title: Transcript profiling of a novel plant meristem, the monocot cambium.
abstract: While monocots lack the ability to produce a vascular cambium or woody growth, some monocot lineages evolved a novel lateral meristem, the monocot cambium, which supports secondary radial growth of stems. In contrast to the vascular cambium found in woody angiosperm and gymnosperm species, the monocot cambium produces secondary vascular bundles, which have an amphivasal organization of tracheids encircling a central strand of phloem. Currently there is no information concerning the molecular genetic basis of the development or evolution of the monocot cambium. Here we report high-quality transcriptomes for monocot cambium and early derivative tissues in two monocot genera, Yucca and Cordyline. Monocot cambium transcript profiles were compared to those of vascular cambia and secondary xylem tissues of two forest tree species, Populus trichocarpa and Eucalyptus grandis. Monocot cambium transcript levels showed that there are extensive overlaps between the regulation of monocot cambia and vascular cambia. Candidate regulatory genes that vary between the monocot and vascular cambia were also identified, and included members of the KANADI and CLE families involved in polarity and cell-cell signaling, respectively. We suggest that the monocot cambium may have evolved in part through reactivation of genetic mechanisms involved in vascular cambium regulation.
authors.affiliation: US Forest Service, Pacific Southwest Research Station, Davis, California, USA.|Department of Computer Science, University of California, Davis, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Zinkgraf
authors.affiliation: US Forest Service, Pacific Southwest Research Station, Davis, California, USA.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Gerttula
authors.affiliation: US Forest Service, Pacific Southwest Research Station, Davis, California, USA.|Department of Plant Biology, University of California, Davis, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Groover
mesh_terms: D005075:Biological Evolution; D058506:Cambium / Q000033:anatomy & histology / Q000378:metabolism*; D031406:Cordyline / Q000033:anatomy & histology / Q000378:metabolism*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D063245:Plant Development; D014157:Transcription Factors / Q000378:metabolism; D059467:Transcriptome; D027623:Yucca / Q000033:anatomy & histology / Q000378:metabolism*
chemical_list: D014157:Transcription Factors