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

普通大麦品系（Nami Akashinriki）和矮大麦品系（uzu Akashinriki）在黑暗条件下生长。在第3天收获胚芽，此时正常菌株的生长速度约为矮菌株的2倍。从胚芽鞘片段（长度为1cm，从尖端以下5mm处切除）中提取并纯化mRNA。将获得的mRNA引入到体外翻译系统中，用放射性标记为^<35> s -蛋氨酸或^ 3h -亮氨酸的小麦胚芽提取物进行翻译。转录本在二维凝胶电泳上溶解。正常菌株与矮株的荧光图比较发现，有11种蛋白质在名义菌株的mRNA转录本中明显出现，而在矮株的mRNA转录本中没有或很少出现。在体外翻译体系中加入IAA，观察外源施加IAA对翻译过程的影响。IAA对蛋氨酸和亮氨酸的翻译均无明显影响，而在stmin Nami中，IAA对标记亮氨酸的结合有明显的抑制作用，对甲基氨酸的结合没有明显的抑制作用。意想不到的结果仍有待解答。如前所述，菌株uzu产生的IAA少于菌株Nami。从菌株uzu和Nami的胚芽鞘段中提取粗酶制剂，以了解菌株uzu中哪一步阻碍了IAA的生物合成。两株菌株均由d -色氨酸产生IAA。d -环丝氨酸（一种d -转氨酶抑制剂）抑制了IAA的产生，表明两种菌株都是通过d -色氨酸产生IAA的。然后，测定将l -色氨酸转化为d -色氨酸的消旋酶活性。外消旋酶的最适pH值为7.6，而uzu的最适pH值大于9.7。纳米和祖祖的消旋酶最适pH值的差异强烈表明，祖祖消旋酶的氨基酸组成与纳米不同，祖祖消旋酶的DNA序列也与纳米不同。目前采用离子交换和凝胶渗透色谱法分离消旋酶。纯化后的酶及其氨基酸组成将为祖祖菌矮缩基因的分析提供便利。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