Boron (B) toxicity is an important environmental constraint that limits crop
productivity. Salicylic acid (SA) and thiamin participate in the processes
underlying plant adaptations to certain types of abiotic and biotic stress.
This study aimed to investigate the individual and combined effects of SA
or thiamin and B on physiological attributes of wheat under normal and B toxicity
conditions. Seeds were soaked in SA or thiamin and excess B was
applied for 10-day after planting the seedlings. Growth parameters, photosynthetic
pigments, B and some elements concentrations, hydrogen peroxide
(H2O2), proline, other free amino acids, soluble proteins, and
carbohydrates were measured. Application of SA or thiamin showed an
increase in tolerance towards high B as indicated by H2O2, amino acids,
soluble proteins, and carbohydrates contents. The results support the conclusion
that SA and thiamin alleviate B toxicity not at the level of B content
but by affecting other elements and osmo-protective metabolite.