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

Abstract

of cell division, patterning and differentiation in Arabidopsis root epidermal cells. [4][5][6][7][8][9][10][11][12][13] In the Arabidopsis root, meristematic epidermis cells divide into a particular pattern 4 . The cells locating over the anticlinal wall separating two cortical cells differentiate into cells that normally bear root hairs (trichoblasts), whereas those lied over the outer periclinal cortical cell walls become hairless cells (atrichoblasts). 4,5 It is known that root epidermal cell fate decisions are trigged by a positional cue from the underlying cortical cell layer, and cell fate specification and subsequent cell differentiation into trichoblasts and atrichoblasts are regulated by a complex transcription factor network that regulates the expression of GL2. Expression of GL2 then determines hair or non-hair cell fate, and it is only expressed in atrichoblasts. [6][7][8] This particular cell patterning is established during embryogenesis and maintained during postembryonically. 9-12 Recent findings also revealed that root epidermal cell division, patterning and differentiation are also modulated through regulation of root epidermis patterning gene expression by histone modification and chromatin reorganization. [13][14][15] Chromatin restructuring at GL2 locus appears to be essential for position-dependent cell fate specification and root epidermal development. Importantly, GL2 expression and cell fate determination are reset in each cell cycle. It is proposed that this regulatory mechanism of cell fate decision may be the molecular basis for cellular plasticity of root epidermis. [13][14][15] Our research examined the developmental plasticity of Arabidopsis root epidermis induced by salt stress. 16 We have shown that salt stress markedly influence root epidermis development and subsequent root hair development. Salt stress reduces the number of non-hair cells and disrupts the determined pattern of root epidermis. The normal pattern of root epidermis is composed of two rows of hairless cells and one row of hair cells next to them under normal conditions. However, root epidermis cell pattern become abnormal when exposed to salt stress (100 mM NaCl) consisting of one row hair by one row of non-hair cells. This observation indicates that salt stress changes root epidermal cell proliferation. Interestingly, by analyzing GL2 expression, we found that salt stress alters cell fate specification. Under salt stress, some trichoblasts become atrichoblasts, because GL2 expression was detected in these cells although they are still in the hair cells position. It is apparent that salt stress disturbed the position-dependent expression pattern of GL2 and subsequent cell fate decision. As a result, number of root hairs was substantially 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 study...

Molecular cloning and characterization of salt overly sensitive gene promoter from Brassica juncea (BjSOS2)

“…Another motif involved in the regulation of genes responsive to water stress, named MYBCORE was also detected (at position -117). Further, auxin responsive cis-acting elements, i.e., Aux RR-core and TGA-elements, were also present in the BjSOS2 promoter (at positions -472 and -411, respectively) which is in agreement with the earlier findings that have suggested a role of SOS signaling pathway in plastic development of root hairs under salt stress [21,22].…”

Arsenic-induced morphogenic response in roots of arsenic hyperaccumulator fern Pteris vittata

“…In addition, environmental signals, such as arsenic exposure, may be one of the components contributing to cell fate switches and reprogramming from a non-hair cell to a root hair [22] with the aim of creating an avenue for the adjustment of the cellular metabolism to the environment. It is likely that root meristematic epidermal cells in P. vittata, as in Arabidopsis, have the capacity to change their determined cell-fate by regulating the activity of homeotic genes during development in response to varying environmental stimuli as well as by epigenetic control, representing the bases for establishing or maintaining determined chromatin states and ultimately adaptive plasticity in response to transient changes of environmental conditions [1,[27][28][29].…”

“…Developmental plasticity is essential for stress adaptation in plants, as sessile organisms have to cope with the dynamics of transiently changing environmental conditions during their lifetime [1]. A key role in this plasticity is played by a range of protective responses, many of which are morphogenic changes which have been observed in many plants exposed to suboptimal environmental conditions, following exposure to many different stressors (e.g.…”

Comprehensive characterization and RNA-Seq profiling of the HD-Zip transcription factor family in soybean (Glycine max) during dehydration and salt stress

“…Glyma1343350 and Glyma07g02220 are orthologs of the Arabidopsis gene GLABRA2, which has been functionally characterized and shown to regulate root hair development, and cell specification of root epidermis in salt stressed plants [78, 110–112]. …”