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Localization of Phloem Oxidases
Author(s) -
Catesson AnneMarie
Publication year - 1980
Publication title -
berichte der deutschen botanischen gesellschaft
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 0365-9631
DOI - 10.1111/j.1438-8677.1980.tb03327.x
Subject(s) - plasmodesma , vacuole , phloem , peroxidase , organelle , cytoplasm , parenchyma , biology , microbiology and biotechnology , biochemistry , sieve tube element , chemistry , biophysics , botany , enzyme
Among oxidases, cytochrome oxidase has been localized in mitochondria of all phloem cells, catalase has been visualized in parenchyma peroxisomes and peroxidase has been localized in cell walls and in several cell organelles. In angiosperms, peroxidase is present in all phloem cell walls; it is sensitive to cyanide inhibition excepted in sieve areas and around plasmodesmata between sieve tubes and companion cells. In some species, this cyanide resistant oxidasic activity can be localized without exogenous H 2 O 2 . Peroxidase is localized on ribosomes, inside vacuoles, on the tonoplast and often on the plasmalemma in companion cells and differentiating sieve elements. In young sieve cells some dictyosomes can exhibit a strong peroxidasic activity. In mature parenchyma cells peroxidase can be associated with ER cisternae but not with vacuoles.