Leaf peroxisomes are directly transformed to glyoxysomes during senescence of pumpkin cotyledons
Leaf peroxisomes are directly transformed to glyoxysomes during senescence of pumpkin cotyledons
复制标题
南瓜子叶衰老过程中叶过氧化物酶体直接转化为乙醛酸酶体
作者：
M. Nishimura;Y. Takeuchi;L. Bellis;I. Hara
摘要：南瓜子叶在绿化过程中由乙氧基酶体向叶片过氧化物酶体的功能转变，在衰老过程中由叶片过氧化物酶体向乙氧基酶体的反向微体转变。用蛋白a -金免疫细胞化学标记分析反微体转化，使用抗叶过氧化物酶、乙醇酸氧化酶和抗两种glyoxysomal酶，即苹果酸合成酶和异柠檬酸裂解酶的抗体。衰老过程中，微体中乙醇酸氧化酶的标记强度降低，而苹果酸合成酶和异柠檬酸裂解酶的标记强度显著增加。不同大小的蛋白a -金颗粒双标记实验表明，衰老南瓜子叶微体中存在叶片过氧化物酶体和乙氧化酶体，说明衰老过程中叶片过氧化物酶体直接转化为乙氧化酶体。
SummaryAfter the functional transition of glyoxysomes to leaf peroxisomes during the greening of pumpkin cotyledons, the reverse microbody transition of leaf peroxisomes to glyoxysomes occurs during senescence. Immunocytochemical labeling with protein A-gold was performed to analyze the reverse microbody transition using antibodies against a leaf-peroxisomal enzyme, glycolate oxidase, and against two glyoxysomal enzymes, namely, malate synthase and isocitrate lyase. The intensity of labeling for glycolate oxidase decreased in the microbodies during senescence whereas in the case of malate synthase and isocitrate lyase intensities increased strikingly. Double labeling experiments with protein A-gold particles of different sizes showed that the leaf-peroxisomal enzymes and the glyoxysomal enzymes coexist in the microbodies of senescing pumpkin cotyledons, indicating that leaf peroxisomes are directly transformed to glyoxysomes during senescence.