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Peroxisomes in Rice Coleoptiles Grown in Air and in Anoxia
Author(s) -
Bellis L.,
Rascio N.,
Pistelli L.,
Alpi A.
Publication year - 1989
Publication title -
botanica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.871
H-Index - 87
eISSN - 1438-8677
pISSN - 0932-8629
DOI - 10.1111/j.1438-8677.1989.tb00080.x
Subject(s) - coleoptile , peroxisome , organelle , anoxic waters , ultrastructure , biology , biochemistry , microbiology and biotechnology , botany , biophysics , ecology , gene
Rice coleoptiles grow under anoxia. When the ultrastructure of anoxic coleoptile cells was examined, it was seen that most organelles maintain their integrity, with the exception of peroxisomes (unspecialized type). The lack of O 2 greatly reduced the number of these organelles and altered the ultrastructure of the remaining ones. To examine the effect of O 2 on peroxisome development in more detail, coleoptiles grown in air were transferred to N 2 and anoxic coleoptiles were transferred to oxygen. Marker enzyme activity was measured in entire coleoptiles as well as in the isolated organelles. As expected, anoxia greatly depressed enzyme activity when imposed from the beginning of the germination process, while it had a lesser effect when imposed for only two days on aerobic seedlings. When coleoptiles were grown constantly under N 2 , the density of the organelles was 1.216 g/cm 3 , while the corresponding aerobic organelles showed a buoyant density of 1.241 g/cm 3 . When transferred to air the anoxic peroxisomes reached the intermediate density of 1.227 g/cm 3 . The results confirm the particular sensitivity of rice peroxisomes to O 2 availability.