scholarly journals Brassinosteroids control root epidermal cell fate via direct regulation of a MYB-bHLH-WD40 complex by GSK3-like kinases

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Yinwei Cheng ◽  
Wenjiao Zhu ◽  
Yuxiao Chen ◽  
Shinsaku Ito ◽  
Tadao Asami ◽  
...  
Keyword(s):  
Hair Cell ◽  
Cell Fate ◽  
Epidermal Cell ◽  
Hair Cells ◽  
Root Hair ◽  
Cell Nuclei ◽  
Brassinosteroid Signaling ◽  
Root Hair Formation ◽  
A Cell ◽  
Transcriptional Complex

In Arabidopsis, root hair and non-hair cell fates are determined by a MYB-bHLH-WD40 transcriptional complex and are regulated by many internal and environmental cues. Brassinosteroids play important roles in regulating root hair specification by unknown mechanisms. Here, we systematically examined root hair phenotypes in brassinosteroid-related mutants, and found that brassinosteroid signaling inhibits root hair formation through GSK3-like kinases or upstream components. We found that with enhanced brassinosteroid signaling, GL2, a cell fate marker for non-hair cells, is ectopically expressed in hair cells, while its expression in non-hair cells is suppressed when brassinosteroid signaling is reduced. Genetic analysis demonstrated that brassinosteroid-regulated root epidermal cell patterning is dependent on the WER-GL3/EGL3-TTG1 transcriptional complex. One of the GSK3-like kinases, BIN2, interacted with and phosphorylated EGL3, and EGL3s mutated at phosphorylation sites were retained in hair cell nuclei. BIN2 phosphorylated TTG1 to inhibit the activity of the WER-GL3/EGL3-TTG1 complex. Thus, our study provides insights into the mechanism of brassinosteroid regulation of root hair patterning.

scholarly journals GLABRA2, a Common Regulator for Epidermal Cell Fate Determination and Anthocyanin Biosynthesis in Arabidopsis

2019 ◽  
Vol 20 (20) ◽  
pp. 4997 ◽  
Author(s):  
Siyu Chen ◽  
Shucai Wang
Keyword(s):  
Transcription Factor ◽  
Cell Fate ◽  
Epidermal Cell ◽  
Root Hair ◽  
Anthocyanin Biosynthesis ◽  
Research Progress ◽  
Cell Fate Determination ◽  
Fate Determination ◽  
Root Hair Formation ◽  
Hair Formation

Epidermal cell fate determination—including trichome initiation, root hair formation, and flavonoid and mucilage biosynthesis in Arabidopsis (Arabidopsis thaliana)—are controlled by a similar transcriptional regulatory network. In the network, it has been proposed that the MYB-bHLH-WD40 (MBW) activator complexes formed by an R2R3 MYB transcription factor, a bHLH transcription factor and the WD40-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1) regulate the expression of downstream genes required for cell fate determination, flavonoid or mucilage biosynthesis, respectively. In epidermal cell fate determination and mucilage biosynthesis, the MBW activator complexes activate the expression of GLABRA2 (GL2). GL2 is a homeodomain transcription factor that promotes trichome initiation in shoots, mucilage biosynthesis in seeds, and inhibits root hair formation in roots. The MBW activator complexes also activate several R3 MYB genes. The R3 MYB proteins, in turn, competing with the R2R3 MYBs for binding bHLH transcription factors, therefore inhibiting the formation of the MBW activator complexes, lead to the inhibition of trichome initiation in shoots, and promotion of root hair formation in roots. In flavonoid biosynthesis, the MBW activator complexes activate the expression of the late biosynthesis genes in the flavonoid pathway, resulting in the production of anthocyanins or proanthocyanidins. Research progress in recent years suggests that the transcriptional regulatory network that controls epidermal cell fate determination and anthocyanin biosynthesis in Arabidopsis is far more complicated than previously thought. In particular, more regulators of GL2 have been identified, and GL2 has been shown to be involved in the regulation of anthocyanin biosynthesis. This review focuses on the research progress on the regulation of GL2 expression, and the roles of GL2 in the regulation of epidermal cell fate determination and anthocyanin biosynthesis in Arabidopsis.

scholarly journals A cell surface arabinogalactan‐peptide influences root hair cell fate

2020 ◽  
Vol 227 (3) ◽  
pp. 732-743 ◽  
Author(s):  
Cecilia Borassi ◽  
Javier Gloazzo Dorosz ◽  
Martiniano M. Ricardi ◽  
Mariana Carignani Sardoy ◽  
Laercio Pol Fachin ◽  
...  
Keyword(s):  
Cell Surface ◽  
Hair Cell ◽  
Cell Fate ◽  
Root Hair ◽  
Root Hair Cell ◽  
A Cell

Hes1 is a negative regulator of inner ear hair cell differentiation

Development ◽  
2000 ◽  
Vol 127 (21) ◽  
pp. 4551-4560 ◽  
Author(s):  
J.L. Zheng ◽  
J. Shou ◽  
F. Guillemot ◽  
R. Kageyama ◽  
W.Q. Gao
Keyword(s):  
Cell Differentiation ◽  
Hair Cell ◽  
Inner Ear ◽  
Cell Fate ◽  
Hair Cells ◽  
Outer Hair Cells ◽  
Negative Regulator ◽  
Pcr Analysis ◽  
Loss Of Function ◽  
Hair Cell Differentiation

Hair cell fate determination in the inner ear has been shown to be controlled by specific genes. Recent loss-of-function and gain-of-function experiments have demonstrated that Math1, a mouse homolog of the Drosophila gene atonal, is essential for the production of hair cells. To identify genes that may interact with Math1 and inhibit hair cell differentiation, we have focused on Hes1, a mammalian hairy and enhancer of split homolog, which is a negative regulator of neurogenesis. We report here that targeted deletion of Hes1 leads to formation of supernumerary hair cells in the cochlea and utricle of the inner ear. RT-PCR analysis shows that Hes1 is expressed in inner ear during hair cell differentiation and its expression is maintained in adulthood. In situ hybridization with late embryonic inner ear tissue reveals that Hes1 is expressed in supporting cells, but not hair cells, of the vestibular sensory epithelium. In the cochlea, Hes1 is selectively expressed in the greater epithelial ridge and lesser epithelial ridge regions which are adjacent to inner and outer hair cells. Co-transfection experiments in postnatal rat explant cultures show that overexpression of Hes1 prevents hair cell differentiation induced by Math1. Therefore Hes1 can negatively regulate hair cell differentiation by antagonizing Math1. These results suggest that a balance between Math1 and negative regulators such as Hes1 is crucial for the production of an appropriate number of inner ear hair cells.

scholarly journals CLE14 peptide signaling in Arabidopsis root hair cell fate determination

2018 ◽  
Vol 35 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Naoto Hayashi ◽  
Takuya Tetsumura ◽  
Shinichiro Sawa ◽  
Takuji Wada ◽  
Rumi Tominaga-Wada
Keyword(s):  
Hair Cell ◽  
Cell Fate ◽  
Root Hair ◽  
Cell Fate Determination ◽  
Arabidopsis Root ◽  
Fate Determination ◽  
Peptide Signaling ◽  
Root Hair Cell

scholarly journals Supra-physiological levels of Gibberellins/DELLAs alter the patterning, morphology and abundance of root hairs in root tips of A. thaliana seedlings

2021 ◽  
Author(s):  
Iva McCarthy-Suarez
Keyword(s):  
Gene Expression ◽  
Cell Fate ◽  
Epidermal Cell ◽  
Root Hair ◽  
Root Hairs ◽  
Root Tip ◽  
Spatial Patterning ◽  
Root Tips ◽  
Root Epidermis

In spite of the known role of gibberellins (GAs), and of their antagonistic proteins, the DELLAs, in leaf hair production, no investigations, however, have assessed their hypothetical function in the production of root hairs. To this aim, the effects of supra-physiological levels of GAs/DELLAs on the spatial patterning of gene expression of the root hair (CPC) and root non-hair (GL2, EGL3 and WER) epidermal cell fate markers, as well as on the distribution, morphology and abundance of root hairs, were studied in root tips of 5-day-old A. thaliana seedlings. Results showed that excessive levels of GAs/DELLAs impaired the spatial patterning of gene expression of the root hair/non-hair epidermal cell fate markers, as well as the arrangement, shape and frequency of root hairs, giving rise to ectopic hairs and ectopic non-hairs, two-haired cells, two-tipped hairs, branched hairs, longer and denser hairs near the root tip under excessive DELLAs, and shorter and scarcer hairs near the root tip under excessive GAs. However, when the gai-1 (GA-insensitive-1) DELLA mutant protein was specifically over-expressed at the root epidermis, no changes in the patterning or abundance of root hairs occurred. Thus, these results suggest that, in seedlings of A. thaliana, the GAs/DELLAs might have a role in regulating the patterning, morphology and abundance of root hairs by acting from the sub-epidermal tissues of the root.

The homeobox gene GLABRA2 is required for position-dependent cell differentiation in the root epidermis of Arabidopsis thaliana

Development ◽  
1996 ◽  
Vol 122 (4) ◽  
pp. 1253-1260 ◽  
Author(s):  
J.D. Masucci ◽  
W.G. Rerie ◽  
D.R. Foreman ◽  
M. Zhang ◽  
M.E. Galway ◽  
...  
Keyword(s):  
Epidermal Cell ◽  
Hair Cells ◽  
Root Hair ◽  
Root Hairs ◽  
Homeobox Gene ◽  
Epidermal Cells ◽  
Wild Type ◽  
Cell Identity ◽  
Root Epidermis ◽  
Root Hair Cells

The role of the Arabidopsis homeobox gene, GLABRA 2 (GL2), in the development of the root epidermis has been investigated. The wild-type epidermis is composed of two cell types, root-hair cells and hairless cells, which are located at distinct positions within the root, implying that positional cues control cell-type differentiation. During the development of the root epidermis, the differentiating root-hair cells (trichoblasts) and the differentiating hairless cells (atrichoblasts) can be distinguished by their cytoplasmic density, vacuole formation, and extent of elongation. We have determined that mutations in the GL2 gene specifically alter the differentiation of the hairless epidermal cells, causing them to produce root hairs, which indicates that GL2 affects epidermal cell identity. Detailed analyses of these differentiating cells showed that, despite forming root hairs, they are similar to atrichoblasts of the wild type in their cytoplasmic characteristics, timing of vacuolation, and extent of cell elongation. The results of in situ nucleic acid hybridization and GUS reporter gene fusion studies show that the GL2 gene is preferentially expressed in the differentiating hairless cells of the wild type, during a period in which epidermal cell identity is believed to be established. These results indicate that the GL2 homeodomain protein normally regulates a subset of the processes that occur during the differentiation of hairless epidermal cells of the Arabidopsis root. Specifically, GL2 appears to act in a cell-position-dependent manner to suppress hair formation in differentiating hairless cells.

Cell specification in theArabidopsisroot epidermis requires the activity ofECTOPIC ROOT HAIR 3– a katanin-p60 protein

Development ◽  
2002 ◽  
Vol 129 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Melanie Webb ◽  
Stefan Jouannic ◽  
Julia Foreman ◽  
Paul Linstead ◽  
Liam Dolan
Keyword(s):  
Molecular Markers ◽  
Cell Fate ◽  
Hair Cells ◽  
Root Hair ◽  
Plant Cell Wall ◽  
Positional Information ◽  
Cell Fates ◽  
Arabidopsis Root ◽  
Radial Cell ◽  
Cell Layers

The Arabidopsis root is composed of radial cell layers, each with distinct identities. The epidermal layer is composed of rows of hair cells flanked on either side by rows of non-hair epidermal cells. The development of hair and non-hair cells is dependent on domains of positional information with strict boundaries. The pattern of cell differentiation and the expression of molecular markers of cell fate is altered in the ectopic root hair 3 (erh3) mutant epidermis indicating that ERH3 is required for the specification of cell fates from early in development (in the meristem) through differentiation. Furthermore the expression of molecular markers indicates that the specification of cell identities is defective within other radial cell layers. ERH3 encodes a p60 katanin protein that is expressed throughout the plant. Katanin proteins are known to sever microtubules, and have a role in the organisation of the plant cell wall since mutants with decreased katanin activity have been shown to have defective walls. We suggest that microtubules are involved in the specification of cell identities in cells of the Arabidopsis root. Microtubules may be required for the localization of positional cues in the wall that have previously been shown to operate in the development of the root epidermis. Alternatively microtubules may be involved in another as yet undefined process required for the specification of cell identity in plants.

EIN3 and RSL4 interfere with an MYB–bHLH–WD40 complex to mediate ethylene-induced ectopic root hair formation in Arabidopsis

2021 ◽  
Vol 118 (51) ◽  
pp. e2110004118
Author(s):  
Yuping Qiu ◽  
Ran Tao ◽  
Ying Feng ◽  
Zhina Xiao ◽  
Dan Zhang ◽  
...  
Keyword(s):  
Root Hair ◽  
Molecular Mechanisms ◽  
Protein Complexes ◽  
Root Hairs ◽  
Elongation Factor ◽  
Root Hair Development ◽  
Root Hair Formation ◽  
Hair Development ◽  
Transcriptional Complex ◽  
Hair Formation

The alternating cell specifications of root epidermis to form hair cells or nonhair cells in Arabidopsis are determined by the expression level of GL2, which is activated by an MYB–bHLH–WD40 (WER–GL3–TTG1) transcriptional complex. The phytohormone ethylene (ET) has a unique effect of inducing N-position epidermal cells to form root hairs. However, the molecular mechanisms underlying ET-induced ectopic root hair development remain enigmatic. Here, we show that ET promotes ectopic root hair formation through down-regulation of GL2 expression. ET-activated transcription factors EIN3 and its homolog EIL1 mediate this regulation. Molecular and biochemical analyses further revealed that EIN3 physically interacts with TTG1 and interferes with the interaction between TTG1 and GL3, resulting in reduced activation of GL2 by the WER–GL3–TTG1 complex. Furthermore, we found through genetic analysis that the master regulator of root hair elongation, RSL4, which is directly activated by EIN3, also participates in ET-induced ectopic root hair development. RSL4 negatively regulates the expression of GL2, likely through a mechanism similar to that of EIN3. Therefore, our work reveals that EIN3 may inhibit gene expression by affecting the formation of transcription-activating protein complexes and suggests an unexpected mutual inhibition between the hair elongation factor, RSL4, and the hair specification factor, GL2. Overall, this study provides a molecular framework for the integration of ET signaling and intrinsic root hair development pathway in modulating root epidermal cell specification.

Notch signaling regulates the pattern of auditory hair cell differentiation in mammals

Development ◽  
2000 ◽  
Vol 127 (15) ◽  
pp. 3373-3383 ◽  
Author(s):  
A. Zine ◽  
T.R. Van De Water ◽  
F. de Ribaupierre
Keyword(s):  
Cell Differentiation ◽  
Hair Cell ◽  
Notch Signaling ◽  
Cell Fate ◽  
Hair Cells ◽  
Expression Patterns ◽  
Sensory Epithelium ◽  
Supporting Cells ◽  
Hair Cell Differentiation ◽  
Notch1 Signaling Pathway

The development of the mammalian cochlea is an example of patterning in the peripheral nervous system. Sensory hair cells and supporting cells in the cochlea differentiate via regional and cell fate specification. The Notch signaling components shows both distinct and overlapping expression patterns of Notch1 receptor and its ligands Jagged1 (Jag1) and Jagged2 (Jag2) in the developing auditory epithelium of the rat. On embryonic day 16 (E16), many precursor cells within the Kolliker's organ immunostained for the presence of both Notch1 and Jag1, while the area of hair cell precursors did not express either Notch1 and Jag1. During initial events of hair cell differentiation between E18 and birth, Notch1 and Jag1 expression predominated in supporting cells and Jag2 in nascent hair cells. Early after birth, Jag2 expression decreased in hair cells while the pattern of Notch1 expression now included both supporting cells and hair cells. We show that the normal pattern of hair cell differentiation is disrupted by alteration of Notch signaling. A decrease of either Notch1 or Jag1 expression by antisense oligonucleotides in cultures of the developing sensory epithelium resulted in an increase in the number of hair cells. Our data suggest that the Notch1 signaling pathway is involved in a complex interplay between the consequences of different ligand-Notch1 combinations during cochlear morphogenesis and the phases of hair cell differentiation.

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