Scientific publications

The effect of zinc excess in the root area (160 mg / kg substrate) on the state of the shoot apex and the rate of organogenesis in spring barley (Hordeum vulgare L.) v. Nur during the stem elongation development phase was studied in a pot experiment. In 30‑days-old plants at the beginning of this phase, zinc in the given concentration inhibited the shoot apex growth, hindered its differentiation, and delayed organogenesis. This effect is supposed to be associated with the direct action of the metal on the meristematic activity of apex cells, as well as its mediated action due to changes in cellular metabolism. In 45‑days-old plants, when the stem elongation phase was completed, the negative effect of zinc on the shoot apex was leveled off, apparently due to the activation of intracellular mechanisms of metal detoxification and, as a consequence, the recovery of cell meristematic activity. Owing to the shortening of the organogenesis stage VI, the experimental plants caught up with the control plants in their development and proceeded to stage VII of organogenesis almost simultaneously with them. It also follows from the obtained results that the morphophysiological method of monitoring the state of shoot apex and the rate of organogenesis allows one to quickly and quite reliably detect the effect of heavy metals on cereals development, even where there are no visible differences in the onset of phenophases between experimental and control plants.