转基因大豆及其安全性

世界转基因作物发展迅猛,其中转基因大豆无论种植面积还是作物产量方面均占有较大比例, 但其安全性受到人们极大关注。该文对转基因大豆进行概述,同时阐述转基因大豆种类、特性及其安全 性,并对转基因大豆前景进行展望。     

转基因抗矮花叶病玉米对子一代雄性大鼠生殖功能的影响

分别采用含33％剂量的转基因抗矮花叶病玉米和非转基因玉米对大鼠进行170d的全食物饲喂,检测F1代大鼠睾丸、附睾的脏器系数,精子的活动率和畸形率,以及睾丸、附睾组织病理学变化。结果显示：试验组与对照组比较,大鼠睾丸、附睾和精子的各项指标均无显著性差异（P〉0．05）;转基因抗矮花叶病玉米对F1代雄性大鼠生殖功能无显著影响。     

抗草甘膦转基因大豆对雄鼠睾丸生殖细胞与精子的影响

以雄性昆明鼠为实验动物,新生小鼠断乳后喂食抗草甘膦转基因大豆饲料,分别在30、60、90、120d取其睾丸和附睾,采用吉姆萨染色（Giemsa）检测小鼠睾丸组织早期精细胞微核率变化,并以荧光素标记的豌豆凝集素（FITC-PSA）检测小鼠附睾精子顶体完整率及顶体反应率变化。结果表明:与对照组相比,30、60、90、120d喂食抗草甘膦转基因大豆对小鼠睾丸组织早期精细胞微核率均无统计学差异,与之对应,30、60、90、120d喂食抗草甘膦转基因大豆对小鼠精子顶体完整率及反应率也无显著变化。研究表明:转基因大豆饲料30、60、90、120d喂食不会对小鼠睾丸组织染色体结构造成损伤,也未对小鼠精子的顶体形态结构和精子顶体反应能力造成影响。      

转基因与非转基因大豆营养及次生物质的比较

对转基因大豆与非转基因大豆种子中主要营养指标及次生代谢物方面进行差异检测。研究结果表明,转基因大豆中粗蛋白、粗脂肪、总酚、酚酸以及黄酮的含量都明显高于非转基因大豆。因此,通过这些研究有望对今后大豆的转基因育种及转基因食品的膳食提供基础数据。同时,对转基因大豆食品安全性评价和检测提供参考。     

转基因大豆检测方法的研究进展

综述了转基因大豆中的蛋白质和核酸的检测技术研究进展,对比各种方法的优缺点,为后续深入研究提供理论基础。     

非转基因和转基因大豆中色氨酸含量分析

目的：对大豆中色氨酸分析的碱水解方法进行研究,比较非转基因和转基因大豆中色氨酸的含量。方法：样品用氢氧化锂溶液水解提取,样液经中和定容、过膜后,用超高效液相-荧光检测器测定,外标法定量。结果：应用氢氧化锂对大豆样品进行碱水解,方法的回收率为90%～93%,相对标准偏差小于5.0%。非转基因和转基因大豆样品的色氨酸分析,转基因大豆的色氨酸含量均不低于非转基因大豆,其中的色氨酸可以满足人体健康需要。结论：该方法准确快速、重现性好,适用于大豆中色氨酸含量分析的检测要求。     

利用蛋白质SDS-PAGE电泳方法检测转基因大豆的初步研究

为建立利用蛋白质检测转基因大豆的较稳定的新方法,采用SDS-PAGE蛋白质电泳方法时转基因大豆和非转基因大豆进行检测,初步研究发现转基因大豆中大约45 ku蛋白带的表达量明显强于非转基因大豆中相对应的蛋白带,通过固定转基因大豆的上样量,逐渐增加非转基因大豆的上样量进一步验证了结果.以国内不同品种的非转基因大豆进行SDS-PAGE蛋白电泳检测,初步排除了结果偶然性的产生.     

建立国产非转基因大豆保护机制正当时

文章针对目前我国国内大豆市场份额已基本被庞大的进口转基因大豆占据,国产非转基因大豆生产每况愈下,非转基因大豆榨油比例逐年缩小,话语权缺失,政策保护不到位等突出问题,对建立国产非转基因大豆保护机制的必要性和可行性进行了深入分析和思考,并结合我国大豆产业发展现状,提出五项保护机制。     

黑龙江省非转基因大豆优势的拓展

本文既分析了黑龙江省非转基因大豆的优势,又分析了在国外转基因大豆进口量剧增的紧逼下,国产非转基因大豆生存和发展的严峻形势。并就如何拓展黑龙江省非转基因大豆优势,振兴大豆产业提出建设性意见。     

转基因大豆食品的安全性

随着我国对外贸易的不断发展和农产品进出口结构的变化,我国自1996年开始由一个纯大豆出口国变成了净进口国,每年从美洲国家进口约300多万吨的大豆,其中有可能包括从美国进口的转基因大豆.     

多品系混杂转基因大豆样品中复合品系的检测

摘要：目的 确认一份多品系混杂转基因大豆样品中是否含有复合性状转基因大豆。方法 采用实时荧光定性PCR方法对实验室留存的一份转基因初筛阳性大豆样品进行品系筛查检测,后分别采用单粒多靶点筛查检测和清洗后单粒多靶点筛查检测方法进行复合性状品系的确认。结果 经鉴定,该大豆样品中混杂了5种转基因大豆品系,检出复合性状转基因大豆为MON87708×MON89788品系,该品系为中国未经批准进口的转基因大豆品系。结论 鉴于目前缺乏完整的检测技术体系和技术标准,这种多品系混杂样品中掺杂未批准复合性状品系的行为非常具有隐蔽性和欺骗性,国内的农业安全监管部门和海关检疫部门都应该对此高度重视。     

鼠李糖乳杆菌发酵大豆酸乳工艺优化研究

以大豆为主要原料,将鼠李糖乳杆菌(Lactobacillus rhamnosus)进行活化、驯化与保加利亚乳杆菌(Lactobacillus bulgaricus)和嗜热链球菌(Streptococcus thermophilus)按一定比例混合制备发酵剂,通过单因素实验和正交实验优化确定酸豆乳发酵的生产工艺。结果通过单因素实验确定上述三个菌种按1∶0.5∶1混合作为工作发酵剂;正交实验研究结果表明影响豆乳发酵的显著因素依次为料水比、接种量、发酵时间和蔗糖添加量,最佳条件是:接种量为5%,磨制豆浆料水比为1∶8,蔗糖添加量为8%,在43℃条件下发酵5h,该条件下生产的酸豆乳,具有浓郁的风味和细腻酸甜的口感。      

菜用大豆籽粒蔗糖积累及蔗糖磷酸合成酶研究进展

探究贮藏温度对鲜毛豆贮藏期品质的影响,并确定鲜毛豆的最佳贮藏温度。分别采用1、5、9、13 ℃贮藏鲜毛豆,监测贮藏期间鲜毛豆的感官指标（失重率、硬度、褐变指数指数、亮度L、红绿值a、黄蓝值b）、营养指标（可溶性蛋白含量、总糖含量、还原糖含量）和生理指标（呼吸强度、丙二醛含量）,并对指标进行相关性分析,采用主成分分析法确定最佳贮藏温度。结果表明：相比9 ℃和13 ℃的贮藏温度,1 ℃和5 ℃的低温贮藏显著（P<0.05）有利于减少鲜毛豆的失重率,延缓褐变,保持色泽,维持适宜的软硬度,保持可溶性蛋白、总糖和还原糖含量的相对平稳,贮藏15 d后仍保留食用价值;而9 ℃和13 ℃的鲜毛豆贮藏时间不宜超过9~12 d。1 ℃贮藏的鲜毛豆丙二醛开始积累时间延迟,贮藏15 d的积累量（仅增加了1倍）远小于其它三个贮藏温度的,在恢复室温时仍保持鲜豆40%的呼吸强度。相关性分析表明,鲜毛豆的感官指标、营养指标和生理指标之间密切相关。PCA分析表明,4个贮藏温度中,以1 ℃贮藏的保鲜效果最佳,5 ℃次之。     

转基因大豆种植对根际土壤酶活性和养分的影响

采用盆栽试验,以耐草甘膦大豆M88、抗虫耐草甘膦大豆ZB及常规大豆中黄13为研究对象,比较分析转基因大豆对根际土壤酶活性和养分含量的影响。结果表明,在大豆成熟期时,与常规大豆中黄13相比,M88、ZB根际土壤碱性磷酸酶活性、过氧化氢酶活性、速效磷含量无显著差异,硝态氮含量显著下降。根际土壤脲酶活性、铵态氮含量则表现不同,其变化随大豆品种的不同而不同。相较于常规大豆中黄13,M88根际土壤脲酶活性和铵态氮含量无显著差异;ZB根际土壤脲酶活性显著下降,而铵态氮含量则显著上升。     

金雀异黄素对青年雌性大鼠卵巢组织中雄激素生成关键酶StAR、P450scc、CYP19基因表达的影响

研究金雀异黄素（genistein,GEN）对青年雌性大鼠卵巢内类固醇合成急性调节蛋白（steroidogenic acute regulatory protein,StAR）、胆固醇侧链裂解酶（side-chain cleavage enzyme,P450scc）、细胞色素P450芳香化酶 （cytochrome P450 aromatase,CYP19）基因表达的影响。选取40 只SD青年雌性大鼠,按体质量随机分为阴性对照 组（NC）、GEN低、中、高剂量组及己烯雌酚阳性对照组,剂量组分别灌胃GEN 15、30、60 mg/（kg·d）,阳性 对照组灌胃己烯雌酚0.5 mg/（kg·d）,持续30 d。采用实时荧光聚合酶链式反应检测大鼠卵巢内StAR、P450scc、 CYP19 mRNA水平;Western blot法检测卵巢内StAR、P450scc的蛋白水平。给予GEN后,与NC组相比,GEN中、 高剂量组StAR、P450scc、CYP19 mRNA相对表达量显著增高（P＜0.05）。卵巢内StAR、P450scc的蛋白检测结果 显示：StAR表达量在GEN高剂量组增加明显（P＜0.05）;P450scc表达量在GEN中、高剂量组均增加明显,且与 NC组相比差异显著（P＜0.05）。得出结论为30～60 mg/kg的GEN可增强青年雌性大鼠体内雄激素生成关键酶的表 达水平,影响卵泡的发育和成熟。     

Effects of feeding rapeseed oil, soybean oil, or linseed oil on stearoyl-CoA desaturase expression in the mammary gland of dairy cows

Stearoyl-CoA desaturase (SCD) is an important enzyme in the bovine mammary gland, and it introduces a double bond at the Δ⁹ location of primarily myristoyl-, palmitoyl-, and stearoyl-CoA. The main objective of this study was to compare the effects of various fatty acids (FA) typically present in dairy cow rations on the expression of SCD1 and SCD5 in the mammary gland of dairy cows. Twenty-eight Holstein-Friesian cows were randomly assigned to 1 of 4 dietary treatments. The dietary treatments were a basal diet supplemented (dry matter basis) with 2.7% rapeseed oil as a source of C18:1 cis-9; 2.7% soybean oil as a source of C18:2 cis-9,12; 2.7% linseed oil as a source of C18:3 cis-9,12,15; or 2.7% of a 1:1:1 mixture of the 3 oils. The oil supplements were included in the concentrate, which was fed together with corn silage and grass silage. In addition, cows were grazing on pasture, consisting mainly of perennial ryegrass, during the day. Biopsies from the mammary gland were taken and analyzed for mRNA expression of SCD1 and SCD5 by using quantitative real-time PCR. Milk yield as well as milk protein and fat contents did not differ among the 4 dietary treatments. Dietary supplementation with rapeseed oil and linseed oil increased proportions of C18:1 cis-9 and C18:3 cis-9,12,15 in blood plasma, respectively, compared with the other treatments. Supplementation with soybean oil and linseed oil increased milk FA proportions of C18:2 cis-9,12 and C18:3 cis-9,12,15, respectively, but supplementation with rapeseed oil did not increase C18:1 cis-9 in milk. Mammary SCD1 expression was reduced by supplementation of soybean oil compared with rapeseed oil and linseed oil. In contrast, SCD5 expression did not differ among the 4 treatments. The C16 and C18 desaturation indices, representing proxies for SCD activity, were lower for the soybean oil diet compared with the diet supplemented with a mixture of the 3 oils. In conclusion, our study shows that mammary SCD1 expression is significantly downregulated in dairy cows by feeding unprotected soybean oil compared with rapeseed oil or linseed oil, and this is partially reflected by the lower desaturase indices in the milk. Furthermore, mammary SCD5 expression appears to be differently regulated than expression of SCD1.     

豆腐中转基因大豆成分的检测

目的探索适合豆腐样品的DNA抽提方法并采用实时荧光聚合酶链反应(PCR)技术对豆腐试样中的转基因大豆成分进行检测。方法分别采用CTAB和SDS配制抽提缓冲液提取18个豆腐样品中的DNA,针对转基因大豆都含有大豆内源基因lectin及共同元件CaMV35S启动子、nos终止子及epsps基因进行实时荧光PCR扩增。结果 SDS法比CTAB法提取的豆腐DNA质量更好;18个豆腐样品均检测到了lectin,其中有2个样品检测到了CaMV35S启动子的荧光信号,4个样品检测到了nos终止子的荧光信号,所有样品均未扩增出epsps基因。结论 SDS法比CTAB法更适合于抽提豆腐样品的DNA,提取到的DNA可用于实时荧光PCR法检测豆腐内源基因和外源基因。     

西式火腿罐头中添加浓缩大豆蛋白工艺技术研究

火腿罐头在加工工艺流程不变的情况下,添加1%的浓缩大豆蛋白粉,成品的感官、理化等技术指标均达到部颁标准,而且弹性、持水性、吸油性、切片性更佳.     

Effects of soybean isoflavone on metabolism of rat osteoblasts and cytokines in vitro

The effects and mechanisms of soybean isoflavone on osteoblast (OB) proliferation in vitro were investigated. Fifty female Wistar rats were randomly divided into five groups with 10 rats in each group. Rat OBs were separated and cultured. The first generation of OBs cultured for 48 hr at various concentrations of isoflavone were set as the experimental groups, the OBs exposed to estradiol (E₂) culture were considered as positive control group. The biological characterization of OBs was investigated by phase contrast microscopy and alkaline phosphatase (ALP) histochemistry. The concentrations of interleukin (IL-1), osteoprotegerin (OPG), transforming growth factor (TGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF) in isoflavone culture solutions were determined. Proliferation rate of OBs was increased in experimental group comparing that in the blank group. ALP activity in experimental group was higher than that in blank group. No significant differences of ALP activity were observed between E₂ culture group and isoflavone group at concentrations of 10⁻⁵ and 10⁻⁷ mM (P > 0.05). Furthermore, in the experimental groups at low isoflavone concentrations, the concentrations of OPG, TGF, and VEGF were increased and positively correlated with OB proliferation. However, the concentrations of IL-1, GM-CSF were decreased at higher concentration of isoflavone and were negatively correlated with OB proliferation. Soybean isoflavone could promote the growth and proliferation of rat OB, it might act as the stimulator of OPG, TGF, and VEGF pathway, and the inhibitor of IL-1, GM-CSF pathway as well.