Salinity effects on macro and micronutrients uptake in medicinal plant King of Bitters (Andrographis paniculata Nees.)

Plants species require macro and micro nutrients to complete the growth cycles such as photosynthesis, enzyme activities and secondary metabolite production. The objective of the present study was to investigate the effects of salinity on biomass as well as macro and micro nutrients uptake in the medicinal plant of Andrographis paniculata (AP). In this regard, a split plot experiment was carried out based on Randomized Complete Block Design (RCBD) with two factors; five salinity levels (control, 4, 8, 12 and 16 dsm ) in main plots and 12 different AP accessions in sub-main plots with three replicates. Seventy-day-plants (before flowering stage) were exposed to different salinity levels on a Hoagland medium. The results indicated that salinity levels had a significant effect on the measured traits. Salinity caused a reduction in dry material and salt tolerance index (STI). The sodium (Na), iron (Fe), zinc (Zn) and copper (Cu) contents significantly increased, while nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg) and manganese (Mn) content decreased in high salinity levels. Furthermore, under salinity stress, tolerant accessions could produce higher K, P, N, Mg and Ca and lower Na, Fe, Zn and Cu than sensitive accessions. Interestingly, Na concentration was highly correlated to STI (r = −0.79), while the lowest correlation was observed between P and Na concentration (r = −0.15). Saltstress caused changes in macro and micro nutrients uptake, which may lead to decline in photosynthesis capacity and respiration. This type of abiotic stress can also disturb metabolism of several cellular components such as protein synthesis.