[Effect of hydrostatic pressure on structural organization of the maize root cells]

We analyzed the effect of hydrostatic pressure at 24 MPa level on the growth and organization of corn seedlings cells. At pressure value of 2 MPa, we observed the clarification of the mitochondrial matrix, clusterization of endoplasmic reticulum elements with formation of ergastorplasm sites and the increasing number of small vacuoles in the cytoplasm. We detected the accumulation of vesicles with electron-dense content on the trans side of dictyosomes, which indicates a change in the endomembranous system traffic. The reduction of electronic density of tonoplast was accompanied by a reduction of osmiophilic inclusions in the vacuoles. Increasing the pressure up to 4 MPa showed the emergence of destructive alterations in the tonoplast. None of the variants showed any violation of plasmalemma integrity, as confirmed by coloring with Evans blue. When we reset the hydrostatic pressure to atmospheric pressure, the frequency of structural distortions of the tonoplast membrane was proportional to the pressure difference: the minimum was at reset from 2 to 0 MPa and the maximum was at reset from 4 to 0 MPa. Thus, it has been concluded, that the endomembraneous system is among the targets of pressure effect on the plant cells.