کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6389664 | 1628238 | 2012 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Susceptibility of Spodoptera frugiperda and S. exigua to Bacillus thuringiensis Vip3Aa insecticidal protein Susceptibility of Spodoptera frugiperda and S. exigua to Bacillus thuringiensis Vip3Aa insecticidal protein](/preview/png/6389664.png)
The Vip3Aa protein is an insecticidal protein secreted by Bacillus thuringiensis during the vegetative stage of growth. The activity of this protein has been tested after different steps/protocols of purification using Spodoptera frugiperda as a control insect. The results showed that the Vip3Aa protoxin was stable and retained full toxicity after being subjected to common biochemical steps used in protein purification. Bioassays with the protoxin in S. frugiperda and S. exigua showed pronounced differences in LC50 values when mortality was measured at 7 vs. 10Â d. At 7Â d most live larvae were arrested in their development. LC50 values of “functional mortality” (dead larvae plus larvae remaining in the first instar), measured at 7Â d, were similar or even lower than the LC50 values of mortality at 10Â d. This strong growth inhibition was not observed when testing the trypsin-activated protein (62Â kDa) in either species. S. exigua was less susceptible than S. frugiperda to the protoxin form, with LC50 values around 10-fold higher. However, both species were equally susceptible to the trypsin-activated form. Processing of Vip3Aa protoxin to the activated form was faster with S. frugiperda midgut juice than with S. exigua midgut juice. The results strongly suggest that the differences in the rate of activation of the Vip3Aa protoxin between both species are the basis for the differences in susceptibility towards the protoxin form.
Highlights⺠Vip3Aa protoxin causes strong growth inhibition in Spodoptera frugiperda and S. exigua. ⺠S. frugiperda is less susceptible than S. exigua to the Vip3Aa protoxin. ⺠Both species are equally susceptible to the trypsin-activated Vip3Aa. ⺠S. frugiperda and S. exigua differ in the rate of Vip3Aa activation by midgut juice.
Journal: Journal of Invertebrate Pathology - Volume 110, Issue 3, July 2012, Pages 334-339