Effect of Soil Salinity and Foliar Application of Jasmonic Acid on Mineral Balance of Carrot Plants Tolerant and Sensitive to Salt Stress

The aim of the study is to determine the effects of soil salinity stress and foliar application of jasmonic acid (JA) on the mineral balance in plants of salt-sensitive doubled haploid carrot line (DH1) and salt-tolerant local DLBA variety (DLBA). Concentrations of 28 elements were determined in roots and leaves and in the soil. The DcNHX4 gene (cation:proton exchange antiporter) expression was assessed. The salinity stress reduced the mass of roots and leaves more in DH1 than in DLBA. DLBA plants accumulated larger amounts of Na and Cl in the roots and had an increased transport of these elements to the leaves. The salt-tolerant and salt-sensitive carrot varieties differed in their ability to uptake and accumulate some elements, such as K, Mg, Zn, S, Cd, P and B, and this response was organ-specific. A selective uptake of K in the presence of high Na concentration was evident in the tolerant variety, and a high Na content in its leaves correlated with the expression of DcNHX4 gene, which was expressed in DLBA leaves only. JA application did not affect the growth of DLBA or DH1 plants. In the sensitive DH1 variety grown under salinity stress, JA induced changes in the mineral balance by limiting the uptake of the sum of all elements, especially Na and Cl, and by limiting Zn and Cd accumulation.