Effects of sodium chloride and salicylic acid on some photosynthetic parameters and mineral nutrition in maize (Zea mays L.) plants

Salinity is a common abiotic stress that affects plant growth and development as well as crop production in most parts of the world. To study the effects of salt stress and salicylic acid pretreatments on the growth parameters, photosynthetic pigments, photochemical efficiency of photosystem II including: quantum yield of PS II (Ø PSII), maximum quantum yield of PS II (Fv/Fm) and non-photochemical quenching (NPQ) and mineral nutrients (Na+, K+, N, P, Ca2+, Mg2+, Fe, Zn2+, Mn, Cu and B) of Zea mays L. (KSC704) a factoriel experiment was conducted in completely randomized design (salinity in tow levels and salicylic acid in three levels) with 5 replicates. Salt stress reduced growth parameters and photosynthetic pigments (chl a, b and total), carotenoids, quantum yield of PS II (Ø PSII), maximum quantum yield of PS II (Fv/Fm) and increased non-photochemical quenching (NPQ). Moreover, salt stress affected mineral elements in the leaves of the plants. Salinity decreased the amounts of K+ and Cu and increased Na+, P, Ca2+, Mg2+, Fe, Zn2+, Mn and B but the contents of N and Ca2+ were not affected by salinity. SA pretreatment increased photosynthetic pigments and carotenoids, quantum yield of PS II (Ø PSII), maximum quantum yield of PS II (Fv/Fm) and decreased non-photochemical quenching (NPQ). SA application changed the absorption and translocation of mineral elements in the leaves and specifically decreased Na content. Positive effects of SA pretreatment appeared in reduction of salt stress and improving the plants growth.