玉米奥帕克-16和奥帕克-2突变的BC_2F_(2∶3)近等基因材料的SDS-PAGE分析

Analysis of BC_2F_(2∶3) Near-isogenic Materials of opaque-16 and opaque-2 Mutants in Maize by SDS-PAGE

为了探知玉米opaque-16（o16）、opaque-2（o2）高赖氨酸突变和普通玉米的蛋白质表达差异,构建了BC2F2∶3世代o16和o2的近等基因材料。结果表明,突变o16、o2近等基因材料与其普通玉米之间,其植株形态相近,但籽粒胚乳质地相异,o16o、2近等基因材料的胚乳不透明,而其普通玉米的胚乳透明。经蛋白质SDS-PAGE分析,苗期叶片的总蛋白质表达相同,而乳熟期籽粒的总蛋白质表达却不同。在籽粒乳熟期,o16、o2近等基因材料的47 kDa蛋白质组分的表达比其普通玉米强,而o16近等基因材料的44kDa蛋白质组分的表达又比o2近等基因材料强。经DBL法测定赖氨酸含量,o16o、2近等基因材料比其普通玉米的籽粒赖氨酸含量提高70%~80%。表明,这2种蛋白质组分表达的增强可能与玉米籽粒赖氨酸含量的提高有关。这对于了解o16突变对赖氨酸含量的调控有重要意义。

BC2F2： 3 nearqsogenic materials （NIMs） of o16 and o2 mutants were bred to know protein expression difference of two high-lysine mutants, opaque-16 （o16） and opaque-2 （o2）, and normal maize. The results showed that between the NIMs of o16 and o2 and normal maize, their plant phenotypes were similar, but their endosperm phenotypes were different with opaque endosperm for the NIMs of the two mutants and vitreous endosperm for normal maize. Analysis of protein expression difference, which was performed by using SDS-PAGE technology, showed that between the o16 and o2 NIMs and normal maize, expressions of their leaf total protein at seedling stage were the same, but expressions of their kernels total protein at milky ripe stage were different. The expression of 47 kDa protein component of the o16 and o2 NIMs was stronger than that of normal maize, and the expression of 44 kDa protein component of the o16 NIMs was stronger than that of the o2 NIMs. In addition, lysine ratios of the o16 and o2 NIMs and normal maize seeds were determined by DBL method. The lysine proportion of the o16 and o2 NIMs was increased by 70%-80% than that of normal maize. It is suggested that the expression enhancement of the two aforementioned protein components may be involved in the increase of lysine content in maize seed. This is of significance for understanding lysine content regulation of o16 mutant.