Survival of <i>M</i>. <i>persicae</i> on <i>B</i>. <i>tabaci</i> nymph-infested tobacco plants.

<p><i>M</i>. <i>persicae</i> survival on (A) local and (B) systemic leaves of WT tobacco plants. <i>M</i>. <i>persicae</i> survival on (C) local and (D) systemic leaves of NahG tobacco plants. Values represent the mean survival of aphids ± standard error.</p

Fecundity of <i>M</i>. <i>persicae</i> on <i>B</i>. <i>tabaci</i> nymph-infested tobacco plants.

<p><i>M</i>. <i>persicae</i> fecundity on local and systemic leaves of (A) WT and (B) NahG tobacco plants. Values represent the mean number of newborn nymphs per female ± standard error. ^** indicates significant differences (<i>P</i> ≤ 0.01) relative to the controls.</p

Quantification of SA hormone levels in <i>B</i>. <i>tabaci</i> nymph-infested tobacco plants.

<p>SA levels in (A) local and (B) systemic leaves of WT plants and in (C) local and (D) systemic leaves of NahG plants after 10, 15, and 20 days of <i>B</i>. <i>tabaci</i> nymphs infestation. Values represent the mean ng SA per g fresh weight (FW) ± standard error. ^**indicates significant differences (<i>P</i> ≤ 0.01) relative to the controls.</p

Infestation by <i>B</i>. <i>tabaci</i> nymphs on defense enzyme activity levels of WT and NahG tobacco plants.

<p>Each value represents the average (± SE) of four replicates. The different capital letters in each of the column indicate significant differences among local and systemic leaves of treated plants in activity levels of each defense enzyme (<i>P</i> < 0.05). The different lowercase letters at each of the rows indicate significant differences between WT and NahG plants in activity levels of each defense enzyme (<i>P</i> < 0.05).</p><p>Infestation by <i>B</i>. <i>tabaci</i> nymphs on defense enzyme activity levels of WT and NahG tobacco plants.</p

<i>M</i>. <i>persicae</i> survival on <i>B</i>. <i>tabaci</i> nymph-infested plants.

<p><i>M</i>. <i>persicae</i> survival on (A) local and (B) systemic leaves of <i>B</i>. <i>tabaci</i> nymph-infested tobacco plants. Values represent the mean survival of aphids ± standard error.</p

Antioxidant Enzyme Responses Induced by Whiteflies in Tobacco Plants in Defense against Aphids: Catalase May Play a Dominant Role

<div><p>Background</p><p><i>Bemisia tabaci</i> MEAM1 (Middle East-Asia Minor 1) feeding alters antioxidative enzyme activity in some plant species. Infestation of <i>B</i>. <i>tabaci</i> nymphs decreases <i>Myzus persicae</i> performance on systemic, but not local leaves of tobacco plants. However, it is unclear if <i>B</i>. <i>tabaci</i> nymphs induced antioxidant activities contributing to the aphid resistance.</p><p>Methodology/Principal Findings</p><p>We investigated the relationship between antioxidants induced by nymphs of <i>B</i>. <i>tabaci</i> feeding on tobacco and aphid resistance. The activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and the concentration of hydrogen peroxide (H₂O₂) were assayed in tobacco leaves at different feeding times following infestation of <i>B</i>. <i>tabaci</i> nymphs. The infestation altered the activities of CAT and POD, but had no significant effect on SOD activity. The highest CAT activity was observed at 15 d after infestation. This was 98.2% greater than control systemic leaves, but 32.6% lower than the control in local leaves. Higher POD activity was recorded in local vs. systemic leaves after 15 d of infestation. POD activity was 71.0% and 112.9% higher in local and systemic leaves, respectively, than in the controls. The changes of CAT, but not POD or SOD activity were correlated to levels of aphid resistance. H₂O₂ levels were higher in local than in systemic leaves in contrast to CAT activity. <i>Tobacco curly shoot virus</i> mediated virus-induced gene silencing was employed to determine if CAT activation was involved in the aphid resistance induced by <i>B</i>. <i>tabaci</i> nymphs. <i>B</i>. <i>tabaci</i> induced CAT activity decreased when the <i>Cat1</i> expression was silenced. The performance assay indicated that <i>Cat1</i> silencing made <i>B</i>. <i>tabaci</i> infested plants a more suitable host for aphids than infested control plants. The aphid survival rate was reduced by 40.4% in infested control plants, but reduced by only 26.1% in <i>Cat1</i>-silenced plants compared to uninfested controls. Also, qPCR results showed that silencing of <i>Cat1</i> led to the suppression of the <i>B</i>. <i>tabaci</i> mediated <i>PR-2a</i> expression.</p><p>Conclusions/Significance</p><p>Aphid resistance in plants infested with <i>B</i>. <i>tabaci</i> nymphs is associated with enhanced antioxidant activities in which CAT may play a dominant role. This resistance probably acted via interactions with SA-mediated defense responses.</p></div

Table_1_Evaluation of peri-plaque pericoronary adipose tissue attenuation in coronary atherosclerosis using a dual-layer spectral detector CT.DOCX

PurposeThis study aimed to evaluate the differences between pericoronary adipose tissue (PCAT) attenuation at different measured locations in evaluating coronary atherosclerosis using spectral computed tomography (CT) and to explore valuable imaging indicators.MethodsA total of 330 patients with suspicious coronary atherosclerosis were enrolled and underwent coronary CT angiography with dual-layer spectral detector CT (SDCT). Proximal and peri-plaque fat attenuation index (FAI) of stenosis coronary arteries were measured using both conventional images (CIs) and virtual monoenergetic images (VMIs) ranging from 40 keV to 100 keV. The slopes of the spectral attenuation curve (λ) of proximal and peri-plaque PCAT at three different monoenergetic intervals were calculated. Additionally, peri-plaque FAI on CI and virtual non-contrast images, and effective atomic number were measured manually.ResultsA total of 231 coronary arteries with plaques and lumen stenosis were finally enrolled. Peri-plaque FAICI and FAIVMI were significantly higher in severe stenosis than in mild and moderate stenosis (p ConclusionPeri-plaque PCAT has more value in assessing coronary atherosclerosis than proximal PCAT. Peri-plaque PCAT attenuation is expected to be used as a standard biomarker for evaluating plaque vulnerability and hemodynamic characteristics.</p

Image_1_Evaluation of peri-plaque pericoronary adipose tissue attenuation in coronary atherosclerosis using a dual-layer spectral detector CT.TIF

PurposeThis study aimed to evaluate the differences between pericoronary adipose tissue (PCAT) attenuation at different measured locations in evaluating coronary atherosclerosis using spectral computed tomography (CT) and to explore valuable imaging indicators.MethodsA total of 330 patients with suspicious coronary atherosclerosis were enrolled and underwent coronary CT angiography with dual-layer spectral detector CT (SDCT). Proximal and peri-plaque fat attenuation index (FAI) of stenosis coronary arteries were measured using both conventional images (CIs) and virtual monoenergetic images (VMIs) ranging from 40 keV to 100 keV. The slopes of the spectral attenuation curve (λ) of proximal and peri-plaque PCAT at three different monoenergetic intervals were calculated. Additionally, peri-plaque FAI on CI and virtual non-contrast images, and effective atomic number were measured manually.ResultsA total of 231 coronary arteries with plaques and lumen stenosis were finally enrolled. Peri-plaque FAICI and FAIVMI were significantly higher in severe stenosis than in mild and moderate stenosis (p ConclusionPeri-plaque PCAT has more value in assessing coronary atherosclerosis than proximal PCAT. Peri-plaque PCAT attenuation is expected to be used as a standard biomarker for evaluating plaque vulnerability and hemodynamic characteristics.</p

Quantification of H₂O₂ levels in <i>B</i>. <i>tabaci</i> nymph-infested tobacco plants.

<p>H₂O₂ levels in (A) local and (B) systemic leaves of tobacco plants after 5, 10, 15, and 20 days of <i>B</i>. <i>tabaci</i> nymphs infestation. Values represent the mean μmol H₂O₂ per g fresh weight (FW) ± standard error. Paired means with the same letter are not significantly different (P > 0.05).</p

SOD activity levels in tobacco plants infested with <i>B</i>. <i>tabaci</i> nymphs.

<p>SOD activity levels in (A) local and (B) systemic leaves of tobacco plants after 5, 10, 15, and 20 days of <i>B</i>. <i>tabaci</i> nymphs infestation. Values represent the mean unit per mg protein ± standard error. Paired means with the same letter are not significantly different (P > 0.05).</p