Tissue-specific oxylipin signature of tomato flowers: allene oxide cyclase is highly expressed in distinct flower organs and vascular bundles
| Autor: | Helmut Maucher, Otto Miersch, Jöörg Ziegler, Claus Wasternack, Robert Kramell, Bettina Hause, Irene Stenzel |
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| Rok vydání: | 2000 |
| Předmět: |
Gynoecium
Transcription Genetic Cyclopentanes Plant Science Plant Roots Gene Expression Regulation Enzymologic chemistry.chemical_compound Solanum lycopersicum Biosynthesis Gene Expression Regulation Plant Botany Genetics Oxylipins RNA Messenger Plant Stems biology Jasmonic acid fungi Allene-oxide cyclase food and beverages Stereoisomerism Cell Biology Oxylipin biology.organism_classification Vascular bundle Intramolecular Oxidoreductases Plant Leaves Biochemistry chemistry Fatty Acids Unsaturated Isoleucine Solanaceae |
| Zdroj: | The Plant Journal. 24:113-126 |
| ISSN: | 1365-313X 0960-7412 |
| DOI: | 10.1046/j.1365-313x.2000.00861.x |
| Popis: | A crucial step in the biosynthesis of jasmonic acid (JA) is the formation of its correct stereoisomeric precursor, cis(+)12-oxophytodienoic acid (OPDA). This step is catalysed by allene oxide cyclase (AOC), which has been recently cloned from tomato. In stems, young leaves and young flowers, AOC mRNA accumulates to a low level, contrasting with a high accumulation in flower buds, flower stalks and roots. The high levels of AOC mRNA and AOC protein in distinct flower organs correlate with high AOC activity, and with elevated levels of JA, OPDA and JA isoleucine conjugate. These compounds accumulate in flowers to levels of about 20 nmol g-1 fresh weight, which is two orders of magnitude higher than in leaves. In pistils, the level of OPDA is much higher than that of JA, whereas in flower stalks, the level of JA exceeds that of OPDA. In other flower tissues, the ratios among JA, OPDA and JA isoleucine conjugate differ remarkably, suggesting a tissue-specific oxylipin signature. Immunocytochemical analysis revealed the specific occurrence of the AOC protein in ovules, the transmission tissue of the style and in vascular bundles of receptacles, flower stalks, stems, petioles and roots. Based on the tissue-specific AOC expression and formation of JA, OPDA and JA amino acid conjugates, a possible role for these compounds in flower development is discussed in terms of their effect on sink-source relationships and plant defence reactions. Furthermore, the AOC expression in vascular bundles might play a role in the systemin-mediated wound response of tomato. |
| Databáze: | OpenAIRE |
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