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

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.

2015 ◽  
Vol 112 (33) ◽  
pp. 10533-10538 ◽  
Author(s):  
Takehiro Kamiya ◽  
Monica Borghi ◽  
Peng Wang ◽  
John M. C. Danku ◽  
Lothar Kalmbach ◽  
...  

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.


2019 ◽  
pp. tpc.00296.2019 ◽  
Author(s):  
Zhigang Wang ◽  
Naoki Yamaji ◽  
Sheng Huang ◽  
Xiang Zhang ◽  
Mingxing Shi ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guilhem Reyt ◽  
Priya Ramakrishna ◽  
Isai Salas-González ◽  
Satoshi Fujita ◽  
Ashley Love ◽  
...  

AbstractLignin is a complex polymer deposited in the cell wall of specialised plant cells, where it provides essential cellular functions. Plants coordinate timing, location, abundance and composition of lignin deposition in response to endogenous and exogenous cues. In roots, a fine band of lignin, the Casparian strip encircles endodermal cells. This forms an extracellular barrier to solutes and water and plays a critical role in maintaining nutrient homeostasis. A signalling pathway senses the integrity of this diffusion barrier and can induce over-lignification to compensate for barrier defects. Here, we report that activation of this endodermal sensing mechanism triggers a transcriptional reprogramming strongly inducing the phenylpropanoid pathway and immune signaling. This leads to deposition of compensatory lignin that is chemically distinct from Casparian strip lignin. We also report that a complete loss of endodermal lignification drastically impacts mineral nutrients homeostasis and plant growth.


Nature ◽  
2011 ◽  
Vol 473 (7347) ◽  
pp. 380-383 ◽  
Author(s):  
Daniele Roppolo ◽  
Bert De Rybel ◽  
Valérie Dénervaud Tendon ◽  
Alexandre Pfister ◽  
Julien Alassimone ◽  
...  

2018 ◽  
Vol 3 (01) ◽  
pp. 62-69
Author(s):  
Eka Corneliyawati ◽  
Massora Massora ◽  
Khikmah Khikmah ◽  
As’ad Syamsul Arifin

The rhizosphere is the zone of soil surrounding a plant root where plant roots, soil and the soil biota interact with each other. Chitinolytic fungi has been effectively used in biological control agens. The chitinase activity causes lysis of the fungi cell wall pathogen. The aim of the research was to find optimization of activity chitinase enzyme from rhizosphere soil was conducted in vitro. Optimal growth chitinase production for TKR3 fungi isolate were concentration of chitin 0,2% (b/v), pH 5,5, temperature 30ºC, agitation 150 rpm and incubation time at four days. The optimum yield of chitinase production is influenced by fungal species and environmental conditions.


2019 ◽  
Vol 42 (6) ◽  
pp. 1788-1801 ◽  
Author(s):  
Chloé Champeyroux ◽  
Jorge Bellati ◽  
Marie Barberon ◽  
Valérie Rofidal ◽  
Christophe Maurel ◽  
...  

2020 ◽  
Vol 133 (22) ◽  
pp. jcs244830
Author(s):  
Kazunari Yamashita ◽  
Keiko Mizuno ◽  
Kana Furukawa ◽  
Hiroko Hirose ◽  
Natsuki Sakurai ◽  
...  

ABSTRACTCell polarity is essential for various asymmetric cellular events, and the partitioning defective (PAR) protein PAR3 (encoded by PARD3 in mammals) plays a unique role as a cellular landmark to establish polarity. In epithelial cells, PAR3 localizes at the subapical border, such as the tight junction in vertebrates, and functions as an apical determinant. Although we know a great deal about the regulators of PAR3 localization, how PAR3 is concentrated and localized to a specific membrane domain remains an important question to be clarified. In this study, we demonstrate that ASPP2 (also known as TP53BP2), which controls PAR3 localization, links PAR3 and protein phosphatase 1 (PP1). The ASPP2–PP1 complex dephosphorylates a novel phosphorylation site, Ser852, of PAR3. Furthermore, Ser852- or Ser889-unphosphorylatable PAR3 mutants form protein clusters, and ectopically localize to the lateral membrane. Concomitance of clustering and ectopic localization suggests that PAR3 localization is a consequence of local clustering. We also demonstrate that unphosphorylatable forms of PAR3 exhibited a low molecular turnover and failed to coordinate rapid reconstruction of the tight junction, supporting that both the phosphorylated and dephosphorylated states are essential for the functional integrity of PAR3.


2001 ◽  
Vol 12 (8) ◽  
pp. 2257-2274 ◽  
Author(s):  
Raul Rojas ◽  
Wily G. Ruiz ◽  
Som-Ming Leung ◽  
Tzuu-Shuh Jou ◽  
Gerard Apodaca

Polarized epithelial cells maintain the asymmetric composition of their apical and basolateral membrane domains by at least two different processes. These include the regulated trafficking of macromolecules from the biosynthetic and endocytic pathway to the appropriate membrane domain and the ability of the tight junction to prevent free mixing of membrane domain-specific proteins and lipids. Cdc42, a Rho family GTPase, is known to govern cellular polarity and membrane traffic in several cell types. We examined whether this protein regulated tight junction function in Madin-Darby canine kidney cells and pathways that direct proteins to the apical and basolateral surface of these cells. We used Madin-Darby canine kidney cells that expressed dominant-active or dominant-negative mutants of Cdc42 under the control of a tetracycline-repressible system. Here we report that expression of dominant-active Cdc42V12 or dominant-negative Cdc42N17 altered tight junction function. Expression of Cdc42V12 slowed endocytic and biosynthetic traffic, and expression of Cdc42N17 slowed apical endocytosis and basolateral to apical transcytosis but stimulated biosynthetic traffic. These results indicate that Cdc42 may modulate multiple cellular pathways required for the maintenance of epithelial cell polarity.


1971 ◽  
Vol 49 (1) ◽  
pp. 35-38 ◽  
Author(s):  
E. B. Dumbroff ◽  
D. R. Peirson

The endodermis, with its associated Casparian strip, is generally believed to act as an effective barrier to the passive movement of ions from the cortex to the xylem in young roots. However, several workers have suggested that the functional integrity of the endodermis might be somewhat impaired with the emergence of branch roots from the pericycle, thus providing pathways for the mass flow of water and ions into the stele. The present work was undertaken to examine the validity of this hypothesis.Sections of lateral roots embedded in glycol methacrylate were stained and examined by fluorescence microscopy, and a general picture of the relationship between branch root development and concomitant changes in the endodermis emerged. The endodermal cells of the parent root were found to maintain a continuous, unbroken, suberized layer over the surface of a very young lateral root, but with continued elongation there is a period when formation of the Casparian strip lags behind division of endodermal cells. It appears likely that, at this stage, water and ions can enter the stele of the parent root by mass flow.


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