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ElSayed AI, Boulila M, Rafudeen MS, Mohamed AH, Sengupta S, Rady M, Omar AA. Melatonin Regulatory Mechanisms and Phylogenetic Analyses of Melatonin Biosynthesis Related Genes Extracted from Peanut under Salinity Stress. PLANTS 2020; 9:plants9070854. [PMID: 32640740 PMCID: PMC7411912 DOI: 10.3390/plants9070854] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/02/2020] [Accepted: 07/04/2020] [Indexed: 01/24/2023]
Abstract
Melatonin improves the tolerance of plants to various environmental stresses by protecting plant cells against oxidative stress damage. The objective of the current study was to determine whether exogenous melatonin (MT) treatments could help protecting peanut (Arachis hypogaea) seedlings against salinity stress. This was achieved by investigating enzymatic and non-enzymatic antioxidant systems and the expression of melatonin biosynthesis related genes in response to salinity stress with or without exogenous MT. The results showed a significant increase in the concentrations of reactive oxygen species (ROS) in peanut seedlings under salinity stress. The exogenous application of melatonin decreased the levels of ROS through the activation of antioxidant enzymes in peanut seedlings under salinity stress. Transcription levels of melatonin biosynthesis related genes such as N-acetylserotonin methyltransferase (ASMT1, ASMT2, ASMT3), tryptophan decarboxylase (TDC), and tryptamine 5-hydroxylase (T5H) were up-regulated with a 150 µM melatonin treatment under salinity stress. The results indicated that melatonin regulated the redox homeostasis by its ability to induce either enzymatic or non-enzymatic antioxidant systems. In addition, phylogenetic analysis of melatonin biosynthesis genes (ASMT1, ASMT2, ASMT3, TDC, T5H) were performed on a total of 56 sequences belonging to various plant species including five new sequences extracted from Arachis hypogaea (A. hypogaea). This was based on pairwise comparison among aligned nucleotides and predicted amino acids as well as on substitution rates, and phylogenetic inference. The analyzed sequences were heterogeneous and the A. hypogaea accessions were primarily closest to those of Manihot esculenta, but this needs further clarification.
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Affiliation(s)
- Abdelaleim I. ElSayed
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig 44519, Egypt;
| | - Moncef Boulila
- Université de Sfax- Institut de l’Olivier- B.P. 14, Ibn Khaldoun, Sousse 4061, Tunisia;
| | - Mohammed S. Rafudeen
- Department of Molecular and Cell Biology, University of Cape Town, Private Bag, Rondebosch 7701, South Africa;
| | - Azza H. Mohamed
- Agricultural Chemistry Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt
- Citrus Research and Education Center, University of Florida, IFAS, Lake Alfred, FL 33850, USA
- Correspondence: (A.H.M.); (A.A.O.); Tel.: +1-863-521-4886 (A.H.M.), +1-863-521-4569 (A.A.O.); Fax: +1-863-956-4631 (A.H.M.); +1-863-956-4631 (A.A.O.)
| | - Sonali Sengupta
- School of Plant, Environmental and Soil Sciences, Louisiana State University, Agricultural Center, Baton Rouge, LA 70808, USA;
| | - Mostafa Rady
- Botany Department, Faculty of Agriculture, Fayoum University, Fayoum 63514, Egypt;
| | - Ahmad A. Omar
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig 44519, Egypt;
- Citrus Research and Education Center, University of Florida, IFAS, Lake Alfred, FL 33850, USA
- Correspondence: (A.H.M.); (A.A.O.); Tel.: +1-863-521-4886 (A.H.M.), +1-863-521-4569 (A.A.O.); Fax: +1-863-956-4631 (A.H.M.); +1-863-956-4631 (A.A.O.)
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