Azam Gholamnia
Asghar Mosleh Arani
Hamid Sodaeezade
Saeed Tarkesh Esfahani
Somaye Ghasemi

The growth and yield of plants in the world particularly in arid and semi-arid regions are affected by salinity stress. In these regions, the effect of salinity stress intensifies by simultaneous drought caused by high temperatures. Investigating and obtaining the best growing conditions, which can lead to the production of plants with higher secondary metabolite contents, are among the most important goals in research on the cultivation of herbs. An experiment was carried out in order to study the effect of three levels of salinity (۰, ۶۰ and ۱۲۰ mM of sodium chloride) and two levels of thermal stresses (۲۵°C and ۳۵°C) on some physiological characteristics Mentha piperita L. in a completely randomized design with three replications. The result showed that the temperature, salinity, time, and their interaction had significant effects on changes in the levels of proline,, K+/Na+ ratio, soluble sugar at a ۱% level (P ≤ ۰.۰۱), by increasing salinity and heat stresses, the proline content increased by ۱.۹۲ times at ۷۲ hours at a salinity of ۱۲۰ mM compared to the control. Also, over time, sugar levels and K+/N+ ratio decreased with increasing temperature and salinity.

Mentha piperita L., Salinity, heat, proline.