title: Lignin and lignans in plant defence: insight from expression profiling of cinnamyl alcohol dehydrogenase genes during development and following fungal infection in Populus.
abstract: Cinnamyl alcohol dehydrogenase (CAD) catalyses the final step in the biosynthesis of monolignol, the main component of lignin. Lignins, deposited in the secondary cell wall, play a role in plant defence against pathogens. We re-analysed the phylogeny of CAD/CAD-like genes using sequences from recently sequenced genomes, and analysed the temporal and spatial expression profiles of CAD/CAD-like genes in Populus trichocarpa healthy and infected plants. Three fungal pathogens (Rhizoctonia solani, Fusarium oxysporum, and Cytospora sp.), varying in lifestyle and pathogenicity, were used for plant infection. Phylogenetic analyses showed that CAD/CAD-like genes were distributed in classes represented by all members from angiosperm lineages including basal angiosperms and Selaginella. The analysed genes showed different expression profiles during development and demonstrated that three genes were involved in primary xylem maturation while five may function in secondary xylem formation. Expression analysis following inoculation with fungal pathogens, showed that five genes were induced in either stem or leaves. These results add further evidence that CAD/CAD-like genes have evolved specialised functions in plant development and defence against various pest and pathogens. Two genes (PoptrCAD11 and PoptrCAD15), which were induced under various stresses, could be treated as universal markers of plant defence using lignification or lignan biosynthesis.
authors.affiliation: Department of General Botany, Institute of Experimental Biology, Faculty of Biology, A. Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland. Electronic address: agabag@amu.edu.pl.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Bagniewska-Zadworna
authors.affiliation: Department of Biology, University of South Dakota, 414 E. Clark Street, Vermillion, SD 57069, USA. Electronic address: Abdelali.Barakat@usd.edu.
authors.forename: Abdelali
authors.initials: A
authors.lastname: Barakat
authors.affiliation: Department of Forest Pathology, Faculty of Forestry, Poznań University of Life Sciences, Wojska Polskiego 71c, 60-625 Poznań, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Łakomy
authors.affiliation: Department of Cell Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Lwowska 1, 87-100 Toruń, Poland.
authors.forename: Dariusz J
authors.initials: DJ
authors.lastname: Smoliński
authors.affiliation: Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Zadworny
mesh_terms: D000429:Alcohol Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017404:In Situ Hybridization, Fluorescence; D017705:Lignans / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D010802:Phylogeny; D063245:Plant Development / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D032107:Populus / Q000201:enzymology / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D052584:Xylem / Q000033:anatomy & histology
chemical_list: D017705:Lignans; D010940:Plant Proteins; D008031:Lignin; D000429:Alcohol Oxidoreductases; C018656:cinnamyl alcohol dehydrogenase
keywords: Functional divergence; Lignification; Plant defence; Populus trichocarpa; Xylogenesis