Joshi S, Santha I M, Mehta S L
Division of Biochemistry, Indian Agricultural Research Institute, New Delhi.
Plant Foods Hum Nutr. 1988;38(4):277-86. doi: 10.1007/BF01091725.
The percent distributions of protein fractions namely albumin + globulin, prolamine and glutelin were studied in developing grains of NP 113 barley and its high lysine mutant Notch-2. During development the percentage of albumin + globulin fraction decreased in NP 113, while those of prolamine and glutelin remained unchanged. The increase in prolamine was substantial from 24 to 31DAA. In Notch-2 the trend followed by albumin + globulin and prolamine was like that in NP 113, while the glutelin fraction showed an increase as compared to 10 DAA. The percent of albumin + globulin was slightly higher in Notch-2 as compared to NP 113. The absolute amount (mg/grain) of all the protein fractions increased during development in both NP 113 and its mutant Notch-2. During the grain development the prolamine content was substantially lower in the mutant than in the parent NP 113. The albumin + globulin content per endosperm was in general also higher in NP 113 than Notch-2. Amino acid analysis of the protein fractions did not reveal significant changes in lysine between NP 113 and Notch-2. Thus, the improvement in lysine in the mutant is primarily due to reduced synthesis of the prolamine fraction and not due to an increase in lysine in the mutant hordein fraction. Part of the improvement in lysine may also be due to increase in the percentage of albumin + globulin fractions which is lysine rich.
研究了NP 113大麦及其高赖氨酸突变体Notch-2发育籽粒中蛋白质组分即白蛋白+球蛋白、醇溶蛋白和谷蛋白的百分比分布。在发育过程中，NP 113中白蛋白+球蛋白组分的百分比下降，而醇溶蛋白和谷蛋白的百分比保持不变。从开花后24天到31天，醇溶蛋白的增加幅度很大。在Notch-2中，白蛋白+球蛋白和醇溶蛋白的变化趋势与NP 113相似，而谷蛋白组分与开花后10天相比有所增加。Notch-2中白蛋白+球蛋白的百分比略高于NP 113。在NP 113及其突变体Notch-2的发育过程中，所有蛋白质组分的绝对量（毫克/粒）均增加。在籽粒发育过程中，突变体中的醇溶蛋白含量明显低于亲本NP 113。一般来说，NP 113中每个胚乳的白蛋白+球蛋白含量也高于Notch-2。对蛋白质组分的氨基酸分析未发现NP 113和Notch-2之间赖氨酸有显著变化。因此，突变体中赖氨酸的改善主要是由于醇溶蛋白组分合成减少，而不是由于突变体大麦醇溶蛋白组分中赖氨酸增加。赖氨酸改善的部分原因也可能是富含赖氨酸的白蛋白+球蛋白组分百分比增加。
