Effect of Two Distinct Types of Salicylic Acid Treatments on Root System Growth and Mitotic Activity of Root Apical Meristem Cells of Barley Plants under Zinc or Copper Deficiency

Inhibition of plant growth due to micronutrient deficiency is a consequence of several structural and functional changes and disorders. In this study, the effect of salicylic acid (SA) treatments on barley root growth and mitotic activity of the root apical meristem cells under micronutrient deficiency was studied. The results demonstrated that plants without SA treatment (Control) under micronutrient deficiency did not have significant changes in root size and biomass. Nevertheless, the proportion of cells with K-mitosis and vagrant chromosomes in metaphase, as well as bridges, forward and laggard chromosomes in anaphase increased at zinc or copper deficiency. The effects of SA on the growth and mitotic activity of barley root cells under zinc or copper deficiency differed depending on the treatment method. SA seed treatment (SA 1) increased root length and raw biomass, but decreased the proportion of cells with ring chromosomes and bridges in metaphase and anaphase, respectively. Leaf spraying with SA (SA 2) increased root length and decreased the proportion of cells with ring chromosomes and laggard chromosomes in metaphase and anaphase, respectively. At the same time, under micronutrient deficiency the proportion of cells with K-mitosis in metaphase, as well as forward chromosomes and chaotic chromosomes segregation in anaphase increased in SA 2. Besides, under copper deficiency the highest number of variants of complex disorder combinations was detected. The findings of this study indicate that SA seed treatment SA is more effective in reducing the negative effect of micronutrient deficiency on the apical meristem of barley roots.