EFFECT OF LOW-TEMPERATURE ON THE RIBOSOMAL-RNA PROCESSING IN WHEAT (TRITICUM-AESTIVUM L)

In the course of the experiments, studies were made on the effect of l ow temperature on rRNA processing. The two wheat lines in this work di ffered from each other only as regards frost resistance. It was proved that in the case of the weakly frost resistant line quantitative and qualitative changes took place in the rRNA maturation process as the r esult of low temperature. During cold treatment the last precursors (1 .4 and 0.9 MD) of the two stable cytoplasmic rRNAs (1.3 and 0.7 MD) ac cumulated at the expense of the stable rRNA fractions. This accumulati on increased as cold treatment proceeded. In the line with good frost resistance this change could not be demonstrated. The results indicate that in the poorly resistant line the cold treatment had an inhibitor y effect on the last step in the maturation process, i.e. at low tempe rature this process is unable to proceed to completion.