Fusarium head blight (FHB), caused by Fusarium graminearum, not only leads to severe yield losses but also poses a threat to food safety due to the mycotoxins produced by the pathogen. Since this disease is preventable but not curable, the current control mainly relies on chemical fungicides, the long-term use of which may lead to pathogen resistance and environmental pollution. To develop green control methods, we screened 13 biocontrol strains from the rhizosphere soil of wheat, among which strain No. 12 (identified as Pythium aphanidermatum) showed significant antifungal effects. In the plate confrontation test, this strain reduced the colony diameter of the pathogen by 69.2% (1.47 mm vs. 4.78 mm in the control group), with an inhibition rate of 77% (P < 0.01). Microscopic observation revealed obvious deformations in the pathogen hyphae, suggesting a lysing effect. The coleoptile experiment further confirmed that the pre-treatment with this strain reduced the incidence rate to 0. These findings provide new candidate strains for the biocontrol of FHB and offer a scientific basis for reducing the use of chemical fungicides and promoting sustainable agricultural development.
Triticum/growth & development* ; Fusarium/growth & development* ; Plant Diseases/prevention & control* ; Soil Microbiology ; Pest Control, Biological/methods* ; Pythium/physiology* ; Biological Control Agents ; Rhizosphere ; Fungicides, Industrial

Objective To investigate the vasodilatory effect of luteolin on isolated denuded-endothelium rat thoracic aorta(DRTA)vascular rings,and the mechanistic role of the Kv7 ion channel.Methods The tension of DRTA vascular rings was measured using an ex vivo tissue perfusion muscle-tone detection system.DRTA vascular rings were pre-contracted with 60 mmol/L KCl or 0.3 μmol/L U46619,and the effect of luteolin on vascular-ring relaxation was observed at 1,3,10,30,100 and 300 μmol/L.The effects of 4-AP,XE-991,and ML213 on luteolin-induced vasodilation were also observed.The effect of luteolin on KCNQ1-KCNQ5 expression in the thoracic aorta was detected by real-time fluorescence quantitative polymerase chain reaction.Expression levels of Kv7.1 and Kv7.4 proteins in the DRTA were detected by Western blot.Results(1)The luteolin-induced maximum vasodilation rates in DRTA pre-contracted with 60 mmol/L KCl and 0.3 μmol/L U46619 were(97.67±8.51)％and(98.42±9.76)％,respectively.The vasodilation effect was concentration-dependent(P＜0.05).(2)4-AP(3 mmol/L)significantly reduced the vasodilatory effect of luteolin on DRTA vascular rings at 10,30,and 100 μmol/L(P＜0.05),and XE-991(3 μmol/L)significantly reduced the effect of luteolin at 30 and 100 μmol/L(P＜0.05),while ML213(1 μmol/L)significantly enhanced the vasodilatory effect of luteolin at 3,10,and 30 μmol/L(P＜0.05).(3)The relative gene expression levels of each subtype of Kv7 channel in normal DRTA were KCNQ1＞KCNQ5＞KCNQ4＞KCNQ3＞KCNQ2,with KCNQ1 being the most highly expressed.(4)Luteolin significantly enhanced the expression levels of KCNQ1 at 3,10,30,and 100 μmol/L,KCNQ2 at 1,3,10,30,and 100 μmol/L(P＜0.05),KCNQ3 at 3,10,30,and 100 μmol/L,and KCNQ4 at 10,30,and 100 μmol/L(P＜0.05),but did not significantly enhance the expression of KCNQ5 at 1,3,10,30,or 100 μmol/L(P＞0.05).(5)Luteolin significantly increased the expression of Kv7.1 protein in DRTA at 3,10,30,and 100 μmol/L(P＜0.05)and the expression of Kv7.4 at 10,30,and 100 μmol/L(P＜0.05).Conclusions Luteolin-induced dilation of DRTA vascular rings may be related to the enhanced gene expression of KCNQ1-4 and increased expression of Kv7.1 and Kv7.4 channel proteins.

Objective To investigate the vasodilatory effect of luteolin on isolated denuded-endothelium rat thoracic aorta(DRTA)vascular rings,and the mechanistic role of the Kv7 ion channel.Methods The tension of DRTA vascular rings was measured using an ex vivo tissue perfusion muscle-tone detection system.DRTA vascular rings were pre-contracted with 60 mmol/L KCl or 0.3 μmol/L U46619,and the effect of luteolin on vascular-ring relaxation was observed at 1,3,10,30,100 and 300 μmol/L.The effects of 4-AP,XE-991,and ML213 on luteolin-induced vasodilation were also observed.The effect of luteolin on KCNQ1-KCNQ5 expression in the thoracic aorta was detected by real-time fluorescence quantitative polymerase chain reaction.Expression levels of Kv7.1 and Kv7.4 proteins in the DRTA were detected by Western blot.Results(1)The luteolin-induced maximum vasodilation rates in DRTA pre-contracted with 60 mmol/L KCl and 0.3 μmol/L U46619 were(97.67±8.51)％and(98.42±9.76)％,respectively.The vasodilation effect was concentration-dependent(P＜0.05).(2)4-AP(3 mmol/L)significantly reduced the vasodilatory effect of luteolin on DRTA vascular rings at 10,30,and 100 μmol/L(P＜0.05),and XE-991(3 μmol/L)significantly reduced the effect of luteolin at 30 and 100 μmol/L(P＜0.05),while ML213(1 μmol/L)significantly enhanced the vasodilatory effect of luteolin at 3,10,and 30 μmol/L(P＜0.05).(3)The relative gene expression levels of each subtype of Kv7 channel in normal DRTA were KCNQ1＞KCNQ5＞KCNQ4＞KCNQ3＞KCNQ2,with KCNQ1 being the most highly expressed.(4)Luteolin significantly enhanced the expression levels of KCNQ1 at 3,10,30,and 100 μmol/L,KCNQ2 at 1,3,10,30,and 100 μmol/L(P＜0.05),KCNQ3 at 3,10,30,and 100 μmol/L,and KCNQ4 at 10,30,and 100 μmol/L(P＜0.05),but did not significantly enhance the expression of KCNQ5 at 1,3,10,30,or 100 μmol/L(P＞0.05).(5)Luteolin significantly increased the expression of Kv7.1 protein in DRTA at 3,10,30,and 100 μmol/L(P＜0.05)and the expression of Kv7.4 at 10,30,and 100 μmol/L(P＜0.05).Conclusions Luteolin-induced dilation of DRTA vascular rings may be related to the enhanced gene expression of KCNQ1-4 and increased expression of Kv7.1 and Kv7.4 channel proteins.

Compared to conventional cancer treatment, combination therapy based on well-designed nanoscale platforms may offer an opportunity to eliminate tumors and reduce recurrence and metastasis. In this study, we prepared multifunctional microspheres loading I-labeled hollow copper sulfide nanoparticles and paclitaxel (I-HCuSNPs-MS-PTX) for imaging and therapeutics of W256/B breast tumors in rats. F-fluordeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) imaging detected that the expansion of the tumor volume was delayed (<0.05) following intra-tumoral (i.t.) injection with I-HCuSNPs-MS-PTX plus near-infrared (NIR) irradiation. The immunohistochemical analysis further confirmed the anti-tumor effect. The single photon emission computed tomography (SPECT)/photoacoustic imaging mediated by I-HCuSNPs-MS-PTX demonstrated that microspheres were mainly distributed in the tumors with a relatively low distribution in other organs. Our results revealed that I-HCuSNPs-MS-PTX offered combined photothermal, chemo- and radio-therapies, eliminating tumors at a relatively low dose, as well as allowing SPECT/CT and photoacoustic imaging monitoring of distribution of the injected agents non-invasively. The copper sulfide-loaded microspheres, I-HCuSNPs-MS-PTX, can serve as a versatile theranostic agent in an orthotopic breast cancer model.