[Protein synthesis in maize haploids and diploids during cultivation under normal conditions and in the presence of phenol].

14C-leucine incorporation in cytoplasmic protein was compared for three haploid forms, three derivative autodiploid lines and four hybrid forms of maize. It has been found that the precursor incorporation in the haploid forms was by 15-20% higher that in appropriate autodiploid lines. However, the level of protein synthesis wes practically the same for all investigated diploid forms. Thus, the increase of the ploidy level correlates with the decrease of the cytoplasmic protein synthesis. It was also shown that the protein content was practically equal in haploid and diploid forms. Proceeding from the authors' data one can conclude that the protein distraction may also have different intensity. The next step of the investigation was the study of the effects of the chemical factor of cytoplasmic protein synthesis in maize seedlings with different ploidy levels in vivo. It has been revealed, that the rate of 14C-leucine incorporation in the cytoplasmic proteins differ for the haploid forms which grew on the Knop media with the addition of phenol (0.05%) and without pollutant. Nevertheless, approximately equal level of 14C-leucine incorporation was observed for autodiploids. Recently it was demonstrated that the synthetic intensity of different RNA fractions is higher in the haploid maize forms than in the diploid ones and that the haploid and diploid forms of maize display the different reaction on phenol pollution. When comparing our data with the published results it is possible to conclude that the hypothesis about the low intensity of metabolism in haploid plants, existing in literature, is not true. The authors suppose that the high activity of synthesis of nuclear, transfer and ribosomal RNA and cytoplasmic proteins in the haploid plants may be connected with high mitotic activity. The authors' data are in agreement with the hypothesis that the ratio of nuclear volume and surface determines the metabolism rate.