Salt stress affects mineral nutrition in shoots and roots and chlorophyll a fluorescence of tomato plants grown in hydroponic culture

Salt stress is considered one of the major constraints limiting plant growth. Here, tomato plants were grown in hydroponic culture with two salt sodium chloride concentrations (S1 = 2.8 dS m(-1) and S2 = 4.8 dS m(-1)). Under salt treatment, a significant decrease in chlorophyll content index and shoot and root dry weight were observed. We found that copper (Cu) was accumulated significantly in the shoot and sodium (Na) was significantly accumulated in the root. Furthermore, a significant nutrient imbalance indicated by a decrease in phosphorus (P), and potassium (K) uptake was measured. These decreases were accompanied by an increase in Na and Cu contents. A decrease in chlorophyll fluorescence yield was also observed indicating an inhibition at photosystem I acceptor sites. It seems that the downregulation of the electron transport between photosystem II and photosystem II under salt stress could be due to an imbalance in nutrient uptake.