Ectopic lignification in the flax lignified bast fiber1 mutant stem is associated with tissue-specific modifications in gene expression and cell wall composition.
Histochemical screening of a flax ethyl methanesulfonate population led to the identification of 93 independent M2 mutant families showing ectopic lignification in the secondary cell wall of stem bast fibers. We named this core collection the Linum usitatissimum (flax) lbf mutants for lignified bast fibers and believe that this population represents a novel biological resource for investigating how bast fiber plants regulate lignin biosynthesis. As a proof of concept, we characterized the lbf1 mutant and showed that the lignin content increased by 350% in outer stem tissues containing bast fibers but was unchanged in inner stem tissues containing xylem. Chemical and NMR analyses indicated that bast fiber ectopic lignin was highly condensed and rich in G-units. Liquid chromatography-mass spectrometry profiling showed large modifications in the oligolignol pool of lbf1 inner- and outer-stem tissues that could be related to ectopic lignification. Immunological and chemical analyses revealed that lbf1 mutants also showed changes to other cell wall polymers. Whole-genome transcriptomics suggested that ectopic lignification of flax bast fibers could be caused by increased transcript accumulation of (1) the cinnamoyl-CoA reductase, cinnamyl alcohol dehydrogenase, and caffeic acid O-methyltransferase monolignol biosynthesis genes, (2) several lignin-associated peroxidase genes, and (3) genes coding for respiratory burst oxidase homolog NADPH-oxidases necessary to increase H2O2 supply.
Université Lille Nord de France, Lille 1, UMR1281, F-59650 Villeneuve d'Ascq Cedex, France INRA, UMR1281, Stress Abiotiques et Différenciation des Végétaux Cultivés, F-59650 Villeneuve d'Ascq, France.
Maxime
M
Chantreau
INRA, UMR614, Fractionnement des AgroRessources et Environnement, F-51100 Reims, France Université de Reims Champagne-Ardenne, UMR614, Fractionnement des AgroRessources et Environnement, F-51100 Reims, France.
Antoine
A
Portelette
Université de Picardie Jules Verne, EA 3900, BIOPI, Laboratoire de Phytotechnologie, F-80037 Amiens Cedex 1, France.
Rebecca
R
Dauwe
INRA, UMR614, Fractionnement des AgroRessources et Environnement, F-51100 Reims, France Université de Reims Champagne-Ardenne, UMR614, Fractionnement des AgroRessources et Environnement, F-51100 Reims, France Laboratory of Tree Cell Biology, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Shingo
S
Kiyoto
INRA, UMR614, Fractionnement des AgroRessources et Environnement, F-51100 Reims, France Université de Reims Champagne-Ardenne, UMR614, Fractionnement des AgroRessources et Environnement, F-51100 Reims, France.
David
D
Crônier
Department of Plant Systems Biology, VIB, 9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, UGent, 9052 Gent, Belgium.
Kris
K
Morreel
Université Lille Nord de France, Lille 1, UMR1281, F-59650 Villeneuve d'Ascq Cedex, France INRA, UMR1281, Stress Abiotiques et Différenciation des Végétaux Cultivés, F-59650 Villeneuve d'Ascq, France.
Sandrine
S
Arribat
Université Lille Nord de France, Lille 1, UMR1281, F-59650 Villeneuve d'Ascq Cedex, France INRA, UMR1281, Stress Abiotiques et Différenciation des Végétaux Cultivés, F-59650 Villeneuve d'Ascq, France.
Godfrey
G
Neutelings
Université Lille Nord de France, Lille 1, UMR1281, F-59650 Villeneuve d'Ascq Cedex, France INRA, UMR1281, Stress Abiotiques et Différenciation des Végétaux Cultivés, F-59650 Villeneuve d'Ascq, France.
Malika
M
Chabi
Department of Plant Systems Biology, VIB, 9052 Gent, Belgium Department of Plant Biotechnology and Bioinformatics, UGent, 9052 Gent, Belgium.
Wout
W
Boerjan
Laboratory of Tree Cell Biology, Division of Forest and Biomaterials Science, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Arata
A
Yoshinaga
Université de Picardie Jules Verne, EA 3900, BIOPI, Laboratoire de Phytotechnologie, F-80037 Amiens Cedex 1, France.
François
F
Mesnard
Université Lille Nord de France, Lille 1, UMR1281, F-59650 Villeneuve d'Ascq Cedex, France INRA, UMR1281, Stress Abiotiques et Différenciation des Végétaux Cultivés, F-59650 Villeneuve d'Ascq, France.
Sebastien
S
Grec
INRA, UMR614, Fractionnement des AgroRessources et Environnement, F-51100 Reims, France Université de Reims Champagne-Ardenne, UMR614, Fractionnement des AgroRessources et Environnement, F-51100 Reims, France.
Brigitte
B
Chabbert
Université Lille Nord de France, Lille 1, UMR1281, F-59650 Villeneuve d'Ascq Cedex, France INRA, UMR1281, Stress Abiotiques et Différenciation des Végétaux Cultivés, F-59650 Villeneuve d'Ascq, France simon.hawkins@univ-lille1.fr.
Simon
S
Hawkins
D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry* / Q000648:ultrastructure; D019295:Computational Biology; D019597:Flax / Q000737:chemistry / Q000201:enzymology / Q000235:genetics* / Q000648:ultrastructure; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D006861:Hydrogen Peroxide / Q000378:metabolism; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018547:Plant Stems / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D059467:Transcriptome; D052584:Xylem / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000648:ultrastructure
D010940:Plant Proteins; D008031:Lignin; D006861:Hydrogen Peroxide; D000429:Alcohol Oxidoreductases; C018656:cinnamyl alcohol dehydrogenase; D000445:Aldehyde Oxidoreductases; C019904:cinnamoyl CoA reductase; D008780:Methyltransferases; C019608:caffeate O-methyltransferase