Decipher Regulatory Networks Controlling Legume Cell Response to Environmental Stresses Using One Single Cell Type Model, the Root Hair Cell

Legume organs are composed of cell types with distinct functions and transcriptional profiles. Hence, -omic studies at the level of plant organs are a reflection of an average contribution of the cell types composing the organ, weighted by their relative abundances in the sample. Consequently, a major limitation in the characterization of legume molecular response to environmental stresses is the multicellular complexity of the organs. Ideally, to fully understand the contribution of each cell type in regulating gene expression, their transcriptome, epigenome and pool of transcription factors should be independently characterized.

Using a single plant cell model, the soybean root hair cell, root epidermal cell type specialized in water and nutrient uptake and first site of infection by Bradyrhizobium japonicum, we are investigating its molecular response to various abiotic and biotic stresses. In addition, the characteristic polar elongation of the root hair cell makes it suitable to characterize in great details the molecular mechanisms controlling plant cell elongation.

We are currently combining the use of aeroponic technology with an updated methodology to isolate gram quantities of soybean root hair cells and functional genomic approaches to characterize the molecular changes of this single cell type in response to various environmental stresses and characterize in more details transcriptional regulatory networks controlling basic aspects of legume biology.