Correction: Cell- and Tissue-Specific Transcriptome Analyses of Medicago truncatula Root Nodules

Abstract

Legumes have the unique ability to host nitrogen-fixing Rhizobium bacteria as symbiosomes inside root nodule cells. To get insight into this key process, which forms the heart of the endosymbiosis, we isolated specific cells/tissues at different stages of symbiosome formation from nodules of the model legume Medicago truncatula using laser-capture microdissection. Next, we determined their associated expression profiles using Affymetrix Medicago GeneChips. Cells were collected from the nodule infection zone divided into a distal (where symbiosome formation and division occur) and proximal region (where symbiosomes are mainly differentiating), as well as infected cells from the fixation zone containing mature nitrogen fixing symbiosomes. As non-infected cells/tissue we included nodule meristem cells and uninfected cells from the fixation zone. Here, we present a comprehensive gene expression map of an indeterminate Medicago nodule and selected genes that show specific enriched expression in the different cells or tissues. Validation of the obtained expression profiles, by comparison to published gene expression profiles and experimental verification, indicates that the data can be used as digital ''in situ''. This digital ''in situ'' offers a genome-wide insight into genes specifically associated with subsequent stages of symbiosome and nodule cell development, and can serve to guide future functional studies.

Transcriptomic analysis with the progress of symbiosis in ‘crack-entry’ legumeArachis hypogaeahighlights its contrast with ‘infection thread’ adapted legumes

“…Transcriptome analyses during symbiosis in several legumes like M. truncatula, L. japonicus, Glycine max and Cicer arietinum provided molecular insights into symbiosis that uses the 'root hair' mode entry (Takanashi et al, 2012;Limpens et al, 2014;Parida et al, 2016;Yuan et al, 2017a). These resources have been useful in determining gene expression associated with different stages of RNS, for example symbiont recognition, onset of infection, meristem activity for nodule organogenesis and functional differentiation of infected cells (Breakspear et al, 2014;Roux et al, 2014).…”