title: Dissecting the molecular signatures of apical cell-type shoot meristems from two ancient land plant lineages.
abstract: Shoot apical meristem (SAM) structure varies markedly within the land plants. The SAMs of many seedless vascular plants contain a conspicuous inverted, pyramidal cell called the apical cell (AC), which is unidentified in angiosperms. In this study, we use transcriptomic sequencing with precise laser microdissections of meristem subdomains to define the molecular signatures of anatomically distinct zones from the AC-type SAMs of a lycophyte (Selaginella moellendorffii) and a monilophyte (Equisetum arvense). The two model species for this study represent vascular plant lineages that diverged > 400 million yr ago. Our data comprise comprehensive molecular signatures for the distinct subdomains within AC-type SAMs, an anatomical anomaly whose functional significance has been debated in the botanical literature for over two centuries. Moreover, our data provide molecular support for distinct gene expression programs between the AC-type SAMs of Selaginella and Equisetum, as compared with the SAM transcriptome of the angiosperm maize. The results are discussed in light of the functional significance and evolutionary success of the AC-type SAM within the embryophytes.
authors.affiliation: Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Margaret H
authors.initials: MH
authors.lastname: Frank
authors.affiliation: Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Molly B
authors.initials: MB
authors.lastname: Edwards
authors.affiliation: Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Eric R
authors.initials: ER
authors.lastname: Schultz
authors.affiliation: Donald Danforth Plant Science Center, St Louis, MO, 63132, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: McKain
authors.affiliation: Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, 14853, USA.|USDA Robert W. Holley Center for Agriculture and Health, Ithaca, NY, 14853, USA.
authors.forename: Zhangjun
authors.initials: Z
authors.lastname: Fei
authors.affiliation: Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Iben
authors.initials: I
authors.lastname: Sørensen
authors.affiliation: Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Jocelyn K C
authors.initials: JK
authors.lastname: Rose
authors.affiliation: Department of Plant Biology, Cornell University, Ithaca, NY, 14853, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Scanlon
mesh_terms: D019669:Embryophyta / Q000166:cytology* / Q000235:genetics*; D020829:Equisetum / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017403:In Situ Hybridization; D061346:Laser Capture Microdissection; D018519:Meristem / Q000166:cytology* / Q000235:genetics*; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D032503:Selaginellaceae / Q000235:genetics; D014158:Transcription, Genetic; D015854:Up-Regulation / Q000235:genetics
chemical_list: D012333:RNA, Messenger
keywords: Equisetum arvense; Selaginella moellendorfii; apical cell (AC); seedless vascular plants; shoot apical meristem (SAM)