Structure of the cinnamyl-alcohol dehydrogenase gene family in rice and promoter activity of a member associated with lignification

• Published in: Planta Vol. 220; no. 5; pp. 678 - 688
• Main Authors: Tobias, C.M, Chow, E.K
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01-03-2005; Springer; Springer Nature B.V
• Subjects: Alcohol Oxidoreductases - genetics; Alcohol Oxidoreductases - metabolism; Alcohols; beta-glucuronidase; Biological and medical sciences; Biosynthesis; Chromosome Mapping; cinnamyl alcohol dehydrogenase; Corn; Dehydrogenase; Dehydrogenases; enzyme activity; Fundamental and applied biological sciences. Psychology; Gene Expression - physiology; Gene Expression Profiling; gene expression regulation; Genes; Genes, Reporter - physiology; Genes. Genome; Genomes; Genomics; lignification; Lignin; Lignin - metabolism; Molecular and cellular biology; Molecular genetics; molecular sequence data; Multigene Family; nucleotide sequences; Oryza - enzymology; Oryza - genetics; Oryza sativa; Phylogeny; plant biochemistry; plant genetics; plant proteins; Plant Stems - physiology; Plant tissues; Plants; promoter regions; Promoter Regions, Genetic - physiology; recombinant fusion proteins; Rice; RNA; transcription (genetics); transcription start site; Lignin; Monocotyledones; Cinnamyl-alcohol dehydrogenase; Zea mays; Root; Oryza saliva; Enzyme; Brown midrib; Biosynthesis; Cell wall; Promoter; Lignification; Oryza; Gene; Gramineae; Angiospermae; Gymnospermae; Above ground plant part; Nipponbare; Spermatophyta; Oxidoreductases
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-004-1385-4

Analysis of lignification in rice has been facilitated by the availability of the recently completed rice genome sequence, and rice will serve as an important model for understanding the relationship of grass lignin composition to cell wall digestibility. Cinnamyl-alcohol dehydrogenase (CAD) is an enzyme important in lignin biosynthesis. The rice genome contains 12 distinct genes present at nine different loci that encode products with significant similarity to CAD. The rice gene family is diverse with respect to other angiosperm and gymnosperm CAD genes isolated to date and includes one member (OsCAD6) that contains a peroxisomal targeting signal and is substantially diverged relative to other family members. Four closely related family members (OsCAD8A—D) are present at the same locus and represent the product of a localized gene duplication and inversion. Promoter-reporter gene fusions to OsCAD2, an orthologue of the CAD gene present at the bm1 (brown midrib 1) locus of maize, reveal that in rice expression is associated with vascular tissue in aerial parts of the plant and is correlated with the onset of lignification. In root tissue, expression is primarily in the cortical parenchyma adjacent to the exodermis and in vascular tissue.