水稻温敏失绿突变体的Rubisco活化酶活性、蛋白质与氨基酸组分的变化

在水稻温敏失绿突变性状表达过程中,对其Rubsico 含量、Rubsico 活化酶活性,全叶蛋白及游离氨基酸组分变化进行测定。结果表明:突变体的Rubisco 结构和含量与野生型一样,保持相对稳定;而其Rubisco 活化酶活性则随一个分子量为56.2kD(PI=4.5)的特异蛋白质的存在与消失发生明显改变。当突变性状表达时,分子量为56.2kD(PT=4.5)的特异蛋白消失,其Rubisco 活化酶活性下降;当叶片失绿区域复绿时,56.2kD(PI=4.5)特异蛋白出现,则Rubisco 活化酶活性上升。这一密切地相关关系表明,突变体的Rubisco 活化酶活性变化在光合作用过程中,除与自身结构和含量有关外,还与叶片中这一特异蛋白的存在密切相关,它可能是Rubisco 活化酶活性的调节蛋白。这种调节具体表现在氨基酸代谢上,是对上游氨基酸的阻遏调控,从而使叶绿体的结构物质合成受阻,最终导致类囊体膜的退化。

ALTERATION OF PROTEIN AND AMINO ACID COMPONENTS AND RUBISCO ACTIVITY IN LEAVES OF THERMO-SENSITIVE MUTANT LINE OF RICE DURING INDUCED OF GREEN AND YELLOW BANDING

We have determined the Rubisco components and activity,whole leaf protein andamino acid components of thermo-sensitive mutant line 1103s of rice (Oryza Sativa ssp.indica)leaves during induces green and yellow banding in this study.The results are as follow:Thestructure and components of Rubisco in the mutant are the same as in the wild form and rela-tively stable,but the activity of the mutant Rubisco greatly changes as a special protein ofmolecular weight 56.2kD (PI=4.5) appears and disappears.When the green-yellow bands appear,the special protein disappears,and the activity of the mutant-rice Rubisco decreases,whereaswhen the green-yellow bands in the same part of the leaves disappear,the special protein appearsand the activity of Rubisco is increase.The above shows the changes of the activity of the mu-tant-rice Rubisco during photosynthesis are closely related to the special protein in the leaves andits structure and components,and possibly to the regulating protein of Rubisco.The protein par-ticularly regulates metableic processes of amino acids preventing regulation of the preceding aminoacids,such that the formation of the structural material in chloroplast is prevented,and finally thechloroplast thylakoid structure degenerates.