Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China; Key Laboratory of Intergraded Management of Harmful Crop Vermin of China North-western Oasis, Ministry of Agriculture, China.
Pestic Biochem Physiol. 2021 Jun;175:104838. doi: 10.1016/j.pestbp.2021.104838. Epub 2021 Apr 3.
Crustacean cardioactive peptide (CCAP), a highly conserved amidated neuropeptide, stimulates feeding in Drosophila melanogaster and Periplaneta americana, and regulates pupa-adult transition in Tribolium castaneum and Manduca sexta. In the present paper, we intended to address whether CCAP plays the dual roles in the Colorado potato beetle Leptinotarsa decemlineata. We found that the levels of Ldccap were high in the dissected samples of brain-corpora cardiaca-corpora allata complex and ventral nerve cord, midgut and hindgut in the final (fourth)-instar larvae. A pulse of 20-hydroxyecdysone triggered the expression of Ldccap in the central nervous system but decreased the transcription in the midgut. In contrast, juvenile hormone intensified the expression of Ldccap in the midgut. RNA interference (RNAi)-aided knockdown of Ldccap at the penultimate instar stage inhibited foliage consumption, reduced the contents of trehalose and chitin, and lowered the mRNA levels of two chitin biosynthesis genes (LdUAP1 and LdChSAb). Moreover, around 70% of the Ldccap RNAi larvae remained as prepupae, completely wrapped in the old larval exuviae, and finally died. The remaining RNAi beetles continually developed to severely-deformed adults: most having wrinkled and smaller elytra and hindwings, and shortened legs. Therefore, CCAP plays three distinct roles, stimulating feeding in foraging larval stage, regulating ecdysis, and facilitating wing expansion and appendage elongation in a coleopteran. In addition, Ldccap can be used as a potential target gene for developing novel management strategies against this coleopteran pest.
甲壳动物心脏活性肽 (CCAP) 是一种高度保守的酰胺化神经肽，可刺激果蝇和美洲蜚蠊的摄食，并调节三化螟和烟青虫的蛹成虫转变。在本文中，我们旨在探讨 CCAP 是否在美洲马铃薯甲虫 Leptinotarsa decemlineata 中发挥双重作用。我们发现，在末期（第四龄）幼虫的脑-心-咽复合体和腹神经索、中肠和后肠的解剖样本中，Ldccap 的水平较高。20-羟基蜕皮酮的脉冲触发了 Ldccap 在中枢神经系统中的表达，但降低了中肠的转录。相比之下，保幼激素增强了 Ldccap 在中肠中的表达。在第二龄末期进行 RNA 干扰 (RNAi)-辅助敲低 Ldccap 抑制了叶片消耗，降低了海藻糖和几丁质的含量，并降低了两个几丁质合成基因 (LdUAP1 和 LdChSAb) 的 mRNA 水平。此外，约 70%的 Ldccap RNAi 幼虫仍处于预蛹期，完全包裹在旧幼虫蜕皮中，最终死亡。其余的 RNAi 甲虫继续发育成严重畸形的成虫：大多数有褶皱和较小的鞘翅和后翅，以及缩短的腿。因此，CCAP 在三个不同的方面发挥作用，刺激觅食幼虫期的摄食，调节蜕皮，以及促进鞘翅目昆虫的翅膀扩张和附肢伸长。此外，Ldccap 可以作为开发针对这种鞘翅目害虫的新型管理策略的潜在靶标基因。
