[The role of Cd-binding proteins and phytochelatins in the formation of cadmium resistance in Nicotiana plumbaginifolia cell lines].

Nicotiana plumbaginifolia callus lines with the equal resistance to cadmium have been produced under different selective conditions--either without inhibition of the phytochelatin synthesis (line Cd-R) or in the presence of the inhibitor butionine sulfoximine (line Cd-Ri). The level of phytochelatin synthesis in the line Cd-R five-fold exceeded the control value and in the line Cd-Ri it was twice as much as in the control. It was shown that in the control line mainly three cadmium-binding proteins are expressed of the molecular weihgts 41, 34 and 19 kD. The common feature of the both resistant lines is the expression of the cadmium-binding proteins of 40, 37 and 19 kD. The resistant lines differ with respect to the synthesis of relatively low-molecular cadmium-binding proteins. The proteins of the molecular weights 12.5, 11.5 and 9 kD are expressed in the line Cd-R, while the proteins of 13 and 10 kD are expressed in the line Cd-Ri. It was supposed that both the phytochelatins and the Cd-binding proteins contribute to the resisitance of N. plumbaginifolia callus lines to cadmium and the lack of the phytochelatins can be equilibrated by the changes in the low-molecular Cd-binding protein synthesis.

[Assessment of phyto- and cytotoxic effects of heavy metals and aluminum compounds using onion apical root meristem]. / Otsenka fito- i tsitotoksicheskoi aktivnosti soedinenii tiazhelykh metallov i aliuminiia s pomoshch'iu kornevoi apikal'noi meristemy luka.

The effects of different concentrations (10(-6)-10(-3) M) of salts of six metals (cadmium, lead, nickel, aluminum, copper, and zinc) on the root growth of onion (Allium cepa L.) seedling and cell division, chromosome and nucleus morphology in root tip cells were studied. The obtained results showed that tested compounds inhibit the root growth, reduce the mitotic activity of meristem cells and cause the chromosome and nucleus irregularities. On the basis of these data two rows of metal salt toxicity were proposed--for effective concentrations (EC50) of toxic action: CuSO4 > CdCl2 > NiSO4 > Pb(CH3COO)2 > Al(NO3)3 > ZnSO4, and for sublethal and lethal effects of investigated substances: CuSO4 > Pb(CH3COO)2 > CdCl2 > ZnSO4 > NiSO4 > Al(NO3)3.

[Cytogenetic effects of toxic metal salts on apical meristem cells of Allium cepa L. seed roots]. / Tsitogeneticheskie effekty solei toksichnykh metallov v kletkakh apikal'noi meristemy kornei prorostkov Allium cepa L.

Comparative analysis of the influence of the salts of Cd, Pb, Ni, Al, Cu and Zn at concentrations 10(-6)-10(-3) M on cytogenetic parameters of Allium cepa apical meristem cells was carried out. It was shown that these metal compounds could induce both the clastogenic and the aneugenic effects (including mitosis and cytokinesis disturbances). Based on ability to cause the chromosome aberrations the metal salts were arranged in such row of genotoxicity: ZnSO4 > Pb(CH3COO)2 > Al(NO3)3 approximately NiSO4 > CdCl2 > CuSO4. The investigated compounds of cadmium, lead, nickel and aluminum were found to be more effective aneugens than clastogens. According to our data NiSO4 had the strongest antimitotic activity (it increased the percentage of chromosome lagging of, multipolar anaphases, C-mitoses in 69.6 times, compared to the control). The ability of other metal salts to induce such abnormalities decreased in the range: CdCl2 > Al(NO3)3 > Pb(CH3COO)2 > CuSO4 > ZnSO4. Increasing of binuclear cells on the slides was revealed after treatment by all tested substances, however Ni sulfate was found as the strongest inducer of cytokinesis abnormalities. Presented results allowed to suggest that cytoskeleton could be a cell target for salts of some metals (especially for NiSO4).