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Effects of low concentrations of ozone on the fine structure of radish leaves
Author(s) -
MIYAKE H.,
MATSUMURA H.,
FUJINUMA Y.,
TOTSUKA T.
Publication year - 1989
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1989.tb00681.x
Subject(s) - chloroplast , raphanus , vacuole , ultrastructure , fumigation , ozone , botany , electron microscope , chemistry , thylakoid , biology , horticulture , biochemistry , cytoplasm , physics , organic chemistry , gene , optics
summary Radish ( Raphanus sativus L.) plants were fumigated with 0.1 or 0.05 μl l −l O 3 for 8 or 24 h a day for 6 to 18 d and the leaf tissues examined by light and electron microscopy. Ultrastructural damage was apparent in the leaves fumigated with as low as 0.05 μl l −1 for 8 h a day for 6 d. Ozone induced an increase in both the number and size of the plastoglobules but a decrease in chloroplast dimensions. These changes in the chloroplasts developed further even after O 3 fumigation had been discontinued. The plastoglobules were electron dense in the early stages of exposure to O 3 but subsequently became electron translucent. Finally large plastoglobules were extruded into the vacuole, a phenomenon which may partly account for the reduction in chloroplast size. Ozone also caused disruption of the tonoplast and this was followed by collapse of the cells. Low concentrations of O 3 appear to accelerate senescence of the chloroplasts.