Gut‐expressed aphid genes, which may be more easily inhibited by RNA interference (RNAi) constructs, are attractive targets for pest control efforts involving transgenic plants. Here we show that expression of cathepsin L, which encodes a cysteine protease that functions in aphid guts, can be reduced by expression of an RNAi construct in transgenic tobacco. The effectiveness of this approach is demonstrated by up to 80% adult mortality, reduced fecundity, and delayed nymph production of Myzus persicae (green peach aphids) when cathepsin L expression was reduced by plant‐mediated RNAi. Consistent with the function of cathepsin L as a gut protease, M. persicae fed on the RNAi plants had a lower protein content in their bodies and excreted more protein and/or free amino acids in their honeydew. Larvae of Coccinella septempunctata (seven‐spotted ladybugs) grew more slowly on aphids having reduced cathepsin L expression, suggesting that prey insect nutritive value, and not just direct negative effects of the RNAi construct, needs to be considered when producing transgenic plants for RNAi‐mediated pest control.

中文翻译：

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沉默组织蛋白酶 L 的表达会降低桃蚜的蛋白质含量以及作为七星瓢虫猎物的营养价值。


肠道表达的蚜虫基因可能更容易被 RNA 干扰 (RNAi) 结构抑制，是涉及转基因植物的害虫防治工作的有吸引力的目标。在这里，我们发现组织蛋白酶 L（编码在蚜虫肠道中发挥作用的半胱氨酸蛋白酶）的表达可以通过在转基因烟草中表达 RNAi 构建体来减少。当植物介导的 RNAi 降低组织蛋白酶 L表达时，桃蚜（ Myzus persicae ）的成虫死亡率高达 80%、繁殖力降低和若虫产生延迟，证明了这种方法的有效性。与组织蛋白酶 L 作为肠道蛋白酶的功能一致，以 RNAi 植物为食的桃蚜体内的蛋白质含量较低，并在其蜜露中分泌更多的蛋白质和/或游离氨基酸。七星瓢虫（七斑瓢虫）的幼虫在组织蛋白酶 L 表达降低的蚜虫上生长得更慢，这表明在生产 RNAi 转基因植物时，需要考虑猎物昆虫的营养价值，而不仅仅是 RNAi 构建体的直接负面影响。介导害虫防治。