ANALYSIS OF DWARF GENE(UZ)OF STRAIN UZU-AKASHINNRIKI OF BARLEY

在黑暗条件下培养普通大麦品系（Nami Akashinriki）和矮秆品系（uzu Akashinriki）。在第3天收获胚芽鞘，此时正常菌株的生长速率约为100%。是侏儒品种的两倍从胚芽鞘段（长度为1cm，从尖端下方5 mm处切除）提取并纯化mRNA。用放射性标记的^<35>S-蛋氨酸或^3 H-亮氨酸将这样获得的mRNA导入体外翻译系统。将转录物溶解在二维凝胶电泳上。通过对正常株和矮化株的荧光图谱的比较，发现有11种蛋白质明显地出现在正常株的mRNA转录产物中，而矮化株的mRNA没有或很少转录。IAA对翻译无影响 关于我们 在uzu中，无论是使用蛋氨酸还是亮氨酸，而在stmin Nami中，IAA基本上抑制标记的亮氨酸掺入到蛋白质中，但不抑制蛋氨酸的掺入。如前所述，菌株uzu产生的IAA比菌株Nami少。为了了解菌株uzu中IAA生物合成的哪个步骤受到阻碍，从uzu和Nami的胚芽鞘片段中提取粗酶制剂。在这两种菌株中，IAA均由D-色氨酸产生。D-环丝氨酸（D-转氨酶的抑制剂）的生产受到抑制，这表明IAA是通过D-色氨酸在两种菌株中产生的。接下来，测定将L-trp转化为D-trp的消旋酶活性。Nami的消旋酶的最适pH为7.6，而uzu的消旋酶的最适pH为9.7以上。Nami和uzu的消旋酶最适pH值的差异表明uzu的消旋酶的氨基酸组成与Nami不同，并且uzu的消旋酶的DNA序列也与Nami不同。用离子交换色谱法和凝胶渗透色谱法分离消旋酶.纯化的酶及其氨基酸组成将为研究旋毛虫dwar基因提供便利。少

Normal barley strain (Nami Akashinnriki) and dwarf strain (uzu Akashinriki) were grown under the dark. The coleopitles were harvested on day 3, when the growth rate of the normal strain was ca. two times as fast as that dwarf strain. mRNA was extracted and purified from the coleoptile segments (1 cm in length, excised from 5 mm below the tip). mRNA thus obtained was introduced into the in vitro translation system using wheat germ extracts with radio labeled ^<35>S-methionine or ^3H-leucine. The transcripts were dissolved on two-dimensional gel electrophoresis. The comparison of the fluorogram of the normal strain with that of the dwarf strain revealed that there were 11 species of proteins distinctly appeared in the transcripts from mRNA of the nominal strain, but were not or little transcribed from mRNA of the dwarf strain.IAA was added to the in vitro translation system to see the effect of exogenously applied IAA on the translation process. IAA did not affect the translation in stra … More in uzu either using methionine or leucine, while in stmin Nami, IAA substantially inhibited the incorporation of labeled leucine into the proteins but not the incorporation of methilnine. The unexpected results remained to be answered.As reported previously, strain uzu produced less IAA than strain Nami. To see which step for IAA bioshynthesis was impeded in strain uzu, crude enzyme preparation was extracted from the coleoptile segments of uzu and Nami. IAA was produced from D-tryptophan in both strains. The production was inhibited by D-cycloserine (an inhibitor of D-transaminase), suggesting that IAA is produced through D-tryptophan in both strains. Next, racemase activity which converts L-trp to D-trp was assayed. pH optimum for the racemase of Nami was 7.6 while that of uzu was over 9.7. The difference of the optimum pH for the racemase between Nami and uzu strongly suggested that the amino acid composition of racemase of uzu was different from that of Nami, and DNA sequence for racemase of uzu was also different from that of Nami. The isolation of the racemase was now undertaken by ion- exchange and gel permeation chromatography. Purified enzyme and its amino acid composition will afford a great facility for the analysis of dwar gene of uzu. Less