Abstract
The substrate-specific induction of wheat (Triticum aestivum L. cv Fenman) leaf cinnamyl alcohol dehydrogenase (CAD, EC 1.1.1.195) was examined in relation to its role in regulating the composition of defensive lignin induced at wound margins. Treatment of wounds with a partially acetylated chitosan hydrolysate or spores of the nonpathogen Botrytis cinerea elicited lignification at wound margins and invoked significant increases in phenylalanine ammonia-lyase (EC 4.3.1.5), peroxidase (EC 1.11.1.7), and CAD activities. The substrate-specific induction of CAD with time was determined in elicitor-treated leaves and in excised lignifying wounds. In whole leaf extracts no significant increases in p-cou-maryl and coniferyl alcohol dehydrogenase activities were detectable, but a significant 5-fold increase in sinapyl alcohol dehydrogenase activity was evident 32 h after elicitor treatment. Similarly, fungal challenge resulted in elevated levels of only sinapyl alcohol dehydrogenase in whole-leaf extracts. In excised lignifying tissues p-coumaryl alcohol dehydrogenase levels were similar to those observed in healthy tissue. A small yet significant increase in coniferyl alcohol dehydrogenase was apparent, but the most dramatic increase occurred in sinapyl alcohol dehydrogenase activity, which increased to values approximately 10 times higher than the untreated controls. Our results show for the first time that CAD induction in lignifying tissues of wheat is predominantly attributable to highly localized increases in sinapyl alcohol dehydrogenase activity.
Full Text
The Full Text of this article is available as a PDF (512.8 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1006/abio.1976.9999. [DOI] [PubMed] [Google Scholar]
- Grand C., Sarni F., Lamb C. J. Rapid induction by fungal elicitor of the synthesis of cinnamyl-alcohol dehydrogenase, a specific enzyme of lignin synthesis. Eur J Biochem. 1987 Nov 16;169(1):73–77. doi: 10.1111/j.1432-1033.1987.tb13582.x. [DOI] [PubMed] [Google Scholar]
- Tsuji A., Kinoshita T., Hoshino M. Analytical chemical studies on amino sugars. II. Determination of hexosamines using 3-methyl-2-benzothiazolone hydrazone hydrochloride. Chem Pharm Bull (Tokyo) 1969 Jul;17(7):1505–1510. doi: 10.1248/cpb.17.1505. [DOI] [PubMed] [Google Scholar]
- Walter M. H., Grima-Pettenati J., Grand C., Boudet A. M., Lamb C. J. Cinnamyl-alcohol dehydrogenase, a molecular marker specific for lignin synthesis: cDNA cloning and mRNA induction by fungal elicitor. Proc Natl Acad Sci U S A. 1988 Aug;85(15):5546–5550. doi: 10.1073/pnas.85.15.5546. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wyrambik D., Grisebach H. Purification and properties of isoenzymes of cinnamyl-alcohol dehydrogenase from soybean-cell-suspension cultures. Eur J Biochem. 1975 Nov 1;59(1):9–15. doi: 10.1111/j.1432-1033.1975.tb02418.x. [DOI] [PubMed] [Google Scholar]
- de Sá M. M., Subramaniam R., Williams F. E., Douglas C. J. Rapid Activation of Phenylpropanoid Metabolism in Elicitor-Treated Hybrid Poplar (Populus trichocarpa Torr. & Gray x Populus deltoides Marsh) Suspension-Cultured Cells. Plant Physiol. 1992 Feb;98(2):728–737. doi: 10.1104/pp.98.2.728. [DOI] [PMC free article] [PubMed] [Google Scholar]