古狗BT的结果: Bt protein; also Bt toxin

Bt protein; also Bt toxin

 A protein that is toxic to chewing insects and is produced by the soil bacterium Bacillus thuringiensis and has long been used as a biological pesticide.

By means of genetic engineering, the genes for Bt toxin can be isolated from Bacillus thuringiensis and transferred to plants. The plant is thus conferred the ability to produce the insect toxin on its own.

There are different forms of Bt toxin that are specifically active against certain groups of insects. About 170 naturally occuring Bt toxins with varying specificities are known. 

For genetically engineered insect resistance, different variants of Bt genes are transferred, e.g. Cry 1Ab, Cry 1Ac and Cry 9c for maize. They differ both in terms of their length and in terms of the promoters used. The transgenic maize varieties differ depending on the Bt gene variant used, both in terms of the amount of Bt protein they produce and its distribution within the plant. Some Bt maize varieties produce the Bt protein primarily in the stem, while other produce it in all plant parts. 

 

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What are Bt proteins?

Bt stands for the naturally occurring bacterium Bacillus thuringiensis. Bt lives in the soil and is found all over the world. Some types of Bt produce a protein crystal that is toxic to insects. These protein crystals have been used in organic farming for over 50 years to control insects. The genes producing these proteins are now engineered so that plants can make the protein in their cells.

 

 

所有跟帖： 

• 是的。这里有个量的问题。事实上出现过不少使用bt不当而导致中毒的事件。但是至少外用的时候 -woth- ♀ (27 bytes) () 08/05/2011 postreply 14:01:13

• 打个比方说，我们把bt杀虫剂作为外用农药的时候，肯定有打药时间，打药浓度等不同规范 -woth- ♀ (133 bytes) () 08/05/2011 postreply 14:13:14

• 好问题！那就比较一下外用和内用 -TBz- ♂ (1653 bytes) () 08/05/2011 postreply 17:06:46

• 那就来分析一下： -woth- ♀ (2244 bytes) () 08/05/2011 postreply 18:05:55

• 结论：此BT非彼BT -TBz- ♂ (151 bytes) () 08/05/2011 postreply 21:44:03

• 有bt作为生物农药使用不当而导致中毒的事件吗？ -viewfinder- ♀ (98 bytes) () 08/05/2011 postreply 22:37:35

• 一个可参考的例子： -viewfinder- ♀ (74 bytes) () 08/05/2011 postreply 22:40:58

• 刚查了一下，不好意思，俺记错了。不是bt杀虫剂的中毒事件，是其他的。 -woth- ♀ (0 bytes) () 08/06/2011 postreply 19:02:37

• 这个王月丹连苏云金杆菌与致病菌蜡样芽孢杆菌都不会区分，你还能指望他什么？ -加州老李- ♀ (1662 bytes) () 08/05/2011 postreply 14:04:04

• 受不了你了，这就是你的支持转基因食品的方式么？ -woth- ♀ (0 bytes) () 08/05/2011 postreply 14:07:43