PLANT PHYSIOLOGY , Vol 112, Issue 2 525-535, Copyright © 1996 by American Society of Plant Biologists
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GENE REGULATION AND MOLECULAR GENETICS |
Tissue-Specific Activity of Two Manganese Superoxide Dismutase Promoters in Transgenic Tobacco
W. Van Camp, D. Herouart, H. Willekens, H. Takahashi, K. Saito, M. Van Montagu and D. Inze
Laboratorium voor Genetica, Department of Genetics, Flanders Interuniversity Institute for Biotechnology (W.V.C., D.H., H.W., M.V.M., D.I.), and Laboratoire Associe de I'Institut National de la Recherche Agronomique (France) (D.I.), Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium
In eukaryotes, manganese superoxide dismutase is a nuclear-encoded protein
that scavenges superoxide radicals in the mitochondrial matrix. We have
isolated two manganese superoxide dismutase genes from Nicotiana
plumbaginifolia L. and fused the 5[prime] upstream regulatory region of
these genes to the [beta]-glucuronidase reporter gene. The two gene fusions
displayed a differential tissue specificity in transgenic tobacco
(Nicotiana tabacum). Promoter activity of the SodA1 gene fusion was found
in the pollen, middle layer, and stomium of anthers, but was usually
undetectable in vegetative organs of mature plants. The SodA2 gene fusion
was expressed in the leaves, stems, roots, and flowers. SodA2 promoter
activity was most prominent in the vascular bundles, stomata, axillary
buds, pericycle, stomium, and pollen. Histochemical analysis of succinate
dehydrogenase activity suggested that the spatial expression of the two
gene fusions is generally correlated with mitochondrial respiratory
activity.
