PLANT PHYSIOLOGY , Vol 107, Issue 2 501-506, Copyright © 1995 by American Society of Plant Biologists
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WHOLE PLANT, ENVIRONMENTAL, AND STRESS PHYSIOLOGY |
Localization of Hydrogen Peroxide Production in Pisum sativum L. Using Epi-Polarization Microscopy to Follow Cerium Perhydroxide Deposition
L. Liu, KEL. Eriksson and JFD. Dean
Department of Biochemistry and Molecular Biology, Center for Biological Resource Recovery, University of Georgia, Athens, Georgia 30602-7229
Cerium is becoming an increasingly popular reagent for histochemical
localization of oxidases and phosphatases because it combines directly with
reaction products to form fine precipitates of electron-dense materials
that can be easily detected using transmission electron microscopy or laser
confocal scanning microscopy. We used epi-polarization microscopy to detect
cerium perhydroxide deposits formed when H2O2 was produced by diamine
oxidase in pea (Pisum sativum L.) epicotyls exposed to exogenous
putrescine. Diamine oxidase activity was abundant in cortical cell walls
but showed little, if any, association with vascular tissues. Maps of
cerium deposition generated using scanning electron microscopy/x-ray
microanalysis verified these observations. This study demonstrates the use
of epi-polarization microscopy to follow cerium deposition, and the ready
accessibility of this microscopy technique should facilitate more
widespread use of cerium for plant histochemistry and cytochemistry.
