al and Cd stress. This mechanism may have potential implications in safe food production.
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Affiliation(s)
- A Sami
- College of Agronomy, Anhui Agricultural University, Hefei, China
| | - F A Shah
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, China
| | - M Abdullah
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - X Zhou
- College of Agronomy, Anhui Agricultural University, Hefei, China
| | - Y Yan
- College of Agronomy, Anhui Agricultural University, Hefei, China
| | - Z Zhu
- College of Agronomy, Anhui Agricultural University, Hefei, China
| | - K Zhou
- College of Agronomy, Anhui Agricultural University, Hefei, China
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27
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Zhou Y, Liao L, Liu X, Liu B, Chen X, Guo Y, Huang C, Zhao Y, Zeng Z. Crystal structure of Oryza sativa TDC reveals the substrate specificity for TDC-mediated melatonin biosynthesis. J Adv Res 2020; 24:501-511. [PMID: 32595985 PMCID: PMC7306523 DOI: 10.1016/j.jare.2020.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 04/20/2020] [Accepted: 06/08/2020] [Indexed: 01/01/2023] Open
Abstract
Plant tryptophan decarboxylase (TDC) is a type II Pyridoxal-5'-phosphate-dependent decarboxylase (PLP_DC) that could be used as a target to genetically improve crops. However, lack of accurate structural information on plant TDC hampers the understanding of its decarboxylation mechanisms. In the present study, the crystal structures of Oryza sativa TDC (OsTDC) in its complexes with pyridoxal-5'-phosphate, tryptamine and serotonin were determined. The structures provide detailed interaction information between TDC and its substrates. The Y359 residue from the loop gate is a proton donor and forms a Lewis acid-base pair with serotonin/tryptamine, which is associated with product release. The H214 residue is responsible for PLP binding and proton transfer, and its proper interaction with Y359 is essential for OsTDC enzyme activity. The extra hydrogen bonds formed between the 5-hydroxyl group of serotonin and the backbone carboxyl groups of F104 and P105 explain the discrepancy between the catalytic activity of TDC in tryptophan and in 5-hydroxytryptophan. In addition, an evolutionary analysis revealed that type II PLP_DC originated from glutamic acid decarboxylase, potentially as an adaptive evolution of mechanism in organisms in extreme environments. This study is, to our knowledge, the first to present a detailed analysis of the crystal structure of OsTDC in these complexes. The information regarding the catalytic mechanism described here could facilitate the development of protocols to regulate melatonin levels and thereby contribute to crop improvement efforts to improve food security worldwide.
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Affiliation(s)
- Yuanze Zhou
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Lijing Liao
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Xikai Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Biao Liu
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Xinxin Chen
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Yan Guo
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Chuanlong Huang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210014, China
| | - Yucheng Zhao
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210014, China
| | - Zhixiong Zeng
- Shandong Provincial Key Laboratory of Microbial Engineering, College of Bioengineering, Qilu University of Technology, Jinan 250353, China
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You D, Feng Y, Wang C, Sun C, Wang Y, Zhao D, Kai G. Cloning, characterization, and enzymatic identification of a new tryptophan decarboxylase from Ophiorrhiza pumila. Biotechnol Appl Biochem 2020; 68:381-389. [PMID: 32353164 DOI: 10.1002/bab.1935] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 04/23/2020] [Indexed: 12/18/2022]
Abstract
Tryptophan decarboxylase (TDC, EC 4.1.1.28) catalyzes tryptophan decarboxylation to form tryptamine through the cofactor pyridoxal-5'-phosphate (PLP), a crucial stage in the production of the terpenoid indole alkaloids like camptothecin (CPT). A new gene encoding TDC was identified from the CPT-producing plant Ophiorrhiza pumila by transcriptome analysis, termed OpTDC2. It contained a 1,536 bp open reading frame that encodes a 511 amino acid protein with a molecular mass of 57.01 kDa and an isoelectric point of 6.39. Multiple sequence alignment and phylogenetic tree analysis showed the closest similarity (85%) with the TDC from Mitragyna speciosa. Moreover, the highest expression of OpTDC2 was observed in the O. pumila root. To achieve high-efficiency expression of OpTDC2 in Escherichia coli, we fused the TF tag onto the N-terminal of the OpTDC2. Optimum enzymatic activity was observed at 45 °C, pH 8 and cofactor concentration of 0.1 mM. The catalytic reaction was strongly inhibited by metal ions of Cu2+ , Zn2+ , and Fe2+ . The l-tryptophan was particularly catalyzed compared with d-tryptophan. Besides, the Km and kcat of the OpTDC2 were 1.08 mM and 0.78 Sec-1 , respectively. The results provided information on new functional OpTDC2 that might be used in synthetic biology for the enhanced biosynthesis of CPT in O. pumila.
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Affiliation(s)
- Dawei You
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Collaborative Innovation Center for Mountain Ecology & Agro-Bioengineering (CICMEAB), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang, Guizhou Province, People's Republic of China.,Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, People's Republic of China
| | - Yue Feng
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, People's Republic of China
| | - Can Wang
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, People's Republic of China
| | - Chengtao Sun
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, People's Republic of China
| | - Yao Wang
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, People's Republic of China
| | - Degang Zhao
- Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region (Ministry of Education), Collaborative Innovation Center for Mountain Ecology & Agro-Bioengineering (CICMEAB), College of Life Sciences/Institute of Agro-bioengineering, Guizhou University, Guiyang, Guizhou Province, People's Republic of China
| | - Guoyin Kai
- Laboratory of Medicinal Plant Biotechnology, College of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, People's Republic of China
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29
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Simultaneous Suppression of Two Distinct Serotonin N-Acetyltransferase Isogenes by RNA Interference Leads to Severe Decreases in Melatonin and Accelerated Seed Deterioration in Rice. Biomolecules 2020; 10:biom10010141. [PMID: 31952365 PMCID: PMC7022895 DOI: 10.3390/biom10010141] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/10/2020] [Accepted: 01/10/2020] [Indexed: 12/20/2022] Open
Abstract
Serotonin N-acetyltransferase (SNAT) is the penultimate enzyme in the melatonin biosynthetic pathway, in which serotonin is converted into N-acetylserotonin (NAS) in plants. To date, two SNAT isogenes with low amino acid sequence homologies have been identified. Their single suppression in rice has been reported, but their double suppression in rice has not yet been attempted. Here, we generated double-suppression transgenic rice (snat1+2) using the RNA interference technique. The snat1+2 exhibited retarded seedling growths in conjunction with severe decreases in melatonin compared to wild-types and single-suppression rice plants (snat1 or snat2). The laminar angle was decreased in the snat1+2 rice compared to that of the wild-types and snat1, but was comparable to that of snat2. The reduced germination speed in the snat1+2 was comparable to that of snat2. Seed-aging testing revealed that snat1 was the most severely deteriorated, followed by snat1+2 and snat2, suggesting that melatonin is positively involved in seed longevity.
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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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31
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Zhu Y, Gao H, Lu M, Hao C, Pu Z, Guo M, Hou D, Chen LY, Huang X. Melatonin-Nitric Oxide Crosstalk and Their Roles in the Redox Network in Plants. Int J Mol Sci 2019; 20:E6200. [PMID: 31818042 PMCID: PMC6941097 DOI: 10.3390/ijms20246200] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/04/2019] [Accepted: 12/06/2019] [Indexed: 01/28/2023] Open
Abstract
Melatonin, an amine hormone highly conserved during evolution, has a wide range of physiological functions in animals and plants. It is involved in plant growth, development, maturation, and aging, and also helps ameliorate various types of abiotic and biotic stresses, including salt, drought, heavy metals, and pathogens. Melatonin-related growth and defense responses of plants are complex, and involve many signaling molecules. Among these, the most important one is nitric oxide (NO), a freely diffusing amphiphilic biomolecule that can easily cross the cell membrane, produce rapid signal responses, and participate in a wide variety of physiological reactions. NO-induced S-nitrosylation is also involved in plant defense responses. NO interacts with melatonin as a long-range signaling molecule, and helps regulate plant growth and maintain oxidative homeostasis. Exposure of plants to abiotic stresses causes the increase of endogenous melatonin levels, with the consequent up-regulation of melatonin synthesis genes, and further increase of melatonin content. The application of exogenous melatonin causes an increase in endogenous NO and up-regulation of defense-related transcription factors, resulting in enhanced stress resistance. When plants are infected by pathogenic bacteria, NO acts as a downstream signal to lead to increased melatonin levels, which in turn induces the mitogen-activated protein kinase (MAPK) cascade and associated defense responses. The application of exogenous melatonin can also promote sugar and glycerol production, leading to increased levels of salicylic acid and NO. Melatonin and NO in plants can function cooperatively to promote lateral root growth, delay aging, and ameliorate iron deficiency. Further studies are needed to clarify certain aspects of the melatonin/NO relationship in plant physiology.
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Affiliation(s)
- Ying Zhu
- Provincial Key Laboratory of Biotechnology of Shaanxi, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an 710069, China; (Y.Z.); (H.G.); (M.L.); (C.H.); (Z.P.); (M.G.); (D.H.)
| | - Hang Gao
- Provincial Key Laboratory of Biotechnology of Shaanxi, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an 710069, China; (Y.Z.); (H.G.); (M.L.); (C.H.); (Z.P.); (M.G.); (D.H.)
| | - Mengxin Lu
- Provincial Key Laboratory of Biotechnology of Shaanxi, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an 710069, China; (Y.Z.); (H.G.); (M.L.); (C.H.); (Z.P.); (M.G.); (D.H.)
| | - Chengying Hao
- Provincial Key Laboratory of Biotechnology of Shaanxi, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an 710069, China; (Y.Z.); (H.G.); (M.L.); (C.H.); (Z.P.); (M.G.); (D.H.)
| | - Zuoqian Pu
- Provincial Key Laboratory of Biotechnology of Shaanxi, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an 710069, China; (Y.Z.); (H.G.); (M.L.); (C.H.); (Z.P.); (M.G.); (D.H.)
| | - Miaojie Guo
- Provincial Key Laboratory of Biotechnology of Shaanxi, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an 710069, China; (Y.Z.); (H.G.); (M.L.); (C.H.); (Z.P.); (M.G.); (D.H.)
| | - Dairu Hou
- Provincial Key Laboratory of Biotechnology of Shaanxi, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an 710069, China; (Y.Z.); (H.G.); (M.L.); (C.H.); (Z.P.); (M.G.); (D.H.)
| | - Li-Yu Chen
- Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xuan Huang
- Provincial Key Laboratory of Biotechnology of Shaanxi, Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, College of Life Science, Northwest University, Xi’an 710069, China; (Y.Z.); (H.G.); (M.L.); (C.H.); (Z.P.); (M.G.); (D.H.)
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Li C, He Q, Zhang F, Yu J, Li C, Zhao T, Zhang Y, Xie Q, Su B, Mei L, Zhu S, Chen J. Melatonin enhances cotton immunity to Verticillium wilt via manipulating lignin and gossypol biosynthesis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:784-800. [PMID: 31349367 PMCID: PMC6899791 DOI: 10.1111/tpj.14477] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/03/2019] [Accepted: 07/15/2019] [Indexed: 05/09/2023]
Abstract
Plants endure challenging environments in which they are constantly threatened by diverse pathogens. The soil-borne fungus Verticillium dahliae is a devastating pathogen affecting many plant species including cotton, in which it significantly reduces crop yield and fiber quality. Melatonin involvement in plant immunity to pathogens has been reported, but the mechanisms of melatonin-induced plant resistance are unclear. In this study, the role of melatonin in enhancing cotton resistance to V. dahliae was investigated. At the transcriptome level, exogenous melatonin increased the expression of genes in phenylpropanoid, mevalonate (MVA), and gossypol pathways after V. dahliae inoculation. As a result, lignin and gossypol, the products of these metabolic pathways, significantly increased. Silencing the serotonin N-acetyltransferase 1 (GhSNAT1) and caffeic acid O-methyltransferase (GhCOMT) melatonin biosynthesis genes compromised cotton resistance, with reduced lignin and gossypol levels after V. dahliae inoculation. Exogenous melatonin pre-treatment prior to V. dahliae inoculation restored the level of cotton resistance reduced by the above gene silencing effects. Melatonin levels were higher in resistant cotton cultivars than in susceptible cultivars after V. dahliae inoculation. The findings indicate that melatonin affects lignin and gossypol synthesis genes in phenylpropanoid, MVA, and gossypol pathways, thereby enhancing cotton resistance to V. dahliae.
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Affiliation(s)
- Cheng Li
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Qiuling He
- Zhejiang Key Laboratory of Plant Secondary Metabolism and RegulationZhejiang Sci‐Tech UniversityHangzhou310018China
| | - Fan Zhang
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Jingwen Yu
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Cong Li
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Tianlun Zhao
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Yi Zhang
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Qianwen Xie
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Bangrong Su
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Lei Mei
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Shuijin Zhu
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
| | - Jinhong Chen
- Zhejiang Key Laboratory of Crop GermplasmZhejiang UniversityHangzhou310058China
- Institute of Crop ScienceZhejiang UniversityHangzhou310058China
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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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Lee K, Back K. Melatonin-deficient rice plants show a common semidwarf phenotype either dependent or independent of brassinosteroid biosynthesis. J Pineal Res 2019; 66:e12537. [PMID: 30403303 DOI: 10.1111/jpi.12537] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 10/11/2018] [Accepted: 10/26/2018] [Indexed: 12/13/2022]
Abstract
Melatonin-deficient rice with a semidwarf erect-leaf phenotype was created by suppressing serotonin N-acetyltransferase 2 (SNAT2). We generated an RNAi transgenic rice that suppressed tryptophan decarboxylase (TDC), which encodes the first TDC enzyme committed step for melatonin biosynthesis in plants catalyzing the conversion of tryptophan into tryptamine, to determine whether other transgenic rice with downregulated melatonin biosynthetic genes exhibited the same erect-leaf phenotype as the snat2 RNAi rice. The TDC RNAi rice produced significantly less melatonin than the wild type and exhibited a semidwarf phenotype, but no erect-leaf phenotype was observed. In contrast, tryptamine 5-hydroxylase (T5H) knockout Sekiguchi rice and caffeic acid O-methyltransferase (COMT) RNAi rice seedlings were semidwarf phenotypes with erect leaves, as was the snat2 RNAi rice due to a melatonin deficiency. All RNAi rice plants showing erect-leaf phenotypes had lower expression levels of the DWARF4 gene, which is a key enzyme for brassinosteroid (BR) biosynthesis, leading to lower BR levels than their respective wild types. Suppressing melatonin synthesis did not alter the contents of indole 3-acetic acid (IAA), suggesting the irrelevance of melatonin deficiency to IAA biosynthesis. These data indicate that a semidwarf seedling is a common rice phenotype by the lack of melatonin synthesis with or without BR suppression in a melatonin biosynthetic gene-specific manner.
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Affiliation(s)
- Kyungjin 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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Commisso M, Negri S, Bianconi M, Gambini S, Avesani S, Ceoldo S, Avesani L, Guzzo F. Untargeted and Targeted Metabolomics and Tryptophan Decarboxylase In Vivo Characterization Provide Novel Insight on the Development of Kiwifruits ( Actinidia deliciosa). Int J Mol Sci 2019; 20:E897. [PMID: 30791398 PMCID: PMC6413197 DOI: 10.3390/ijms20040897] [Citation(s) in RCA: 18] [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: 01/29/2019] [Revised: 02/14/2019] [Accepted: 02/17/2019] [Indexed: 12/13/2022] Open
Abstract
Kiwifruit (Actinidia deliciosa cv. Hayward) is a commercially important crop with highly nutritional green fleshy fruits. The post-harvest maturation of the fruits is well characterized, but little is known about the metabolic changes that occur during fruit development. Here we used untargeted metabolomics to characterize the non-volatile metabolite profile of kiwifruits collected at different time points after anthesis, revealing profound metabolic changes before the onset of ripening including the depletion of many classes of phenolic compounds. In contrast, the phytohormone abscisic acid accumulated during development and ripening, along with two indolamines (serotonin and its precursor tryptamine), and these were monitored in greater detail by targeted metabolomics. The role of indolamines in kiwifruit development is completely unknown, so we also characterized the identity of genes encoding tryptophan decarboxylase in A. deliciosa and its close relative A. chinensis to provide insight into the corresponding biological processes. Our results indicate that abscisic acid and indolamines fulfill unrecognized functions in the development and ripening of kiwifruits.
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Affiliation(s)
- Mauro Commisso
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
- Demethra Biotech, Strada dell'Innovazione 1, Camisano Vicentino, 36043 Vicenza, Italy.
| | - Stefano Negri
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Martino Bianconi
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
- Demethra Biotech, Strada dell'Innovazione 1, Camisano Vicentino, 36043 Vicenza, Italy.
| | - Sofia Gambini
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Sara Avesani
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Stefania Ceoldo
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Linda Avesani
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Flavia Guzzo
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
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Melatonin: A Small Molecule but Important for Salt Stress Tolerance in Plants. Int J Mol Sci 2019; 20:ijms20030709. [PMID: 30736409 PMCID: PMC6387279 DOI: 10.3390/ijms20030709] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Revised: 02/03/2019] [Accepted: 02/04/2019] [Indexed: 01/09/2023] Open
Abstract
Salt stress is one of the most serious limiting factors in worldwide agricultural production, resulting in huge annual yield loss. Since 1995, melatonin (N-acetyl-5-methoxytryptamine)—an ancient multi-functional molecule in eukaryotes and prokaryotes—has been extensively validated as a regulator of plant growth and development, as well as various stress responses, especially its crucial role in plant salt tolerance. Salt stress and exogenous melatonin lead to an increase in endogenous melatonin levels, partly via the phyto-melatonin receptor CAND2/PMTR1. Melatonin plays important roles, as a free radical scavenger and antioxidant, in the improvement of antioxidant systems under salt stress. These functions improve photosynthesis, ion homeostasis, and activate a series of downstream signals, such as hormones, nitric oxide (NO) and polyamine metabolism. Melatonin also regulates gene expression responses to salt stress. In this study, we review recent literature and summarize the regulatory roles and signaling networks involving melatonin in response to salt stress in plants. We also discuss genes and gene families involved in the melatonin-mediated salt stress tolerance.
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Pérez-Llorca M, Muñoz P, Müller M, Munné-Bosch S. Biosynthesis, Metabolism and Function of Auxin, Salicylic Acid and Melatonin in Climacteric and Non-climacteric Fruits. FRONTIERS IN PLANT SCIENCE 2019; 10:136. [PMID: 30833953 PMCID: PMC6387956 DOI: 10.3389/fpls.2019.00136] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 01/28/2019] [Indexed: 05/20/2023]
Abstract
Climacteric and non-climacteric fruits are differentiated by the ripening process, in particular by the involvement of ethylene, high respiration rates and the nature of the process, being autocatalytic or not, respectively. Here, we focus on the biosynthesis, metabolism and function of three compounds (auxin, salicylic acid and melatonin) sharing not only a common precursor (chorismate), but also regulatory functions in plants, and therefore in fruits. Aside from describing their biosynthesis in plants, with a particular emphasis on common precursors and points of metabolic diversion, we will discuss recent advances on their role in fruit ripening and the regulation of bioactive compounds accumulation, both in climacteric and non-climacteric fruits.
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Affiliation(s)
- Marina Pérez-Llorca
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
| | - Paula Muñoz
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
- Institute for Research on Nutrition and Food Safety, University of Barcelona, Barcelona, Spain
| | - Maren Müller
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
- Institute for Research on Nutrition and Food Safety, University of Barcelona, Barcelona, Spain
| | - Sergi Munné-Bosch
- Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Spain
- Institute for Research on Nutrition and Food Safety, University of Barcelona, Barcelona, Spain
- *Correspondence: Sergi Munné-Bosch,
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Zhao D, Yu Y, Shen Y, Liu Q, Zhao Z, Sharma R, Reiter RJ. Melatonin Synthesis and Function: Evolutionary History in Animals and Plants. Front Endocrinol (Lausanne) 2019; 10:249. [PMID: 31057485 PMCID: PMC6481276 DOI: 10.3389/fendo.2019.00249] [Citation(s) in RCA: 296] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/29/2019] [Indexed: 12/12/2022] Open
Abstract
Melatonin is an ancient molecule that can be traced back to the origin of life. Melatonin's initial function was likely that as a free radical scavenger. Melatonin presumably evolved in bacteria; it has been measured in both α-proteobacteria and in photosynthetic cyanobacteria. In early evolution, bacteria were phagocytosed by primitive eukaryotes for their nutrient value. According to the endosymbiotic theory, the ingested bacteria eventually developed a symbiotic association with their host eukaryotes. The ingested α-proteobacteria evolved into mitochondria while cyanobacteria became chloroplasts and both organelles retained their ability to produce melatonin. Since these organelles have persisted to the present day, all species that ever existed or currently exist may have or may continue to synthesize melatonin in their mitochondria (animals and plants) and chloroplasts (plants) where it functions as an antioxidant. Melatonin's other functions, including its multiple receptors, developed later in evolution. In present day animals, via receptor-mediated means, melatonin functions in the regulation of sleep, modulation of circadian rhythms, enhancement of immunity, as a multifunctional oncostatic agent, etc., while retaining its ability to reduce oxidative stress by processes that are, in part, receptor-independent. In plants, melatonin continues to function in reducing oxidative stress as well as in promoting seed germination and growth, improving stress resistance, stimulating the immune system and modulating circadian rhythms; a single melatonin receptor has been identified in land plants where it controls stomatal closure on leaves. The melatonin synthetic pathway varies somewhat between plants and animals. The amino acid, tryptophan, is the necessary precursor of melatonin in all taxa. In animals, tryptophan is initially hydroxylated to 5-hydroxytryptophan which is then decarboxylated with the formation of serotonin. Serotonin is either acetylated to N-acetylserotonin or it is methylated to form 5-methoxytryptamine; these products are either methylated or acetylated, respectively, to produce melatonin. In plants, tryptophan is first decarboxylated to tryptamine which is then hydroxylated to form serotonin.
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Affiliation(s)
- Dake Zhao
- Biocontrol Engineering Research Center of Plant Disease and Pest, Yunnan University, Kunming, China
- Biocontrol Engineering Research Center of Crop Disease and Pest, Yunnan University, Kunming, China
- School of Life Science, Yunnan University, Kunming, China
| | - Yang Yu
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan University, Kunming, China
| | - Yong Shen
- College of Agriculture and Biotechnology, Yunnan Agricultural University, Kunming, China
| | - Qin Liu
- School of Landscape and Horticulture, Yunnan Vocational and Technical College of Agriculture, Kunming, China
| | - Zhiwei Zhao
- State Key Laboratory for Conservation and Utilization of Bio-resources in Yunnan, Yunnan University, Kunming, China
| | - Ramaswamy Sharma
- Department of Cell Systems and Anatomy, The University of Texas Health Science Center at San Antonio (UT Health), San Antonio, TX, United States
| | - Russel J. Reiter
- Department of Cell Systems and Anatomy, The University of Texas Health Science Center at San Antonio (UT Health), San Antonio, TX, United States
- *Correspondence: Russel J. Reiter
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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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Huang Q, Li L, Zheng M, Chen F, Long H, Deng G, Pan Z, Liang J, Li Q, Yu M, Zhang H. The Tryptophan decarboxylase 1 Gene From Aegilops variabilis No.1 Regulate the Resistance Against Cereal Cyst Nematode by Altering the Downstream Secondary Metabolite Contents Rather Than Auxin Synthesis. FRONTIERS IN PLANT SCIENCE 2018; 9:1297. [PMID: 30233630 PMCID: PMC6132075 DOI: 10.3389/fpls.2018.01297] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/17/2018] [Indexed: 05/24/2023]
Abstract
Cereal cyst nematode (CCN, Heterodera avenae) is a most important pathogen of wheat and causes tremendous yield loss annually over the world. Since the lack of resistance materials among wheat cultivars, identification and characterization of the resistance-related genes from the relatives of wheat is a necessary and efficient way. As a close relative of wheat with high resistance against CCN, Aegilops variabilis No.1 is believed to be a valuable source for wheat breeding against this devastating disease. However so far, very few resistance-associated genes have been characterized from this species. In this study, we present that the tryptophan decarboxylase genes from Ae. variabilis No.1 (AeVTDC1 and AeVTDC2) were both induced by CCN juveniles at the early stage of resistance response (30 h post-inoculation), with AeVTDC1 more sensitive to CCN infection than AeVTDC2. Silencing of AeVTDC1 led to compromised immunity to CCN with more CCN intrusion into roots; while overexpression AeVTDC1 in Nicotiana tabacum dramatically enhanced the resistance of plants by reducing the knots formed on roots. Metabolism analysis showed that the contents of secondary metabolites with activity of resistance to varied pathogens correlated with the expression level of AeVTDC1 in both Ae. variabilis No.1 and the transgenic tobacco plants. In addition, the content of IAA was not affected by either silencing or overexpressing of AeVTDC1. Hence, our research provided AeVTDC1 a valuable target that mediates resistance to CCN and root knot nematode (RKN, Meloidogyne naasi) without influencing the auxin biosynthesis.
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Affiliation(s)
- Qiulan Huang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- College of Life Sciences, Sichuan University, Chengdu, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Lin Li
- School of Basic Medical Sciences, Zunyi Medical University, Zunyi, China
| | - Minghui Zheng
- School of Basic Medical Sciences, Zunyi Medical University, Zunyi, China
| | - Fang Chen
- College of Life Sciences, Sichuan University, Chengdu, China
| | - Hai Long
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Guangbing Deng
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Zhifen Pan
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Junjun Liang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Qiao Li
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Maoqun Yu
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Haili Zhang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
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Melatonin and Expression of Tryptophan Decarboxylase Gene ( TDC) in Herbaceous Peony ( Paeonia lactiflora Pall.) Flowers. Molecules 2018; 23:molecules23051164. [PMID: 29757219 PMCID: PMC6100325 DOI: 10.3390/molecules23051164] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 05/08/2018] [Accepted: 05/10/2018] [Indexed: 12/31/2022] Open
Abstract
Melatonin is a bioactive, edible ingredient that promotes human health and exists widely in plants, but little is known about its biosynthetic routes and underlying molecular mechanisms in the herbaceous peony. In this contribution, we found that herbaceous peony flowers are rich in melatonin that is found in the greatest quantities in the white series, followed by the ink series, the red series and then the pink series. On this basis, the melatonin content fluctuates during flower development and peaks during the bloom stage. Moreover, it is apparent that sun exposure and blue light induce melatonin production whereas green light restrains it during a 24-h light/dark cycle of melatonin content, as there were ‘dual peaks’ at 2 p.m. and 2 a.m. Additionally, the corresponding expression pattern of the herbaceous peony tryptophan decarboxylase gene (TDC) was positively related with melatonin production. These results suggest that color series, development stage and light play an important role in melatonin accumulation, and that TDC is a rate-limiting gene in melatonin biosynthesis.
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Exogenous Melatonin Confers Cadmium Tolerance by Counterbalancing the Hydrogen Peroxide Homeostasis in Wheat Seedlings. Molecules 2018; 23:molecules23040799. [PMID: 29601513 PMCID: PMC6017192 DOI: 10.3390/molecules23040799] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 12/22/2022] Open
Abstract
Melatonin has emerged as a research highlight regarding its important role in regulating plant growth and the adaptation to the environmental stresses. In this study, we investigated how melatonin prevented the cadmium toxicity to wheat seedlings. The results demonstrated that cadmium induced the expression of melatonin biosynthesis-related genes and cause a significant increase of endogenous melatonin level. Melatonin treatment drastically alleviated the cadmium toxicity, resulting in increased plant height, biomass accumulation, and root growth. Cadmium and senescence treatment significantly increased the endogenous level of hydrogen peroxide, which was strictly counterbalanced by melatonin. Furthermore, melatonin treatment caused a significant increase of GSH (reduced glutathione) content and the GSH/GSSG (oxidized glutathione) ratio. The activities of two key antioxidant enzymes, ascorbate peroxidase (APX) and superoxide dismutase (SOD), but not catalase (CAT) and peroxidase (POD), were specifically improved by melatonin. Additionally, melatonin not only promoted the primary root growth, but also drastically enhanced the capacity of the seedling roots to degrade the exogenous hydrogen peroxide. These results suggested that melatonin played a key role in maintaining the hydrogen peroxide homeostasis, via regulation of the antioxidant systems. Conclusively, this study revealed a crucial protective role of melatonin in the regulation of cadmium resistance in wheat.
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Lee K, Lee HY, Back K. Rice histone deacetylase 10 and Arabidopsis histone deacetylase 14 genes encode N-acetylserotonin deacetylase, which catalyzes conversion of N-acetylserotonin into serotonin, a reverse reaction for melatonin biosynthesis in plants. J Pineal Res 2018; 64. [PMID: 29247559 DOI: 10.1111/jpi.12460] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/05/2017] [Indexed: 12/16/2022]
Abstract
In plants, melatonin production is strictly regulated, unlike the production of its precursor, serotonin, which is highly inducible in response to stimuli, such as senescence and pathogen exposure. Exogenous serotonin treatment does not greatly induce the production of N-acetylserotonin (NAS) and melatonin in plants, which suggests the possible existence of one or more regulatory genes in the pathway for the biosynthesis of melatonin from serotonin. In this report, we found that NAS was rapidly and abundantly converted into serotonin in rice seedlings, indicating the presence of an N-acetylserotonin deacetylase (ASDAC). To clone the putative ASDAC gene, we screened 4 genes that were known as histone deacetylase (HDAC) genes, but encoded proteins targeted into chloroplasts or mitochondria rather than nuclei. Of 4 recombinant Escherichia coli strains expressing these genes, one E. coli strain expressing the rice HDAC10 gene was found to be capable of producing serotonin in response to treatment with NAS. The recombinant purified rice HDAC10 (OsHDAC10) protein exhibited ASDAC enzyme activity toward NAS, N-acetyltyramine (NAT), N-acetyltryptamine, and melatonin, with the highest ASDAC activity for NAT. In addition, its Arabidopsis ortholog, AtHDAC14, showed similar ASDAC activity to that of OsHDAC10. Both OsHDAC10 and AtHDAC14 were found to be expressed in chloroplasts. Phylogenetic analysis indicated that ASDAC homologs were present in archaea, but not in cyanobacteria, which differs from the distribution of serotonin N-acetyltransferase (SNAT). This suggests that SNAT and ASDAC may have evolved differently from ancestral eukaryotic cells.
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Affiliation(s)
- Kyungjin Lee
- Department of Biotechnology, Bioenergy Research Center, Chonnam National University, Gwangju, Korea
| | - Hyoung Yool Lee
- 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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Erland LAE, Shukla MR, Singh AS, Murch SJ, Saxena PK. Melatonin and serotonin: Mediators in the symphony of plant morphogenesis. J Pineal Res 2018; 64. [PMID: 29149453 DOI: 10.1111/jpi.12452] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/16/2017] [Indexed: 12/30/2022]
Abstract
Melatonin and serotonin are important signaling and stress mitigating molecules that play important roles across growth and development in plants. Despite many well-documented responses, a systematic investigation of the entire metabolic pathway (tryptophan, tryptamine, and N-acetylserotonin) does not exist, leaving many open questions. The objective of this study was to determine the responses of Hypericum perforatum (L.) to melatonin, serotonin, and their metabolic precursors. Two well-characterized germplasm lines (#4 and 112) created by mutation and a haploid breeding program were compared to wild type to identify specific responses. Germplasm line 4 has lower regenerative and photosynthetic capacity than either wild type or line 112, and there are documented significant differences in the chemistry and physiology of lines 4 and 112. Supplementation of the culture media with tryptophan, tryptamine, N-acetylserotonin, serotonin, or melatonin partially reversed the regenerative recalcitrance and growth impairment of the germplasm lines. Quantification of phytohormones revealed crosstalk between the indoleamines and related phytohormones including cytokinin, salicylic acid, and abscisic acid. We hypothesize that melatonin and serotonin function in coordination with their metabolites in a cascade of phytochemical responses including multiple pathways and phytohormone networks to direct morphogenesis and protect photosynthesis in H. perforatum.
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Affiliation(s)
- Lauren A E Erland
- Department of Plant Agriculture, Gosling Research Institute for Plant Preservation, University of Guelph, Guelph, ON, Canada
| | - Mukund R Shukla
- Department of Plant Agriculture, Gosling Research Institute for Plant Preservation, University of Guelph, Guelph, ON, Canada
| | - Amritpal S Singh
- Summerland Research and Development Centre, Agriculture and Agri-Food Canada, Summerland, BC, Canada
| | - Susan J Murch
- Department of Chemistry, University of British Columbia, Kelowna, BC, Canada
| | - Praveen K Saxena
- Department of Plant Agriculture, Gosling Research Institute for Plant Preservation, University of Guelph, Guelph, ON, Canada
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45
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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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Koca Çalişkan U, Aka C, Bor E. Melatonin in Edible and Non-Edible Plants. Turk J Pharm Sci 2017; 14:75-83. [PMID: 32454597 DOI: 10.4274/tjps.33043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 06/09/2016] [Indexed: 12/31/2022]
Abstract
The concept of melatonin has become more important recently both in plants and in human who utilize plants for nutritional and health purposes. Melatonin, synthesized from L-tryptophan by enzyms, protects plants against difficult conditions. People have consumed these plants for their antioxidant, immunomodulator, antiinflammatory and anticancer effects. In parts of edible and non-edible plants, levels of melatonin are determined by cyclodextrin-modified micellar electrokinetic chromatography, enzyme-linked immuno sorbent assay, radioimmunoassay, high-performance liquid chromatography, liquid chromatography with electrochemical detection, liquid chromatography with fluorimetric detection, liquid chromatography-mass spectrometry, and liquid chromatography-ultraviolet spectrophotometry. In this review, biosynthesis of melatonin in both animal and plants, function of melatonin in plant kingdom, especially in medicinal/edible and nonedible plants, and detection of phytomelatonin content in those plants are presented.
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Affiliation(s)
- Ufuk Koca Çalişkan
- Gazi University, Faculty Of Pharmacy, Department Of Pharmacognosy, Ankara, Turkey
| | - Ceylan Aka
- Gazi University, Faculty Of Pharmacy, Department Of Pharmacognosy, Ankara, Turkey
| | - Emrah Bor
- Gazi University, Faculty Of Pharmacy, Department Of Pharmacognosy, Ankara, Turkey
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Meng X, Li Y, Li S, Zhou Y, Gan RY, Xu DP, Li HB. Dietary Sources and Bioactivities of Melatonin. Nutrients 2017; 9:E367. [PMID: 28387721 PMCID: PMC5409706 DOI: 10.3390/nu9040367] [Citation(s) in RCA: 180] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 03/14/2017] [Accepted: 03/31/2017] [Indexed: 12/14/2022] Open
Abstract
Insomnia is a serious worldwide health threat, affecting nearly one third of the general population. Melatonin has been reported to improve sleep efficiency and it was found that eating melatonin-rich foods could assist sleep. During the last decades, melatonin has been widely identified and qualified in various foods from fungi to animals and plants. Eggs and fish are higher melatonin-containing food groups in animal foods, whereas in plant foods, nuts are with the highest content of melatonin. Some kinds of mushrooms, cereals and germinated legumes or seeds are also good dietary sources of melatonin. It has been proved that the melatonin concentration in human serum could significantly increase after the consumption of melatonin containing food. Furthermore, studies show that melatonin exhibits many bioactivities, such as antioxidant activity, anti-inflammatory characteristics, boosting immunity, anticancer activity, cardiovascular protection, anti-diabetic, anti-obese, neuroprotective and anti-aging activity. This review summaries the dietary sources and bioactivities of melatonin, with special attention paid to the mechanisms of action.
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Affiliation(s)
- Xiao Meng
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
| | - Ya Li
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
| | - Sha Li
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong 999077, China.
| | - Yue Zhou
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
| | - Ren-You Gan
- School of Biological Sciences, The University of Hong Kong, Hong Kong 999077, China.
| | - Dong-Ping Xu
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
| | - Hua-Bin Li
- Guangdong Provincial Key Laboratory of Food, Nutrition and Health, Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
- South China Sea Bioresource Exploitation and Utilization Collaborative Innovation Center, Sun Yat-sen University, Guangzhou 510006, China.
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Lee K, Back K. Overexpression of rice serotonin N-acetyltransferase 1 in transgenic rice plants confers resistance to cadmium and senescence and increases grain yield. J Pineal Res 2017; 62. [PMID: 28118490 DOI: 10.1111/jpi.12392] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/20/2017] [Indexed: 12/14/2022]
Abstract
While ectopic overexpression of serotonin N-acetyltransferase (SNAT) in plants has been accomplished using animal SNAT genes, ectopic overexpression of plant SNAT genes in plants has not been investigated. Because the plant SNAT protein differs from that of animals in its subcellular localization and enzyme kinetics, its ectopic overexpression in plants would be expected to give outcomes distinct from those observed from overexpression of animal SNAT genes in transgenic plants. Consistent with our expectations, we found that transgenic rice plants overexpressing rice (Oryza sativa) SNAT1 (OsSNAT1) did not show enhanced seedling growth like that observed in ovine SNAT-overexpressing transgenic rice plants, although both types of plants exhibited increased melatonin levels. OsSNAT1-overexpressing rice plants did show significant resistance to cadmium and senescence stresses relative to wild-type controls. In contrast to tomato, melatonin synthesis in rice seedlings was not induced by selenium and OsSNAT1 transgenic rice plants did not show tolerance to selenium. T2 homozygous OsSNAT1 transgenic rice plants exhibited increased grain yield due to increased panicle number per plant under paddy field conditions. These benefits conferred by ectopic overexpression of OsSNAT1 had not been observed in transgenic rice plants overexpressing ovine SNAT, suggesting that plant SNAT functions differently from animal SNAT in plants.
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Affiliation(s)
- Kyungjin 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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KORKMAZ A, YAKUPOĞLU G, KÖKLÜ Ş, CUCİ Y, KOCAÇINAR F. Determining diurnal and seasonal changes in melatonin andtryptophan contents of eggplant (Solanum melongena L.). TURKISH JOURNAL OF BOTANY 2017; 41:356-366. [PMID: 0 DOI: 10.3906/bot-1611-48] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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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: 222] [Impact Index Per Article: 27.8] [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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