转Bt基因抗虫棉田棉铃虫消长规律及危害特点

通过对转 Bt基因抗虫棉田棉铃虫的系统调查研究表明 :(1)转 Bt基因抗虫棉对棉铃虫蛾、卵无抗性表现 ,田间落卵量与常规棉田无明显差异 ,相反 ,二代棉铃虫百株累计卵量倒比常规棉处理区增加了 2 16～ 2 74粒 ,增长幅度为 30 %～ 38% ;(2 )转 Bt基因抗虫棉对二代棉铃虫幼虫的抗性及控制作用较强 ,基本不用进行药剂防治 ,但对三代棉虫幼虫的抗性控制效果明显下降 ,田间 3龄以上幼虫平均达2 0～ 4 0头 /百株 ,多者达 6 0头以上 ,仍需进行必要的药剂防治 ;(3)棉铃虫在转 Bt基因抗虫棉株上的危害特点与常规棉株有明显的差异 ,表现在幼虫和危害症状均较隐蔽 ,不易被发现。     

转新型双抗虫基因棉花的遗传分析

首次用含合成的BtCrylAc活性杀虫蛋白嵌合基因及慈菇蛋白酶抑制剂B(API-B)基因表达框的双抗虫基因植物表达载体,通过土壤根癌杆菌介导转化棉花品种冀合321,获得一批抗虫的转化再生棉花植株。利用叶片涂抹卡那霉素、叶片离体养虫和PCR扩增等检测方法对6个不同转双抗虫基因株系的抗虫性进行遗传分析。结果显示,转化株系自交的T1抗虫性状遗传较为复杂;农杆菌介导获得的转基因抗虫棉在早期世代不易选到纯合系,但是随着对抗虫性状进行单向选择,到T4和T5就能获得抗虫纯合系。利用抗虫性稳定的转化后代材料和转化受体进行田间杂交,发现F2抗虫性分离完全符合一对或两对显性基因的分离规律,并证明了DR248和DR193两个材料为外源基因双拷贝插入。转化株系的Southern杂交也证明了上述结果。     

转新型抗虫基因Vip3A棉花新种质的创制

该研究构建植物表达载体pBin438 Vip3A,通过农杆菌介导法转化棉花品种‘冀合713’,将新型抗虫基因Vip3A导入到棉花植株,创制对棉铃虫抗性的转基因棉花新种质。结果表明：(1)PCR检测Vip3A基因已经导入到棉花基因组中且能够稳定遗传。(2)室内抗虫性鉴定表明,与对照相比转基因植株对棉铃虫的抗性显著提高,并获得2株高抗和3株抗棉铃虫的转Vip3A基因株系。(3)Southern blotting结果显示,转基因株系BV01为单拷贝。(4)Elisa检测表明,外源Vip3A基因在BV01的根、茎、叶、花、种子中都有表达,在叶片中的Vip3A蛋白表达为苗期>蕾期>花期>铃期>吐絮期。该研究创制了新型抗虫转基因棉花材料,为培育棉花新型抗虫品种提供了种质资源。     

青菜的高效再生和农杆菌介导B.t.及CpTI基因的转化

分别对培养基中适宜的激素组成和AgNO3 添加浓度进行研究 ,建立了青菜下胚轴和子叶外植体的高效再生系统 ,青菜品种“矮抗青”的最高芽分化频率下胚轴可达 6 5 % ,子叶为 5 2 %左右。在此基础上 ,对影响转化频率的不同因素进行了探讨 ,共获 94株卡那霉素抗性植株。对转基因植株总DNA的Southernblot ting分析证明 ,B .t .基因和CpTI基因已整合到青菜植株的细胞核基因组中。经过抗虫性筛选试验 ,从转基因植株的T3 代筛选到 7个转B .t.基因的抗虫纯合株系和 5个转CpTI基因的抗虫纯合株系 ,并进入田间小区青菜抗虫新品种试验     

转三价抗虫基因彩色棉的获得

采用农杆菌介导法将外源三价抗虫基因Bt-CpTI-GNA导入彩色棉中,经分子检测已整合到受体植株体内,并已得到表达。目前已得到纯化株行。外源标记基因NPTII检测在T。代就有分离现象,各代检测淘汰3～4次才能基本清除分离株或非转化株。抗虫性检测表明转三价抗虫基因彩色棉对棉铃虫具有较高抗性,而对棉蚜则作用小大。     

陆地棉栽培品种转复合启动子控制下cry1Ac3基因获得高效虫植株

以根癌土壤杆菌（Agrobacterium tumefaciens)介导法分别将植物表达工体pBinMoBc和pBinoBc导入陆地棉（Gossypium hirsutum L.)栽培品种“新陆早1号”,“晋棉7号”,“晋棉12号”和“冀合321”,pBinMoBc携带有高效启动子复合OM启动子控制下的cry1Ac3基因,pBinoBc携带有35S启动子控制下的cry1Ac3基因,经过共培养,卡那霉素筛选抗性愈伤组织及体细胞胚的诱导,得到了再生植株,对T2代的PCR,Southern blotting ELISA检测及Western blotting证明cry1Ac3基因已整合人受体棉花基因并得到表达,抗虫性检测表明转基因后代对棉铃虫（Heliothis armigera)具有良好的抗性,转pBinMoBc T2代与转pBinoBc T2代相比,对棉铃虫具有更快的致死速度,本研究建立了一套高效的陆地棉栽培品种转化体系;进一步的检测结果表明,复合OM启动子可以提高外源基因的表达量从而增强转基因棉的抗虫性。     

陆地棉栽培品种转复合启动子控制下的cry 1Ac3基因获得高效抗虫植株

以根癌土壤杆菌( Agrobacterium tumefaciens )介导法分别将植物表达载体pBinMoBc和pBinoBc导入陆地棉( Gossypium hirsutum L.)栽培品种"新陆早1号"、"晋棉7号"、"晋棉12号"和"冀合321".pBinMoBc携带有高效启动子复合OM启动子控制下的 cry 1Ac3基因,pBinoBc携带有35S启动子控制下的 cry 1Ac3基因.经过共培养、卡那霉素筛选抗性愈伤组织及体细胞胚的诱导,得到了再生植株.对T2代的PCR、Southern blotting、ELISA检测及Western blotting证明 cry 1Ac3基因已整合入受体棉花基因组并得到表达.抗虫性检测表明转基因后代对棉铃虫( Heliothis armigera ) 具有良好的抗性,转pBinMoBc T2代与转pBinoBc T2代相比,对棉铃虫具有更快的致死速度.本研究建立了一套高效的陆地棉栽培品种转化体系;进一步的检测结果表明,复合OM启动子可以提高外源基因的表达量从而增强转基因棉的抗虫性.     

陆地棉栽培品种转复合启动子控制下的cry1Ac3基因获得高效抗虫植株(英文)

以根癌土壤杆菌 (Agrobacteriumtumefaciens)介导法分别将植物表达载体pBinMoBc和pBinoBc导入陆地棉(GossypiumhirsutumL .)栽培品种“新陆早 1号”、“晋棉 7号”、“晋棉 12号”和“冀合 32 1”。pBinMoBc携带有高效启动子复合OM启动子控制下的cry1Ac3基因 ,pBinoBc携带有 35S启动子控制下的cry1Ac3基因。经过共培养、卡那霉素筛选抗性愈伤组织及体细胞胚的诱导 ,得到了再生植株。对T2 代的PCR、Southernblotting、ELISA检测及Westernblotting证明cry1Ac3基因已整合入受体棉花基因组并得到表达。抗虫性检测表明转基因后代对棉铃虫 (Heliothisarmigera )具有良好的抗性 ,转pBinMoBcT2 代与转pBinoBcT2 代相比 ,对棉铃虫具有更快的致死速度。本研究建立了一套高效的陆地棉栽培品种转化体系 ;进一步的检测结果表明 ,复合OM启动子可以提高外源基因的表达量从而增强转基因棉的抗虫性。     

转单、双Bt基因741杨外源基因表达和抗虫性比较

【目的】研究联合使用两种或两种以上的抗虫基因的抗虫效果, 同时鉴定并筛选出转双Bt基因741杨对鳞翅目和鞘翅目害虫有较强抗性的株系。【方法】选取转三基因（Cry3Aa+Cry1Ac+API）741杨8个株系、 转双基因（Cry1Ac+API）741杨1个株系和转单基因（Cry3Aa）741杨3个株系为试材, 从外源基因PCR检测、 毒蛋白表达和抗虫性三方面对转基因株系进行对比分析。【结果】经PCR扩增后各转基因株系出现了预期的电泳条带。ELISA蛋白检测显示转基因株系中都有与所含基因相应的Bt杀虫蛋白表达。用转基因株系新鲜叶片进行柳蓝叶甲Plagiodera versicolora和美国白蛾Hyphantria cunea室内饲虫实验表明： 转入不同抗虫基因的杨树对昆虫的抗性具有选择性, 对非靶标昆虫没有毒杀作用。转双Bt基因741杨具有双抗性, 不同转基因株系表现出高中低的抗性水平： 在对柳蓝叶甲的抗性上, 筛选出的其中5个高抗株系（pCCA1, pCCA2, pCCA5, pCCA6和pCCA9）的抗性水平明显比含Cry3Aa单Bt基因的3个高抗株系（pCC11, pCC53和pCC84）高; 在对美国白蛾的抗性上, 有7个株系（pCCA2~pCCA7和pCCA9）的抗性水平与含Cry1Ac单Bt基因株系（pB29）表现一致, 只有1个株系（pCCA1）对美国白蛾表现出了极低的抗性。【结论】多个抗虫基因在741杨上的联合使用, 不仅扩大了抗虫谱, 其中的高抗株系还具有了更高的抗虫能力, 有效地发挥了基因的叠加效应。     

蛋白激发子基因peaT1转基因棉花的获得及初步鉴定

将来源于极细链格孢菌的蛋白激发子基因pesT1克隆到植物表达载体pCAMBIA2300上,成功构建了含有增强子和多联终止子的植物表达载体pCAM BI A2300-G4AS-peaT1.通过花粉管通道法转化棉花,经卡那霉素抗性筛选、PCR和RT-PCR检测获得一株转基因棉花植株,其植株茎粗和成铃数均高于非转基因对照株.     

Control of resistant pink bollworm (Pectinophora gossypiella) by transgenic cotton that produces Bacillus thuringiensis toxin Cry2Ab

Crops genetically engineered to produce Bacillus thuringiensis toxins for insect control can reduce use of conventional insecticides, but insect resistance could limit the success of this technology. The first generation of transgenic cotton with B. thuringiensis produces a single toxin, Cry1Ac, that is highly effective against susceptible larvae of pink bollworm (Pectinophora gossypiella), a major cotton pest. To counter potential problems with resistance, second-generation transgenic cotton that produces B. thuringiensis toxin Cry2Ab alone or in combination with Cry1Ac has been developed. In greenhouse bioassays, a pink bollworm strain selected in the laboratory for resistance to Cry1Ac survived equally well on transgenic cotton with Cry1Ac and on cotton without Cry1Ac. In contrast, Cry1Ac-resistant pink bollworm had little or no survival on second-generation transgenic cotton with Cry2Ab alone or with Cry1Ac plus Cry2Ab. Artificial diet bioassays showed that resistance to Cry1Ac did not confer strong cross-resistance to Cry2Aa. Strains with >90% larval survival on diet with 10 microg of Cry1Ac per ml showed 0% survival on diet with 3.2 or 10 microg of Cry2Aa per ml. However, the average survival of larvae fed a diet with 1 microg of Cry2Aa per ml was higher for Cry1Ac-resistant strains (2 to 10%) than for susceptible strains (0%). If plants with Cry1Ac plus Cry2Ab are deployed while genes that confer resistance to each of these toxins are rare, and if the inheritance of resistance to both toxins is recessive, the efficacy of transgenic cotton might be greatly extended.     

Control of Resistant Pink Bollworm (Pectinophora gossypiella) by Transgenic Cotton That Produces Bacillus thuringiensis Toxin Cry2Ab

Crops genetically engineered to produce Bacillus thuringiensis toxins for insect control can reduce use of conventional insecticides, but insect resistance could limit the success of this technology. The first generation of transgenic cotton with B. thuringiensis produces a single toxin, Cry1Ac, that is highly effective against susceptible larvae of pink bollworm (Pectinophora gossypiella), a major cotton pest. To counter potential problems with resistance, second-generation transgenic cotton that produces B. thuringiensis toxin Cry2Ab alone or in combination with Cry1Ac has been developed. In greenhouse bioassays, a pink bollworm strain selected in the laboratory for resistance to Cry1Ac survived equally well on transgenic cotton with Cry1Ac and on cotton without Cry1Ac. In contrast, Cry1Ac-resistant pink bollworm had little or no survival on second-generation transgenic cotton with Cry2Ab alone or with Cry1Ac plus Cry2Ab. Artificial diet bioassays showed that resistance to Cry1Ac did not confer strong cross-resistance to Cry2Aa. Strains with >90% larval survival on diet with 10 μg of Cry1Ac per ml showed 0% survival on diet with 3.2 or 10 μg of Cry2Aa per ml. However, the average survival of larvae fed a diet with 1 μg of Cry2Aa per ml was higher for Cry1Ac-resistant strains (2 to 10%) than for susceptible strains (0%). If plants with Cry1Ac plus Cry2Ab are deployed while genes that confer resistance to each of these toxins are rare, and if the inheritance of resistance to both toxins is recessive, the efficacy of transgenic cotton might be greatly extended.     

转基因抗棉铃虫抗草甘膦棉花对棉铃虫的抗虫性及对二种地老虎幼虫生长发育的影响

为了明确转Bt Cry1A+CP4EPSPS基因抗棉铃虫抗草甘膦棉花对棉铃虫Helicoverpa armigera(Hübner)的抗性水平及对八字地老虎Amathes c-nigrum和黄地老虎Agrotis segetum的影响,作者用转基因棉花和非转基因棉花叶片对棉铃虫、八字地老虎和黄地老虎幼虫进行了室内饲养观察。结果表明,转基因抗棉铃虫抗草甘膦棉花对新疆南部第2代棉铃虫表现为中抗,幼虫校正死亡率为70.4%;棉花叶片在整个生育期均能表达Bt毒蛋白,整个生育期Bt毒蛋白含量呈逐渐降低的趋势。转基因抗棉铃虫抗草甘膦棉花对八字地老虎幼虫有强烈的毒杀作用,可以引起幼虫大量死亡,对存活幼虫的生长发育也有明显的抑制作用,幼虫发育迟缓,不能顺利化蛹;但对黄地老虎幼虫没有明显的影响,幼虫可以正常生长。     

Transgenic cotton co-expressing chimeric Vip3AcAa and Cry1Ac confers effective protection against Cry1Ac-resistant cotton bollworm

Wide planting of transgenic Bt cotton in China since 1997 to control cotton bollworm (Helicoverpa armigera) has increased yields and decreased insecticide use, but the evolution of resistance to Bt cotton by H. armigera remains a challenge. Toward developing a new generation of insect-resistant transgenic crops, a chimeric protein of Vip3Aa1 and Vip3Ac1, named Vip3AcAa, having a broader insecticidal spectrum, was specifically created previously in our laboratory. In this study, we investigated cross resistance and interactions between Vip3AcAa and Cry1Ac with three H. armigera strains, one that is susceptible and two that are Cry1Ac-resistant, to determine if Vip3AcAa is a good candidate for development the pyramid cotton with Cry1Ac toxin. Our results showed that evolution of insect resistance to Cry1Ac toxin did not influence the sensitivity of Cry1Ac-resistant strains to Vip3AcAa. For the strains examined, observed mortality was equivalent to the expected mortality for all the combinations of Vip3AcAa and Cry1Ac tested, reflecting independent activity between these two toxins. When this chimeric vip3AcAa gene and the cry1Ac gene were introduced into cotton, mortality rates of Cry1Ac resistant H. armigera larvae strains that fed on this new cotton increased significantly compared with larvae fed on non-Bt cotton and cotton producing only Cry1Ac. These results suggest that the Vip3AcAa protein is an excellent option for a “pyramid” strategy for pest resistance management in China.     

转Cry1Ac+Cry2Ab棉对棉铃虫的控制作用及对天敌捕食烟粉虱功能反应的影响

文章以转Cry1Ac基因棉(中棉所41)和常规棉(中棉所49)为对照,研究了转Cry1Ac+Cry2Ab基因棉(639020)在棉花生长的关键时期——蕾期(二代棉铃虫发生期)、花期(三代棉铃虫发生期)和花铃期(四代棉铃虫发生期)对棉铃虫的控制作用,同时研究了639020棉田主要捕食性天敌(中华草蛉幼虫、龟纹瓢虫、小花蝽和草间小黑蛛)对烟粉虱的捕食功能,明确了639020棉花在生长的关键时期对棉铃虫的控制效果及对棉田主要捕食性天敌捕食功能反应的影响。结果表明,639020棉花对二代和三代棉铃虫具有良好的控制作用,抗虫性分别比中棉所41提高了52.85%和16.22%,其中前者差异达显著水平,后者差异不显著。在棉花蕾期、花期和花铃期,639020棉田棉铃虫落卵量都比中棉所41棉田和中棉所49棉田低(除二代棉铃虫发生期);棉铃虫幼虫数量都极显著低于常规棉,且都低于防治指标,但与中棉所41棉田无显著差异。639020棉田中华草蛉、龟纹瓢虫、小花蝽和草间小黑蛛对烟粉虱的捕食功能与中棉所41棉田和常规棉田相比无显著变化。研究结果以期为新型转基因棉花环境安全性研究及其外源基因的抗虫遗传效应和生产应用前景进行安全性评价。     

不同Bt蛋白对棉铃虫存活率和生长发育的影响

在我国Bt棉主要以Cry1Ab或Cry1Ac为主,其他新型Bt基因未被转入棉花中用来控制害虫,然而大面积种植单价Bt基因的棉花,将可能会大大增加靶标害虫对该类型Bt棉花抗性频率,因此研究其他新型Bt蛋白对靶标害虫的控制作用显得十分必要。采用蛋白混入人工饲料的生物测定方法,在室内测定了6种Bt蛋白对棉铃虫初孵幼虫的毒力,比较了浓度为1．0μg· g-1时不同Bt蛋白对棉铃虫幼虫生长发育的影响。毒力测定结果表明,不同Bt蛋白对棉铃虫初孵幼虫的毒力不同,LC50值由低到高依次为Cry1Ab 0．065μg· g-1、Cry1Ac 0．074μg· g-1、Cry2Ab 0．133μg· g-1、Cry2Aa 11．670μg· g-1、Cry1Ah 13．010μg· g-1和Cry1Ca＞20μg· g-1。生长发育测定结果表明,Cry1Ab和Cry1Ac对棉铃虫幼虫的生长发育影响最大,Cry2Ab次之;Cry1Ah和Cry2Aa对1龄幼虫的校正死亡率和体重抑制率差别不大,但对2龄幼虫的差异较大,Cry1Ah处理2龄幼虫后体重和生长发育参数与Cry2Ab接近,而Cry1Ca对棉铃虫幼虫生长发育几乎没影响。Cry1Ah、Cry2Aa和Cry2Ab的毒力不如Cry1Ac和Cry1Ab,但仍可以作为控制棉铃虫幼虫的替代策略。     

Increased frequency of pink bollworm resistance to Bt toxin Cry1Ac in China

Transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) kill some key insect pests, but evolution of resistance by pests can reduce their efficacy. The main approach for delaying pest adaptation to Bt crops uses non-Bt host plants as "refuges" to increase survival of susceptible pests. To delay evolution of pest resistance to transgenic cotton producing Bt toxin Cry1Ac, the United States and some other countries have required refuges of non-Bt cotton, while farmers in China have relied on "natural" refuges of non-Bt host plants other than cotton. The "natural" refuge strategy focuses on cotton bollworm (Helicoverpa armigera), the primary target of Bt cotton in China that attacks many crops, but it does not apply to another major pest, pink bollworm (Pectinophora gossypiella), which feeds almost entirely on cotton in China. Here we report data showing field-evolved resistance to Cry1Ac by pink bollworm in the Yangtze River Valley of China. Laboratory bioassay data from 51 field-derived strains show that the susceptibility to Cry1Ac was significantly lower during 2008 to 2010 than 2005 to 2007. The percentage of field populations yielding one or more survivors at a diagnostic concentration of Cry1Ac increased from 0% in 2005-2007 to 56% in 2008-2010. However, the median survival at the diagnostic concentration was only 1.6% from 2008 to 2010 and failure of Bt cotton to control pink bollworm has not been reported in China. The early detection of resistance reported here may promote proactive countermeasures, such as a switch to transgenic cotton producing toxins distinct from Cry1A toxins, increased planting of non-Bt cotton, and integration of other management tactics together with Bt cotton.     

转基因抗虫棉Bt基因不同剂量的聚合与抗虫性表现

通过有性杂交手段培育出聚有不同数目Bt基因的植株,在不同生育期进行抗虫性测定和Bt毒蛋白表达的ELISA检测,旨在揭示聚合不同数目Bt基因的植株抗虫性的互作表达机理。聚合有1－4个Bt基因的植株在整个生育期的抗虫性、毒蛋白表达特性和单价抗虫棉时空表达一致,生育前期抗虫性好、毒蛋白表达量高;生育中、后期抗虫性有所下降,毒蛋白表达量降低。聚合有4个Bt基因的纯合材料并未因Bt基因的增加而起到抗性增强的效果,相反还因同源抑制而有所降低。不同来源的Bt基因处于杂合状态时其抗虫性和Bt毒蛋白量均得到充分表达。     

转基因玉米2HVB5的性状鉴定及遗传稳定性分析

为了明确转基因玉米2HVB5的目标性状及遗传稳定性,对回交转育郑58的BC₅S₁、BC₅S₂代转基因玉米2HVB5分别进行了Southern blot、ELISA、室内和田间生物活性测定、靶标除草剂草铵膦耐受性分析及农艺性状调查。结果显示,2HVB5中目的基因cry2Ah-vp和bar都是以单拷贝的形式整合到玉米基因组并稳定遗传,Cry2Ah-vp和PAT蛋白在2HVB5植株的不同时期、不同组织部位均有表达,其中在叶片中的表达量相对较高,分别达到2-3.5 μg/g FW（鲜重）和8-17 μg/g FW（鲜重）。室内生物活性检测结果表明,2HVB5转基因玉米对东方粘虫和棉铃虫有很高的抗性,接虫后4-5 d幼虫死亡率达100%,对草地贪夜蛾有明显的体重抑制。田间抗虫性鉴定结果也表明,2HVB5转基因玉米对东方粘虫和棉铃虫均达到高抗水平,平均抗性级别分别为1.19-1.29和0.60-0.73。2HVB5转基因玉米可耐受田间使用中剂量4倍量的草铵膦,农艺性状与对照郑58相比无显著差异。转基因玉米2HVB5遗传稳定,高抗虫耐除草剂,可用于玉米害虫尤其是夜蛾科害虫的防治,具有产业化应用前景。     

Characterization of Chimeric Bacillus thuringiensis Vip3 Toxins

Bacillus thuringiensis vegetative insecticidal proteins (Vip) are potential alternatives for B. thuringiensis endotoxins that are currently utilized in commercial transgenic insect-resistant crops. Screening a large number of B. thuringiensis isolates resulted in the cloning of vip3Ac1. Vip3Ac1 showed high insecticidal activity against the fall armyworm Spodoptera frugiperda and the cotton bollworm Helicoverpa zea but very low activity against the silkworm Bombyx mori. The host specificity of this Vip3 toxin was altered by sequence swapping with a previously identified toxin, Vip3Aa1. While both Vip3Aa1 and Vip3Ac1 showed no detectable toxicity against the European corn borer Ostrinia nubilalis, the chimeric protein Vip3AcAa, consisting of the N-terminal region of Vip3Ac1 and the C-terminal region of Vip3Aa1, became insecticidal to the European corn borer. In addition, the chimeric Vip3AcAa had increased toxicity to the fall armyworm. Furthermore, both Vip3Ac1 and Vip3AcAa are highly insecticidal to a strain of cabbage looper (Trichoplusia ni) that is highly resistant to the B. thuringiensis endotoxin Cry1Ac, thus experimentally showing for the first time the lack of cross-resistance between B. thuringiensis Cry1A proteins and Vip3A toxins. The results in this study demonstrated that vip3Ac1 and its chimeric vip3 genes can be excellent candidates for engineering a new generation of transgenic plants for insect pest control.