Cell Identity Mediates the Response of Arabidopsis Roots to Abiotic Stress

Abstract

Little is known about the way developmental cues affect how cells interpret their environment. We characterized the transcriptional response to high salinity of different cell layers and developmental stages of the Arabidopsis root and found that transcriptional responses are highly constrained by developmental parameters. These transcriptional changes lead to the differential regulation of specific biological functions in subsets of cell layers, several of which correspond to observable physiological changes. We showed that known stress pathways primarily control semiubiquitous responses and used mutants that disrupt epidermal patterning to reveal cell-layer-specific and inter-cell-layer effects. By performing a similar analysis using iron deprivation, we identified common cell-type-specific stress responses and revealed the crucial role the environment plays in defining the transcriptional outcome of cell-fate decisions.

Cell-Type-Specific H+-ATPase Activity in Root Tissues Enables K+ Retention and Mediates Acclimation of Barley (Hordeum vulgare) to Salinity Stress

“…It is thought that the limited success of transgenic manipulations to increase some of these traits (and, specifically, those related to ion exclusion from the shoot) is due largely to the inability to express important exclusion genes in a cell-specific manner . 1 While the importance of cell-specific responses for plant adaptive responses to the environment is widely accepted (Ma and Bohnert, 2007;Dinneny et al, 2008;Dinneny, 2010), only a limited number of studies have attempted to address this issue with respect to salt stress. Dinneny et al (2008) used fluorescence-activated cell sorting to generate a genome-scale high-resolution expression map to demonstrate cell type-specific responses of various root cell types to salinity.…”

“…1 While the importance of cell-specific responses for plant adaptive responses to the environment is widely accepted (Ma and Bohnert, 2007;Dinneny et al, 2008;Dinneny, 2010), only a limited number of studies have attempted to address this issue with respect to salt stress. Dinneny et al (2008) used fluorescence-activated cell sorting to generate a genome-scale high-resolution expression map to demonstrate cell type-specific responses of various root cell types to salinity. Several thousand genes were shown to be expressed in a cell-specific manner, both in terms of longitudinal and radial root profiles (Dinneny et al, 2008).…”

“…Dinneny et al (2008) used fluorescence-activated cell sorting to generate a genome-scale high-resolution expression map to demonstrate cell type-specific responses of various root cell types to salinity. Several thousand genes were shown to be expressed in a cell-specific manner, both in terms of longitudinal and radial root profiles (Dinneny et al, 2008). Although highlighting the complexity of plant adaptive responses to salinity, these results cannot be easily translated into breeding programs.…”

Embryogenesis: Pattern Formation from a Single Cell

“…The result is a high ratio of initiated lateral roots to emerged lateral roots under high nitrogen conditions; in nitrogen-depleted conditions, these initiated lateral roots can then emerge and explore the surrounding soil environment for nutrients. A similar study has also been undertaken for cell-type-specifi c responses of root cells to salt (Dinneny et al, 2008). Some instances exist where the signal of upregulation of a given gene in one tissue could be cancelled out by the downregulation of the same gene in another tissue if one were to examine just the RNA from the whole root in response to salt stress, as opposed to the response in specifi c cell types.…”

Regulation of ZAT12 protein stability: The role of hydrogen peroxide

“…8 Of special interest is to understand the role of ROS, in the form of hydrogen peroxide (H 2 O 2 ), in the regulation of ZAT12 stability in the epidermis of the early differentiation zone of the root, which is the essential zone for Fe acquisition under deficient Fe supply. 11,[13][14][15] It was found that ZAT12 undergoes proteasome-dependent degradation, which occurs also in the presence of elevated H 2 O 2 levels. 8 Deletion analysis showed that the EAR motif, which ZAT12 employs for the interaction with FIT, is essential for this proteasome targeting.…”