Tenberge K B, Eising R
Institut für Botanik, Westfälische Wilhelms-Universität, Münster, Federal Republic of Germany.
Histochem J. 1995 Mar;27(3):184-95.
Immunogold labelling and electron microscopy were used to investigate whether catalase was present in peroxisomal inclusions, the composition of which has not yet been determined in plant cells. In the mesophyll cells of sunflower (Helianthus annuus L.) cotyledons, the catalase gold label was confined to peroxisomes. At day 2 of postgerminative growth in darkness, peroxisomes were free of inclusions, and the matrix was homogeneously labelled with gold particles. Thereafter, amorphous inclusions appeared, but by day 5 of growth, conspicuous crystalline inclusions (cores) were the predominant type. This developmental change, first observed in cotyledons grown in continuous light between day 2.5 and 5, also took place in cotyledons kept in permanent darkness. Both amorphous and crystalline inclusions showed a much higher immunogold label than did the peroxisomal matrix, indicating that catalase was a component of both types of peroxisomal inclusions. In contrast to catalase, the immunogold label of glycolate oxidase was almost completely absent from cores and was confined to the peroxisomal matrix. Together with reports on the absence of other enzymes from peroxisomal inclusions in sunflower and other species (Vaughn, 1989) our results suggest that catalase is a major constituent of amorphous and crystalline peroxisomal inclusions in plants.
采用免疫金标记和电子显微镜技术，研究过氧化氢酶是否存在于过氧化物酶体包涵体中，过氧化物酶体包涵体的组成在植物细胞中尚未确定。在向日葵（Helianthus annuus L.）子叶的叶肉细胞中，过氧化氢酶金标记局限于过氧化物酶体。在黑暗中萌发后生长的第2天，过氧化物酶体没有包涵体，基质被金颗粒均匀标记。此后，出现无定形包涵体，但到生长第5天，明显的晶体包涵体（核心）成为主要类型。这种发育变化首先在2.5至5天之间持续光照下生长的子叶中观察到，在一直处于黑暗中的子叶中也会发生。无定形和晶体包涵体的免疫金标记均比过氧化物酶体基质高得多，表明过氧化氢酶是两种类型过氧化物酶体包涵体的组成成分。与过氧化氢酶不同，乙醇酸氧化酶的免疫金标记在核心中几乎完全不存在，局限于过氧化物酶体基质。连同关于向日葵和其他物种过氧化物酶体包涵体中不存在其他酶的报道（Vaughn，1989），我们的结果表明，过氧化氢酶是植物中无定形和晶体过氧化物酶体包涵体的主要成分。
