Effect of <i>seed priming</i> with NaCl on the induction of salinity tolerance in <i>Myracrodruon urundeuva</i> Allemão <i>in vitro</i>

Abstract

Soil salinization is an environmental factor that frequently occurs in semi-arid regions around the world and seed priming technique is one of the alternatives to obtain the greatest establishment of seedlings in the field, through the induction of tolerance to environmental stresses. This research aimed to evaluate the effect of seed priming with NaCl on the induction of salinity tolerance in Myracrodruon urundeuva Allemão in vitro. The research was carried out at the Center for Strategic Technologies of the Northeast, in Recife / PE-Brazil M. urundeuva seeds were disinfected and submitted to two treatments: water (control) or NaCl (2mM), and inoculated in WPM medium at three saline concentrations (0.0; 25.0 and 50.0 mM NaCl) for 45 days. Plant height, number of leaves, fresh biomass (total, shoot, and root), shoot/root ratio, sodium and potassium and Na/K ratio, antioxidant enzyme activity, and peroxide content were evaluated malondialdehyde hydrogen. The data were subjected to variance analysis and the results were compared using the Student-Newman-Keuls test at 5% probability, using the R software. Seed priming with NaCl promoted a beneficial effect on the height of seedlings exposed to salinity. On the other hand, height was inversely proportional to saline concentrations, regardless of seed priming. The shoot/root ratio was also lower in seedlings cultivated under 25 and 50 mM NaCl. Despite being favorable for most growth variables, seed priming with NaCl induced an increase in lipid peroxidation in seedlings that were not exposed to salinity, which is linked to a decrease in the activity of antioxidant enzymes. The antagonistic response to NaCl stimulation between growth parameters and plant defense observed in the present research raises the need for further complementary studies that make it possible to delineate the metabolic alterations of M. urundeuva against a chemical stimulus to induce tolerance to a given stress.