PLANT PHYSIOLOGY , Vol 109, Issue 3 891-898, Copyright © 1995 by American Society of Plant Biologists
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WHOLE PLANT, ENVIRONMENTAL, AND STRESS PHYSIOLOGY |
Ozone-Induced Ethylene Emission Accelerates the Loss of Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase and Nuclear-Encoded mRNAs in Senescing Potato Leaves
R. E. Glick, C. D. Schlagnhaufer, R. N. Arteca and E. J. Pell
Environmental Resources Research Institute and Department of Plant Pathology (R.E.G., E.J.P.) and Department of Horticulture (C.D.S., R.N.A.), The Pennsylvania State University, University Park, Pennsylvania 16802
The relationships among O3-induced accelerated senescence, induction of
ethylene, and changes in specific mRNA and protein levels were investigated
in potato (Solanum tuberosum L. cv Norland) plants. When plants were
exposed to 0.08 [mu]L L-1 O3 for 5 h d-1, steady-state levels of rbcS mRNA
declined at least 5-fold in expanding leaves after 3 d of O3 exposure and
ethylene levels increased 6- to 10-fold. The expression of OIP-1, a
1-aminocyclopropane-1-carboxylate synthase cDNA from potato, correlated
with increased production of ethylene and decreased levels of rbcS mRNA in
foliage of plants treated with O3. In plants exposed to 0.30 [mu]L L-1 O3
for 4 h, rbcS transcript levels were reduced 4-fold, whereas nuclear run-on
experiments revealed that rbcS transcription declined an average of 50%.
The loss of rbcS mRNA may be due, in part, to posttranscriptional
regulation. The levels of transcripts for other chloroplast proteins,
glyceraldehyde-3-phosphate dehydrogenase, and a photosystem II chlorophyll
a/b-binding protein decreased in O3-treated plants, in parallel with the
decrease in rbcS mRNA. The steady-state mRNA level of a cytosolic
glyceral-dehyde-3-phosphate dehydrogenase increased in O3-treated plants.
The induction of ethylene and changes in transcript levels preceded visible
leaf damage and decreases in ribulose-1,5-bisphosphate
carboxylase/oxygenase protein levels.
