中国不同春麦区小麦地方种质抗条锈病评价及抗性基因分析

为明确中国不同春麦区小麦地方种质对当前小麦生产上流行的条锈病菌Puccinia striiformis f.sp.tritic的抗性水平及其所含抗性基因,利用条锈病菌生理小种条中32（CYR32）和条中34（CYR34）及混合生理小种（致病类群）对来自5个春麦区的196份小麦地方种质进行苗期、成株期抗性鉴定,并通过6个已知条锈病抗性基因Yr9、Yr18、Yr26、Yr48、Yr65和Yr67对其所含重要抗性基因进行分子标记检测。结果显示,在苗期,有11份小麦地方种质对CYR32表现出抗性,有12份对CYR34表现出抗性,分别占供试种质总数的5.61%和6.12%;有6份对CYR32和CYR34均表现出抗性;在成株期,有59份小麦地方种质在5个田间诱导环境下表现出稳定的抗性。有119份小麦地方种质检测到含抗性基因,其中有3份携带Yr9,有50份携带Yr18,有43份携带Yr48,有54份携带Yr65,所有供试种质均未检测到Yr26和Yr67,抗性基因的组合分析发现,共有31份小麦地方种质携带4种抗性基因组合类型Yr9+Yr18、Yr18+Yr48、Yr18+Yr65和Yr48+Yr65。表明来自中国5个春麦区的小麦地方种质条锈病抗性表型呈多样性,且携带目前在小麦抗病育种和生产上有效的条锈病抗性基因（组合）,建议加大对小麦地方种质的保护和应用力度。     

土霉素对柑橘黄龙病的防治效果及对柑橘产量和品质的影响

为有效防控柑橘黄龙病,于2017年在佛罗里达大学柑橘研究与教育中心的奥本代尔市柑橘试验场进行田间试验筛选黄龙病的防治药剂及其浓度,测定注射土霉素后叶片中柑橘黄龙病菌亚洲种Cadidatus Liberibacter asiaticus、土霉素、淀粉含量、柑橘产量、出汁率、可溶性固形物含量和酸度,显微镜下观察注射土霉素后淀粉粒的分布。结果表明,浓度为1.6g/株土霉素处理180 d后柑橘叶片中黄龙病菌亚洲种含量减少幅度最大,为91.78%;注射浓度为1.6g/株土霉素后7d,叶片中土霉素含量达142.2 μg/kg,注射后11 d叶片中土霉素含量达到最大,为239.8 μg/kg,注射后45 d叶片中土霉素含量低至99.6 μg/kg以下;注射后7~90d,叶片中黄龙病菌亚洲种含量呈波浪形变化,注射90 d后叶片中黄龙病菌亚洲种含量一直处于增长趋势,叶片中黄龙病菌亚洲种含量总体随着土霉素含量的升高而降低;注射浓度为1.6g/株土霉素后,叶片中淀粉含量大幅度下降,60d时达到最低值,为3.3 μg/mm²,90d时达到峰值,为14.5 μg/mm²;单株产量为16.7 kg,与注射浓度为0.8 g/株土霉素处理差异不显著,但均显著高于其它2个处理;柑橘出汁率、可溶性固形物和酸度均与清水对照差异不显著。表明土霉素可有效抑制黄龙病菌亚洲种,减少柑橘叶片内淀粉含量,增加柑橘产量,但对果实品质未产生显著影响。     

天维菌素酰化衍生物的合成及杀虫杀螨活性

以天维菌素B、天维菌素B单糖苷和天维菌素B苷元为原料,经选择性C-5羟基保护,在C-13、C-4′和C-4″位引入不同酰基基团,合成了3个系列共23个天维菌素B酰化衍生物,并通过1H NMR、13C NMR和高分辨质谱对所有目标化合物的结构进行了表征。生物活性测定结果表明,所有衍生物对小菜蛾Plutella xylostella、朱砂叶螨Tetranychus cinnabarinus以及松材线虫Bursaphelenchus xylophilus均表现出不同程度的毒杀活性,其中天维菌素B C-4″位衍生物的活性优于C-4′位衍生物及13位衍生物。化合物8e对小菜蛾和松材线虫的毒杀活性最优,LC50值分别为9.2 mg/L和0.42 mg/L,化合物8b对朱砂叶螨的毒性最高,LC50值为0.0019 mg/L,均优于对照药天维菌素B。     

呋喃磺草酮原药中主要杂质的结构鉴定及其合成

针对HPPD除草剂呋喃磺草酮原药生产中产生的3个质量分数均大于0.1%的主要杂质,通过高效液相色谱、核磁共振氢谱和高分辨质谱对3个杂质的结构进行了结构鉴定,发现其中2个为未见文献报道的化合物。结合生产工艺对杂质产生的路径进行了分析,并成功进行了合成。该研究对呋喃草酮原药质量控制和安全产生具有重要意义。     

水分和盐胁迫下小麦种子萌发相关性状的QTL定位

小麦萌发期对水分和盐胁迫敏感,对该时期水分和盐胁迫下种子萌发性状进行QTL定位具有重要的意义。本研究以小麦“泰农18×临麦6号” RIL群体为材料,以20%PEG-6000溶液和100 mmol·L^-1 NaCl溶液分别模拟水分和盐胁迫环境,对种子萌发期10个性状进行了QTL定位。结果表明,在正常、水分胁迫和盐胁迫3种不同处理下各性状变异较大。相关分析表明,抗旱和耐盐可能是两个独立遗传的性状,胚芽鞘长可以作为节水抗旱的鉴定指标。3种处理下共检测到10个萌发相关性状的103个QTL,其中,17个为相对高频QTL（RHF-QTL）,分布在7条染色体（1A、3A、3B、4B、7A、7B和7D）上,平均贡献率为7.55%~15.97%。这些RHF-QTL形成4个QTL簇（QTL cluster,QC）,分布在3A、7A和7D染色体上。其中,7A染色体上的QC2包括3个RHF-QTLs（ QSdw-7A.1、 QGf-7A.1和 QGi-7A.1）,均与小麦耐盐性相关;7D染色体上的QC3包括2个RHF-QTLs（ QGi-7D.1、 QGdrc-7D.1）,均与小麦节水抗旱性相关。这2个QCs增加效应均来自母本泰农18。本研究获得的RHF-QTLs和QCs,可为小麦萌发期节水抗旱和耐盐分子标记辅助选择提供理论和技术支持。     

Roles of protein phosphatase 4 in down-regulation of eNOS Ser633 phosphorylation induced by palmitic acid in human umbilical vein endotheli?al cells

AIMTo investigate the roles of protein phosphatase 4 (PP4) in down-regulation of endothelial nitric oxide synthase (eNOS) Ser633 phosphorylation induced by palmitic acid (PA). METHODSHuman umbilical vein endothelial cells (HUVECs) were treated with PA at 25 μmol/L, 50 μmol/L, 100 μmol/L and 200μmol/L for 36 h, or treated with PA at 100 μmol/L for 12 h, 24 h, 36 h and 48 h. Protein phosphatase 2A (PP2A) family inhibitor fostriecin (FST, 20 nmol/L) or okadaic acid (OA, 5 nmol/L) was selected to pretreat the HUVECs for 30 min. Protein phosphatase 4 catalytic subunit (PP4c) siRNA or protein phosphatase 2A catalytic subunit (PP2Ac) siRNA was transfected into the HUVECs. The protein expression levels of of eNOS, PP4c and PP2Ac, as well as the level of eNOS Ser633 phosphorylation, were detected by Western blot. The intracellular nitric oxide (NO) content was measured by DAF-FM DA. RESULTS(1) Compared with control group, the levels of eNOS Ser633 phosphorylation were decreased in PA groups in which the HUVECs were treated with 25 μmol/L, 50 μmol/L, 100 μmol/L and 200 μmol/L PA for 36 h (P<0.05) and 100 μmol/L PA for 24 h, 36 h and 48 h (P<0.05). No significant difference in the level of total eNOS protein expression among all the groups was observed. (2) Compared with control group, both FST and OA pretreatment reversed the reduction of eNOS Ser633 phosphorylation (P<0.05) and the decrease in intracellular NO content (P<0.05) induced by PA. No significant difference in the level of total eNOS protein expression among all the groups was observed. (3) Compared with si-Control group, the PP4c protein expression was significantly reduced (P<0.05), while the level of eNOS Ser633 phosphorylation was significantly increased in si-PP4c group (P<0.05). Although the levels of PP2Ac protein expression declined significantly (P<0.05), the level of eNOS Ser633 phosphorylation remained unchanged in si-PP2Ac group. No significant differencein the level of total eNOS protein expression among all the groups was found. CONCLUSION PA significantly reduces the level of eNOS Ser633 phosphorylation and the content of NO in the HUVECs, which may be due to PA inducing the activation of the PP2A family member PP4 rather than PP2A.     

Mouse melanoma cell exosomes promote expression of Rac1 protein in fibroblasts

AIM To investigate the effect of exosomes secreted by mouse melanoma cells on the expression of Ras-related C3 botulinum toxin substrate 1 (Rac1) protein in fibroblasts. METHODS Ultracentrifugation was adopted to separete exosomes secreted by mouse melanoma B16-F10 cells. The morphological structure of exosomes was observed by negative-staining electron microscopy. The size distribution of exosomes was determined by nanoparticle tracking analysis (NTA). The exosomal markers, tumor susceptibility gene 101 (Tsg101) and tyrosinase-related protein 2 (Tyrp2), were identified by Western blot. Laser confocal microscopy was used to observe the process that mouse embryonic fibroblasts (MEF) took in exosomes during co-culture. Immunocytochemical staining and Western blot were used to detect the expression of Rac1 protein in MEF. RESULTS B16-F10 cell exosomes showed a typical tea tray-like structure, with a size range of 141~255 nm, and expressed protein markers Tsg101 and Tyrp2. The results of laser confocal microscopy showed that compared with co-culture at 0 h, a small number of exosomes appeared in the MEF at 12 h, and a large number of exosomes accumulated in the MEF after co-cultured for 24 and 36 h. Western blot analysis showed that compared with co-culture at 0 h, the expression of Rac1 protein in the MEF was significantly increased at 24 h and 36 h of co-culture (P<0.01). The results of immunocytochemical staining showed that compared with co-culture at 0 h, the positive expression level of Rac1 in the MEF cells was significantly increased at 12 h, 24 h and 36 h of co-culture (P<0.05 or P<0.01). CONCLUSION Intake of exosomes secreted by mouse melanoma cells promotes the expression of Rac1 protein in fibroblasts.     

Mechanism of elemene enhancing radiosensitivity of human glioma U251 cells

AIM To investigate the effect of elemene on the radiosensitivity of human glioma U251 cells and its mechanism. METHODS The U251 cells were used as a glioma model in vitro, and were exposed to different concentrations of elemene and different doses of radiation. The cell viability was measured by MTT assay, the apoptosis and cell cycle distribution were analyzed by flow cytometry, and the related protein levels were determined by Western blot. RESULTS Elemene inhibited the viability of U251 cells in vitro and enhanced the radiosensitivity of the cells. The cells in radiotherapy combined with elemene group had higher rates of early apoptosis, secondary necrosis and total cell death than those in radiation group. Elemene induced G₂/M phase arrest in the U251 cells. Elemene reduced the protein expression of cell division cycle protein 2 （Cdc2）, which resulted in the decrease in cyclin B1 expression induced by radiotherapy, thereby inhibiting the formation of cyclin B-Cdc2 complex. Elemene reduced Cdc2 activity by inhibiting the phosphorylation of Cdc2 protein at threonine 161, thereby inducing G₂/M phase arrest in the cells. It also mediated apoptosis by down-regulating survivin expression. CONCLUSION Elemene may increase the sensitivity of U251 cells to radiotherapy by down-regulating Cdc2 protein, decreasing cyclin B1 expression, inhibiting the formation of cylcin B-Cdc2 complex and down-regulating the expression of survivin.     

Effects of different active constituents of Gynostemma pentaphyllum on mitochondrial energy metabolism-related proteins in endothelial cells induced by ox-LDL

AIM To investigate the effects of different components of Gynostemma pentaphyllum ［gypenosides (Gps), gypenoside XLIX (GpXLIX) and ginsenoside Rb3 (GRb3)］ on mitochondrial energy metabolism-related proteins in endothelial cells induced by oxidized low-density lipoprotein (ox-LDL). METHODS EA.hy926 cells were divided into control group, model group, Gps group, GpXLIX group and GRb3 group. The cells in control group were cultured only in DMEM complete medium. The cells in model group were treated with 100 mg/L ox-LDL for 48 h. The cells in Gps group, GpXLIX group and GRb3 group were treated with 100 mg/L ox-LDL for 24 h, and then treated with Gps, GpXLIX and GRb3 at 100 mg/L for another 24 h, respectively. The ATP content in each group was detected by ELISA. The expression levels of mitochondrial energy metabolism-related proteins, cytochrome C oxidase subunit 5a （Cox5a）, NADH:ubiquinone oxidoreductase core subunit S1 （Ndufs1）, ATP synthase F1 subunit alpha (ATP5a) and cytochrome C (Cyt C）, were determined by Wes automatic Western blot quantitative analysis system and Western blot. RESULTS Compared with control group, the ATP content in model group was decreased (P<0.01). After drug intervention, the ATP content increased to different degrees in Gps group, GpXLIX group and GRb3 group (P<0.01). The results of Wes automatic Western blot quantitative analysis system were consistent with those of Western blot. These results showed that compared with control group, the protein expression of Cox5a, Ndufs1 and ATP5a in model group was decreased, and the protein expression of Cyt C was increased (P<0.01). After intervention, the protein expression of Cox5a, Ndufs1 and ATP5a was increased and the protein expression of Cyt C was decreased in Gps group, GpXLIX group and GRb3 group (P<0.05 or P<0.01). Among them, the effect of Gps on the protein expression of Cox5a, Ndufs1 and Cyt C was significantly stronger than those of the 2 monomer components, and the effect of GRb3 was found to be superior in the 2 monomer components. The effect of GpXLIX on ATP5a protein was superior to the other 2 components. CONCLUSION Gynostemma total saponins and related active ingredients protect ox-LDL-induced endothelial cells by affecting mitochondrial energy metabolism-related proteins, thereby preventing and treating atherosclerosis.     

虎雪兰玻璃化超低温法脱毒技术的研究

以兰属花卉虎雪兰组培原球茎为试材,采用玻璃化超低温法对兰花病毒脱除进行了研究,以期为虎雪兰玻璃化超低温法脱毒体系的建立提供参考依据。结果表明:在蔗糖浓度0.5 mol·L-1预培养4 d,然后在蔗糖0.6 mol·L-1加载液冰上处理50 min,之后转入PVS2溶液冰上玻璃化处理120 min,再液氮冷冻40 min,37℃水浴解冻3 min,最后卸载液(1/2MS+1.2 mol·L-1蔗糖)卸载20 min,待恢复培养后,原球茎成活率可达到65%以上,随机检测不同处理样品的脱毒率可达97%。