title: Auxin and ABA act as central regulators of developmental networks associated with paradormancy in Canada thistle (Cirsium arvense).
abstract: Dormancy in underground vegetative buds of Canada thistle, an herbaceous perennial weed, allows escape from current control methods and contributes to its invasive nature. In this study, ~65 % of root sections obtained from greenhouse propagated Canada thistle produced new vegetative shoots by 14 days post-sectioning. RNA samples obtained from sectioned roots incubated 0, 24, 48, and 72 h at 25°C under 16:8 h light-dark conditions were used to construct four MID-tagged cDNA libraries. Analysis of in silico data obtained using Roche 454 GS-FLX pyrosequencing technologies identified molecular networks associated with paradormancy release in underground vegetative buds of Canada thistle. Sequencing of two replicate plates produced ~2.5 million ESTs with an average read length of 362 bases. These ESTs assembled into 67358 unique sequences (21777 contigs and 45581 singlets) and annotation against the Arabidopsis database identified 15232 unigenes. Among the 15232 unigenes, we identified processes enriched with transcripts involved in plant hormone signaling networks. To follow-up on these results, we examined hormone profiles in roots, which identified changes in abscisic acid (ABA) and ABA metabolites, auxins, and cytokinins post-sectioning. Transcriptome and hormone profiling data suggest that interaction between auxin- and ABA-signaling regulate paradormancy maintenance and release in underground adventitious buds of Canada thistle. Our proposed model shows that sectioning-induced changes in polar auxin transport alters ABA metabolism and signaling, which further impacts gibberellic acid signaling involving interactions between ABA and FUSCA3. Here we report that reduced auxin and ABA-signaling, in conjunction with increased cytokinin biosynthesis post-sectioning supports a model where interactions among hormones drives molecular networks leading to cell division, differentiation, and vegetative outgrowth.
authors.affiliation: USDA-Agricultural Research Service, Biosciences Research Laboratory, U.S. Department of Agriculture, 1605 Albrecht Blvd., Fargo, ND 58102-2765, USA. james.anderson@ars.usda.gov
authors.forename: James V
authors.initials: JV
authors.lastname: Anderson
authors.forename: Münevver
authors.initials: M
authors.lastname: Doğramacı
authors.forename: David P
authors.initials: DP
authors.lastname: Horvath
authors.forename: Michael E
authors.initials: ME
authors.lastname: Foley
authors.forename: Wun S
authors.initials: WS
authors.lastname: Chao
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Suttle
authors.forename: Jyothi
authors.initials: J
authors.lastname: Thimmapuram
authors.forename: Alvaro G
authors.initials: AG
authors.lastname: Hernandez
authors.forename: Shahjahan
authors.initials: S
authors.lastname: Ali
authors.forename: Mark A
authors.initials: MA
authors.lastname: Mikel
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics; D002453:Cell Cycle; D031180:Cirsium / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D003583:Cytokinins / Q000096:biosynthesis; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D015723:Gene Library; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D058977:Molecular Sequence Annotation; D017440:Photoperiod; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000254:growth & development; D015398:Signal Transduction
chemical_list: D003583:Cytokinins; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D000040:Abscisic Acid