Dynamic aspects of microbody transition in pumpkin cotyledons.

南瓜子叶绿化过程中，微体发生功能转化，由乙氧基体向叶片过氧化物体转化。为了阐明微体转化的调控机制，我们纯化了乙氧基体酶和叶片过氧化物酶，并制备了它们的特异性抗体和cDNA。通过对这些抗体和cDNA克隆的分析，发现叶片过氧化物体酶的增加是由于其mRNA水平的增加，而乙氧体酶的下降不仅是由于其mRNA的水平降低，而且是由于在微体转化过程中诱导了微体中的乙氧体酶的特异性降解系统。在南瓜花衰老过程中，花瓣中也观察到乙氧基体酶的发育，说明乙氧基体酶在衰老过程中起着重要作用。

There occurs functional transformation of microbodies from glyoxysomes to leaf peroxisomes during greening of pumpkin cotyledons. In order to clarify the regulatory mechanisms underlying the microbody transformation, glyoxysomal and leaf peroxisomal enzymes were purified and their specific antibodies and cDNA were prepared. By the analysis using these antibodies and cDNA clones, it was found that increase of leaf peroxisomal enzymes is due to increase in level of their mRNA and decrease in glyoxysomal enzymes is came not only by decrease in level of their mRNA but also by induction of specific degradation system for glyoxysomal enzymes in microbodies during microbody transformation.Reversible transformation of microbodies from leaf peroxisomes to glyoxysomes was found to occur in the cotyledons during the senescence. The development of glyoxysomal enzymes was also observed in petals of the pumpkin flower during senescence, indicating that glyoxysomes play an important roles in senesceing process.