Lehrstuhl für Genetik, Institut für Biologie II der Universität Tübingen, Auf der Morgenstelle 28, 7400, Tübingen, F.R.G..
Plant Mol Biol. 1984 May;3(3):137-45. doi: 10.1007/BF00016061.
The expression of the key enzyme of flavonoid biosynthesis, chalcone synthase (CHS), has been followed in different genotypes of Matthiola incana R.Br. (Brassicaceae) which are genetically defined with respect to anthocyanin production. Enzyme activity was determined by a radioactive assay in crude flower extracts. The amount of enzyme protein in the developing flower was determined by use of SDS-PAGE, protein blotting, reaction with an antiserum against CHS of parsley (Petroselinum hortense), and PAP staining. The molecular weight of about 41 500 of the CHS subunits corresponds with that obtained from other higher plants. Steps of flower development were subdivided into stages-1,0, I-IV. During flower development of a Matthiola line with coloured petals (line 07) a defined pattern of CHS enzyme production can be observed: At the stage of bud opening (stage 0-I) a dramatic increase of the amount of CHS enzyme prodein in the petals occurs. This is quite different from results obtained with petals of the white flowering mutant line 18 bearing a genetic defect in the gene f coding for CHS. Here a reduced and nearly constant level of CHS enzyme protein can be observed during flower development. This line is most attractive for our studies of the regulation of enzyme synthesis because under stress conditions a slight colouring of the flower petals occurs, which is uniformly distributed and line-specific. This suggests that we are dealing with a CHS mutant producing a rather inactive enzyme protein at a low level. This protein may regain enzyme activity under certain environmental conditions. Preliminary investigations suggest a rather high level of CHS mRNA transcription at the bud opening stage of the flowers. Other white flowering mutant lines, line 17 (genotype ee) and line 19 (gg) with a late block in the flavonoid biosynthesis pathway, exhibit a concomitant reduction of CHS enzyme activity and protein content in comparison to anthocyanin-producing lines with the f(+)f(+)e(+)e(+)g(+)g(+)-genotype.
花色苷生物合成的关键酶查尔酮合酶 (CHS) 的表达已在花色苷生产方面具有遗传定义的不同堇菜属 (Brassicaceae) 基因型的 Matthiola incana R.Br. 中进行了研究。通过在粗提花提取物中的放射性测定来确定酶活性。在发育中的花中用 SDS-PAGE、蛋白印迹、与来自欧芹（Petroselinum hortense）的 CHS 抗血清反应以及 PAP 染色来确定酶蛋白的量。CHS 亚基的大约 41500 的分子量与从其他高等植物获得的分子量一致。花发育的阶段被细分为 0、I-IV 期。在带有有色花瓣的 Matthiola 系（07 系）的花发育过程中，可以观察到 CHS 酶产生的明确模式：在芽开放（0-I 期）阶段，花瓣中 CHS 酶原蛋白的量急剧增加。这与具有 CHS 基因 f 编码缺陷的白色开花突变体系 18 的花瓣结果完全不同。在这里，在花发育过程中可以观察到 CHS 酶蛋白的水平降低且几乎恒定。该系最适合我们研究酶合成的调节，因为在胁迫条件下花瓣会出现轻微着色，且分布均匀且具有系特异性。这表明我们正在处理一种产生低水平的相当不活跃的酶蛋白的 CHS 突变体。该蛋白可能在某些环境条件下恢复酶活性。初步研究表明，在花芽开放阶段，CHS mRNA 转录水平相当高。其他白色开花突变体系 17（基因型 ee）和 19（gg）在类黄酮生物合成途径中存在晚期阻断，与具有 f(+)f(+)e(+)e(+)g(+)g(+)-基因型的产生花色苷的系相比，CHS 酶活性和蛋白含量同时降低。
