蒋高明 由于转基因是在很短的时间内强行让不同物种之间的基因产生“结合”,基因转进去容易,逃逸出来也容易。转基因植物出现于 30 年前,其商业化种植开始于 20 年前。在这期间转基因流从田野逃逸,对大部分地区的非转基因作物造成了污染,其中转基因油菜籽是典型案例。本报告从全球角度出发,基于发表的文献,对全球受到转基因油菜籽污染的国家的情况进行了总结。受影响的国家和地区包括:加拿大、美国、日本、澳大利亚、欧盟和瑞士。其中对加拿大和日本给予了重点关注,因为意识到在这两个国家转基因油菜籽的基因流已经扩展到了其野生近缘种中。 下面转载第三网络中文网对转基因油菜失控现象的分析,供读者参考。 更多资讯,欢迎浏览第三世界网络中文网页: http://twnchinese.net 转基因逃逸:以全球视角审视转基因油菜失控现象 Transgene Escape: Genetically engineered oilseed rape out of control - a globalperspective 作者: Andreas Bauer-Panskus Christoph Then ( 2013 年 9 月) 翻译:张渊媛、高英 概要 转基因植物出现于 30 年前,其商业化种植开始于 20 年前。在这期间转基因流从田野逃逸,对大部分地区的非转基因作物造成了污染 (Ellstrand,2012) ,其中转基因油菜籽是典型案例。本报告从全球角度出发,基于发表的文献,对全球受到转基因油菜籽污染的国家的情况进行了总结。受影响的国家和地区包括:加拿大、美国、日本、澳大利亚、欧盟和瑞士。其中对加拿大和日本给予了重点关注,因为意识到在这两个国家转基因油菜籽的基因流已经扩展到了其野生近缘种中。 除了商业化种植(如加拿大和美国)以及田间试验(如德国)之外,造成转基因逃逸失控的原因是食物和饲料的进出口与运输。在欧盟国家,从未商业化种植过转基因油菜籽,这类油菜籽的市场授权也在 2007 年被取消;然而还是能发现由拜耳公司生产的油菜籽造成的污染现象。 很难制定出可靠的标准来确定哪些转基因植物会易于扩散和入侵,其长期的环境影响将会是怎样。转基因植物的入侵潜力受到很多因素的影响,如持续的气候变化可能会影响到一些植物的扩散能力和生态特征。本报告呼吁有必要对转基因逃逸现象进行即时和全面的监控,并强调了预警原则的重要性。除非在紧急情况下,被释放到环境中的转基因生物可以立即被从环境中去除,否则的话就不该批准这类生物的环境释放。 1. 加拿大案例 1995 年加拿大成为第一个批准转基因耐除草剂油菜籽商业化种植的国家,目前的种植面积为 800 万公顷 (ISAAA, 2012) ,主要的种植区域为 Manitoba, Alberta 和 Saskatchewan 省。转基因油菜籽扩散事件的东窗事发开始于一项研究,这项研究宣称其发现加拿大境内所有的传统油菜籽中都含有转基因成分 (Friesen etal., 2003) 。紧接着发表的一些研究结果显示,贯穿所有主要的种植区,野化种群已遍及田块周围以及路边。加拿大生产的大部分油菜籽是用于出口的(主要出口给日本),那么种子就得被运输至海外港口,如温哥华,因此相应的在温哥华周边也发现了转基因油菜籽的痕迹。研究显示,在 Manitoba 省检测的野化种群中,有 88% 是耐草甘膦的,有 81% 是耐草铵膦的,有 50% 对两种除草剂均有抗性 (Yoshimura et al.,2006) 。 大面积的种植有利于转基因流的扩散,也利于野化种群的定植,这将进一步加剧转基因的污染。 2. 美国案例 美国种植油菜籽的联邦州并不多,种植总面积为 150 万公顷,其中 North Dakota 的种植面积为 130 万公顷 (NASS, 2012) ,其他州如 Idaho, Minnesota,Montana, Oklahoma, Oregon 和 Washington 的种植面积较小。美国的转基因油菜籽商业化种植始于 1998 年,目前其国内 90% 以上的油菜田种植的都是转基因品种。关于转基因油菜籽无意扩散的第一份研究指出, North Dakota 州的道路旁和田块周围已经有大量的耐除草剂转基因油菜籽野化种群分布 (Schafer etal., 2011) 。检测结果显示,部分扩散种群为抗草甘膦品种,部分为抗草铵膦品种,其他一些种群对草甘膦和草铵膦均有抗性。后续的一些研究指出,转基因的野化种群已经扩散至铁道边,以及所有的与种子储存、运输有关的设施周边。 3. 日本案例 油菜籽在 19 世纪被引入日本,但即便是现在,其种植面积依然不大。而其他一些相关的物种如 B. rapa 和 B. juncea 却被广泛种植,问题是,这两种作物极易被用来与油菜籽进行杂交。日本是转基因油菜籽的主要进口国之一,其每年进口的 200 万吨油菜籽中 90% 来自加拿大。而加拿大种植的油菜籽有 90% 以上是经过转基因的,如抗草甘膦除草剂品种。日本第一份关于转基因油菜的研究发表于 2005 年 (Saji et al., 2005) 。结果显示,日本的各个货物港口和码头周围都有耐草甘膦和草铵膦的油菜品种的分布,如 Kashima,Chiba, Nagoya 和 Kobe 周边,同时在种子被运至工厂加工的沿途也发现了油菜野化种群 ( Aono et al.2006) 。的研究 (Mizuguti etal. 2011) 得出的结论是,转基因油菜种群具有较强的自我维持能力,其野化种群处于不断增长的趋势。 2008 年,对 Yokkaichi 港口周边的植物检测得出的结果是,其中有 90% 属于转基因品种。据考证,野化转基因油菜种群的生物特征会受到气候条件的影响。从生态学角度来讲,值得注意的一点是,野化的杂交转基因种群逐渐演变成了多年生植物,而油菜籽和芸苔属其他植物都是一年生的。 4. 澳大利亚案例 转基因油菜在西澳洲的种植开始于 2009 年。西澳洲是一个非转基因区域,种植转基因油菜完全是一个特例,因此还对耐除草剂油菜的种植区进行了明显标注。可事实上,由于各种环境因素,尤其是在缺乏政府监控的情况下,一旦种植就难免造成扩散,一旦扩散就很难将其从环境中根除,这是一个恶性的生态循环。 5. 欧盟案例 自 1990 年开始,在德国和欧盟其他国家都有对转基因油菜的封闭式的田野试验,且好些试验田是持续多年的长期试验。 以下几个环节可能会增加转基因逃逸的可能性:试验点的信息透明度不够;试验田之外的监控不够;试验田与周边的隔离距离太短 (100-200 米,没有缓冲带 ) (Arndt Pohl,2005) ;由主管当局出台的关于隔离区和缓冲带的政策不稳定 (Arndt Pohl, 2005) ;企业对相关政策的履行力度不够 (Arndt Pohl, 2005) 。 6. 瑞士案例 瑞士科学家最近对转基因油菜籽在运输过程中的损耗开展了研究 (SchoenenbergerD’Andrea, 2012) 。研究人员沿着瑞士的铁路轨道采集了 2400 份样本,结果发现其中的 50 个样本中都含有一种特殊的酶,而这种酶是抗草甘膦除草剂的特征酶之一。虽然瑞士是禁止将转基因产品投入市场的,但研究结果显示,转基因种子可以沿着铁轨存活很长时间,具有潜在扩撒或逃逸的风险。 讨 论 转基因植物的释放所产生的长期的生态后果是不受时空局限的,因此需要从进化的角度来考虑问题。进化进程使得一些低概率事件具有合理的发生的机会。据 Breckling 的分析,我们需要考虑以下几个影响因素。进化动态将种群水平与分子水平链接了起来,即便是极小概率事件也会有出现的可能性;由于具体环境因素各异,生物个体的增值、扩散水平与范围将会很难预测;基因漂变可导致随机基因的固定,尤其是在小种群中;不能基于对当前环境因素的评估,来预测转基因植物释放后所产生的长期的生态效应,因为环境受到很多时空因素的影响,在很多情况下是一种动态变量,特别是在气候变化的条件下。据专家介绍,当前的气候波动或者变化将会引起野生生物种群的不稳定性。具有入侵潜力的动植物种可能会占据新的生态区。如专家预测,气候变化将导致外来入侵植物的种群数量呈几何级数增长 (Clements Ditommaso, 2011) 。气候变化将增加入侵物种与野生植物异型杂交的可能性。有研究指出极端气候事件将提高基因漂移的概率 (Franks Weis, 2009) 。 建 议 在受到影响的国家和地区,需要采取即时、中期和长效的措施和策略来应对转基因漂移对环境和人类健康所造成的不利影响。最即时和直接的措施是尽快禁止种植和引进转基因植物;中期来讲,需要加强对预警原则的重视,提高监管力度以防止新的不利影响的持续产生;从长效的或者从国际层面来讲,需要首先对生物多样性起源中心加以保护,因为这些区域将是未来的育种中心。保护生物多样性起源中心不仅仅是本国主管当局的责任,同时从长效来讲,也是国际社会共同的责任。 参考文献 Aono, M., Wakiyama, S., Nagatsu, M., Nakajima, N., Tamaoki, M., Kubo, A., Saji,H. 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来源: 植物研究所 作者:不详 阅读次数: 909 《美国国家科学院院刊》( PNAS )日前发表中科院植物所关于水稻油菜素内酯信号转导调控的最新研究成果。该研究发现水稻油菜素内酯信号转导途径新的调节因子 14-3-3 蛋白,并揭示了一种新的 OsBZR1 蛋白活性调控机制,为油菜素内酯在水稻中的应用,提高水稻产量和增加植物抗逆性提示了一个新的思路和手段。 油菜素内酯是一类重要的植物激素,控制水稻株型等重要农艺性状。王志勇和种康研究组的博士生白明义等人利用反向遗传学研究了水稻 OsBZR1 蛋白的功能。研究发现通过 RNAi 技术抑制水稻体内 OsBZR1 的表达会导致水稻植株矮小、叶片直立、育性下降等与水稻油菜素内酯合成及不敏感突变体类似的表型。同时抑制 OsBZR1 的表达还降低了水稻叶枕对油菜素内酯的敏感性和减弱了水稻对油菜素内酯合成基因的反馈调节。利用酵母双杂交发现 14-3-3 蛋白可与 OsBZR1 发生相互作用。而去除推定的 14-3-3 结合位点的 OsBZR1 则不能与 14-3-3 蛋白在酵母和植物体内发生相互作用。此外这种相互作用还受到油菜素内酯的调节,油菜素内酯处理可显著抑制 OsBZR1 与 14-3-3 蛋白在植物体内的相互作用。 14-3-3 蛋白与 OsBZR1 的结合在酵母和植物中都抑制了 OsBZR1 的活性,作者通过翔实的实验证据表明这种抑制作用是由于 14-3-3 蛋白与 OsBZR1 的结合使得 OsBZR1 滞留在细胞质,不能进核行使功能造成的。 白明义等人通过对 OsBZR1 和 14-3-3 蛋白的研究,找到一种新的调控 OsBZR1 活性的机制。这些机制的了解可使人们通过基因工程的方法精细调控水稻体内的油菜素内酯响应,为水稻高产育种提供重要的理论依据和新的操作手段。 研究揭示油菜素内酯信号转导正负调控机制 近日来自山东农业大学、美国加州Salk生物研究所、日本横滨的理化学研究所植物科学中心(Riken Plant Science Center)、美国威斯康星大学麦迪逊分校等研究结构的科学家,在对植物类固醇激素油菜素内酯(Brassinosteroids,BRs)信号转导调控研究中取得突破性进展,相关研究论文发布在国际顶级期刊《科学》( Science )旗下的《科学——信号传导》( Science Signaling )杂志上。 山东农业大学的特聘教授吴光博士以及Salk生物研究所著名女科学家Joanne Chory为这篇论文的共同通讯作者。吴光教授早年毕业于南京农业大学,长期从事植物光形态建成和植物激素转导等方面的分子生物学研究,在突变体基因分离、遗传分析、功能鉴定等方面取得了优异成绩和突破性进展,先后在 Plant Cell 、 Plant Physiology 等学术刊物发表论文数十篇,2002年至2006年在美国加州Salk生物研究所从事博士后研究。于2006年5月被山东农业大学聘为首批“特聘教授”。 油菜素内酯是一种与植物细胞的生长、分裂、分化和生殖发育有关的天然植物激素,这种植物类固醇激素能将光等环境因素与植物生长和发育耦合起来。目前,在各种作物中已经发现60多种油菜素内酯化合物,其中BL是其中活性最高的, 其广泛存在于植物的花粉、种子、茎和叶等器官中。它能充分激发植物内在潜能,促进作物生长和增加作物产量,提高作物的抗病、抗盐和抗冻能力,使作物的抗逆性增强,减轻除草剂对作物的药害。近年来人们对其作用及信号转导通路进行了大量研究,获得了许多有意义的成果,重要的一点就是发现BRI1是BR的细胞膜受体,但是目前科学家们对于BRI1与BR相互作用介导的信号传导及其调控机制仍知之甚少。 在这篇文章中,研究人员发现蛋白质磷酸酶2A (PP2A)可对BRI1起重要的脱磷酸化作用,并证实在拟南芥中进入rcn1(PP2A亚基的一个突变体)可引起BRI1丰度增高,促进BR信号转导。拟南芥bri1 突变体是一种对外施油菜素内酯(BR)不敏感的突变体,常表现为明显矮化及早熟表型。在这篇文章中,研究人员筛选获得了bri1的恢复突变体sbi1,并证实突变体sbi1中BR选择性激活并导致BRI1在膜区室积聚。此外,研究人员还证实BRs可诱导生成SBI1 mRNA ,SBI1编码生成LCMT,促使PP2A甲基化,甲基化的PP2A进一步与活化的BRI1结合,促使BRI1的脱磷酸化和降解,从而实现了对BR信号的负调控。 新研究结果揭示了油菜素内酯信号转导的正负调控机制,从而为科学家们进一步了解BRs信号转导及细胞生长调控提供了重要信息 The Plant Cell:储成才等水稻油菜素内酯信号传导机制研究获进展 作者: 遗传发育所 来源: 遗传发育所 2012-6-11 20:54:55 0 1 油菜素内酯(BR)是一类重要的植物激素,参与植物生长发育的各个方面,其在调控植物株型、器官大小及抗病抗逆等过程中的功能决定了BR在生产上具有巨大的应用潜力,然而其在粮食作物中的信号传导机制的研究仍知之甚微。 中国科学院遗传发育所储成才课题组童红宁博士通过大规模筛选水稻突变体,获得一个BR不敏感材料,并通过图位克隆方法克隆到相应基因DLT。DLT编码一个植物特异的GRAS蛋白家族成员,为水稻BR信号传导中一个新的关键正调控因子(Tong et al., Plant Journal 58: 803–816, 2009)。进一步研究发现,DLT作为转录因子,可能为水稻中GSK3/SHAGGY-like激酶的直接底物,童红宁博士克隆了该激酶基因,命名为GSK2。分子、生理、生化及遗传等技术证明,GSK2为BR信号传导中的一个关键负调控子,通过与DLT直接相互作用对其磷酸化来调控DLT的蛋白水平及活性,这一成果揭示了水稻中GSK2与DLT相互作用介导的BR信号传导的分子及生化机制。 该研究结果已于2012年6月8日在线发表于国际主流杂志 Plant Cell 上,储成才课题组童红宁博士为论文的第一作者,该项研究得到了科技部和自然科学基金委项目的资助。( 生物谷 Bioon.com) doi:10.1105/tpc.112.097394 PMC: PMID: DWARF AND LOW-TILLERING Acts as a Direct Downstream Target of a GSK3/SHAGGY-Like Kinase to Mediate Brassinosteroid Responses in Rice Hongning Tonga, Linchuan Liua, Yun Jina, Lin Dua, Yanhai Yinb, Qian Qianc, Lihuang Zhua and Chengcai Chua,1 In Arabidopsis thaliana, the GSK3/SHAGGY-like kinase BRASSINOSTEROID-INSENSITIVE2 (BIN2) plays a critical role in the brassinosteroid (BR) signaling pathway by negatively regulating the activities of bri1-EMS-SUPPRESSOR1/BRASSINAZOLE-RESISTANT1 family transcription factors that regulate the expression of downstream BR-responsive genes. In this study, we analyzed the function of a rice (Oryza sativa) GSK3/SHAGGY-like kinase (GSK2), which is one of the orthologs of BIN2. Overexpression of GSK2 (Go) led to plants with typical BR loss-of-function phenotype s, and suppression of GSK2 resulted in enhanced BR signaling phenotype s. DWARF AND LOW-TILLERING (DLT) is a positive regulator that mediates several BR responses in rice. Suppression of DLT can enhance the phenotypes of BR receptor mutant d61-1, and overexpression of DLT obviously suppressed the BR loss-of-function phenotypes of both d61-1 and Go, suggesting that DLT functions downstream of GSK2 to modulate BR responses. Indeed, GSK2 can interact with DLT and phosphorylate DLT. Moreover, brassinolide treatment can induce the dephosphorylation of DLT, leading to the accumulation of dephosphorylated DLT protein. In GSK2 transgenic plants, the DLT phosphorylation level is dictated by the GSK2 level. These results demonstrate that DLT is a GSK2 substrate, further reinforcing that the BIN2/GSK2 kinase has multiple substrates that carry out various BR responses. DWARF AND LOW-TILLERING Acts as a Direct Downstream Target of a GSK3/SHAGGY-Like Kinase to Mediate Brassinosteroid Responses in Rice Hongning Tong; Linchuan Liu; Yun Jin; Lin Du; Yanhai Yin; Qian Qian; Lihuang Zhu; Chengcai Chu The Plant Cell , 2012-06-01, 24 ( 6 ) : 2562-2577 DOI: 10.1105/tpc.112.097394 In Arabidopsis thaliana , the GSK3/SHAGGY-like kinase BRASSINOSTEROID-INSENSITIVE2 (BIN2) plays a critical role in the brassinosteroid (BR) signaling pathway by negatively regulating the activities of bri1 -EMS-SUPPRESSOR1/BRASSINAZOLE-RESISTANT1 family transcription factors that regulate the expression of downstream BR-responsive genes. In this study, we analyzed the function of a rice ( Oryza sativa ) GSK3/SHAGGY-like kinase (GSK2), which is one of the orthologs of BIN2. Overexpression of GSK2 ( Go ) led to plants with typical BR loss-of-function phenotypes, and suppression of GSK2 resulted in enhanced BR signaling phenotypes. DWARF AND LOW-TILLERING (DLT) is a positive regulator that mediates several BR responses in rice. Suppression of DLT can enhance the phenotypes of BR receptor mutant d61-1 , and overexpression of DLT obviously suppressed the BR loss-of-function phenotypes of both d61-1 and Go , suggesting that DLT functions downstream of GSK2 to modulate BR responses. Indeed, GSK2 can interact with DLT and phosphorylate DLT. Moreover, brassinolide treatment can induce the dephosphorylation of DLT, leading to the accumulation of dephosphorylated DLT protein. In GSK2 transgenic plants, the DLT phosphorylation level is dictated by the GSK2 level. These results demonstrate that DLT is a GSK2 substrate, further reinforcing that the BIN2/GSK2 kinase has multiple substrates that carry out various BR responses. DWARF AND LOW-TILLERING是介导水稻油菜素内酯应答的类GSK3/SHAGGY激酶的直接下游靶标 拟南芥中类GSK3/SHAGGY激酶BRASSINOSTEROID-INSENSITIVE2 (BIN2)在油菜素内酯(BR)信号途径中发挥重要作用,负向调节参与调控下游BR应答基因表达的bri1-EMS-SUPPRESSOR1/BRASSINAZOLE RESISTANT1转录因子家族的活性。本研究我们分析了水稻中一个与BIN2同源的类GSK3/SHAGGY激酶(GSK2)的功能。过量表达GSK2(Go)导致植株表现出典型的BR功能缺失的表型,抑制GSK2导致BR信号增强表型。DWARF AND LOW-TILLERING(DLT)是水稻中介导BR应答的一个正向调节子。抑制DLT可以增强BR受体突变体d61-2表型,过量表达DLT则明显抑制了d61-1和Go的BR功能缺失的表型,说明DLT作用于受GSK2调节的BR应答的下游。实际上GSK2可以直接作用于DLT并磷酸化DLT。此外,油菜素内酯处理可以诱导DLT的去磷酸化,导致去磷酸化的DLT蛋白积累。GSK2转基因植株中,DLT的磷酸化水平受GSK水平决定。这些结果证明DLT是GSK2的直接底物,进一步表明BIN2/GSK2激酶具有多种底物执行不同的BR响应。 ► 本文研究的功能基因 ◄ 矮化少分蘖基因 DLT; OsGRAS-32;D62 类GSK3/SHAGGY激酶 GSK2
Barnase is toxic to humans and other mammals! http://www.ibiblio.org/ecolandtech/SoilWiki/message-archives/JoeCummins/msg00853.html *Barnase Ribonuclease is toxic to Humans and other Mammals* Barnase ribonuclease is an enzyme toxic to cells, it is produced in nature by the bacterium, Bacillus amyloliquefaciens, which synthesizes and secretes the enzyme . The enzyme is not toxic to the bacterium that produces it because it is inhibited by another protein, barstar, produced within that bacterium. As the enzyme is secreted from the bacterial cell barstar is removed from its complex with barstar. The bacterial gene for barnase and the gene for barstar have been employed extensively in transgenic plants and animals to set up regulatory systems that are capable of ablating (killing) specific organs or tissues of the organism by the interplay of barnase and barstar. Mustard (Brassica Juncea) was modified with the barnase gene driven by a pollen specific (tapetum) promoter that produced male sterile lines of the mustard plants by ablating pollen cells (1) Male sterile plants can be used to limit pollen release from a crop or to produce hybrids. United States Patent 6,509,516 deals with producing male sterile Brassica employing barnase (2), while United States patent 6,969.786 deals with producing hybrid canola (Brassica napa or B.napus) using a male sterile line created using barnase and barstar genes (3).The production of Brassica hybrids using the barnase-barstar system has been illustrated and explained (4). Barnase, unaccompanied by its specific inhibitor barstar, is known to be a potent cell poison . Traces of barnase are toxic to the rat kidney and to human cell lines . Barnase is actually being exploited as a conditional ‘suicide gene’ to cause celldeath in mammalian and human cells when it is induced. Cell toxicity caused by barnase may be affected by RNA interference (RNAi) (10).The hazard associated with RNAi is shown by experiments over saturating small RNA pathways leading to the death of many experimental mice (11).RNAi is known to circulate among the cells of plants (12) so the ablation of anther cells may be accompanied by RNAi spread throughout the entire plant. The pollen produced by the hybrid mustard actually contains the barnase gene combined with the barstar. Is barnase expressed at low basal levels in the plant tissues when it is not in the induced state (is the regulatory transgene leaky)? Are the constructs sufficiently stable to ensure that the barnase is only active in the anther? How much RNAi is translocated throughout the plant?As indicated earlier, Barnase, even if expressed at low levels could prove toxic to a wide range of animals that interact with the plant, including not only humans, but also rodents and bees. It could also enter the human food chain in bee honey. As pointed out earlier, in bacteria, barnase is synthesized but immediately joined to barstar to avoid cell death. The newly synthesized barnase (combined with barstar) has a short leader sequence at the N-terminus, that sequence directs t the barnase –barstar complex to the cell membrane. As barnase is secreted from the cell membrane barstar is separated from barnase and left behind in the cell interior (13). If barnase can be separated from barstar at the cell membrane of bacteria there are likely to be situations where plant cells separate barnase from barstar. The pathway for folding and the stability of barnase has been studied extensively (14). It seems likely that the barstar-barnase complex is very stable and likely to persist in the grain of food crops such as mustard. However, in spite of the extensive use of the barnase-barstar systems in Brassica such as mustard and oilseed rape (canola), there does not seem to have been any effort to measure the quantity of the barnase-barstar complex in the grain of the food crops. The barnase-barstar complex in transgenic mustard is likely to be produce a strong immunological response such as inflammation or it may even be an allergen. However, these aspects to not appear to have been studied. There is evidence that barstar induces a strong immune response (15). However, the barnase-barstart complex needs fuller study in terms of immune responses, including allergy. The barnase-barstar system for pollen control has been used with both mustard and with canola. The canola label is used with two species Brassica rapa (Polish rapeseed) and Brassic napus (Argentine rapeseed) (16) Mustard (Brassica juncea) may produce inter specific hybrids with canola (B. rapa) (17) but such hybrids are not yet grown commercially. It is wisest to consider the hazards of barnase-barstar transgenic crops as being separate but related , not as being identical as has been done in some safety evaluations. In conclusion, the actual toxicity of barnase and the toxicity of the barnase-barstar complex in food and feed cries out for fuller study regarding the impact on humans and animals. The main areas requiring fuller study prior to the exposure of millions of people and millions of animals to the toxins are the exposure to the highly toxic barnase ribonuclease on consuming transgenic food and the potential toxic immune responses to the bartnase-barstar complex in the transgenic crops. References 1.Jagannath,A,Bandyopadhyay,P,Arumugam,N, Gupta,V,Burma,P and Pental,D. The use of a spacer DNA fragment insulates the tissue-specific expression of a cytotoxic gene (barnase) and allows high frequency generation of transgenic male sterile lines in Brassica juncea. Molecular Breeding 2001,8,11-21 2. Weston,B. and deBeuckeleer,M Male sterile brassica plants and methods for producing same 2003 US Patent 6,509,516 3.Grombacker,A and Patel,D. Canola line 43A56 2003 US Patent 6,969,786 4. Ho, M-W and Cummins,J. Chronicle of an ecological disaster foretold Isis Report 2003 http://www.isis.org.uk/ 5. Cummins J. Terminator gene product alert, ISIS News 6, September 2000, ISSN: 1474-1547 (print), ISSN: 1474-1814 (online). 6. Ilinskaya O and Vamvakas S. Nephrotic effect of bacterial ribonucleases in the isolated and perfused rat kidney. Toxicology 1997, 120, 55-63. 7. Prior T, Kunwar S and Pastan I. Studies on the activity of barnase toxins in vitro and in vivo. Biocong Chem 1996, 7,23-9. 8. Leuchtenberger S, Perz A, Gatz C and Bartsch JW. Conditional cell ablation by stringent tetracycline-dependent regulation of barnase in mammalian cells. Nucleic Acids Research 2001, 29 (16). 9. Bi YM, Rothstein SJ and Wildeman AG. A novel strategy for regulated expression of a cytotoxic gene. Gene 2001, 279, 175-9. 10.Ilinskaya,O and Makarov,A. Why ribonucleases induce tumor cell death Molecular Biology 2005,39,3-13 11. Grimm D, Streetz KL, Jopling CL, Storm TA, Pandey K, Davis CR, Marion P, Salazar F and Kay MA. Fatality in mice due to oversaturation of cellular microRNA/short hairpin RNA pathways. Nature. 2006 May 25;441(7092):537-41 12. Tournier B, Tabler M and Kalantidis K. Phloem flow strongly influences the systemic spread of silencing in GFP Nicotiana benthamiana plants. Plant J. 2006 Aug;47(3):383-94 13. Paddon CJ, Vasantha N and Hartley RW. Translation and processing of Bacillus amyloliquefaciens extracellular RNase. J Bacteriol. 1989 Feb;171(2):1185-7 14. Fersht AR. The sixth Datta Lecture. Protein folding and stability: the pathway of folding of barnase. FEBS Lett. 1993 Jun 28;325(1-2):5-16 15.Kirkham,P,Nori,D and Winter,G. Towards the design of an antibody that recognizes a given protein epitope J. Mol. Biol. 1999,285,909-15 16. Canola Council of Canada Origin and History of Canola 2006 http://www.canola-council.org/PDF/canola/english/originhistory.pdf#zoom=100 17. Choudhary,R,Joshi,P and Rao,R. Cytogenetics of Brassica junceaXBrassica rapa hybrids and patterns of variation in the hybrid derivatives Plant Breeding 2002 ,121,292-6