PLANT PHYSIOLOGY , Vol 104, Issue 1 67-74, Copyright © 1994 by American Society of Plant Biologists
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ENVIRONMENTAL AND STRESS PHYSIOLOGY |
Biochemical Plant Responses to Ozone (IV. Cross-Induction of Defensive Pathways in Parsley (Petroselinum crispum L.) Plants)
H. Eckey-Kaltenbach, D. Ernst, W. Heller and H. Sandermann Jr
GSF-Forschungszentrum fur Umwelt und Gesundheit GmbH, Institut fur Biochemische Pflanzenpathologie, Ingolstadter Landstrasse 1, D-85758 Oberschleissheim, Germany
Parsley (Petroselinum crispum L.) is known to respond to ultraviolet
irradiation by the synthesis of flavone glycosides, whereas fungal or
elicitor stress leads to the synthesis of furanocoumarin phytoalexins. We
tested how these defensive pathways are affected by a single ozone
treatment (200 nL L-1; 10 h). Assays were performed at the levels of
transcripts, for enzyme activities, and for secondary products. The most
rapid transcript accumulation was maximal at 3 h, whereas flavone
glycosides and furanocoumarins were maximally induced at 12 and 24 h,
respectively, after the start of ozone treatment. Ozone acted as a
cross-inducer because the two distinct pathways were simultaneously
induced. These results are consistent with the previously observed ozone
induction of fungal and viral defense reactions in tobacco, spruce, and
pine.
