耐低温耐低氧萌发野败不育系赣野A的选育

赣野A是江西省农科院水稻研究所将东乡野生稻的耐冷性和耐低氧萌发能力导入抗稻瘟病保持系赣香B后再与赣香A测交和回交育成的野败型三系籼稻不育系。该不育系败育彻底,异交结实率高,配合力较强,具有较强的耐冷性和耐低氧萌发能力,在直播杂交稻育种中应用前景广阔。2019年通过了江西省品种审定。     

超表达OsPR1A增强了Xa21介导的水稻对白叶枯病的抗性反应

【背景】前期研究发现,水稻病程相关蛋白质OsPR1A的表达受上游抗病基因Xa21调控,接菌后早期启动Xa21介导的OsPR1A较高水平表达对水稻抵抗白叶枯病菌至关重要。同时OsPR1A也受到水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae,Xoo）的诱导表达。对于OsPR1A的研究绝大部分是作为抗性反应发生的标志基因佐证其他基因或途径在抗性中的作用,缺乏直接的证据证实OsPR1A本身的生物学功能。【目的】通过获得OsPR1a-OX超表达转基因植株,调查其表型及农艺性状,并明确OsPR1A蛋白质表达与抗性的关系,为鉴定OsPR1A功能提供依据。【方法】通过农杆菌介导法,将构建的OsPR1a-OX转化载体转入到水稻受体4021中,利用PCR和免疫印迹（western blot,WB）技术分别在基因水平和蛋白质水平上筛选并鉴定OsPR1A超表达阳性纯合株系。在成熟期,调查OsPR1A超表达转基因植株的表型及农艺性状（株高、穗长、分蘖数、结实率和籽粒大小等）。在31℃条件下,将生长2周的水稻幼苗TP309、4021和OsPR1A超表达转基因植株接种水稻白叶枯病菌,并在接菌0、2、4、6、8、10和12 d时测量病斑长度。在接菌0、4和6 d时,收集TP309、4021和OsPR1A超表达转基因植株的水稻叶片,提取蛋白质,利用WB技术检测OsPR1A的表达特征。【结果】构建了OsPR1a-OX转化载体,并转入到受体4021中,筛选并鉴定到2个OsPR1A超表达转基因纯合株系（#704和#709）。调查了OsPR1A超表达转基因植株在成熟期的表型及农艺性状,与对照4021相比,#704和#709的株高较矮、穗长较短、分蘖数减少、结实率降低,但籽粒稍大,可能与结实率低有关。在31℃条件下,OsPR1A超表达转基因植株的病斑长度与对照4021相比明显缩短,结果具有显著性差异（P<0.05）。在接菌0、4和6 d的材料中,超表达转基因植株#704和#709中OsPR1A始终有较高水平的表达丰度,从而提高了对白叶枯病菌的抗性。【结论】采用农杆菌介导法,获得OsPR1A超表达转基因植株;超表达OsPR1A影响到水稻的正常发育过程;超表达OsPR1A后增强了Xa21介导的水稻对白叶枯病的抗性。     

Tanshinone ⅡA induces apoptosis via JNK signaling pathway in human osteosarcoma HOS cells

AIM: To explore the effect of tanshinone ⅡA on human osteosarcoma HOS cells and the underlying mechanism.METHODS: The cell viability and the appropriate dose of tanshinone ⅡA were determined by CCK-8 assay. Colony formation assay and Transwell assay were used to investigate the proliferation and migration abilities of the HOS cells treated with tanshinone ⅡA. The apoptosis of the HOS cells was monitored by Hoechst 33258 staining, transmission electron microscopy and flow cytometry. The protein levels of apoptosis-related molecules and JNK signaling-associated proteins were determined by Western blot. Meanwhile, a JNK inhibitor was added for confirming the relationship between the pathway and apoptosis mentioned above.RESULTS: Tanshinone ⅡA inhibited both HOS cell proliferation and migration in a dose-and time-dependent manner. Exposure of the HOS cells to tanshinone ⅡA resulted in the activation of apoptosis. Tanshinone ⅡA treatment increased the protein levels of cleaved caspase-3, Bax and JNK signaling-associated proteins, and decreased the protein level of Bcl-2, which were reversed by JNK inhibitor SP600125. Moreover, the result of CCK-8 assay revealed that tanshinone ⅡA-induced cell death was alleviated by JNK inhibitor.CONCLUSION: Tanshinone ⅡA induces cell growth inhibition and the activation of apoptosis via JNK signaling pathway in human osteosarcoma HOS cells.     

The effects of various plant protection methods on the development of Zymoseptoria tritici and Cephalosporium gramineum,grain yield and protein profile

Septoria leaf blotch progresses rapidly, leading to the development of Zymoseptoria titici forms resistant to fungicides. Cephalosporium stripe is caused by Cephalosporium gramineum. The aim of this study was to evaluate the effectiveness of selected pesticides in limiting the symptoms of both diseases on winter wheat leaves, and to determine their influence on grain yield and the content and composition of protein fractions in wheat kernels. Propiconazoles were most effective in inhibiting the development of Septoria leaf blotch (symptoms were reduced from 54.7% to 78.6%). Strobilurins were less effective due to the presence of isolates with the G143A mutation. Symptoms of Cephalosporium stripe were rarely observed, and protective treatments did not reduce their severity. The highest content of grain protein (14.81%) was found in plants most intensely protected with the fungicides containing fenpropimorph, pyraclostrobin and epoxiconazole. The principal component analysis revealed that the plant protection method influenced the grain protein profile. The accumulation of HMW glutenins and α/β gliadins was mutually interrelated and higher in high-input treatments; control grain was characterized by close relationships between ω-gliadins, LMW glutenins, albumins and globulins, whereas low-input treatments influenced mostly γ-gliadins.     

Effect of miRNA-33 on ABCA1/ABCG1 expression in RAW264.7 macrophage-derived foam cells after Hcy treatment

AIM:To study whether homocysteine (Hcy) inhibits the expression of ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) by microRNA-33 (miRNA-33) signaling, and reduces the efficiency of reverse cholesterol transport (RCT).METHODS:RAW264.7 macrophages were induced by oxidized low-density lipoprotein (ox-LDL) to establish foam cell model. Oil red O staining was used to determine whether the model was established successfully. miRNA-33 mimics and miRNA-33 inhibitor were transfected into the cells by Lipofectamine 2000, and the cells were exposed to Hcy at concentration of 5 mmol/L for 24 h. The intracellular lipid droplets were observed by Oil red O staining. The expression of ABCA1 and ABCG1 at mRNA and protein levels was determined by real-time PCR and Western blot. The cellular cholesterol content was analyzed by HPLC, and effluent rate of cholesterol was detected by the method of liquid scintillation counting.RESULTS:Compared with blank control group, the lipid content in miRNA-33 mimics group was increased, and the expression of ABCA1 and ABCG1 at mRNA and protein levels was decreased (P<0.05). The intracellular cholesterol content was increased gradually (P<0.05), and the cellular cholesterol efflux rate was gradually decreased (P<0.05) in miRNA-33 mimics group. Compared with blank control group, the testing results in miRNA-33 inhibitor group were the opposition of those in miRNA-33 mimics group (P<0.05). No diffe-rence of the above indexes among blank control group, miRNA-33 mimics-NC group and miRNA-33 inhibitor-NC group was observed.CONCLUSION:Hcy inhibits the mRNA and protein expression of ABCA1 and ABCG1 through miRNA-33 signaling, and reduces the efficiency of RCT in RAW264.7 macrophage-derived foam cells.     

一个潜在催化莱鲍迪D苷合成的新型糖基转移酶

尿苷二磷酸糖基转移酶(uridine diphosphate glycosyltransferases,UGTs)催化糖基转移反应,与植物次生代谢密切相关。本研究根据甜叶菊(Stevia rebaudiana)转录组数据库,克隆到一个催化莱鲍迪D苷(rebaudioside D,RD)合成的新型糖基转移酶候选基因,对其开展生物信息学分析。结果表明,该基因开放阅读框长1380 bp,编码459个氨基酸,等电点(pI)预测为5.54,理论分子量约49.66 kD,系统发育分析表明该基因与向日葵中的UGT89A2同源,故将其命名为SrUGT89A2。构建pET28a-SrUGT89A2原核表达载体,并在大肠杆菌(BL21(DE3))中诱导表达得到重组蛋白,HPLC检测表明粗酶液能催化甜叶菊提取液形成一个新的色谱峰,该峰保留时间与莱鲍迪D苷一致。经进一步纯化UGT89A2蛋白,添加不同甜菊糖苷标准品为催化底物,但未鉴定出该蛋白催化的具体糖苷。该潜在催化甜菊糖RD苷合成的新型糖基转移酶基因SrUGT89A2的发现,为RD苷的生物合成和甜菊糖苷的生物途径研究提供新的理论依据。     

多酚类化合物协同抗氧化性研究进展

多酚类化合物是一种大量存在于植物体内的物质，因其具有优良的抗氧化、抗癌、抗衰老等 性能而受到研究者们的广泛关注。多项研究表明具有抗氧化性能的物质之间大多具有协同作用，两 种或两种以上的物质化合，其抗氧化能力往往强于单一物质的抗氧化能力。近年来，许多研究者将目 光聚焦到多酚类物质与小分子物质化合所具有的协同抗氧化能力的研究上并做出多项试验。本文论 述了多酚类化合物的抗氧化机理及协同抗氧化机理，并以茶多酚与维生素C、维生素E 化合为例对协 同抗氧化进行论述。     

用免疫荧光、酶标技术检测赭曲霉毒素A的研究

该项研究采用本课题组提纯的赭曲霉毒素A(Ochratoxin A·简称OA)和研制的兔抗OA抗体等,进行间接荧光法和ELISA间接法检测OA的试验。通过对不同浓度的OA纯品和含毒饲料浸提液及中毒死亡鸡内脏的间接荧光染色,均能检出分布均匀、大小有别的黄绿色荧光亮点;用OA为被检抗原和兔抗OA抗体与羊抗兔IgG-HRP进行ELISA间接法试验,对含不同浓度OA的试验孔和对照孔的检测,结果均正确稳定。研究结果证明,以上两种检测方法检测OA均具有灵敏、特异、快速等优点。     

狗枣猕猴桃果实软化过程中阶段性专一酶的研究

狗枣猕猴桃果实采后软化过程分两个阶段，第一阶段软化较快，起主要作用的阶段性专一酶是淀粉酶；第二阶段软化较慢，起主要作用的阶段性专一酶是多聚半乳糖醛酸酶。乙烯释放对果实软化有促进作用；保护性酶（过氧化物酶。过氧化氢酶）出现在果实软化后期，因而不是果实软化的阶段性专一酶。