fpls-09-01629 November 12, 2018 Time: 18:56 # 1 ORIGINAL RESEARCH published: 14 November 2018 doi: 10.3389/fpls.2018.01629 Comparative Analysis of the Nodule Transcriptomes of Ceanothus thyrsiflorus (Rhamnaceae, Rosales) and Datisca glomerata (Datiscaceae, Cucurbitales) Marco G. Salgado1, Robin van Velzen2, Thanh Van Nguyen1, Kai Battenberg3, Alison M. Berry3, Daniel Lundin4,5 and Katharina Pawlowski1* 1 Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden, 2 Laboratory of Molecular Biology, Department of Plant Sciences, Wageningen University, Wageningen, Netherlands, 3 Department of Plant Sciences, University of California, Davis, Davis, CA, United States, 4 Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden, 5 Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden Edited by: Stefan de Folter, Two types of nitrogen-fixing root nodule symbioses are known, rhizobial and actinorhizal Centro de Investigación y de Estudios symbioses. The latter involve plants of three orders, Fagales, Rosales, and Cucurbitales. Avanzados (CINVESTAV), Mexico To understand the diversity of plant symbiotic adaptation, we compared the nodule Reviewed by: Luis Wall, transcriptomes of Datisca glomerata (Datiscaceae, Cucurbitales) and Ceanothus Universidad Nacional de Quilmes thyrsiflorus (Rhamnaceae, Rosales); both species are nodulated by members of the (UNQ), Argentina Costas Delis, uncultured Frankia clade, cluster II. The analysis focused on various features. In Technological Educational Institute both species, the expression of orthologs of legume Nod factor receptor genes of Peloponnese, Greece was elevated in nodules compared to roots. Since arginine has been postulated as *Correspondence: export form of fixed nitrogen from symbiotic Frankia in nodules of D. glomerata, the Katharina Pawlowski
[email protected] question was whether the nitrogen metabolism was similar in nodules of C.