Lin Yiguang, Ji Huijun, Cao Xiaocong, Cen Yongjie, Chen Yumei, Ji Shuangshun, Zheng Sichun
Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China; Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China; Guangzhou Key Laboratory of Insect Development Regulation and Applied Research, Institute of Insect Science and Technology, School of Life Sciences, South China Normal University, Guangzhou 510631, China.
Pestic Biochem Physiol. 2021 Jun;175:104856. doi: 10.1016/j.pestbp.2021.104856. Epub 2021 Apr 13.
Insecticides are the main tools used to control Nilaparvata lugens (Stål), a serious pest of rice in Asia. However, repeated application of insecticides has caused many negative effects. Reducing the amount of insecticide used, while maintaining good pest population control, would be valuable. AMP-activated protein kinase (AMPK), a sensor of cellular energy status, helps to maintain insect energy balance at the cellular and whole-body level. The role of AMPK in insect response to insecticide stimulation is unknown. We studied the functions of AMPK catalytic subunit alpha (NlAMPKα) in the development of N. lugens and in response to pymetrozine, an insecticide used to control insect pests with piercing-sucking mouthparts. A phylogenetic analysis of protein sequences from 12 species in six orders showed that insects have only the AMPKα 2 subtype. RNA interference against NlAMPKα demonstrated that blocking the AMPK pathway led to a decrease in the systemic ATP level and an increase in N. lugens mortality. NlAMPKα responded to the energy stress caused by pymetrozine treatment, which activated downstream energy metabolic pathways to compensate for the energy imbalance. However, the ATP level in pymetrozine- treated nymphs was not increased, suggesting that ATP is consumed more than synthesized. When NlAMPKα expression was reduced in pymetrozine-treated nymphs by RNAi, the ATP level was decreased and the mortality was significantly increased. At day eight post 0.5 g/3 L of pymetrozine and dsNlAMPKα treatment, nymph survival was 29.33%, which was similar to the 27.33% survival of 1 g/3 L pymetrozine-treated nymphs. Addition of dsNlAMPKα can reduce the concentration of pymetrozine used by 50% while providing comparable efficacy. These results indicate that AMPK helps maintain the energy metabolism of N. lugens in response to pymetrozine treatment. Knockdown of NlAMPKα increases the insecticidal efficiency of pymetrozine to N. lugens.
杀虫剂是用于防治褐飞虱（Nilaparvata lugens (Stål)）的主要工具，褐飞虱是亚洲水稻的一种严重害虫。然而，反复施用杀虫剂已造成许多负面影响。在保持对害虫种群良好控制的同时减少杀虫剂的用量将很有价值。AMP激活的蛋白激酶（AMPK）是细胞能量状态的传感器，有助于在细胞和全身水平维持昆虫的能量平衡。AMPK在昆虫对杀虫剂刺激的反应中的作用尚不清楚。我们研究了AMPK催化亚基α（NlAMPKα）在褐飞虱发育以及对吡虫啉（一种用于防治刺吸式口器害虫的杀虫剂）反应中的功能。对六个目12个物种的蛋白质序列进行系统发育分析表明，昆虫仅具有AMPKα 2亚型。对NlAMPKα进行RNA干扰表明，阻断AMPK途径会导致全身ATP水平降低以及褐飞虱死亡率增加。NlAMPKα对吡虫啉处理引起的能量应激作出反应，激活下游能量代谢途径以补偿能量失衡。然而，吡虫啉处理的若虫中的ATP水平并未增加，这表明ATP的消耗超过了合成。当通过RNAi降低吡虫啉处理的若虫中NlAMPKα的表达时，ATP水平降低且死亡率显著增加。在0.5 g/3 L吡虫啉和dsNlAMPKα处理后第8天，若虫存活率为29.33%，这与1 g/3 L吡虫啉处理的若虫27.33%的存活率相似。添加dsNlAMPKα可将吡虫啉的使用浓度降低50%，同时提供相当的效果。这些结果表明，AMPK有助于维持褐飞虱在吡虫啉处理后的能量代谢。敲低NlAMPKα可提高吡虫啉对褐飞虱的杀虫效率。
