scholarly journals Turgor Regulation in Osmotically Stressed Arabidopsis Epidermal Root Cells. Direct Support for the Role of Inorganic Ion Uptake as Revealed by Concurrent Flux and Cell Turgor Measurements

2002 ◽  
Vol 129 (1) ◽  
pp. 290-299 ◽  
Author(s):  
Sergey N. Shabala ◽  
Roger R. Lew
Keyword(s):  
Ion Uptake ◽  
Root Cells ◽  
Inorganic Ion ◽  
Turgor Regulation ◽  
Direct Support ◽  
Cell Turgor

Phloem water relations and root growth

2000 ◽  
Vol 27 (6) ◽  
pp. 539 ◽  
Author(s):  
Jeremy Pritchard ◽  
Sam Winch ◽  
Nick Gould
Keyword(s):  
Cell Expansion ◽  
Control Point ◽  
Turgor Pressure ◽  
Significant Proportion ◽  
Physiological Data ◽  
Solute Flux ◽  
Root Cells ◽  
Cell Turgor ◽  
The Relationship

In this paper the biophysical basis of cell expansion is described, paying particular attention to the waterrelations that underpin the process. The connection of growing root cells to the rest of the plant will be addressed and possible control points in the hardware identified. Examples of environmental modification of root extension, and therefore water and solute import, are given, and the relationship with current accepted theories of solute translocation discussed. The opportunities for delivery of solutes and water to be regulated by the growing root itself will be considered, in particular the dual role of cell wall loosening in decreasing both sink cell turgor and water potential. We conclude that a significant proportion of the water for cell expansion can enter growing root cells through the phloem. The physiological data presented rule out alterations in the turgor pressure difference between sieve element and cell as a modulator of solute flux. The plasmodesmata are identified as the major control point of solute flux along the symplastic pathway.

scholarly journals A novel putative microtubule-associated protein is involved in arbuscule development during arbuscular mycorrhiza formation

2021 ◽  
Author(s):  
Tania Ho-Plágaro ◽  
Raúl Huertas ◽  
María I Tamayo-Navarrete ◽  
Elison Blancaflor ◽  
Nuria Gavara ◽  
...  
Keyword(s):  
Plant Root ◽  
Arbuscular Mycorrhizal ◽  
Host Cells ◽  
Root Cells ◽  
Filament Dynamics ◽  
Fungal Structure ◽  
Genes Encoding ◽  
Associated Proteins ◽  
Mycorrhizal Development

Abstract The formation of arbuscular mycorrhizal (AM) symbiosis requires plant root host cells to undergo major structural and functional reprogramming in order to house the highly branched AM fungal structure for the reciprocal exchange of nutrients. These morphological modifications are associated with cytoskeleton remodelling. However, molecular bases and the role of microtubules (MTs) and actin filament dynamics during AM formation are largely unknown. In this study, the tomato tsb gene, belonging to a Solanaceae group of genes encoding MT-associated proteins for pollen development, was found to be highly expressed in root cells containing arbuscules. At earlier stages of mycorrhizal development, tsb overexpression enhanced the formation of highly developed and transcriptionally active arbuscules, while tsb silencing hampers the formation of mature arbuscules and represses arbuscule functionality. However, at later stages of mycorrhizal colonization, tsb OE roots accumulate fully developed transcriptionally inactive arbuscules, suggesting that the collapse and turnover of arbuscules might be impaired by TSB accumulation. Imaging analysis of the MT cytoskeleton in cortex root cells overexpressing tsb revealed that TSB is involved in MT-bundling. Taken together, our results provide unprecedented insights into the role of novel MT-associated protein in MT rearrangements throughout the different stages of the arbuscule life cycle.

scholarly journals Adaptation, Ecology, and Evolution of the Halophilic Stromatolite ArchaeonHalococcus hamelinensisInferred through Genome Analyses

Archaea ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Reema K. Gudhka ◽  
Brett A. Neilan ◽  
Brendan P. Burns
Keyword(s):  
Unknown Function ◽  
Energy Production ◽  
Extreme Environment ◽  
Evolutionary Significance ◽  
Base Pairs ◽  
Protein Coding ◽  
Inorganic Ion ◽  
Damage Repair ◽  
Genome Analyses

Halococcus hamelinensiswas the first archaeon isolated from stromatolites. These geomicrobial ecosystems are thought to be some of the earliest known on Earth, yet, despite their evolutionary significance, the role of Archaea in these systems is still not well understood. Detailed here is the genome sequencing and analysis of an archaeon isolated from stromatolites. The genome ofH. hamelinensisconsisted of 3,133,046 base pairs with an average G+C content of 60.08% and contained 3,150 predicted coding sequences or ORFs, 2,196 (68.67%) of which were protein-coding genes with functional assignments and 954 (29.83%) of which were of unknown function. Codon usage of theH. hamelinensisgenome was consistent with a highly acidic proteome, a major adaptive mechanism towards high salinity. Amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, ribosomal structure, and unknown function COG genes were overrepresented. The genome ofH. hamelinensisalso revealed characteristics reflecting its survival in its extreme environment, including putative genes/pathways involved in osmoprotection, oxidative stress response, and UV damage repair. Finally, genome analyses indicated the presence of putative transposases as well as positive matches of genes ofH. hamelinensisagainst various genomes of Bacteria, Archaea, and viruses, suggesting the potential for horizontal gene transfer.

ROLE OF ROOTSTOCKS ON ION UPTAKE OF TOMATO PLANTS GROWN UNDER SALINE CONDITIONS

2009 ◽  
pp. 637-642 ◽  
Author(s):  
G.B. Öztekin ◽  
C. Leonardi ◽  
E. Caturano ◽  
M. Martorana ◽  
Y. Tüzel
Keyword(s):  
Ion Uptake ◽  
Tomato Plants

scholarly journals Human cell transformation by combined lineage conversion and oncogene expression

Oncogene ◽  
2021 ◽  
Author(s):  
Biswajyoti Sahu ◽  
Päivi Pihlajamaa ◽  
Kaiyang Zhang ◽  
Kimmo Palin ◽  
Saija Ahonen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Liver Cancer ◽  
Human Cell ◽  
Genetic Disease ◽  
Cell Transformation ◽  
Human Fibroblasts ◽  
Driver Mutations ◽  
Primary Hepatocytes ◽  
Direct Support

AbstractCancer is the most complex genetic disease known, with mutations implicated in more than 250 genes. However, it is still elusive which specific mutations found in human patients lead to tumorigenesis. Here we show that a combination of oncogenes that is characteristic of liver cancer (CTNNB1, TERT, MYC) induces senescence in human fibroblasts and primary hepatocytes. However, reprogramming fibroblasts to a liver progenitor fate, induced hepatocytes (iHeps), makes them sensitive to transformation by the same oncogenes. The transformed iHeps are highly proliferative, tumorigenic in nude mice, and bear gene expression signatures of liver cancer. These results show that tumorigenesis is triggered by a combination of three elements: the set of driver mutations, the cellular lineage, and the state of differentiation of the cells along the lineage. Our results provide direct support for the role of cell identity as a key determinant in transformation and establish a paradigm for studying the dynamic role of oncogenic drivers in human tumorigenesis.

Abstract T MP102: Hotline Use for Recruitment Support in Acute Stroke Trials: Lessons learned To Date in Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH)-II

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Kathryn A France ◽  
Mushtaq Qureshi ◽  
Jessy Thomas ◽  
Emily Abbott ◽  
Logan Brau ◽  
...  
Keyword(s):  
Acute Stroke ◽  
Lessons Learned ◽  
Local Network ◽  
Drug Management ◽  
Safe Operation ◽  
Team Members ◽  
Clinical Support ◽  
Direct Support ◽  
Protocol Compliance

Background: Use of hotline services for clinical support and safe operation of a research trial is common and important. The value of such services has not been objectively assessed within the context of a large acute stroke clinical trial. Methods: The use of three different hotline services have been tested, and cell and Email- options have also been explored for their advantages. US and Non-US sites are provided access to central hotline services, but for efficiency a local network for managing calls is established in each region. All sites may access both data management and the trial PI via hotline services when needed and this is supported by other technologies in addition. A means for supporting overall trial communications in light of these interactions has been developed and valuable insights are gained. Results: Data gathered from 211 calls logged at the Clinical Coordinating Center through the course of the ATACH-II trial have been summarized: Total Calls Reviewed: 211; Year 2 of trial: 92 calls, Year 3 of trial: 100 calls. Calls received midnight to 8 AM: 19 (9.0%), 8 AM - 5 PM 130 (61.6 %) 5 PM - 12:00 PM 65 (30.8%). Issues Resolved in < 5 min 143/211 (67.8%) Taking > 30 min to resolution 51/211 (24.2%). Purpose of calls: Eligibility 89 (42.2%). protocol compliance including drug management: 77 (36.5%%), randomization/emergency randomization: 16 (7.6%), protocol deviation:13 (6.2%), technological difficulties: 12 (5.7%), AE/SAE: 9 (4.3%), Subject enrollments directly associated with calls: 57 (20.8% of domestic subjects); excluded candidates directly associated with calls: 46 (% not available). Conclusions: In an international trial requiring rapid enrollment of subjects with intracerebral hemorrhage, the role of direct support via a hotline and other immediate communications means has proven to be instrumental in maintaining good protocol compliance and supporting enrollment by site team members .

scholarly journals Two tonoplast MATE proteins function as turgor-regulating chloride channels inArabidopsis

2017 ◽  
Vol 114 (10) ◽  
pp. E2036-E2045 ◽  
Author(s):  
Haiwen Zhang ◽  
Fu-Geng Zhao ◽  
Ren-Jie Tang ◽  
Yuexuan Yu ◽  
Jiali Song ◽  
...  
Keyword(s):  
Chloride Channels ◽  
Ectopic Expression ◽  
Root Hairs ◽  
Large Family ◽  
Patch Clamp Recording ◽  
Mesophyll Cells ◽  
Environmental Signals ◽  
Turgor Regulation ◽  
Cell Turgor ◽  
Definition Of

The central vacuole in a plant cell occupies the majority of the cellular volume and plays a key role in turgor regulation. The vacuolar membrane (tonoplast) contains a large number of transporters that mediate fluxes of solutes and water, thereby adjusting cell turgor in response to developmental and environmental signals. We report that two tonoplast Detoxification efflux carrier (DTX)/Multidrug and Toxic Compound Extrusion (MATE) transporters, DTX33 and DTX35, function as chloride channels essential for turgor regulation inArabidopsis. Ectopic expression of each transporter inNicotiana benthamianamesophyll cells elicited a large voltage-dependent inward chloride current across the tonoplast, showing that DTX33 and DTX35 each constitute a functional channel. Both channels are highly expressed inArabidopsistissues, including root hairs and guard cells that experience rapid turgor changes during root-hair elongation and stomatal movements. Disruption of these two genes, either in single or double mutants, resulted in shorter root hairs and smaller stomatal aperture, with double mutants showing more severe defects, suggesting that these two channels function additively to facilitate anion influx into the vacuole during cell expansion. In addition,dtx35single mutant showed lower fertility as a result of a defect in pollen-tube growth. Indeed, patch-clamp recording of isolated vacuoles indicated that the inward chloride channel activity across the tonoplast was impaired in the double mutant. Because MATE proteins are widely known transporters of organic compounds, finding MATE members as chloride channels expands the functional definition of this large family of transporters.

Sign in / Sign up

Export Citation Format

Share Document