Mitigation of Drought Stress Effects on Pepper Seedlings by Exogenous Methylamine Application

The study was conducted to determine effects of a new synthesis of methylamine on the plant growth, physiological and biochemical characteristics in pepper.  There were four irrigation levels [full irrigation (100%) (I0), 80% (I1), 60% (I2) and 40% (I3)] and two methylamine (MA) treatments (0, 2.5 mM). At the end of the study, it was observed that there were significant differences between applications and levels. Effects of MA treatments on plant growth (plant height, stem diameter, fresh, dry weight etc.), plant physiological and biochemical parameters [tissue electrical conductivity (TEC), tissue relative water content (TRWC), hydrogen peroxide (H2O2), malondialdehyde (MDA), proline, antioxidant enzyme activity], and plant nutrient element content of pepper seedlings under different irrigation levels were significantly important.  The results of the study showed that the drought stress conditions negatively affected the plant growth, increased the content of TEC, H2O2 and MDA, and decreased the TRWC and  plant mineral content in pepper. However, MA application improved plant growth and decreased TEC, H2O2 and MDA content compared to control in pepper under drought conditions. MA treated plants at I3 had higher shoot fresh weight and shoot dry weight than non-treated plants by 12 and 20%, respectively.  In conclusion, MA application could mitigate the deleterious effects of the drought stress on the pepper seedlings.