Journal of Ethno-Pharmaceutical Products

Abstract Drought stress affects many morphological characteristics and biochemical processes related to plant growth and development. In this sense, drought, as a multidimensional stress, has various destructive effects on plants. By inhibiting the transfer of electrons, this stress creates a secondary stress in the production of reactive oxygen species, causing double damage to the cell membrane, photosynthetic pigments, and other physiological parameters. Today, the use of metal nanoparticles such as zinc and iron in improving activities and dealing with plant stresses can create beneficial effects in plant and agricultural biotechnology. The treatments include drought stress at two levels (drought stress and no drought stress) as the main factor and three levels of iron, zinc separately and integrative of iron and zinc nanoparticles. The results showed that all investigated traits were affected by drought stress conditions, so that under drought stress the fresh and dry weight. Chlorophyll a and b, decreased and the usage of iron and zinc nanoparticles reduced the effects of drought stress in mentioned growth parameters in tomato plants. Therefore, the application of the above nanoparticles can be very effective in improving the growth of tomato plants, especially in dry areas.

Abstract More than 22% of the world's agricultural land is saline, and this trend continues to increase with climate changes. Salinity stress causes leaf color change, osmotic stress, ionic toxicity, prevents growth, photosynthesis and plant performance. Due to their size less than micron, metal nanoparticles have a great absorption and transmission power in plants. Salinity stress is a major problem in hot and dry areas under tomato cultivation. For this purpose, investigating the mutual effects of the size and type of zinc oxide and iron oxide nanoparticles on the improvement and change of growth and increasing the resistance to salt stress in tomato plants of the early urbana variety were carried out in the form of a completely randomized and factorial design with 4 replications, at a significant level of 5%. In this research, zinc oxide nanoparticles in 25 and 50 nm sizes, iron oxide in 25 nm sizes and sodium chloride in 0 and 75 mM levels were used. Nanoparticles and salinity treatments were both applied to the plants. The results showed that salt stress led to a decrease in plant growth parameters such as shoot and root length, leaf area, RWC, ion leakage. Also, NaCl led to an increase in the accumulation of prolin and other aldehydes, sodium, iron and zinc. The application of nanoparticles had a slight effect in stress-free conditions, but in stressed conditions, these two nanoparticles alone and especially in combination neutralized the effect of salinity and reduced the damage caused by salinity stress.