Salt stress-induced cell reprogramming, cell fate switch and adaptive plasticity during root hair development in Arabidopsis.

Developmental plasticity defines an adaptive mechanism, which plays a fundamental role in plant development and survival. How intrinsic or extrinsic factors are integrated to specify cell fates and subsequent organ and body building of a plant is still poorly understood. By studying developmental plasticity of Arabidopsis root hair in response to salt stress, we have begun to understand more about the basis of cellular plasticity. This paper summarizes our recent paper in which it described salt stress induced plasticity of root epidermis and root hair development in Arabidopsis. Analysis of gene expression of the homeobox transcription factor GLABRA2 (GL2), which determines hair/non-hair cell fate, showed that salt stress modulates root epidermal cell proliferation and changes the cell fate decisions. Furthermore, by analyzing the salt overly sensitive (sos) mutants, we showed that salt-induced root hair plastic response is caused by ion disequilibrium and it appears to be adaptive mechanism. Based on the most recent discoveries, we propose here that chromatin remodeling and epigenetic control may be the basis for cell fate changes and the ultimately adaptive plasticity in response to transient changes of environmental conditions.