Seung Hee Eom, Heekyu Kim, Tae Kyung Hyun


Cinnamyl alcohol dehydrogenase (CAD) is a key enzyme in the biosynthesis of lignin and lignans as it catalyzes the final step of monolignol biosynthesis, using NADPH as a cofactor. In higher plants, CAD is encoded by a multigene family consisting of three major classes. Based on the recently released flax (Linum usitatissimum L.) whole-genome sequences, in this study we identified six CAD family genes that contain an ADH_N domain and an ADH_zinc_N domain, which suggests that the putative flax CADs (LuCADs) are zinc-dependent alcohol dehydrogenases and members of the plant CAD family. In addition, expression analysis using quantitative real-time PCR revealed spatial variations in the expression of LuCADs in different organs. Comparative analysis between LuCAD enzymatic activity and LuCAD transcripts indicates that the variation of LuCAD enzymatic activities by elicitors is reflected by transcription of LuCADs in flax suspension-cultured cells. Taken together, our genome-wide analysis of CAD genes and the expression profiling of these genes provide valuable information for understanding the function of CADs, and will assist future studies on the physiological role of monolignols associated with plant defense.


Key words: elicitation; cinnamyl alcohol dehydrogenase; suspension-cultured cells; flax; monolignol


Received: September 21, 2015; Revised: October 15, 2015; Accepted: October 21, 2015; Published online: April 27, 2016

Full Text:



Tanaka Y, Sassaki N, Akemi O. Biosynthesis of plant pigments: anthocyanins, betalains and carotenoids. Plant J. 2008;54(4):733-749.

Vogt T. Phenylpropanoid biosynthesis. Mol Plant. 2010;3(1):2-20.

Valdés-López O, Hernández G. Phenylpropanoids as master regulators: state of the art and perspectives in common bean (Phaseolus vulgaris). Front Plant Sci. 2014;5:336.

Harmatha J, Dinan L. Biological activities of lignans and stilbenoids associated with plant-insect chemical interactions. Phytochem Rev. 2003;2(3):321-30.

Landete JM. Plant and mammalian lignans: A review of source, intake, metabolism, intestinal bacteria and health. Food Res Int. 2012;46(1):410-24.

Hano C, Addi M, Bensaddek L, Crônier D, Baltora-Rosset S, Doussot J, Maury S, Mesnard F, Chabbert B, Hawkins S, Lainé E, Lamblin F. Differential accumulation of monolignol-derived compounds in elicited flax (Linum usitatissimum) cell suspension cultures. Planta. 2006;223(5):975-89.

O’malley DM, Porter S, Sederoff RR. Purification, characterization, and cloning of cinnamyl alcohol dehydrogenase in Loblolly pine (Pinus taeda L.). Plant Physiol. 1992;98(4):1364-71.

Blanco-Portales R, Medina-Escobar N, López-Ráez JA, González-Reyes JA, Villalba JM, Moyano E, Caballero JL, Muñoz-Blanco J. Cloning, expression and immunolocalization pattern of a cinnamyl alcohol dehydrogenase gene from strawberry (Fragaria x ananassa cv. Chandler). J Exp Bot. 2002;53(375):1723-34.

Ralph J, Peng J, Lu F, Hatfield RD, Helm RF. Are lignins optically active? J Agric Food Chem. 1999;47(8):2991-6.

Baucher M, Bernard-Vailhé MA, Chabbert B, Besle JM, Opsomer C, Van Montagu M, Botterman J. Down-regulation of cinnamyl alcohol dehydrogenase in transgenic alfalfa (Medicago sativa L.) and the effect on lignin composition and digestibility. Plant Mol Biol. 1999;39(3):437-47.

Pilate G, Guiney E, Holt K, Petit-Conil M, Lapierre C, Leplé JC, Pollet B, Mila I, Webster EA, Marstorp HG, Hopkins DW, Jouanin L, Boerjan W, Schuch W, Cornu D, Halpin C. Field and pulping performances of transgenic trees with altered lignification. Nat Biotechnol. 2002;20(6):607-12.

Li X, Weng JK, Chapple C. Improvement of biomass through lignin modification. Plant J. 2008;54(4): 569-81.

Barakat A, Bagniewska-Zadworna A, Choi A, Plakkat U, DiLoreto DS, Yellanki P, Carlson JE. The cinnamyl alcohol dehydrogenase gene family in Populus: phylogeny, organization, and expression. BMC Plant Biol. 2009;9:26.

Sibout R, Eudes A, Mouille G, Pollet B, Lapierre C, Jouanin L, Séguin A. CINNAMYL ALCOHOL DEHYDROGENASE-C and -D are the primary genes involved in lignin biosynthesis in the floral stem of Arabidopsis. Plant Cell. 2005;17(7):2059-76.

Jourdes M, Cardenas CL, Laskar DD, Moinuddin SG, Davin LB, Lewis NG. Plant cell walls are enfeebled when attempting to preserve native lignin configuration with poly-p-hydroxycinnamaldehydes: evolutionary implications. Phytochemistry. 2007;68(14):1932-56.

Touré A, Xueming X. Flaxseed lignans: Source, biosynthesis, metabolism, antioxidant activity, bio-active components, and health benefits. Compr Rev Food Sci F. 2010;9(3):261-9.

Hyun TK, Kumar D, Cho YY, Hyun HN, Kim JS. Computational identification and phylogenetic analysis of the oil-body structural proteins, oleosin and caleosin, in castor bean and flax. Gene. 2013;515(2):454-60.

Setchell KD, Brown NM, Zimmer-Nechemias L, Wolfe B, Jha P, Heubi JE. Metabolism of secoisolariciresinol-diglycoside the dietary precursor to the intestinally derived lignan enterolactone in humans. Food Funct. 2014;5(3):491-501.

Preisner M, Kulma A, Zebrowski J, Dymińska L, Hanuza J, Arendt M, Starzycki M, Szopa J. Manipulating cinnamyl alcohol dehydrogenase (CAD) expression in flax affects fibre composition and properties. BMC Plant Biol. 2014;14:50.

Hyun TK, Rim Y, Kim E, Kim JS. Genome-wide and molecular evolution analyses of the KT/HAK/KUP family in tomato (Solanum lycopersicum L.). Genes Genom. 2014;36(3):365-74.

Hyun TK, Eom SH, Jeun YC, Han SH, Kim JS. Identification of glutamate decarboxylases as a γ-aminobutyric acid (GABA) biosynthetic enzyme in soybean. Ind Crop Prod. 2013;49:864-70.

Murashige T, Skoog F. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol Plant. 1962;15(3): 473-9.

Ahmed SA, Baig MM. Biotic elicitor enhanced production of psoralen in suspension cultures of Psoralea corylifolia L. Saudi J Biol Sci. 2014;21(5):499-504.

Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976;72:248-54.

Saathoff AJ, Sarath G, Chow EK, Dien BS, Tobias CM. Downregulation of cinnamyl-alcohol dehydrogenase in switchgrass by RNA silencing results in enhanced glucose release after cellulase treatment. PLoS One. 2011;6(1): e16416.

Murzin AG. Structural classification of proteins: new superfamilies. Curr Opin Struct Biol. 1996;6(3):386-94.

Jin Y, Zhang C, Liu W, Qi H, Chen H, Cao S. The cinnamyl alcohol dehydrogenase gene family in melon (Cucumis melo L.): bioinformatic analysis and expression patterns. PLoS One. 2014;9(7):e101730.

Hyun TK, Eom SH, Kim JS. Genomic analysis and gene structure of the two invertase families in the domesticated apple (Malus × domestica Borkh.). Plant Omics. 2011;4(7):391-9.

Saathoff AJ, Hargrove MS, Haas EJ, Tobias CM, Twigg P, Sattler S, Sarath G. Switchgrass PviCAD1: understanding residues important for substrate preferences and activity. Appl. Biochem. Biotechnol. 2012;168(5):1086-100.

Bukh C, Nord-Larsen PH, Rasmussen SK. Phylogeny and structure of the cinnamyl alcohol dehydrogenase gene family in Brachypodium distachyon. J Exp Bot. 2012;63(17):6223-36.

Mitchell HJ, Hall SA, Stratford R, Hall JL, Barber MS. Differential induction of cinnamyl alcohol dehydrogenase during defensive lignification in wheat (Triticum aestivum L.): characterisation of the major inducible form. Planta. 1999;208(1):31-7.

Mandal S. Induction of phenolics, lignin and key defense enzymes in eggplant (Solanum melongena L.) roots in response to elicitors. Afr J Biotechnol. 2010;9(47):8038-47.

Moura JC, Bonine CA, de Oliveira Fernandes Viana J, Dornelas MC, Mazzafera P. Abiotic and biotic stresses and changes in the lignin content and composition in plants. J Integr Plant Biol. 2010;52(4):360-76.

Sattler SE, Funnell-Harris DL. Modifying lignin to improve bioenergy feedstocks: strengthening the barrier against pathogens? Front Plant Sci. 2013;4:70.

Saballos A, Ejeta G, Sanchez E, Kang C, Vermerris W. A genome-wide analysis of the cinnamyl alcohol dehydrogenase family in sorghum [Sorghum bicolor (L.) Moench] identifies SbCAD2 as the brown midrib6 gene. Genetics. 2009;181(2):783-95.

Zhao Q, Tobimatsu Y, Zhou R, Pattathil S, Gallego-Giraldo L, Fu C, Jackson LA, Hahn MG, Kim H, Chen F, Ralph J, Dixon RA. Loss of function of cinnamyl alcohol dehydrogenase 1 leads to unconventional lignin and a temperature-sensitive growth defect in Medicago truncatula. Proc Natl Acad Sci USA. 2013;110(33):13660-5.

Tang R, Zhang XQ, Li YH, Xie XM. Cloning and in silico analysis of a cinnamyl alcohol dehydrogenase gene in Pennisetum purpureum. J Genet. 2014;93(1):145-58.

Li X, Yang Y, Yao J, Chen G, Li X, Zhang Q, Wu C. FLEXIBLE CULM 1 encoding a cinnamyl-alcohol dehydrogenase controls culm mechanical strength in rice. Plant Mol Biol. 2009;69(6):685-97.

Kim SJ, Kim KW, Cho MH, Franceschi VR, Davin LB, Lewis NG. Expression of cinnamyl alcohol dehydrogenases and their putative homologues during Arabidopsis thaliana growth and development: lessons for database annotations? Phytochemistry. 2007;68(14):1957-74.

Baldoni A, Von Pinho EV, Fernandes JS, Abreu VM, Carvalho ML. Gene expression in the lignin biosynthesis pathway during soybean seed development. Genet Mol Res. 2013;12(3):2618-24.

Smýkal P, Vernoud V, Blair MW, Soukup A, Thompson RD. The role of the testa during development and in establishment of dormancy of the legume seed. Front Plant Sci. 2014;5:351.

Bagniewska-Zadworna A, Barakat A, Lakomy P, Smoliński DJ, Zadworny M. Lignin and lignans in plant defence: Insight from expression profiling of cinnamyl alcohol dehydrogenase genes during development and following fungal infection in Populus. Plant Sci. 2014;229:111-21.

Pauwels L, Morreel K, De Witte E, Lammertyn F, Van Montagu M, Boerjan W, Inzé D, Goossens A. Mapping methyl jasmonate-mediated transcriptional reprogramming of metabolism and cell cycle progression in cultured Arabidopsis cells. Proc Natl Acad Sci USA. 2008;105(4):1380-5.

Concha CM, Figueroa NE, Poblete LA, Oñate FA, Schwab W, Figueroa CR. Methyl jasmonate treatment induces changes in fruit ripening by modifying the expression of several ripening genes in Fragaria chiloensis fruit. Plant Physiol Biochem. 2013;70:433-44.

Mandal S, Kar I, Mukherjee AK, Acharya P. Elicitor-induced defense responses in Solanum lycopersicum against Ralstonia solanacearum. ScientificWorldJournal. 2013;2013:561056.

Sun Y, Wu Y, Zhao Y, Han X, Lou H, Cheng A. Molecular cloning and biochemical characterization of two cinnamyl alcohol dehydrogenases from a liverwort Plagiochasma appendiculatum. Plant Physiol Biochem. 2013;70:133-41.

Cheng H, Li L, Xu F, Cheng S, Cao F, Wang Y, Yuan H, Jiang D, Wu C. Expression patterns of a cinnamyl alcohol dehydrogenase gene involved in lignin biosynthesis and environmental stress in Ginkgo biloba. Mol Biol Rep. 2013;40(1):707-21.


  • There are currently no refbacks.


Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.