scholarly journals The MYB36 transcription factor orchestrates Casparian strip formation

2015 ◽  
Vol 112 (33) ◽  
pp. 10533-10538 ◽  
Author(s):  
Takehiro Kamiya ◽  
Monica Borghi ◽  
Peng Wang ◽  
John M. C. Danku ◽  
Lothar Kalmbach ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Ectopic Expression ◽  
Casparian Strip ◽  
Strip Domain ◽  
Genes Encoding ◽  
Casparian Strips ◽  
Endodermal Cells ◽  
Respiratory Burst Oxidase ◽  
Strip Formation

The endodermis in roots acts as a selectivity filter for nutrient and water transport essential for growth and development. This selectivity is enabled by the formation of lignin-based Casparian strips. Casparian strip formation is initiated by the localization of the Casparian strip domain proteins (CASPs) in the plasma membrane, at the site where the Casparian strip will form. Localized CASPs recruit Peroxidase 64 (PER64), a Respiratory Burst Oxidase Homolog F, and Enhanced Suberin 1 (ESB1), a dirigent-like protein, to assemble the lignin polymerization machinery. However, the factors that control both expression of the genes encoding this biosynthetic machinery and its localization to the Casparian strip formation site remain unknown. Here, we identify the transcription factor, MYB36, essential for Casparian strip formation. MYB36 directly and positively regulates the expression of the Casparian strip genes CASP1, PER64, and ESB1. Casparian strips are absent in plants lacking a functional MYB36 and are replaced by ectopic lignin-like material in the corners of endodermal cells. The barrier function of Casparian strips in these plants is also disrupted. Significantly, ectopic expression of MYB36 in the cortex is sufficient to reprogram these cells to start expressing CASP1–GFP, correctly localize the CASP1–GFP protein to form a Casparian strip domain, and deposit a Casparian strip-like structure in the cell wall at this location. These results demonstrate that MYB36 is controlling expression of the machinery required to locally polymerize lignin in a fine band in the cell wall for the formation of the Casparian strip.

scholarly journals Laccase3-based extracellular domain provides possible positional information for directing Casparian strip formation inArabidopsis

2020 ◽  
Vol 117 (27) ◽  
pp. 15400-15402 ◽  
Author(s):  
Yan Zhuang ◽  
Daqing Zuo ◽  
Yihan Tao ◽  
Huaqing Cai ◽  
Lei Li
Keyword(s):  
Cell Wall ◽  
Tight Junction ◽  
Positional Information ◽  
Extracellular Domain ◽  
Multicopper Oxidase ◽  
Plant Roots ◽  
Membrane Domain ◽  
Casparian Strip ◽  
Endodermal Cells ◽  
Strip Formation

The Casparian strip (CS) is a tight junction-like structure formed by lignin impregnation on the walls of endodermal cells in plant roots. The CS membrane domain (CSDM), demarked by the CASP proteins, is important for orienting lignification enzymes. Here, we report that an endodermis-expressed multicopper oxidase, LACCASE3 (LAC3) inArabidopsis, locates to the interface between lignin domains and the cell wall during early CS development prior to CASP1 localizing to CSDMand eventually flanks the mature CS. Pharmacological perturbation of LAC3 causes dispersed localization of CASP1 and compensatory ectopic lignification. These results support the existence of a LAC3-based CS wall domain which coordinates with CSDMto provide bidirectional positional information that guides precise CS lignification.

Ectopic expression of a R2R3 MYB transcription factor of dove tree (Davidia involucrata) aggravates seed abortion in Arabidopsis thaliana

2020 ◽  
Vol 47 (5) ◽  
pp. 454
Author(s):  
Jian Li ◽  
Tian Chen ◽  
Fengzhen Huang ◽  
Penghui Dai ◽  
Fuxiang Cao ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factor ◽  
Transgenic Plants ◽  
Ectopic Expression ◽  
Myb Transcription Factor ◽  
Seed Abortion ◽  
Transgenic Seeds ◽  
Genes Encoding ◽  
Colour Changes ◽  
R2r3 Myb

Serious seed abortion of dove tree (Davidia involucrate Baill.) is one of the critical factors leading to the low fecundity of this species. Seed abortion is a complicated process and various factors have been verified to synergistically determine the fate of seeds. To reveal the mechanism of seed abortion in D. involucrata, we performed transcriptome analysis in normal and abortive seeds of D. involucrata. According to the transcriptome data, we noticed that most of the genes encoding a MYB transcription factor were predominantly expressed in abortive seeds. Among these, a gene named DiMYB1 was selected and its function was validated in this study. Overexpression of DiMYB1 resulted in obviously reduced viability of transgenic seeds and seedlings, and caused a significantly higher seed abortion rate. The vegetative growth of transgenic plants was hindered, resulting in an earlier flowering time. In addition, colour changes occurred in transgenic plants. Some transgenic sprouts, stems and pods appeared purple instead of green in colour. Our finding demonstrated that DiMYB1 participates in multiple plant developmental processes, especially in seed development in Arabidopsis thaliana (L.) Heynh., which indicated the similar role of this gene in D. involucrata.

Demonstration of a complete Casparian strip in Avena and Ipomoea by a fluorescent staining technique

1969 ◽  
Vol 47 (12) ◽  
pp. 1869-1871 ◽  
Author(s):  
D. R. Peirson ◽  
E. B. Dumbroff
Keyword(s):  
Staining Technique ◽  
New Combination ◽  
High Contrast ◽  
Fluorescent Staining ◽  
Casparian Strip ◽  
Casparian Strips ◽  
Endodermal Cells

A new combination of embedding material and high contrast stain has provided the means for demonstrating, photographically, tangential sections of endodermal cells showing complete Casparian strips.

scholarly journals OsCASP1 is required for Casparian strip formation at endodermal cells of rice roots for selective uptake of mineral elements

2019 ◽  
pp. tpc.00296.2019 ◽  
Author(s):  
Zhigang Wang ◽  
Naoki Yamaji ◽  
Sheng Huang ◽  
Xiang Zhang ◽  
Mingxing Shi ◽  
...  
Keyword(s):  
Mineral Elements ◽  
Selective Uptake ◽  
Rice Roots ◽  
Casparian Strip ◽  
Endodermal Cells ◽  
Strip Formation

scholarly journals Role of Transcription Factor CaNdt80p in Cell Separation, Hyphal Growth, and Virulence in Candida albicans

2010 ◽  
Vol 9 (4) ◽  
pp. 634-644 ◽  
Author(s):  
Adnane Sellam ◽  
Christopher Askew ◽  
Elias Epp ◽  
Faiza Tebbji ◽  
Alaka Mullick ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Candida Albicans ◽  
Cell Separation ◽  
Hyphal Growth ◽  
Functional Domain ◽  
Transcription Factor Family ◽  
Content Type ◽  
Genes Encoding

ABSTRACT The NDT80/PhoG transcription factor family includes ScNdt80p, a key modulator of the progression of meiotic division in Saccharomyces cerevisiae. In Candida albicans, a member of this family, CaNdt80p, modulates azole sensitivity by controlling the expression of ergosterol biosynthesis genes. We previously demonstrated that CaNdt80p promoter targets, in addition to ERG genes, were significantly enriched in genes related to hyphal growth. Here, we report that CaNdt80p is indeed required for hyphal growth in response to different filament-inducing cues and for the proper expression of genes characterizing the filamentous transcriptional program. These include noteworthy genes encoding cell wall components, such as HWP1, ECE1, RBT4, and ALS3. We also show that CaNdt80p is essential for the completion of cell separation through the direct transcriptional regulation of genes encoding the chitinase Cht3p and the cell wall glucosidase Sun41p. Consistent with their hyphal defect, ndt80 mutants are avirulent in a mouse model of systemic candidiasis. Interestingly, based on functional-domain organization, CaNdt80p seems to be a unique regulator characterizing fungi from the CTG clade within the subphylum Saccharomycotina. Therefore, this study revealed a new role of the novel member of the fungal NDT80 transcription factor family as a regulator of cell separation, hyphal growth, and virulence.

scholarly journals Overexpression of OsCASP1 Improves Calcium Tolerance in Rice

2021 ◽  
Vol 22 (11) ◽  
pp. 6002
Author(s):  
Zhigang Wang ◽  
Zhiwei Chen ◽  
Xiang Zhang ◽  
Qiuxing Wei ◽  
Yafeng Xin ◽  
...  
Keyword(s):  
Xylem Sap ◽  
Essential Metals ◽  
Wild Type ◽  
Endodermal Cell ◽  
Casparian Strip ◽  
Strip Domain ◽  
Cell Layers ◽  
Apoplastic Barrier ◽  
Apoplastic Pathway ◽  
Endodermal Cells

The Casparian strip domain protein 1 (OsCASP1) is necessary for the formation of the Casparian strip (CS) in the rice endodermis. It also controls Ca2+ transport to the stele. Here, we demonstrated that OsCASP1 overexpression enhanced Ca tolerance in rice. Under normal conditions, OsCASP1-overexpressed lines showed similar concentrations of essential metals in the roots and shoots compared to the wild type, while under high Ca conditions, Ca in the roots, shoots, and xylem sap of the OsCASP1-overexpressed lines was significantly decreased. This did not apply to other essential metals. Ca-inhibited growth was significantly alleviated in the OsCASP1-overexpressed lines. Furthermore, OsCASP1 overexpression resulted in earlier formation of both the CS and functional apoplastic barrier in the endodermis but did not induce ectopic CS formation in non-endodermal cell layers and affect suberin accumulation in the endodermis. These results indicate that the overexpression of OsCASP1 promotes CS formation in endodermal cells and inhibits Ca2+ transport by the apoplastic pathway, restricting Ca accumulation in the roots and shoots under high Ca conditions. Taken together, the results suggest that OsCASP1 overexpression is an effective way to improve rice adaptation to high Ca environments.

scholarly journals Molecular shifts in limb identity underlie development of feathered feet in two domestic avian species

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Eric T Domyan ◽  
Zev Kronenberg ◽  
Carlos R Infante ◽  
Anna I Vickrey ◽  
Sydney A Stringham ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Ectopic Expression ◽  
Single Species ◽  
Specific Transcription Factor ◽  
Regulatory Changes ◽  
Genes Encoding ◽  
Domestic Pigeons ◽  
Phenotypic Convergence

Birds display remarkable diversity in the distribution and morphology of scales and feathers on their feet, yet the genetic and developmental mechanisms governing this diversity remain unknown. Domestic pigeons have striking variation in foot feathering within a single species, providing a tractable model to investigate the molecular basis of skin appendage differences. We found that feathered feet in pigeons result from a partial transformation from hindlimb to forelimb identity mediated by cis-regulatory changes in the genes encoding the hindlimb-specific transcription factor Pitx1 and forelimb-specific transcription factor Tbx5. We also found that ectopic expression of Tbx5 is associated with foot feathers in chickens, suggesting similar molecular pathways underlie phenotypic convergence between these two species. These results show how changes in expression of regional patterning genes can generate localized changes in organ fate and morphology, and provide viable molecular mechanisms for diversity in hindlimb scale and feather distribution.

scholarly journals The zinc cluster transcription factor Rha1 is a positive filamentation regulator in Candida albicans

2020 ◽  
Author(s):  
Raha Parvizi Omran ◽  
Chris Law ◽  
Vanessa Dumeaux ◽  
Joachim Morschhäuser ◽  
Malcolm Whiteway
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Candida Albicans ◽  
Transcription Factors ◽  
Transcriptional Profiling ◽  
Hyphal Growth ◽  
Growth Conditions ◽  
Hyphal Development ◽  
Zinc Cluster ◽  
Genes Encoding

AbstractZinc cluster transcription factors are essential fungal specific regulators of gene expression. In the dimorphic pathogen Candida albicans, they control processes ranging from metabolism and stress adaptation to mating, virulence, and antifungal resistance. Here, we have identified the gene CaORF19.1604 as encoding a zinc cluster transcription factor that acts as a regulator of filament development. Hyperactivation of CaORF19.1604, which we have named RHA1 for Regulator of Hyphal Activity, leads to a wrinkled colony morphology under non-hyphal growth conditions, to pseudohyphal growth and filament formation, to invasiveness and enhanced biofilm formation.  Cells with activated Rha1 are sensitive to cell wall modifying agents such as Congo red and the echinocandin drug caspofungin but show normal sensitivity to fluconazole. RNA-sequencing-based transcriptional profiling of the activated Rha1 strain reveals the up-regulation of genes for core filamentation and cell-wall-adhesion-related proteins such as Als1, Als3, Ece1, and Hwp1. Upregulation is also seen for the genes for the hyphal-inducing transcription factors Brg1 and Ume6 and genes encoding several enzymes involved in arginine metabolism, while downregulation is seen for the hyphal repressor Nrg1. The deletion of BRG1 blocks the filamentation caused by activated Rha1, while null mutants of UME6 result in a partial block. Deletion of RHA1 can partially reduce healthy hyphal development triggered by environmental conditions such as Spider medium or serum at 37°C.In contrast to the limited effect of either single mutant, the double rha1 ume6 deletion strain is totally defective in both serum and Spider medium stimulated hyphal development. While the loss of Brg1 function blocks serum-stimulated hyphal development, this block can be significantly bypassed by Rha1 hyperactivity, and the combination of Rha1 hyperactivity and serum addition can generate significant polarization in even brg1 ume6 double mutants. Our results thus suggest that in response to external signals, Rha1 functions to facilitate the switch from an Nrg1 controlled yeast state to a Brg1/Ume6 regulated hyphal state.Author SummaryCandida albicans is the predominant human fungal pathogen, generating a mortality rate of 40% in systemically infected patients. The ability of Candida albicans to change its morphology is a determinant of its tissue penetration and invasion in response to variant host-related stimuli. The regulatory mechanism for filamentation includes a complex network of transcription factors that play roles in regulating hyphae associated genes. We identify here a new regulator of filamentation from the zinc cluster transcription factor family. We present evidence suggesting that this transcription factor assists the Nrg1/Brg1 switch regulating hyphal development.

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