Five winter wheat cultivars--GK Othalom (HMW-GS composition 2*, 7+8, 5+10), Ukrainka (1, 7+8, 5+10), Palotás (2*, 7+9, 5+10), Ködmön (2*, 7+8, 5+10), and Csongrád (2*, 7+9, 2+12)--grown in Hungary and harvested in the year 2005 were studied. The biosynthesis of gluten-forming polypeptides was followed starting at the 12th day after anthesis to the 53rd. Fresh kernel weight, moisture, and dry matter content of fresh kernels and gliadin and glutenin contents were determined. Gliadin components, total amounts of HMW and LMW polypeptides, and individual HMW polypeptides were determined using a RP-HPLC technique. Although considerable quantitative differences were observed concerning the content of total protein, gliadin, glutenin, and individual gluten-forming polypeptides, the character of accumulation of protein components--determined on the basis protein mass/kernel--was the same for the all of the cultivars studied and could be presented by a sigmoid curve. Small quantities of the gliadin and glutenin monomers may be detected in early stages of kernel development, but the bulk of these proteins is synthesized in later stages of development. It is generally suggested by specialists that the formation and accumulation of glutenin polymers starts later than the synthesis of monomers. Experimental data presented in this paper confirm this suggestion and show that in the first phase of protein synthesis the monomers are in "free" form; polymeric glutenin is detected only later. HMW glutenin subunits are synthesized synchronously, and quantitatively the polypeptides coded by chromosomes D and B dominate.

Both qualitative and quantitative differences in the minor nucleotide constituents of rRNA from normally grown and from etiolated wheat plants (Triticum aestivum L.) were established. Using different degradation methods and separation techniques the 18S+26S RNA of 8-day-old wheat seedlings grown in the light was found to contain 5-methylcytidine, 3-methylcytidine, 5-methyluridine, 3-methyluridine, 5-carboxymethyluridine, 1-methyladenine, N-methyladenine, 5-hydroxymethylcytidine, O(2')-methyluridine, O(2')-methylcytidine, pseudouridine, O(2')-methylpseudouridine, N(2),N(2)-dimethylguanine, 1-methylguanine, ribothymidine and some unknown minor constituents. On the other hand, there were only a few minor nucleotides in the rRNA of etiolated wheat seedlings. Cycloheximide, a cytoplasmic protein synthesis inhibitor, simulated etiolation in that it reduced the number of minor nucleotides in rRNA, whereas chloramphenicol, a chloroplast protein synthesis inhibitor, had no significant effect on the minor nucleotide content of rRNA. This finding suggests that illumination may cause de novo synthesis of cytoplasmic modifying enzymes leading to the formation of highly modified rRNAs.

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