Document Type : Research Paper

Authors

• parvaaneh hemmati Hassan gavyar ¹
• Hamzeh Amiri ²
• Marino B. Arnao ³
• Seifollah Bahramikia ⁴

¹ Departement of Biology, Factually of science, Lorestan University, Khoram- Abad, Iran.

² Department of Biology, Lorestan University.

³ Department of Plant Biology (Plant Physiology), Faculty of Biology, University of Murcia, 30100 Murcia, Spain

⁴ Departement of Biology, Factually of science, Lorestan University, Khorramabad, Iran

Abstract

In recent years the role of serotonin as a plant growth regulator which is effective in increasing plants' resistance to stress has been considered. The aim of this study was to investigate the effect of serotonin on some morphophysiological and biochemical characteristics of saffron under drought stress conditions. Polyethylene glycol 6000 was used and drought stress was applied at 10% and 20% levels. The root treatment of serotonin was applied at a concentration of 100 μM. The results showed that drought stress, especially 20% stress, led to a decrease in fresh weight (42.19%), dry weight (50.30%), height (46.44%), relative water content (21.32%), Chlorophyll a (36.41%), chlorophyll b (30.66%), carotenoids (39.71%) and photosynthesis rate (57.26%) compared to the control group. In these conditions, the content of sugar, proline, phenol, flavonoid, hydrogen peroxide and ion leakage were increased by 7.33%, 28.37%, 18.08%, 19.75%, 34.77% and 7.56%, respectively. In the condition of 20% drought stress, serotonin treatment, 22.37% fresh weight, 24.51% dry weight, 46.72% height and 6.25% the relative water content were increased. During seretonin application chlorophyll a chlorophyll b carotenoids and net photosynthesis were increased by 17.38%, 20.26%, 18.44%, 41.55% respectively. The amount of sugar, proline, ion leakage and H2O2 were decreased by 3.37%, 10.4%, 15.29% and 11.41% respectively. Also, phenol and flavonoid were increased by 17.14% and 18.70%, respectively .Overall, due to the positive effects of serotonin, its exogenous application by affecting physiological characteristics such as photosynthetic and antioxidant parameters leads to an increase in plant resistance to drought stress.

Keywords

• photosynthesis rate
• saffron
• compatible osmolytes
• Serotoni

Main Subjects

• Physiology