Sadeghi Amin, Smagghe Guy, Broeders Sylvia, Hernalsteens Jean-Pierre, De Greve Henri, Peumans Willy J, Van Damme Els J M
Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium.
Transgenic Res. 2008 Feb;17(1):9-18. doi: 10.1007/s11248-007-9069-z. Epub 2007 Jan 31.
The insecticidal activity of the leaf (ASAL) and bulb (ASAII) agglutinins from Allium sativum L. (garlic) against the cotton leafworm, Spodoptera littoralis Boisd. (Lepidoptera: Noctuidae) was studied using transgenic tobacco plants expressing the lectins under the control of the constitutive CaMV35S promoter. PCR analysis confirmed that the garlic lectin genes were integrated into the plant genome. Western blots and semi-quantitative agglutination assays revealed lectin expression at various levels in the transgenic lines. Biochemical analyses indicated that the recombinant ASAL and ASAII are indistinguishable from the native garlic lectins. Insect bioassays using detached leaves from transgenic tobacco plants demonstrated that the ectopically expressed ASAL and ASAII significantly (P < 0.05) reduced the weight gain of 4th instar larvae of S. littoralis. Further on, the lectins retarded the development of the larvae and their metamorphosis, and were detrimental to the pupal stage resulting in weight reduction and lethal abnormalities. Total mortality was scored with ASAL compared to 60% mortality with ASAII. These findings suggest that garlic lectins are suitable candidate insect resistance proteins for the control of S. littoralis through a transgenic approach.
利用在组成型CaMV35S启动子控制下表达凝集素的转基因烟草植株，研究了大蒜（葱属植物）叶片凝集素（ASAL）和鳞茎凝集素（ASAII）对棉铃虫，即滨海夜蛾（鳞翅目：夜蛾科）的杀虫活性。PCR分析证实大蒜凝集素基因已整合到植物基因组中。蛋白质免疫印迹和半定量凝集试验表明转基因株系中凝集素在不同水平表达。生化分析表明重组ASAL和ASAII与天然大蒜凝集素没有区别。使用转基因烟草植株的离体叶片进行的昆虫生物测定表明，异位表达的ASAL和ASAII显著（P<0.05）降低了滨海夜蛾四龄幼虫的体重增加。此外，凝集素延缓了幼虫的发育及其变态，并对蛹期有害，导致体重减轻和致命异常。与ASAII导致60%的死亡率相比，ASAL导致的总死亡率更高。这些发现表明，大蒜凝集素是通过转基因方法控制滨海夜蛾的合适候选抗虫蛋白。
