Document Type : Original Article

Authors

1 PhD Student, Ilam University

2 Assistant Professor, Graduate University of Advanced Technology

3 Assistant Professor, Shahid Bahonar University of Kerman

4 Associate Professor, Shahid Bahonar University of Kerman

5 Assistant Professor, Ilam University

Abstract

To evaluate the effect of melatonin pretreatment on germination, early seedling growth and some physiological characteristics of Dracocephalum moldavica under osmotic stress, an experiment was conducted in a factorial arrangement based on completely randomized design with 25 treatments and three replications. The experimental treatments were including different concentrations of melatonin (0, 5, 10, 50 and 100 µmol) and osmotic stress (0, -0.2, -0.4, -0.6 and -0.8 MPa). The seeds of moldavian balm which were primed with different concentrations of melatonin for 24 hours, then in order to germination test under osmotic stress, they transferred into sterile petri dishes which contain 10 ml PEG. Results showed that increasing in stress caused reducing of germination percentage and rate, seedling dry weight, seed vigor index, radicle length, radicle dry weight, shoot length, shoot dry weight, photosynthetic pigments, protein content ,increasing and soluble sugar content. Seed priming with melatonin caused an increase of plant tolerance to osmotic stress. Melatonin caused the increment of germination percentage and rate of germination, seed vigor index and ultimately enhanced dry weight of moldavian balm seedlings under stress condition. The seeds which were pretreated with higher concentrations of melatonin (50 and 100 µmol) showed an increasing of physiological characteristics (photosynthetic pigments, soluble sugar content and protein) under stress condition compared to control. No germination was observed in seeds which were pretreated with distilled water at the levels of -0.6 and -0.8 MPa, while the concentrations of 50 and 100 µmol melatonin caused a seed germination at all levels of osmotic stress.

Keywords

Abdul-baki, A.A., and J.D. Anderson. 1970. Viability and leaching of sugars from germinating barely. Crop Sci. 10: 31-34.
Afreen, F., S. Zobayed, and T. Kozai. 2006. Melatonin in Glycyrrhiza uralensis: response of plant roots to spectral quality of light and UV-B radiation. J. Pineal Res. 41:108-115.
Ahmadi, A., and A. Ceiocemardeh. 2004. Effect of drought stress on soluble carbohydrate, chlorophyll and proline in four adopted Wheat cultivars with various climate of Iran. Iranian J. Agr. Sci. 35: 753-763. (In Persian).
Amiri, M.B., P. Rezvani Moghadam, H.R. Ehiaei, J. Falahi, and M. Aghvani Shajari. 2011. Response of germination and seedling growth of Hyssop (Hyssopus officinalis) and Marguerite (Chrysanthemum superbum) medicinal plants to water stress. J. Plant Ecophysiol. 3: 65-77. (In Persian).
Arnao, M.B. 2014. Phytomelatonin: discovery, content, and role in plants. Adv. Bot. 2014: 1-11.
Arnao, M.B., and J. Hernandez-Ruiz. 2007. Melatonin promotes adventitious and lateral root regeneration in etiolated hypocotyls of Lupinus albus L. J. Pineal Res. 42: 147-152.
Arnao, M.B., and J. Hernandez-Ruiz. 2014. Melatonin: plant growth regulator and/or biostimulator during stress. Trends in Plant Sci. 19: 789-797.
Bradford, M.M. 1976. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal. Biochem. 72: 248-254.
Broomand Reza Zadeh, Z., and A. Koochaki. 2005. Study the seed germination response of Trachyspermum ammi, Foeniculum vulgare and Anethum graveolens to matric and osmotic potential induced by NaCl and poly ethylene glycol on different temperatures. Iran. J. Field Crops Res. 3: 207-217. (In Persian).
Byeon, Y., and K.W. Back. 2013. Melatonin synthesis in rice seedlings in vivo is enhanced at high temperatures and under dark conditions due to increased serotonin N-acetyltransferase and N-acetylserotonin methyltransferase activities. J Pineal Res. 56: 189-195.
Chen, Q., W.B. Qi, R.J. Reiter, W. Wei, and B.M. Wang. 2009. Exogenously applied melatonin stimulates root growth and raises endogenous indoleacetic acid in roots of etiolated seedlings of Brassica juncea. J Plant Physiol. 166: 324-328.
D. Emami., S., and N. M.Hosseini. 2008. Cultivation and production of certain herbs and spices. Univ. Tehran Press. P.93-97. (In Persian).
Emmerich, W.E., and S.P. Hardgree. 1990. Polyethylene glycol solution contact effect on seed germination. Agron. J. 82:1103-1107.
Hosseini, H., and P. Rezvani Moghadam. 2006. Effect of water and salinity stress in seed germination on Isabgol (Plantago ovata). Iran. J. Field Crops Res. 4: 15-22. (In Persian).
Janas, K.M., and M.M. Posmyk. 2013. Melatonin, an underestimated natural substance with great potential for agricultural application. Acta Physiol. Plant. 35:3285-3292.
Judi, M., and F. Sharifzadeh. 2004. Hydropriming effects on different varieties of Hordeum. J. Desert. 3: 99-108.
Kabir, R., A. Hatami, and M. Naghizadeh. 2014. Effect of Drought Stress and its Interaction with Salicylic Acid on Fennel (Foeniculum vulgare Mill.) Germination and Early Seedling Growth. J. Medicinal Plants and By-products. 2: 107-116
Kaya, M.D., and S. Day. 2008. Relationship between seed size and NaCl on germination, seed vigor and early seedling growth of sunflower (Helianthus annuus L.). Afr. J. Agr. Res. 3: 787-791.
Khorramdel, S., P. Rezvani Moghaddam, A. Amin Ghafoori, and J. Shabahang. 2013. Study the effect of priming with salicylic acid and drought stress on germination of black cumin (Nigella sativa). Iran. J. Field Crops Res. 10: 709-725. (In Persian).
Li, C., D.X. Tan, D. Liang, C. Chang, D. Jia, and F. Ma. 2014. Melatonin mediates the regulation of ABA metabolism, free-radical scavenging, and stomatal behaviour in two Malus species under drought stress. J. Exp. Bot. 66: 669-80.
Lichtenthaler, H.K. 1987. Chlorophylls and carotenoids: pigments of photosynthetic biomembranes. Methods in Enzymol.148: 350-382.
Maguire, J.D. 1962. Speed of germination-aid in selection and evaluation for seedling emergence and vigor. Crop Sci. 2: 176-177.
Noor zad, S., A. Ahmadian, and M. Moghaddam. 2015. Study proline content, chlorophyll index, carbohydrate and nutrient absorption in Coriandrum sativum under drought stress and fertilizer treatment. Iran. J. Field crops Rese. 13: 131-139. (In Persian).
Opoku, G., F.M. Davies, E.V. Zetrio, and E.E. Camble. 1996. Relationship between seed vigor and yield of white beans (Phaseolos vulgaris L.). Plant Variety Seed. 9: 119-125.
Posmyk, M.M., H. Kuran, K. Marciniak, and K.M. Janas. 2008. Presowing seed treatment with melatonin protects red cabbage seedlings against toxic copper ion concentrations. J. Pineal Res. 45: 24-31.
Roe, J.H. 1955. The determination of sugar in blood and spinal fluid with anthrone reagent. J. Biol. Chem. 212: 335-343.
Sarropoulou, V.N., K. Dimassi-Theriou, I. Therios, and M. Koukourikou-Petridou. 2012. Melatonin enhances root regeneration, photosynthetic pigments, biomass, total carbohydrates and proline content in the cherry rootstock PHL-C (Prunus avium×Prunus cerasus). Plant Physiol. Biochem. 61: 162-168.
Setayesh Mehr, Z., and A. Ganjali. 2013. Study the effect of drought stress on growth and physiological characteristics of Anethum graveolens. J Hort. Sci. 27: 27-35. (In Persian).
Soltani, A., M. Gholipoor, and E. Zeinali. 2006. Seed reserve utilization and seedling growth of wheat as affected by drought and salinity. Environ. Exp. Bot., 55: 195-200.
Takel, A. 2000. Seedling emergence and growth of sorghum genotypes under variable soil moisture deficit. Acta Agron. Hung. 48: 95-102.
Tan, D.X., L.C. Manchester, P. Helton, and R.J. Reiter. 2007. Phytoremediative capacity of plants enriched with melatonin. Plant Signal Behav. 2: 514-516.
Turk, H., S. Erdal, M. Genisel, O. Atici, Y. Demir, and D. Yanmis. 2014. The regulatory effect of melatonin on physiological, biochemical and molecular parameters in cold-stressed wheat seedlings. Plant Growth Regul. 74: 139-152.
Wang, P., X. Sun, Y.P. Xie, M.J. Li, W. Chen, S. Zhang, D. Liang, and F.W. Ma. 2014. Melatonin regulates proteomic changes during leaf senescence in Malus hupehensis. J Pineal Res. 57: 291-307.
Yordanov, V., and T. Tsoev. 2000. Plant responses to drought, acclimation and stress tolerance. Photosynthica. 38: 171-186.
Zhang, N., B. Zhao, H.J. Zhang, S. Weeda, C. Yang, Z.C. Yang, S. Ren, and Y.D. Guo. 2013. Melatonin promotes water-stress tolerance, lateral root formation and seed germination in cucumber (Cucumis sativus L.). J. Pineal Res. 54: 15-23.
Zhang, N., Q. Sun, H. Zhang, Y. Cao, S. Weeda, S.H. Ren, and Y.D. Guo. 2015. Roles of melatonin in abiotic stress resistance in plants. J Exp. Bot. 66: 647-56.