优质蛋白玉米胚乳贮存蛋白积累的电泳分析

玉米胚乳的２２ ｋＤ和２０ ｋＤ醇溶蛋白在授粉后１５ 天开始积累，编码２２ ｋＤ 和２０ ｋＤ醇溶蛋白的结构基因在胚乳发育过程中同时表达。优质蛋白玉米和ｏ２ 玉米的胚乳中，２２ ｋＤ和２０ ｋＤ醇溶蛋白的合成受到抑制，即ｏ２ 基因对２２ ｋＤ和２０ ｋＤ醇溶蛋白的合成有负的调节作用。Ｍｏ１７／ｏ２ 和Ｍｏ１７ 胚乳醇溶蛋白的双向电泳结果表明，Ｍｏ１７／ｏ２ 的２７ ｋＤ、２２ ｋＤ、２０ ＫＤ和１５ ｋＤ醇溶蛋白的合成均受到强烈的抑制。遗系０４１／ｏ２ 和遗系０４０／ｏ２ 胚乳醇溶蛋白的双向电泳结果表明，二者只在高分子量的蛋白质斑点区域有一些细微的差别。可溶性蛋白的ＳＤＳ－ＰＡＧＥ分析表明，Ｍｏ１７／ｏ２ 胚乳的可溶性蛋白比其同型系Ｍｏ１７ 少３８．７ ｋＤ 和２６．７ ｋＤ两条谱带，多２７．２ ｋＤ和２６．１ ｋＤ两条谱带。二者出现的可溶性蛋白的差异是ｏ２ 基因调控的结果。遗系０４１／ｏ２ 胚乳的可溶性蛋白比其同型系０４０／ｏ２ 多１８．６ ｋＤ和１７．６ ｋＤ两条谱带，少４０．２ ｋＤ 一条谱带，这与ｏ２ 基因修饰因子的作用密切关联

ELECTROMICROGRAPHIC ANALYSIS STORAGE PROTEIN ACCUMULATION IN ENDOSPERMS OF MAIZE WITH QUALIFIED PROTEIN

The characteristics of storage protein accumulation of maize with qualified protein (MQP) and o 2 maize were analysed basing on the genetical and biochemical point of views. The 22 kD and 20 kD zeins in the developing endosperms of maize accumulated 15 days after pollination. The structural genes encoding 22 kD and 20 kD zeins in the developing endosperms were simutaneously expressed. In the endosperms of MPQ and o 2 maize the synthesis of 22 kD and 20 kD zeins was suppressed. That is to say, o 2 gene negatively regulated the synthesis of 22 kD and 20 kD zeins. Two dimentional electrophoretic analysis of zeins in the maize endosperms further revealed the effects of o 2 gene and its modifiers on the synthesis of zeins.In Mo17 and Mo17/o 2 endosperms the synthesis of 27 kD, 22 kD, 20 kD and 15 kD zeins was severely suppressed. In 041/o 2 and 040/o 2 endosperms little difference existed SDS PAGE analysis of the soluble proteins of Mo17 and Mo17/o 2 endosperms revealted that two bands with molecular weight(MW) of 38 7 kD and 26 7 kD were present in wild type but absent in o 2 mutant, while two bands with MW 27 2 kD and 26 1 kD were present in o 2 mutant but absent in wild type. These differences were resulted from the effect of o 2 gene.In 040/o 2 and 041/o 2 endosperms two bands with MW 18 6 kD and 17 6 kD were present in 041/o 2 but absent in 040/o 2 while one band with MW 40 2 kD was present in 040/o 2 and absent in 041/o 2, which was closely related to the effects of the modifiers of o 2 gene.