title: Loss of function of cinnamyl alcohol dehydrogenase 1 leads to unconventional lignin and a temperature-sensitive growth defect in Medicago truncatula.
abstract: There is considerable debate over the capacity of the cell wall polymer lignin to incorporate unnatural monomer units. We have identified Tnt1 retrotransposon insertion mutants of barrel medic (Medicago truncatula) that show reduced lignin autofluorescence under UV microscopy and red coloration in interfascicular fibers. The phenotype is caused by insertion of retrotransposons into a gene annotated as encoding cinnamyl alcohol dehydrogenase, here designated M. truncatula CAD1. NMR analysis indicated that the lignin is derived almost exclusively from coniferaldehyde and sinapaldehyde and is therefore strikingly different from classical lignins, which are derived mainly from coniferyl and sinapyl alcohols. Despite such a major alteration in lignin structure, the plants appear normal under standard conditions in the greenhouse or growth chamber. However, the plants are dwarfed when grown at 30 °C. Glycome profiling revealed an increased extractability of some xylan and pectin epitopes from the cell walls of the cad1-1 mutant but decreased extractability of others, suggesting that aldehyde-dominant lignin significantly alters cell wall structure.
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, OK 73401, USA.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Zhao
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tobimatsu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhou
authors.forename: Sivakumar
authors.initials: S
authors.lastname: Pattathil
authors.forename: Lina
authors.initials: L
authors.lastname: Gallego-Giraldo
authors.forename: Chunxiang
authors.initials: C
authors.lastname: Fu
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Jackson
authors.forename: Michael G
authors.initials: MG
authors.lastname: Hahn
authors.forename: Hoon
authors.initials: H
authors.lastname: Kim
authors.forename: Fang
authors.initials: F
authors.lastname: Chen
authors.forename: John
authors.initials: J
authors.lastname: Ralph
authors.forename: Richard A
authors.initials: RA
authors.lastname: Dixon
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives / Q000032:analysis; D000429:Alcohol Oxidoreductases / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry; D003001:Cloning, Molecular; D019295:Computational Biology; D008031:Lignin / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D046913:Medicago truncatula / Q000201:enzymology* / Q000254:growth & development*; D046228:Microarray Analysis; D008860:Microscopy, Ultraviolet; D016296:Mutagenesis; D061848:Optical Imaging; D018626:Retroelements / Q000235:genetics; D013696:Temperature
chemical_list: D018626:Retroelements; C075384:coniferaldehyde; C075386:sinapaldehyde; D000171:Acrolein; D008031:Lignin; D000429:Alcohol Oxidoreductases; C018656:cinnamyl alcohol dehydrogenase
keywords: model legume; monolignol pathway; transposon mutagenesis
references.citation: Nature. 2011 Nov 16;480(7378):520-4
references.pmid: 22089132
references.citation: Proc Natl Acad Sci U S A. 2011 Mar 1;108(9):3803-8
references.pmid: 21321194
references.citation: Plant Physiol. 2005 Aug;138(4):2245-59
references.pmid: 16006598
references.citation: Plant J. 2008 Aug;55(3):504-13
references.pmid: 18410479
references.citation: Proc Natl Acad Sci U S A. 2004 Feb 10;101(6):1455-60
references.pmid: 14745009
references.citation: Annu Rev Genet. 2010;44:337-63
references.pmid: 20809799
references.citation: Plant Cell. 2000 Dec;12(12):2529-2540
references.pmid: 11148295
references.citation: Plant Cell. 2007 Jan;19(1):237-55
references.pmid: 17237350
references.citation: Org Biomol Chem. 2003 Jan 21;1(2):268-81
references.pmid: 12929422
references.citation: Plant Physiol. 2006 Mar;140(3):972-83
references.pmid: 16443696
references.citation: Plant Physiol. 2003 Jun;132(2):848-60
references.pmid: 12805615
references.citation: Plant J. 2008 Jan;53(2):368-79
references.pmid: 18184422
references.citation: Plant Cell. 2004 Jun;16(6):1446-65
references.pmid: 15161961
references.citation: Curr Opin Biotechnol. 2013 Apr;24(2):336-43
references.pmid: 23228388
references.citation: Methods Mol Biol. 2012;908:61-72
references.pmid: 22843389
references.citation: Proc Natl Acad Sci U S A. 2012 Jan 31;109(5):1772-7
references.pmid: 22307645
references.citation: Plant Cell. 2010 May;22(5):1620-32
references.pmid: 20511296
references.citation: Mol Gen Genet. 1995 Jun 10;247(5):537-45
references.pmid: 7603432
references.citation: New Phytol. 2012 Dec;196(4):978-1000
references.pmid: 23035778
references.citation: Plant J. 2013 Jan;73(2):201-11
references.pmid: 22957702
references.citation: Plant J. 2009 Dec;60(5):771-82
references.pmid: 19682296
references.citation: Plant Cell. 2004 Feb;16(2):544-54
references.pmid: 14729911
references.citation: Carbohydr Res. 2008 Nov 3;343(16):2830-3
references.pmid: 18786667
references.citation: Phytochemistry. 2004 Feb;65(3):313-21
references.pmid: 14751302
references.citation: Methods Mol Biol. 2006;343:115-27
references.pmid: 16988338
references.citation: Planta. 2008 Apr;227(5):943-56
references.pmid: 18046574
references.citation: Plant Physiol. 2004 Dec;136(4):4159-68
references.pmid: 15557093
references.citation: Plant Cell. 2008 Oct;20(10):2763-82
references.pmid: 18952777
references.citation: Nat Biotechnol. 2007 Jul;25(7):759-61
references.pmid: 17572667
references.citation: Org Lett. 2000 Jul 27;2(15):2197-200
references.pmid: 10930242
references.citation: Planta. 2008 Sep;228(4):663-74
references.pmid: 18563436
references.citation: Plant Cell. 2011 Apr;23(4):1536-55
references.pmid: 21467581
references.citation: Plant Cell. 2005 Jul;17(7):2059-76
references.pmid: 15937231
references.citation: Phytochemistry. 2003 Jan;62(1):53-65
references.pmid: 12475619
references.citation: Org Biomol Chem. 2010 Feb 7;8(3):576-91
references.pmid: 20090974
references.citation: J Biol Chem. 2002 Dec 6;277(49):47412-9
references.pmid: 12351655
references.citation: Plant Physiol. 2009 Jun;150(2):584-95
references.pmid: 19363091
references.citation: Nat Protoc. 2012 Sep;7(9):1579-89
references.pmid: 22864199
references.citation: Plant J. 2008 Apr;54(2):335-47
references.pmid: 18208518
references.citation: Plant J. 2002 Apr;30(1):47-59
references.pmid: 11967092
references.citation: Plant J. 2013 Feb;73(3):496-508
references.pmid: 23078216
references.citation: Proc Natl Acad Sci U S A. 2005 Nov 15;102(46):16573-8
references.pmid: 16263933
references.citation: New Phytol. 2011 May;190(3):627-39
references.pmid: 21251001
references.citation: Plant J. 2010 Jul 1;63(1):100-14
references.pmid: 20408998
references.citation: Curr Opin Biotechnol. 2005 Aug;16(4):407-15
references.pmid: 16023847