title: C3 cotyledons are followed by C4 leaves: intra-individual transcriptome analysis of Salsola soda (Chenopodiaceae).
abstract: Some species of Salsoleae (Chenopodiaceae) convert from C3photosynthesis during the seedling stage to the C4pathway in adult leaves. This unique developmental transition of photosynthetic pathways offers the exceptional opportunity to follow the development of the derived C4syndrome from the C3condition within individual plants, avoiding phylogenetic noise. Here we investigate Salsola soda, a little-studied species from tribe Salsoleae, using an ontogenetic approach. Anatomical sections, carbon isotope (δ13C) values, transcriptome analysis by means of mRNA sequencing, and protein levels of the key C4enzyme phosphoenolpyruvate carboxylase (PEPC) were examined from seed to adult plant stages. Despite a previous report, our results based on δ13C values, anatomy and transcriptomics clearly indicate a C3phase during the cotyledon stage. During this stage, the entire transcriptional repertoire of the C4NADP-malic enzyme type is detected at low levels compared to a significant increase in true leaves. In contrast, abundance of transcripts encoding most of the major photorespiratory enzymes is not significantly decreased in leaves compared to cotyledons. PEPC polypeptide was detected only in leaves, correlating with increased PEPC transcript abundance from the cotyledon to leaf stage.
authors.affiliation: Institut für Allgemeine und Spezielle Botanik und Botanischer Garten der Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany mlauter@uni-mainz.de.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Lauterbach
authors.affiliation: Institut für Entwicklungs- und Molekularbiologie der Pflanzen, D-40225 Düsseldorf, Germany.|Cluster of Excellence on Plant Sciences (CEPLAS), D-06225 Düsseldorf, Germany.
authors.forename: Kumari
authors.initials: K
authors.lastname: Billakurthi
authors.affiliation: Institut für Allgemeine und Spezielle Botanik und Botanischer Garten der Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Kadereit
authors.affiliation: School of Chemistry and Biochemistry, University of Western Australia, Crawley, WA 6009, Australia.
authors.forename: Martha
authors.initials: M
authors.lastname: Ludwig
authors.affiliation: Institut für Entwicklungs- und Molekularbiologie der Pflanzen, D-40225 Düsseldorf, Germany.|Cluster of Excellence on Plant Sciences (CEPLAS), D-06225 Düsseldorf, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Westhoff
authors.affiliation: Institut für Entwicklungs- und Molekularbiologie der Pflanzen, D-40225 Düsseldorf, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Gowik
mesh_terms: D002247:Carbon Isotopes / Q000378:metabolism; D018548:Cotyledon / Q000033:anatomy & histology / Q000378:metabolism*; D020869:Gene Expression Profiling; D010788:Photosynthesis; D018515:Plant Leaves / Q000033:anatomy & histology / Q000378:metabolism*; D031248:Salsola / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D002247:Carbon Isotopes
keywords: 
  Salsola
  ; C4 photosynthesis; Caryophyllales; Chenopodiaceae; RNA seq; cotyledon; development; leaf; transcriptome.