title: Comparison of the nodule vs. root transcriptome of the actinorhizal plant Datisca glomerata: actinorhizal nodules contain a specific class of defensins.
abstract: Actinorhizal root nodule symbioses are very diverse, and the symbiosis of Datisca glomerata has previously been shown to have many unusual aspects. In order to gain molecular information on the infection mechanism, nodule development and nodule metabolism, we compared the transcriptomes of D. glomerata roots and nodules. Root and nodule libraries representing the 3'-ends of cDNAs were subjected to high-throughput parallel 454 sequencing. To identify the corresponding genes and to improve the assembly, Illumina sequencing of the nodule transcriptome was performed as well. The evaluation revealed 406 differentially regulated genes, 295 of which (72.7%) could be assigned a function based on homology. Analysis of the nodule transcriptome showed that genes encoding components of the common symbiosis signaling pathway were present in nodules of D. glomerata, which in combination with the previously established function of SymRK in D. glomerata nodulation suggests that this pathway is also active in actinorhizal Cucurbitales. Furthermore, comparison of the D. glomerata nodule transcriptome with nodule transcriptomes from actinorhizal Fagales revealed a new subgroup of nodule-specific defensins that might play a role specific to actinorhizal symbioses. The D. glomerata members of this defensin subgroup contain an acidic C-terminal domain that was never found in plant defensins before.
authors.affiliation: Department of Botany, Stockholm University, Stockholm, Sweden.
authors.forename: Irina V
authors.initials: IV
authors.lastname: Demina
authors.forename: Tomas
authors.initials: T
authors.lastname: Persson
authors.forename: Patricia
authors.initials: P
authors.lastname: Santos
authors.forename: Marian
authors.initials: M
authors.lastname: Plaszczyca
authors.forename: Katharina
authors.initials: K
authors.lastname: Pawlowski
mesh_terms: D000595:Amino Acid Sequence; D019295:Computational Biology; D023082:Defensins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007887:Fabaceae / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D059014:High-Throughput Nucleotide Sequencing; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics* / Q000378:metabolism; D053204:Root Nodules, Plant / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction; D013559:Symbiosis / Q000502:physiology; D013831:Thiamine / Q000096:biosynthesis; D064028:Tracheophyta / Q000235:genetics* / Q000378:metabolism; D059467:Transcriptome
chemical_list: D023082:Defensins; D010940:Plant Proteins; D013831:Thiamine