Data_Sheet_1_Flagellin C decreases the expression of the Gossypium hirsutum cation/proton exchanger 3 gene to promote calcium ion, hydrogen peroxide, and nitric oxide and synergistically regulate the resistance of cotton to Verticillium wilt.docx

To date, no ideal effective method for controlling Verticillium wilt in upland cotton (Gossypium hirsutum) has been defined. The purpose of this study was to determine the effects and mechanism through which flagellin C (FLiC) regulates the Gossypium hirsutum cation/proton exchanger 3 gene (GhCAX3), induces plant immunity, and increases resistance to Verticillium wilt. The FLiC gene was cloned from an endophytic bacterium (Pseudomonas) isolated from roots of the upland cotton cultivar Zhongmiansuo 41. The biocontrol effects of FLiC purified in vitro on resistant and susceptible upland cotton cultivars were 47.50 and 32.42%, respectively. FLiC induced a hypersensitive response (HR) in leaves of tobacco and immune responses in upland cotton. Transcriptome data showed that treatment with FLiC significantly enriched the calcium antiporter activity-associated disease-resistant metabolic pathway in seedlings. Moreover, FLiC downregulated GhCAX3 expression to increase intracellular calcium ion (Ca2+) content and stimulate increases in the intracellular hydrogen peroxide (H2O2) and nitric oxide (NO) contents. The coordinated regulation of Ca2+, H2O2, and NO enhanced cotton resistance to Verticillium wilt. Furthermore, transgenic Arabidopsis plants overexpressing FLiC showed significantly improved resistance to Verticillium wilt. FLiC may be used as a resistance gene and a regulator to improve resistance to Verticillium dahliae (VD) in upland cotton.</p

Modeling of the axon membrane skeleton structure and implications for its mechanical properties

<div><p>Super-resolution microscopy recently revealed that, unlike the soma and dendrites, the axon membrane skeleton is structured as a series of actin rings connected by spectrin filaments that are held under tension. Currently, the structure-function relationship of the axonal structure is unclear. Here, we used atomic force microscopy (AFM) to show that the stiffness of the axon plasma membrane is significantly higher than the stiffnesses of dendrites and somata. To examine whether the structure of the axon plasma membrane determines its overall stiffness, we introduced a coarse-grain molecular dynamics model of the axon membrane skeleton that reproduces the structure identified by super-resolution microscopy. Our proposed computational model accurately simulates the median value of the Young’s modulus of the axon plasma membrane determined by atomic force microscopy. It also predicts that because the spectrin filaments are under entropic tension, the thermal random motion of the voltage-gated sodium channels (Na_v), which are bound to ankyrin particles, a critical axonal protein, is reduced compared to the thermal motion when spectrin filaments are held at equilibrium. Lastly, our model predicts that because spectrin filaments are under tension, any axonal injuries that lacerate spectrin filaments will likely lead to a permanent disruption of the membrane skeleton due to the inability of spectrin filaments to spontaneously form their initial under-tension configuration.</p></div

Young's moduli of rat hippocampal neuronal subcompartments determined by AFM.

<p>Histograms of Young’s moduli of rat hippocampal (A) soma, (B) dendrites, (C) axons, and (D) axons treated with 20μm Latrunculin B. The median Young's modulus of the soma is 0.7 ± 0.2 <i>kPa</i> (A), of dendrites is 2.5 ± 0.7 <i>kPa</i> (B). For the axon plasma membrane, the median Young’s modulus is 4.6 ± 1.5 <i>kPa</i> (C). When axons were treated with Latrunculin B (20μm, 1 hour) the median value of the axon plasma membrane Young’s modulus was reduced to 2.2 ± 0.6 <i>kPa</i>. Number of samples (N = 2), total number of tested neurons (n = 8). N = 1 and n = 6 for axon + Latrunculin B. (E) Box-whisker plots of mean Young's moduli of the soma, dendrites, axon, and axon treated with Latrunculin B. *** indicates statistical significance of <i>p</i> < 0.001 (Kruskal-Wallis test).</p

Axon membrane skeleton model.

<p>(A) Illustration of the axon membrane skeleton based on super-resolution microscopy results [<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005407#pcbi.1005407.ref003" target="_blank">3</a>] exhibiting actin rings connected by spectrin tetramers. Ankyrin associated Na_v channels anchor the lipid bilayer to the membrane skeleton. Adducin has also been observed to colocalize with the actin rings possibly capping actin filaments. (B) A coarse-grain membrane skeleton dynamics model comprising representation of actin rings, spectrin filaments, and ankyrin. The insert shows the dimensions of the considered particles. (<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1005407#pcbi.1005407.s003" target="_blank">S2 Fig</a>)</p

Laceration of spectrin filaments.

<p>(A) Axon membrane skeleton with severed spectrin filaments in the marked area between two consecutive rings. (B) None of the severed spectrin filaments (blue color) were reconnected to their initial junction points.</p

Membrane skeleton dynamics simulations.

<p>(A) The membrane skeleton was equilibrated at a distance of approximately 185 <i>nm</i> between actin rings while the trajectory of ankyrin particles (insert) was recorded for 10×10⁶ time steps every 10⁵ time steps. (B) The skeleton was equilibrated at a distance of approximately 110 <i>nm</i> between actin rings while the trajectory of ankyrin particles (insert) was recorded for 10×10⁶ 10⁵ time steps. (C, D) Normalized probability distribution of the ratio <i>d</i>(<i>z</i>)/<i>L</i>_<i>c</i>, where <i>d</i>(<i>z</i>) is the deviation of an ankyrin point from its mean position during its thermal motion along the z-direction and <i>L</i>_<i>c</i> is the mean distance between two consecutive ankyrin points along the z-direction when the spectrin is under tension <i>L</i>_<i>c</i> = 185.78 <i>nm</i> (C) and when the spectrin is almost at equilibrium <i>L</i>_<i>c</i> = 112.32 <i>nm</i> (D). The longitudinal and circumferential separations of the trajectories of neighboring ankyrin particles, and consequently of the corresponding Na_v channels, are well-defined in (A) but not in (B).</p

Fig 3 -

Student academic performance by subject, English (A), Computer Science (B), Chinese History (C), Sports (D), Biochemistry (E), Anatomy (F), Histology (G) and Histology Practice (H). The white, light grey, middle grey and dark grey bars represent the men student in 2019, women student in 2019, men students in 2020 and women students in 2020, respectively. The Y-axis represents the mark in percentage points.</p

Diagrammatic illustration of the experimental design sequence.

Chinese education consists of two semesters each year. Semester 1 includes September to the following February. Semester 2 March to July. Thus the COVID-19 cohort undertook the second semester of their medical course during pandemic lockdown between March and July 2020.</p

Fig 2 -

The comparison between the students’ demographics for the pre-COVID-19 cohort (white bars) and COVID-19 cohort (grey bars) (A), students’ numbers stratified by sex (B), the average age of the students (C) and the students’ age stratified by sex (D).</p

S1 Fig -

Validation of the pre-pandemic academic performance between the pre-COVID-19 cohort and COVID-19 cohort for the semester 1 studies undertaken prior to the pandemic on the subjects: Cell Biology, Advanced Mathematics, Chemistry and Medical Physics (A). The Y-axis represents the mark in percentage points. Validation of the marks achieved following stratification by sex for the two cohorts (B). (DOCX)</p