Down Rachel E, Ford Louise, Woodhouse Stephen D, Davison Gillian M, Majerus Michael E N, Gatehouse John A, Gatehouse Angharad M R
School of Biology, King George VI Building, University of Newcastle, NE1 7RU, Newcastle upon Tyne, UK.
Transgenic Res. 2003 Apr;12(2):229-41. doi: 10.1023/a:1022904805028.
Tritrophic interactions between transgenic potato expressing the insecticidal lectin from snowdrop (Galanthus nivalis agglutinin; GNA), an aphid pest, Myzus persicae (Sulz.), and a beneficial predator, the 2-spot ladybird (Adalia bipunctata L.) were investigated. Clonal plants expressing GNA at 0.1-0.2% total soluble protein in leaves were used. No significant effects on development and survival of ladybird larvae fed on aphids from these transgenic plants were observed, with larval survival in the experimental group being 90% compared to 89% for controls. There were also no effects on subsequent female or male longevity. Female fecundity was also investigated. Although no significant differences (p > 0.05) were observed in egg production between control and experimental groups, a 10%, reduction (p < 0.01) in egg viability (determined by % hatch) occurred in ladybirds fed aphids reared on transgenic plants. Additional studies were carried out using aphids fed on artificial diet containing GNA, to deliver quantified levels of the protein to ladybird adults. GNA had no deleterious effects upon adult longevity, but resulted in a consistent trend for improved fecundity. Egg production was increased by up to 70% and egg viability also increased significantly. The results suggest that GNA is not deleterious to ladybirds. Results from these studies highlight the need to discriminate between direct and indirect effects when studying tritrophic interactions between plants/pests/natural enemies. Furthermore, it emphasises the importance of demonstrating 'cause and effect'.
对表达雪花莲（Galanthus nivalis）杀虫凝集素（GNA）的转基因马铃薯、蚜虫害虫桃蚜（Myzus persicae (Sulz.)）和有益捕食者二斑瓢虫（Adalia bipunctata L.）之间的三级营养相互作用进行了研究。使用了叶片中总可溶性蛋白含量为0.1 - 0.2%的GNA表达克隆植物。未观察到取食这些转基因植物上蚜虫的瓢虫幼虫的发育和存活受到显著影响，实验组幼虫存活率为90%，而对照组为89%。对随后的雌虫或雄虫寿命也没有影响。还研究了雌虫的繁殖力。虽然对照组和实验组之间在产卵量上未观察到显著差异（p > 0.05），但取食转基因植物上饲养的蚜虫的瓢虫所产的卵，其活力（由孵化率确定）降低了10%（p < 0.01）。还进行了额外的研究，用取食含GNA人工饲料的蚜虫来向瓢虫成虫提供定量的该蛋白。GNA对成虫寿命没有有害影响，但导致繁殖力有持续提高的趋势。产卵量增加了多达70%，卵的活力也显著提高。结果表明GNA对瓢虫无害。这些研究结果强调了在研究植物/害虫/天敌之间的三级营养相互作用时区分直接和间接影响的必要性。此外，它强调了证明“因果关系”的重要性。
