Determination of the effects of dopamine on tomato under salinity and drought stress in terms of certain physiological and moleculer parameters

The aim of the study was to determine the effects of salinity and drought stress and to reveal the effects of dopamine application against salinity and drought stress. For this purpose, 100 ml/l dopamine hydrochloride was applied into Hoagland solution from the seed planting stage to plants under drought and salinity stress. During the application, anatomical effects such as body/stem tissue lengths, body/root dry weights and water content, physiological effects such as relative water content, ion leakage, proline amount of MDA and gene expressions of ACS2, APX, CAT, GR1, P5CS and SOD antioxidative defense enzymes were looked at. As a result of the study, it was determined that drought and salinity stress decreased the stem tissue length, dry weight, water content, root tissue water content of the plants compared to the control application, whereas the use of dopamine significantly increased the stem tissue dry weight, root tissue length and root tissue dry weight. However, it was determined that there was a decrease in the relative water content, ion leakage and MDA amount with dopamine application. When the results were examined, it was determined that dopamine application had a decreasing effect on the negative results of drought and salinity stress. When the antioxidative gene expressions of plants under salinity and drought stress were examined, administration of dopamine under salt stress did not cause a significant change in CAT, GR1, P5CS, SOD expressions, increased APX gene activity, and decreased ACS2 gene expression. Dopamine administration under drought stress decreased ACS2, APX, GR1, P5CS gene expressions, while increased CAT and SOD expressions. When all these values were examined, it was concluded that dopamine application to plants under drought and salinity could be effective in reducing stress. Apart from our study, no study was found in which the effects of dopamine application on plant development were determined under normal conditions or under abiotic and biotic stress conditions.