scholarly journals Guard Cell Microfilament Analyzer Facilitates the Analysis of the Organization and Dynamics of Actin Filaments in Arabidopsis Guard Cells

2019 ◽  
Vol 20 (11) ◽  
pp. 2753
Author(s):  
Xin Li ◽  
Min Diao ◽  
Yanan Zhang ◽  
Guanlin Chen ◽  
Shanjin Huang ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Dynamic Behavior ◽  
Guard Cell ◽  
Actin Filaments ◽  
De Novo ◽  
Guard Cells ◽  
Stomatal Movement ◽  
Selection Of

The actin cytoskeleton is involved in regulating stomatal movement, which forms distinct actin arrays within guard cells of stomata with different apertures. How those actin arrays are formed and maintained remains largely unexplored. Elucidation of the dynamic behavior of differently oriented actin filaments in guard cells will enhance our understanding in this regard. Here, we initially developed a program called ‘guard cell microfilament analyzer’ (GCMA) that enables the selection of individual actin filaments and analysis of their orientations semiautomatically in guard cells. We next traced the dynamics of individual actin filaments and performed careful quantification in open and closed stomata. We found that de novo nucleation of actin filaments occurs at both dorsal and ventral sides of guard cells from open and closed stomata. Interestingly, most of the nucleated actin filaments elongate radially and longitudinally in open and closed stomata, respectively. Strikingly, radial filaments tend to form bundles whereas longitudinal filaments tend to be removed by severing and depolymerization in open stomata. By contrast, longitudinal filaments tend to form bundles that are severed less frequently in closed stomata. These observations provide insights into the formation and maintenance of distinct actin arrays in guard cells in stomata of different apertures.

scholarly journals Comparison of actin and cell surface dynamics in motile fibroblasts.

1992 ◽  
Vol 119 (2) ◽  
pp. 367-377 ◽  
Author(s):  
J A Theriot ◽  
T J Mitchison
Keyword(s):  
Actin Cytoskeleton ◽  
Dynamic Behavior ◽  
Actin Filaments ◽  
Half Life ◽  
Dorsal Surface ◽  
Cell Types ◽  
3T3 Cells ◽  
3T3 Fibroblasts ◽  
Continuous Filament ◽  
Time Required

We have investigated the dynamic behavior of actin in fibroblast lamellipodia using photoactivation of fluorescence. Activated regions of caged resorufin (CR)-labeled actin in lamellipodia of IMR 90 and MC7 3T3 fibroblasts were observed to move centripetally over time. Thus in these cells, actin filaments move centripetally relative to the substrate. Rates were characteristic for each cell type; 0.66 +/- 0.27 microns/min in IMR 90 and 0.36 +/- 0.16 microns/min in MC7 3T3 cells. In neither case was there any correlation between the rate of actin movement and the rate of lamellipodial protrusion. The half-life of the activated CR-actin filaments was approximately 1 min in IMR 90 lamellipodia, and approximately 3 min in MC7 3T3 lamellipodia. Thus continuous filament turnover accompanies centripetal movement. In both cell types, the length of time required for a section of the actin meshwork to traverse the lamellipodium was several times longer than the filament half-life. The dynamic behavior of the dorsal surface of the cell was also observed by tracking lectin-coated beads on the surface and phase-dense features within lamellipodia of MC7 3T3 cells. The movement of these dorsal features occurred at rates approximately three times faster than the rate of movement of the underlying bulk actin cytoskeleton, even when measured in the same individual cells. Thus the transport of these dorsal features must occur by some mechanism other than simple attachment to the moving bulk actin cytoskeleton.

scholarly journals Molecular to organismal chirality is induced by the conserved myosin 1D

Science ◽  
2018 ◽  
Vol 362 (6417) ◽  
pp. 949-952 ◽  
Author(s):  
G. Lebreton ◽  
C. Géminard ◽  
F. Lapraz ◽  
S. Pyrpassopoulos ◽  
D. Cerezo ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Actin Filaments ◽  
De Novo ◽  
Molecular Motor ◽  
Break Symmetry ◽  
Motor Domain ◽  
Whole Body ◽  
Living Organisms ◽  
Chiral Interaction

The emergence of asymmetry from an initially symmetrical state is a universal transition in nature. Living organisms show asymmetries at the molecular, cellular, tissular, and organismal level. However, whether and how multilevel asymmetries are related remains unclear. In this study, we show that Drosophila myosin 1D (Myo1D) and myosin 1C (Myo1C) are sufficient to generate de novo directional twisting of cells, single organs, or the whole body in opposite directions. Directionality lies in the myosins’ motor domain and is swappable between Myo1D and Myo1C. In addition, Myo1D drives gliding of actin filaments in circular, counterclockwise paths in vitro. Altogether, our results reveal the molecular motor Myo1D as a chiral determinant that is sufficient to break symmetry at all biological scales through chiral interaction with the actin cytoskeleton.

scholarly journals Actin Filaments in Mature Guard Cells Are Radially Distributed and Involved in Stomatal Movement

1995 ◽  
Vol 109 (3) ◽  
pp. 1077-1084 ◽  
Author(s):  
M. Kim ◽  
P. K. Hepler ◽  
S. O. Eun ◽  
K. S. Ha ◽  
Y. Lee
Keyword(s):  
Actin Filaments ◽  
Guard Cells ◽  
Stomatal Movement

scholarly journals Dynamics of vacuoles and actin filaments in guard cells and their roles in stomatal movement

2009 ◽  
Vol 32 (8) ◽  
pp. 1108-1116 ◽  
Author(s):  
XIN-QI GAO ◽  
XIU-LING WANG ◽  
FEI REN ◽  
JIA CHEN ◽  
XUE-CHEN WANG
Keyword(s):  
Actin Filaments ◽  
Guard Cells ◽  
Stomatal Movement

scholarly journals Pathogen-Mediated Stomatal Opening: A Previously Overlooked Pathogenicity Strategy in the Oomycete Pathogen Phytophthora infestans

2021 ◽  
Vol 12 ◽  
Author(s):  
Li-Na Yang ◽  
Hao Liu ◽  
Yan-Ping Wang ◽  
Jenifer Seematti ◽  
Laura J. Grenville-Briggs ◽  
...  
Keyword(s):  
Phytophthora Infestans ◽  
Guard Cell ◽  
Metabolic Pathways ◽  
Guard Cells ◽  
Defense Responses ◽  
Stomatal Opening ◽  
Starch Degradation ◽  
Stomatal Movement ◽  
Oomycete Pathogen ◽  
Antagonistic Interactions

Phytophthora infestans, the most damaging oomycete pathogen of potato, is specialized to grow sporangiophore through opened stomata for secondary inoculum production. However, it is still unclear which metabolic pathways in potato are manipulated by P. infestans in the guard cell–pathogen interactions to open the stomata. Here microscopic observations and cell biology were used to investigate antagonistic interactions between guard cells and the oomycete pathogen. We observed that the antagonistic interactions started at the very beginning of infection. Stomatal movement is an important part of the immune response of potato to P. infestans infection and this occurs through guard cell death and stomatal closure. We observed that P. infestans appeared to manipulate metabolic processes in guard cells, such as triacylglycerol (TAG) breakdown, starch degradation, H2O2 scavenging, and NO catabolism, which are involved in stomatal movement, to evade these stomatal defense responses. The signal transduction pathway of P. infestans-induced stomatal opening likely starts from H2O2 and NO scavenging, along with TAG breakdown while the subsequent starch degradation reinforces the opening process by strengthening guard cell turgor and opening the stomata to their maximum aperture. These results suggest that stomata are a barrier stopping P. infestans from completing its life cycle, but this host defense system can be bypassed through the manipulation of diverse metabolic pathways that may be induced by P. infestans effector proteins.

scholarly journals The Effect of Sonication on Plant Stomatal Movement

2020 ◽  
Vol 22 ◽  
Author(s):  
Suren Jeevaratnam ◽  
Chuwei Lin ◽  
Sixue Chen
Keyword(s):  
Arabidopsis Thaliana ◽  
Guard Cell ◽  
Guard Cells ◽  
Neutral Red ◽  
Time Interval ◽  
Stomatal Movement ◽  
Mesophyll Cells ◽  
Cell Purification ◽  
Cell Enrichment ◽  
A Minor

The primary goal of this study was to determine the effect of sonication on stomatal movement. A minor goal was to determine the best time interval at which sonication is the most effective at removing mesophyll cells and enriching guard cells. For this study, abaxial leaf peels of Arabidopsis thaliana were sonicated for 1, 3, 5, and 7-minute intervals at a set amplitude to analyze the removal of mesophyll cells. To juxtapose the leaves and to determine guard cell enrichment, microscopic images were taken prior to and after sonication. Furthermore, to establish that the stomata are alive, neutral red staining was used in conjunct with 40x magnification. It was hypothesized that sonication is an effective method for the removal of mesophyll cells and the enrichment of guard cells. The results of this study suggest that sonication is in fact an effective protocol for guard cell enrichment; however, it is not as effective for guard cell purification. This is due to the presence of mesophyll cells and epidermal layers present after sonication. Previous research dealing with sonication is very prevalent; however, research on sonication dealing with the removal of mesophyll cells in Arabidopsis thaliana is not widely studied. Thus, previous information to support this study could not be attained. Results from the first part of the experiment were then extended to determine how sonication affects stomatal movement. It was determined that in the experimental group, the average stomatal aperture decreased over a two-hour period.

Posttransplant CMV infection and the role of immunosuppression (Sponsor: Novartis Pharma GmbH, Nürnberg)

2016 ◽  
Vol 04 (01) ◽  
pp. 4-10
Keyword(s):  
Lower Incidence ◽  
Paradigm Shift ◽  
Mtor Inhibitor ◽  
De Novo ◽  
Expert Panel ◽  
Risk Of Infection ◽  
Cmv Infection ◽  
Expert Meeting ◽  
Selection Of

AbstractImmunosuppression permits graft survival after transplantation and consequently a longer and better life. On the other hand, it increases the risk of infection, for instance with cytomegalovirus (CMV). However, the various available immunosuppressive therapies differ in this regard. One of the first clinical trials using de novo everolimus after kidney transplantation [1] already revealed a considerably lower incidence of CMV infection in the everolimus arms than in the mycophenolate mofetil (MMF) arm. This result was repeatedly confirmed in later studies [2–4]. Everolimus is now considered a substance with antiviral properties. This article is based on the expert meeting “Posttransplant CMV infection and the role of immunosuppression”. The expert panel called for a paradigm shift: In a CMV prevention strategy the targeted selection of the immunosuppressive therapy is also a key element. For patients with elevated risk of CMV, mTOR inhibitor-based immunosuppression is advantageous as it is associated with a significantly lower incidence of CMV events.

Crosstalk of NO with Ca2+ in Stomatal Movement in Vicia faba Guard Cells

2009 ◽  
Vol 35 (8) ◽  
pp. 1491-1499 ◽  
Author(s):  
Lin ZHANG ◽  
Xiang ZHAO ◽  
Ya-Jing WANG ◽  
Xiao ZHANG
Keyword(s):  
Vicia Faba ◽  
Guard Cells ◽  
Stomatal Movement
Sign in / Sign up

Export Citation Format

Share Document